VDM Report No. 27 Soft magnetic Ni-Fe base alloys.B, J BR BS B µ -HC H HC H -BR -BS A company of ThyssenKrupp Steel ThyssenKrupp VDM TK VDM Report No. 27 Soft magnetic Ni-Fe base alloys. Physical basics and specific applications. Dr. Heike Hattendorf ThyssenKrupp VDM GmbH 58791 Werdohl Contents. Introduction Physical basics Magnetic variables Exchange integral Anisotropy constants The Ni-Fe alloy system Adjusting the properties High permeabilities in high-nickel alloys Permeability as a function of temperature Effects on the shape of the hysteresis loop - Hysteresis loop - Flat loop - Rectangular loop - Lattice defects Textures of medium-nickel alloys Annealing under a longitudinal magnetic field Ni-Fe alloy types Ni-Fe alloys with a high nickel content Ni-Fe alloys with a medium nickel content Alloy production, processing and final anneal Applications Residual current circuit breakers Relays for residual current circuit breakers Transducers Pulse transformers Low-distortion transformers for modems Shielding Summary List of variables and units used Literature Material tables Forms supplied Sales organisation Imprint 2 3 5 6 8 9 11 12 14 16 16 17 18 20 22 25 28 30 31 32 33 34 35 36 37 40 41 45 46 49 2 Introduction. Soft magnetic alloys have played a decisive role in electrical engineering for over 100 years now. Typical applications include the pole pieces of electric motors, transformer sheet packs (Figure 1), shielding, and yokes and armatures in relays. Starting from the original pure iron, a large number of soft magnetic alloy types have been developed over time, each of them improving on specific magnetic properties. Today, soft magnetic alloys include: - Fe-Si alloys - Fe-Ni alloys - Fe-Co alloys - amorphous alloys - nano-crystalline alloys, and - ferrites This report describes the properties and application areas of nickel-iron alloys. It starts with a brief outline of the basics of magnetism. Figure 1: Transformer station (5000/125 volt) from Augsburg, designed as a poster column, 1900 (original). (Photo: German Museum, Munich) Physical basics. Magnetic variables. 3 A magnetic field can be generated with the aid of a current-carrying conductor coil. If a soft magnetic material is introduced into the coil's interior, the magnetic field strength within this material will be higher than the field in the coil would be without the soft magnetic alloy [1], [2]. In other words, the soft magnetic material acts as a sort of amplifier for the magnetic field. The term "magnetic field", however, requires further definition. The magnetic field strength H describes the generating field which in the case of a currentcarrying coil, for example, depends only on the current and the coil geometry. To describe the amplifying effect, a further field parameter must be introduced, namely the magnetic flux density B. The generating field is the same in the soft magnetic material and in air. The magnetic flux density B is greater in the soft magnetic material than in air, depending on the effective amplification. B is the magnetic parameter, which is responsible for the induction of currents! The quotient B/H indicates the absolute permeability. In practice, relative permeability is used more frequently: µ = B/µ0H where µ0 = magnetic field constant = 1.257·10-4 Tcm/A. = 1.257·10-6 Tm/A. H is measured in amperes / metre (A/m), B in tesla (T). For a field in vacuum conditions µ = 1. For a field in air, µ ≈ 1. The difference between the magnetic flux density B in a soft magnetic material and the magnetic flux density B0 in a vacuum is designated the magnetic polarization J: J = B - B0 = µµ0H -µ0H Soft magnetic materials are characterized by high permeabilities, i.e. as a rule B0 can be neglected. e. If a specimen is run through multiple full remagnetization cycles with Remagnetization loss can be broken down into various types. which is why it is also termed a virgin curve. As the magnetic field strength H increases. and this process is repeated with various magnetic field strength values H. J BR BS Initial curve ≈ Commutation curve B µ a fixed peak value of magnetic field strength H. Special permeabilities which are frequently used for characterizing a material include the initial permeability (amplitude permeability) µi for H ¡ 0. Normal and anomalous eddy current losses and the residual loss are the loss types that cause the hysteresis loop to widen at frequencies greater than zero [4]. The relationship between B and H is not unique. i. The area covered by the magnetization curve yields the remagnetization loss per unit volume for a complete cycle [1].4 B. . HC rises. the remanent magnetic flux density BR will remain within the material. B assumes the value 0 at HC and finally saturation induction BS. i. The hysteresis loss is the reduction in area covered by the static hysteresis loop. the measured value pairs (H. their permeabilities are high. It is therefore important to differentiate between the values of the above mentioned variables according to the frequency at which they have been measured. This loss is proportional to the area covered by the hysteresis loop. B = Magnetic flux density H = Magnetic field strength BR = Remanence HC = Coercive force ˆ B ˆ µo H at the peak value of magnetic flux density B. B) will lie on the commutation curve which is practically identical with the initial magnetization curve. Applying magnetic field strength levels right up ˆ to the peak value of H during alternating magnetization cycles will result in an amplitude permeability µa [3] of µa = -HC H HC H -BR -BS Figure 2: The hysteresis loop.e. As H increases in the positive direction. The zero value of the magnetic flux density is only reached with a negative applied magnetic field strength. the coercive force -HC. and the permeabilities are reduced. at a quasi-static frequency close to 0 Hz or – as is often the case – at 50 Hz or even higher frequencies (Figure 3). Each time the direction of magnetization is reversed. As the frequency increases. and the maximum permeability µmax. The initial magnetization curve is unique. permeability µ4 at H = 4 mA/cm. o ∫ B dH = hysteresis loss unit volume Figure 3: Hysteresis loops for various frequencies (schematized). and a plot of B versus H will take the shape of a hysteresis loop (Figure 2). B 50 Hz Hysteresis loop Static hysteresis loop H Eddy current losses Soft magnetic materials are used in alternating fields with varying frequencies. and the peak value of the magnetic flux density B is measured. Soft magnetic materials can be readily remagnetized. B (or J) will reach saturation. the hysteresis loop widens. and both remagnetization loss and the coercive force are low. If the magnetic field strength is reduced to H = 0. some useful energy is wasted in overcoming internal friction. the saturation flux density BS (or saturation polarization JS) is obtained as a result. A further increase of H in the negative direction yields B = -BR. This leads to spontaneous magnetization. they react to an external magnetic field just like the magnetic needle of a compass. 5 Soft magnetic materials are designated "ferromagnetic" substances after their best-known representative. Mn and rare earths. . When the temperature rises beyond the Curie temperature TC. The magnetic moment of ferromagnetic elements in particular originates from the spin of electrons from open electron shells within atoms.e. As the temperature increases. The atoms of ferromagnetic substances have a "magnetic moment". Exchange integral. the presence of a magnetic moment in a material's atoms alone does not make it a ferromagnetic substance. i. i. iron (Latin: ferrum). an effect called paramagnetism. they tend to align in parallel to this field to some extent. thermal oscillation becomes so strong that the ferromagnetism is broken down.e. without an external magnetic field acting on the material (Figure 4). However. S the spin quantum number (proportional to the atom's magnetic moment). [2]: wA = IA S φ 2 2 Ferromagnetism Paramagnetism Figure 4: Orientation of magnetic moments in atoms in the ferromagnetic and paramagnetic states. thermal oscillation competes with the ferromagnetic tendency for spins to align and causes them to fluctuate around the ideal parallels. The directions of the atomic magnetic moments are then statistically distributed. Cr. Other ferromagnetic substances include Co. and φ the angle between two neighbouring magnetic moments.Physical basics. In a ferromagnet. Spinning a magnetic moment out of its parallel position requires energy. the magnetic moments of the individual atoms are aligned in parallel by interaction energies of inner-shell electrons. the so-termed exchange energy wA between two magnetic moments [1]. (for small φ values) where IA is the exchange integral. Ni. The magnetic moment is the sum total of the "magnetic moments" of all the electron spins (electron rotation around its own axis) and the angular momentums of the electrons orbiting around the nucleus. In the presence of an external magnetic field. as described in the following. the lower the amount of energy required to deflect the magnetic moments from a preferred direction. the orientation of its magnetic moments is changed 100 times per second. Such anisotropies can be induced. by stresses in the material. K1 is significantly greater than K2. Changing the orientation of magnetic moments from the preferred direction requires energy.6 Physical basics. φ the enclosed angle between the preferred direction and the magnetization direction. A large number of metals are arranged in such a cubic lattice. e. K2 are proportionality constants. If the cube edges are the preferred directions. K1 will suffice to describe experimental findings. In most cases. the face-centred lattice.g. are characterized by their symmetry (Figures 5. for example. while nickel-iron alloys are arranged in another specific type. 6). such as the edges or the diagonals. if a material is used in a 50 Hz transformer. Figure 5 shows a simple two-dimensional case. These are the easy magnetization directions. The magnetic moments do not follow a random orientation but specific preferred directions. by magnetic fields during annealing or. It can be described by the following equation [1]. For example. V is the volume unit. Anisotropy constants. In specific cases. where the above formula applies in a simplified form [1]: EU/V = KU sin2 φ KU is the uniaxial anisotropy constant. the preferred magnetic directions are the cube edges. such as ferrites. α3 are the cosines of the angle between the magnetization direction and the relevant cube edge. In the case of Fe and Ni-Fe with medium nickel contents. K1 > 0 Preferred directions K1 > 0 Preferred directions Examples: Fe. α2. The energy required for this is termed the crystal anisotropy energy Ek. and K1. for example. K1 is > 0. the edges or diagonals. Figure 6: Preferred magnetic directions for K1 > 0 and K1 < 0. materials. Although other crystalline magnetic . This denotes a case of uniaxial anisotropy energy EU. The smaller the amount of K1. if the body diagonals are the preferred directions. [2]: Ek/V = K1 (α12 α22 + α22 α32 + α12 α32 ) + K2 α12 α22 α32 Preferred magnetic directions: Edges Diagonals Figure 5: A simple two-dimensional cubic lattice. there is only one preferred direction. a cubic lattice is obtained. the basics explained below for a simple cubic lattice apply to all of them. 50% Ni-Fe Example: Ni where α1. and for pure nickel the body diagonals (Figure 6). For example. have a far more complex structure. If this is extended into the third dimension. The atoms of substances such as metals do not follow a random orientation but are regularly arranged on a crystal lattice. K1 < 0. Edge Edge Diagonal In a cubic lattice. specific directions. the cube edges are the preferred directions. If. then there are 3 preferred directions. iron and Fe-Si alloys of a specific type are arranged in a bodycentred cubic lattice. high permeabilities and low coercive forces. Magnetostriction is measured as the relative change in length in the direction of the magnetic field at saturation polarization (Figure 7). the crystal anisotropy constant K1 and the magnetostriction constants λ should be small and internal stresses should be minimized by careful treatment of the material. The permeabilities behave in reverse proportion to the coercive force values. with negative magnetostriction it becomes the most difficult direction. while the directions perpendicular to the direction of tensile stress become preferred magnetic directions. φ the angle of deflection from the preferred direction. However. no matter how carefully it has been treated. ship between µ or HC and the anisotropy constants K is governed in many cases by the following proportionalities [1]: HC ≈ K/JS . The two constants may differ considerably from each other. the hum of transformers. it undergoes minor changes in length. the stress anisotropy energy Eσ : Eσ/V = 3/2 λS σ sin2 φ KU = 3/2 λS σ (for an isotropic polycrystalline material) σ is the tensile stress. two constants are sufficient: λ100 in the cube edge directions and λ111 in the direction of body diagonals. among other things. This phenomenon is termed magnetostriction [1] and it causes. they are lower. The relation- H ∆l/2 J = Js λ= 2 3 J=0 l ✽ ∆l l Magnetostriction constant ∆l/2 Figure 7: Change of length when applying a magnetic field to a ferromagnetic specimen. . Internal stresses that exist in every material. have the same effect as external stresses. It varies as a function of the direction within the lattice. where magnetization leads to a reduction in length – or a positive value – as with Ni-Fe alloys with a medium nickel content. or a sum. In other words.7 If a ferromagnet is magnetized. In a material with positive magnetostriction. if stress anisotropy energies do occur. There is a further anisotropy energy. Magnetostriction may assume a negative value – as in the case of pure nickel. With cubic lattices. of the anisotropy constants mentioned above. the smaller the values of the magnetostriction constants. µ ≈ JS2/µ0K where K can be one. Frequently the mean magnetostriction constant λS is used for polycrystalline materials with statistical distribution of the grain directions. the direction of tensile stress becomes the preferred magnetic direction. Soft magnetic materials are characterized by low hysteresis losses. An essential prerequisite for achieving these properties is to keep all anisotropy energies at the lowest possible level because they make remagnetizing more difficult. The anisotropy energies can thus be reduced to very low levels in the range of highnickel Ni-Fe alloys which are characterized by high permeabilities.4 40 60 80 Ni content in % by mass 0 100 200 Figure 8: Crystal anisotropy constant K1. and the two magnetostriction constants λ100 and λ111 pass through zero at between 80 % and 82 % Ni*). quenched 1 0 K1 in 10 -3 Ws/cm 3 -1 -2 -3 FeNi3 To achieve good soft magnetic properties in a material. magnetostriction constants λ100. This alloy group has the highest saturation polarization among Ni-Fe alloys. In some cases permeabilities can be improved by a specific treatment of the alloy. *) All units in % in the text denote % by mass. cooled slowly 111 20 in 10 -6 0 -20 100 40 60 80 100 Ni content in % by mass 1.6 1.8 The Ni-Fe alloy system. saturation polarization JS and Curie temperature TC as a function of the nickel content (according to [5] [9]).0 0. This is the case where the crystal anisotropy constant K1 and the magnetostriction constants λ100 and λ111 are very small or close to zero. [2] (see section "Anisotropy constants").2 TC 600 400 JS J S in T 1. Permeabilities are lower than with 75 % to 80 % nickel. λ111.6 0. . low coercive forces. Figure 8 plots these constants as a function of the nickel content in the Ni-Fe system. because K1 is always greater than 0. Other Ni-Fe alloys are positioned in the range of approximately 50 % Ni. K1 passes through zero at approximately 75 % Ni. the anisotropy energies must be low [1].8 0.4 1. low hysteresis loss and a saturation polarization below 1 T. It has been shown though that the highest permeabilities can be achieved for λ100 ≈ 0 or λ111 ≈ 0.e. K1 = 0 varies considerably according to heat treatment. bal. This has specific consequences: . Figure 9 presents the multicomponent system Ni.065 0. their passage through zero shifts to lower nickel contents. > Curves for different cooling conditions from temperatures ~ 900 °C. As the molybdenum content increases.Adjusting the properties. 5 % Mo. 9 Figure 8 shows that K1 and λ100 or λ111 in the twocomponent system nickel-iron never assume the value zero simultaneously. Fe Magnifer ® 7754 77 % Ni. High permeabilities in high nickel alloys. the curves for λ100 or λ111 stay the same with nickel content. Fe Strip thickness 50 Hz permeabilities in mm µ4 µmax 0. This can however be achieved by alloying with Cu. Mo or Cr. So it is possible to influence K1 subsequently and take it down to zero by targeted heat treatment. Fe Magnifer ® 75 76 % Ni. The technically relevant alloys are positioned close to the curve for "Cooled quickly from 550 °C". The behaviour of the magnetostriction constants is exactly the reverse: their passage through zero as a function of heat treatment varies by less than 0. bal. The curves shift to higher molybdenum contents with slower cooling rates. the curves for K1 = 0 are shifted toward higher nickel contents. The K1 = 0 curves are plotted for various cooling conditions from tem> peratures ~ 900 °C. Mo.065 200-300 000 200-300 000 150-200 000 320-420 000 320-420 000 240-320 000 Table 1: Alloys with λ111 ≈ 0 and K1 ≈ 0. 2 % Cr. A few examples can be seen in Table 1. K1 is strongly influenced by heat treatment (Figure 8). When iron is replaced with copper.05 % Ni. i. Figure 9: The multicomponent system Ni. Fe + Cu (according to [10] – [12]). 4 % Mo. On the addition of molybdenum. bal. Composition Magnifer ® 7904 80 % Ni. Unfortunately there is no way of reducing all magnetostriction constants to zero. there are many ways of reducing K1 and one of the three magnetostriction constants to zero. Fe + Cu ([10] -[12]). 5 % Cu.065 0. The same effect can be achieved with a tempering treatment at around 500 °C after > quick cooling from temperatures ~ 900 °C. Iron can be replaced with copper without any significant shift in the curves for K1 = 0. 5 % Cu. as Figure 8 shows. balance Fe. K1 = 0. Figure 10 shows the permeabilities of toroidal strip wound cores in an alloy with 80 % Ni. faster cooling in the furnace or a higher withdrawal temperature TE will result in K1 > 0. . At the maximum.Cooling rate 0. followed by cooling in the furnace at a rate of 0. Missing the optimum withdrawal temperature by only a few degrees will result in a significant drop in permeability.9 °C/min 500 000 K1< 0 400 000 µmax Permeability 300 000 µ4 200 000 K1 = 0 K1> 0 100 000 440 460 480 Withdrawal temperature TE in °C 500 520 Figure 10: µ4 and µmax as a function of the withdrawal temperature TE. This means that the temperature control system of an annealing furnace must meet the highest requirements in terms of precision. 5 % Mo. with slower cooling or a lower TE. Further. if maximum permeabilities are to be achieved outside the laboratory as well. permeability will suffer a sharp drop. K1 < 0.10 Magnifer 7904 1200 °C . it should be noted that the maximum is asymmetrical.9 °C/min. The toroidal strip wound cores were annealed at 1200 °C. The permeability µ4 at 4 mA/cm and the maximum permeability µmax depend strongly on TE.4h . They were taken from the furnace at the withdrawal temperature TE and then allowed to cool quickly in air. At temperatures above the optimum withdrawal temperature. 9 °C/min 400 000 K1 = 0 TE 515 °C 500 °C 495 °C 490 °C 475 °C 300 000 Permeability µ 4 200 000 460 °C K1< 0 100 000 K1> 0 0 -20 0 20 40 60 80 100 Measuring temperature °C Figure 11: µ4 as a function of the measuring temperature and withdrawal temperature TE. this temperature dependance is less marked at higher measuring temperatures and shows a significant drop at low measuring temperatures. At lower withdrawal temperatures.Cooling rate 0. and smaller than 0 in the range of the less marked ˝flat˝ temperature dependance. . but the permeability level drops as well. Roughly constant permeabilities and magnetic flux densities between -25 °C and 80 °C are important for many applications. In the specimens taken at 495 °C. K1 = 0 at the maximum of this curve.4h . Permeability as a function of temperature. 11 Magnifer 7904 1200 °C . The dependence of permeability on temperature decreases. the passage of K1 through zero shifts to lower temperatures and so the flat section of the curve covers an ever increasing measuring temperature range. This means a compromise has to be found for the individual application between a low dependence on temperature and high permeability.Adjusting the properties. greater than 0 in the range of the significant fall. Figure 11 shows the temperature dependence of permeability µ4 between -25 °C and 80 °C. BM stands for < a defined magnetic flux density ≈ BS (Table 2).9 Table 2: Hysteresis loop description by of BR/BM. which probably reflects practical conditions more correctly. Hysteresis loop shape Round Flat Square BR/BM approximately 0. .12 Adjusting the properties. Round Flat Rectangular Hysteresis loop Figure 12: Hysteresis loop shapes. These are described by the ratio BR/BS or by the ratio BR/BM. Effects on the shape of the hysteresis loop.5 approximately 0.7 < 0. The hysteresis loop can have a variety of shapes (Figure 12).6 – 0. on the other hand. to ensure that pulsating direct currents also induce a sufficiently large magnetic flux change in the core.8 T B B H B B H 5A/m H t 5A/m Sinus-shaped (50 Hz) 0. the magnetic flux density swing is greater because the remanent magnetic flux density is lower. in the case of pulsating direct current exci- tation. Compared to a sinusshaped magnetic field strength of identical value. With pulsating direct current. With a pulsating direct current the hysteresis loop will run in the region above to the upper remanent magnetic flux density. During the period with no current.13 Magnetic field strength H Rectangular loop 0. . the achievable change in magnetic flux density or flux density swing ∆B is much smaller for a core with a rectangular hysteresis loop than for a core with a flat loop. a material with a flat loop is required. Figure 13 shows this for a toroidal strip wound core with a rectangular and flat hysteresis loop respectively.8 T B ∆B 0. The shape of the hysteresis loop can be influenced and varied over a wide range by means of targeted heat treatment. For residual current circuit breakers with pulsed current sensitivity. [11] [13]. the change in magnetic flux density will be somewhat smaller in a core with a flat loop than in a core with a more rectangular loop.8 T B ∆B H t 5A/m 5A/m Pulsating Figure 13: Magnetic flux change in sinus-shaped current and pulsating DC with a flat and a rectangular hysteresis loop. For a core with a rectangular hysteresis loop. Hence. the magnetic flux density drops to the static remanent magnetic flux density from which the next pulse starts.8 T Flat loop 0. the static remanent magnetic flux density is very high. In a demagnetized specimen the Weiss domains are so arranged that their magnetic moments cancel each other (Figure 16. i. The magnetization cycle has now reached the steep section of the hysteresis loop. The individual Weiss domains have different magnetization directions. Of course real materials usually have lattice defects such as dislocations. the favourably positioned Weiss domains grow at the cost of the unfavourably positioned domains. This movement can be observed: it is known as the Barkhausen jumps which can. These inclusions or defects are often referred to as pinning sites. in reality it is somewhat more complex. be clearly heard as clicks in a loudspeaker. They are separated from each other by Bloch walls (Figure 15). Magnetization is still reversible. Weiss domains Figure 14: A ferromagnetic specimen broken down into Weiss domains (according to [1]. Do m ain Bl . Although this is correct. m ain Do oc h wa ll Figure 15: Rotation of the magnetization direction in a Bloch wall (according to [1]. [2]. grain boundaries and impurities that impede the Bloch wall movement. if the magnetic field strength H drops to zero. upper section). With greater magnetic field strengths the Bloch walls gradually detach themselves from their pinning sites and move towards a new equilibrium position. The specimen shows a magnetic polarization J and magnetic flux density B unequal to zero. A Bloch wall is a transition area between two Weiss domains in which the neighbouring spin magnetic moments rotate gradually from the magnetization direction of one Weiss domain to another. for example. The atomic magnetic moments are not polarized parallel to each other throughout the material but within individual regions – the Weiss domains (Figure 14) [1]. This phenomenon is termed reversible Bloch wall movement. [2]). [2]).14 Hysteresis loop In the section "Exchange integral" it was mentioned that all magnetic moments in a ferromagnetic material are parallel. the magnetic polarization disappears (Figure 17). the Bloch walls are forced to move (Figure 16). a minor bulge in a Bloch wall between its pinning sites suffices as movement.e. J assumes a value different from zero. With very small magnetic field strengths. If H drops to zero now. When an external magnetic field is applied to a demagnetized specimen. The Bloch wall movement is now no longer reversible. it reaches the saturation polarization JS. B. On the application of a magnetic field strength in the opposite direction. and so on. If the magnetic field strength is now reduced to zero. Hence obstacles to Bloch wall movement must be avoided. (coercive force). The magnetic field strength H required to cause the Bloch walls to bulge. on completion of all spin rotation processes. J > 0 Figure 16: Magnetization of a demagnetized ferromagnetic specimen. the magnetization direction within the individual Weiss domains also rotate out of the preferred direction (spin rotation processes. loosen and move varies with the number and type of lattice defects. If H is further increased in the negative direction.15 Weiß domain H=0 Bloch wall B. B JS JR Spin rotation processes Irreversible Bloch wall movement Reversible Bloch wall movement -HC HC Initial curve H Figure 17: The various types of Bloch wall movement through the hysteresis loop. The magnetization curve becomes flatter until. Permeability and coercive force increases with greater numbers of Bloch wall pinning sites. the same processes will take place in the other direction. J. further Bloch walls form. The total polarization becomes zero again only with a sufficiently high magnetic field strength -HC. . J = 0 Demagnetized H>0 With further increased magnetic field strengths. Figure 17). The remanent polarization JR remains within the material. the magnetization direction returns to the nearest preferred direction and the formation of Bloch walls commences. With a sinus-shaped magnetic field strength it decreases continuously.0 1. An annealing treatment under a magnetic field can also produce uniaxial anisotropy in mediumnickel alloys all of which always have K1 > 0. Magnifer 7904 F 600 400 B in mT ˆ B ∆Bstat 200 0 0 0. with pulsating direct current (index "stat") it reaches a maximum. Such an example will be discussed in the section on medium-nickel alloys. start at a very early stage of the remagnetization cycle (Figure 17). there is no preferred magnetization direction. ∆Bstat as a function of the annealing time t under a transverse field.16 Toroidal strip wound core Later magnetic flux direction Flat hysteresis loop A flat hysteresis loop is obtained.5 Transverse field annealing at 340 °C for tQ Magnetic field strength H (50 Hz) ˆ ∆H stat } = 15 mA/cm ˆ Figure 19: B. Rectangular hysteresis loop A rectangular hysteresis loop is obtained when magnetization (Figure 17) is more or less exclusively governed by Bloch wall movement and almost no spin rotation processes are required. when the spin rotation processes that govern the flat section of the loop.e. It generates uniaxial anisotropy with a correspondingly high uniaxial anisotropy constant KU transverse to the later flux direction. i.5 t Q in h 1. This is the case with a preferred direction perpendicular to the later magnetic flux direction. To achieve this in high-alloy nickel alloys it is necessary to make sure that K1 ≈ 0. Figure 19 shows how the magnetic flux density B ˆ in a field with a peak value H = 15 mA/cm varies with the transverse magnetic field annealing time tQ. for example. so most of the Weiss domains are magnetized perpendicular to the later magnetization direction (Figure 18). Q . This is the case if there is a preferred direction parallel to the later magnetic flux direction. Preferred direction = direction of the magnetic field applied during annealing = induced uniaxial anisotropy energy ~ Ku Figure 18: Heat treatment under a magnetic field transverse to the later direction of magnetic flux (transverse field annealing). will result in very flat loops with a higher flux density swing than in the high-nickel alloys [11]. Then the material should be heat treated at temperatures between 300 and 350 °C for 1 to 1.5 hours under a magnetic field perpendicular to the later flux direction (Figure 18). This treatment is termed transverse magnetic field annealing. A transverse magnetic field annealing. With longer times tQ ∆Bstat also decreases because the hysteresis loop becomes too flat and permeabilities drop to very low values. a k K1 TC The smaller K1. Soft magnetic materials are not just magnetically soft but often mechanically soft as well. 4 % Mo. Generally. Indirectly. Ti. In high-nickel alloys with K1 ≈ 0 this effect is limited because the diameter of the precipitates is significantly smaller than the Bloch wall thickness [11]. the thicker and the more blurred the Bloch wall. Fe is essentially determined by the grain size in the final annealed condition. etc. but the thicker the Bloch wall. which increases along with φ. for example. The permeability of the alloy 80 % Ni.130 HV5 (Table 12) in the final annea- . the permeability of a classic crystalline material will be higher. the greater its grain size. the magnetic polarization vector rotates towards its new orientation along the length δ (Figure 15).Adjusting the properties. for example. for example. greater hardness coupled with good soft magnetic characteristics would be desirable for components susceptible to wear. the following relationship applies: kTC aK1 lattice constant Bolzmann's constant crystal anisotropy constant Curie temperature Permeability Degree of purity Grain diameter in Figure 20: µ 4 as a function of the degree of purity r (reciprocal of the volume in % take up by inclusions. according to JIS). Al. has a hardness of only 110 .e. δ= led condition. Yet a targeted annealing treatment leads to the formation of fine precipitates which have an adverse effect on permeability. The significantly smaller or larger inclusions are "overlooked" [2]. the crystal anisotropy EK is not equal to zero. The structure of a Bloch wall is influenced by interaction of the anisotropy energy and the exchange energy. the smaller wA. As the magnetic moments within the wall are not aligned in a preferred direction. The smaller φ. Figure 20 plots µ4 as a function of the grain size for heats with a varying degree of purity r (reciprocal of the volume in % taken up by inclusions. the degree of purity is important. and the smaller the number of dislocations. the lower a material's permeability. deformation should be avoided. independent of the degree of purity. because heats of the highest degree of purity always have the greatest grain sizes. according to JIS G 0555) and grain diameter. EK increases with the Bloch wall thickness and thus acts in the opposite direction. Not all inclusions are equally important but it is mainly those whose diameter is roughly equal to the Bloch wall thickness δ that act as pinning sites. 17 The magnetic field strength H required to cause the Bloch walls to bulge. In this condition. These pinning sites should be avoided because the greater the number of these obstacles to Bloch wall movement. [11]. i. The magnetic moments of two neighbouring atoms form the angle φ between them. Lattice defects. the lower the amount of impurities (nonmagnetic inclusions) it contains. All the points lie on one straight line. The degree of purity of these heats is so high that the direct importance of the few relevant inclusions (in this case those in the µm-range) in their role as pinning sites for the Bloch walls is insignificant when compared with the grain boundaries. detach from their pinning sites and move depends on the number and type of lattice defects. such as sound recording heads. This relationship is relevant in the context of inclusions. The optimum Bloch wall thickness δ is obtained when the total wall energy assumes its minimum [1]. This is achieved by alloying with Nb. However. however. This explains why. The 80 % NiMoFe alloy. This increases their exchange energy wA. In a 180° Bloch wall. the cube edges are preferred magnetization directions. It is named ”(210) [001] texture”. In an isotropic texture where only very few grains are aligned in the preferred direction. In a further texture.18 Adjusting the properties. Permeability is therefore generally lower than with high-nickel alloys. 27° . . It can. various types of textures can be generated (Figure 23): in the cubic texture [15] one side of the cube lies on the strip plane and one cube edge points to the rolling direction which later becomes the magnetic flux direction. Textures of medium-nickel alloys. but the cube edge pointing in the rolling direction/later magnetic flux direction retains its orientation. The result is a rectangular loop with high permeabilities (see section ”Rectangular hysteresis loop”). because the spin rotation processes are energetically less favourable. This can be achieved by a specific rolling and annealing procedure. Figure 21: Grains and grain boundaries in crystalline materials. Figure 23: Textures of NiFe alloys. the saturation flux density reaches a maximum yet the crystal anisotropy constant K1 is always greater than zero. all grains are oriented approximately in the same direction. This results in a somewhat flatter loop (see section "Flat hysteresis loop") with somewhat lower permeabilities. Grain boundary Grain In medium-nickel alloys. the cube edge directions are statistically distributed in each grain within the lattices (Figure 22 left).e. the cube is rotated through approx. The crystal lattice does not usually extend across the material but only over a specific area i. the spin rotation processes commence at an earlier stage.e.e. In the neighbouring grain it is turned through an arbitrary angle [14] (Figure 21). i. Strip plane Strip plane [001] Rolling direction Magnetic flux direction (210) [001] texture [001] Rolling direction Magnetic flux direction Cubic texture In nickel-iron alloys. This terminology will be used to designate this texture in the following text. two-dimensional). remagnetization up to high flux densities is governed by Bloch wall movements. the grain.e. In an isotropic texture. 27° about the rolling direction. i. the cube edge direction [15]. a preferred magnetization direction – lies approximately in the direction of magnetic flux. be increased via a specific texture [11]. If a cube edge direction – i. however. In the second texture in Figure 22. Figure 22: Explaining the term "texture" (schematic. ∆l Final stain in % lo Figure 24: Primary recrystallization in medium-nickel alloys at temperatures of 1100°C – 1200°C (according to [16]).0 3. a second recrystallizing process [17]. Structure RG TG T Isotropic Secondary-recrystallized (210) [001] texture µ4 9.60 %.900 16.19 25 Primary recrystallization Initial grain diameter in µm 900 20 fine-grained 850 15 cubic texture 800 increasing intensity 10 80 85 90 95 97 25 Initial grain diameter in µm 1100 . strip thickness 0. magnetically unfavourable orientation directions (coarse grain). As a result. -In (l/lo) 2.10 mm for T). the cubic texture will be destroyed and a (210) [001] texture with a millimetre-range grain size will be generated instead. Fe. A coarse-grained microstructure has lower permeabilities because the grain orientation does not follow a preferred direction. the material will have a fine-grained. [18] – called secondary recrystallization – will take place after the formation of the cubic texture.1050 °C .20 mm for RG and TG.000 Table 3: Effect of textures on Magnifer® 50 (48% Ni. The cubic texture will become more marked as the strain increases. Excessively high strains will lead to centimetre-range grain growth with varying. bal.0 2.000 95. once again. Each of the textures is clearly identifiable by its very marked grain structure (Figure 25).5 3.000 40.5 3. Figure 25: Secondary recrystallization in medium-nickel alloys at temperatures of 1100 °C – 1200 °C (according to [16]). Table 3 gives an overview of how texture influences a 48 % nickel-iron alloy. however.5 001 Temperatur of intermediate annealing in °C If a material of a specific grain size is deformed by a strain of only some 30 .1200 °C Primary recrystallization Secondary recrystallization 900 The highest permeabilities are achieved with a texture of the (210) [001] type. Depending on the initial grain size mainly the cubic texture is formed after strains between 90 % and 96 % (Figure 24). Temperatur of intermediate annealing in °C If the material is annealed at temperatures between 1100 °C and 1200 °C. approximately isotropic microstructure. A cubic texture generates a marked rectangular loop. isotropic microstructure are also lower because the grain size is significantly smaller. then after recrystallization annealing in the range of 900 °C to 1050 °C. With higher strains the intensity of cubic texture increases. The grain size varies with the annealing temperature.000 µmax 82.0 2. Permeabilities in a fine-grained. and 0. -In (l/lo) 2. The transition area between the individual texture types varies with the degree of impurity and the chemical composition of the alloy.95 <1.000 20 fine-grained ] pr efe rred 850 15 10 80 85 90 (21 0) [ coarse-grained 800 95 ∆l Final stain in % lo 97 20 mm Cubic texture BR/BM > 0. the very small grain size results in low permeabilities.5 900 .0 3. Toroidal strip wound core Current I The following section looks at the process of annealing under a longitudinal magnetic field parallel to the later flux direction (Figure 26) [11]. K1 becomes smaller. which is where the difference between the Curie temperature and the tempering temperature is greatest. Figure 27 plots a comparison of the uniaxial anisotropy constant KU and the crystal anisotropy constant K1. [19. With an annealing temperature of 450 °C. A precondition for this treatment is that the uniaxial anisotropy constant KU induced under the magnetic field can assume a value larger than the crystal anisotropy constant K1. the lower the annealing temperature and the longer the duration of the annealing treatment because its value shifts toward the "cooled slowly" curve (Figure 27). In addition to cause generation of uniaxial anisotropy. Annealing under a longitudinal magnetic field. KU increases with decreased annealing temperatures and increased annealing times.20 Adjusting the properties. a process referred to as longitudinal magnetic field anneal. KU reaches its maximum at approximately 65 % Ni. By contrast. K1 can be reduced to a value of K1 ≈ KU. The values of K1 and KU vary with the annealing temperature and time. Later magnetic flux direction = magnetic field direction during annealing = preferred direction of induced uniaxial anisotropy energy. strength ~ KU Figure 26: Heat treatment under a magnetic field parallel to the later direction of magnetic flux (longitudinal magnetic field annealing). The toroidal strip wound cores are strung onto an isolated electrical conductor through which current of a suitable intensity is conducted during the heat treatment. the magnetic field annealing also changes the value of K1. From approximately < 55 % Ni. 20]. . [23]). the loop is extremely flat. At even higher temperatures. From this it follows that a magnetic field treatment is essential for these materials. BR/BM and ∆B as a function of the annealing temperature during longitudinal field treatment.8 0. K in 10 -3 Ws/cm 3 quenched 1 K1 FeNi3 K U after annealing at 450 °C 0 -1 cooled slowly -2 -3 40 60 80 Ni content in % by mass 100 Figure 27: Ku as a function of the nickel content (according to [6] . 20].6 0. and ∆B for pulsating direct current increases significantly.2 0 500 Figure 28: µ4.[9]. The hysteresis loop is rectangular because the spin rotation processes start at a very late stage in the cycle (Figure 28). [19.21 At lower temperatures (approx. BR /B M µ max . Slightly higher temperatures generate a state where K1 ≈ KU. Below the Curie point of approximately 530 °C. Permeabilities drop. 420 °C) K1 < KU for an alloy with 55 % Ni [11]. The hysteresis loop is round and permeabilities are very high.4 B R /B M µ4 50 000 25 000 0 800 µ4 ∆B in mT 600 400 200 ∆B for ∆H=20 A/m 0 400 420 440 460 480 Annealing temperature in °C 0. despite the longitudinal field annealing. In these conditions. KU << K1 [13]. Annealing without a magnetic field produces very low permeabilities in alloys with 53 % to 65 % nickel. Magnifer 53 after longitudinal field anneal 100 000 75 000 µ max 200 000 150 000 100 000 50 000 0 0. The permeability µ4 is low. µmax. This means that during cooling it is exposed to magnetization which has a different direction in each CurieWeiss region. What has been said previously about the influence of texture also remains valid here: maximum permeabilities can only be achieved where the optimum (210) [001] texture has been formed. a material with 55 % Ni is magnetized to saturation in its Weiß regions. The preferred direction is the direction of the magnetic flux density. electronic differential current switches.8 T. as well as stamped parts for relays. 37 and 38). The soft-magnetic nickel-iron alloy Magnifer 7904 with approximately 80 % nickel and approximately 5 % molybdenum has the highest technically achievable permeability values of all nickeliron alloys . Material Magnifer ® 7904 1) 80 % Ni.i. Figure 31). .065 mm – also with very small coercive forces of HC ≤ 1 A/m (Table 4. 2 % Cr and 5 % Cu can reach initial permeabilities of µ4 = 150. Ni-Fe alloys with a high nickel content. Its ductility is superior to that of the alloy with 80 % Ni and 5 % Mo (Table 10).000 in strip of 0.7 and 0.000 for a strip thickness of 0. Measured at 50Hz on toroidal strip cores of 0. Figure 31). transducers. stepped motors. 80 % nickel. as well as stamped parts for relays. Magnifer® 8105 data sheets and in the appropriate material tables. stepped motors. transducers. 33.22 Ni-Fe alloy types. This group includes the nickel-iron alloys with the highest initial and maximum permeabilities.065 mm thickness (Table 5. Their saturation flux density BS lies between 0. laminations for LF transformers. µ4 ≥ 240. Figure 29: Stamped core sheets in Magnifer® 7904 for low-distortion transmitters in modems. sensors and shielding cases (Figures 29. low-distortion transformers in modems. 5 % Mo.0002) Hc < 1 A/m solid material Applications Magnifer ® 7904 MP 240 1) Highest permeability Magnifer ® 7904 MP H1 Toroidal strip wound cores for integrating current transformers for residual current circuit breakers. laminations for LF transformers. bal.065 mm thickness. electronic differential current switches. Fe Characteristic properties Magnetic properties Bs = 0. Magnifer 75 alloy with 75 % Ni. Further information is contained in the Magnifer® 7904. Major application areas include toroidal wound strip cores for integrating current transformers in residual current circuit breakers.000 (DC) Bs = 0.e. 30. 34. lowdistortion transformers in modems. sensors and shielding Magnifer ® 7904 F 25 1) Flat loop ∆Bstat > 200 mT for Toroidal strip wound cores ∆Hstat = 15 mA/cm2) for residual current circuit breakers with pulsed current sensitivity µ4 > 100.7 T Stamped parts and shielding cases for magnetic heads Magnifer ® 8105 Negative magnetostriction 1) 2) For further quality grades see appropriate material data sheets and/or tables. Table 4: Alloys with approx.74 T µ4 > 240. g. ∆ B in mT A transverse field annealing permits a flat hysteresis loop with a very high unipolar flux density swing to be generated for both alloys (Tables 4 and 5. The main application of these alloys is in the manufacture of integrating current transformers for residual current circuit breakers with pulsed current sensitivity.065 mm 1000 ˆ Bsin ∆Bstat ∆Bdyn ˆ B.10 Figure 30: Toroidal strip cores in Magnifer® alloys.10 ˆ B in mT 10 50 RG 0. Magnifer 7904 F 25 TK Strip thickness 0. It is therefore mainly used in the manufacture of shielding cases and pole pieces for magnetic heads in audio equipment (Table 4).23 10 000 1 000 100 Magnifer d/mm 7904 MP 0. e. An increase of approximately 1 % in the nickel content of an 80 % nickel alloy produces a nickel-iron alloy with negative saturation magnetostriction – Magnifer 8105. Figure 32). The indices "stat" and "dyn" stand for excitation via half-wave and full wave rectified current respectively. 100 10 1 10 100 ˆ H. Fe).06 75 ME 0.10 53 MG 0. ∆H in mA/cm Figure 32: Magnetic flux density/Magnetic field strength curves for Magnifer® 7904 F25 TK (80 % Ni. The negative magnetostriction increases this alloy's resistance to mechanical loads. 1 1 10 100 1 000 ˆ H in mA/cm Figure 31: Magnetic flux density/Magnetic field strength curves for nickel-iron alloys.10 36 W 0. . By means of an annealing treatment all these variants can be produced in a grade with improved temperature coefficient between -25 °C and 80 °C (TC materials). 5 % Mo. when sealing it in synthetic resins. bal. Fe Flat loop Precipitationhardening: HV = 150 . Figure 34: Shielding made of Magnifer® alloys. The most important applications for this alloy include magnet armatures and legs for release relays in residual current circuit breakers (Figure 37) as well as magnetic heads in audio and video equipment.200 finish annealed. Figure 33: Integrating current transformers made of Magnifer® alloys for residual current circuit breakers. 2 % Cr. 1 % Ti 2 % Nb. Further information is contained in the Magnifer® 75 data sheet and in the material tables. In addition to relatively high initial permeabilities of µ4 ≥ 40. which are responsible for the rise in mechanical hardness. 5 % Cu.8 T Applications High permeability. high hardness and wear resistance are achieved as well as good corrosion behaviour in cyclic climate conditions as per DIN VDE 664.000 (50Hz) (0. Fe Magnifer ® 75 ME 81) Characteristic properties Magnetic properties BS = 0.20 mm strip) HC < 2 A/m solid material ∆Bstat ≥ 200 mT for ∆Hstat = 20 mA/cm2) µ4 > 40.000 and a coercive force of HC ≤ 2 A/m. increased ductility Magnifer ® 75 MH 2 Magnifer ® 75 F Magnifer ® 77 TiNb So 77 % Ni. Table 5: Alloys with 75 % nickel.065 mm Bd.) µ4 > 80. Material Magnifer ® 751) 76 % Ni. fully aged.000 (DC) HC ≤ 2 A/m BS = 0. This is due to the precipitation of fine inclusions containing titanium and niobium. shielding Toroidal strip wound cores Stamped parts for relays.7 T Toroidal strip wound cores for transducers. magnetic heads 1) For further quality grades see appropriate material data sheets and/or tables. bal. laminations for LF transformers. good corrosion behaviour µ4 >150. 5 % Cu.000 (50Hz) (0. . the usually very soft and therefore not particularly wear-resistant nickel-iron alloys are improved in terms of their mechanical properties.24 By alloying Magnifer 77 Ti Nb with niobium and titanium. bal. In the case of the Magnifer 54 F variant. With variant TG. integrating (0. the final anneal produces an anisotropic microstructure with coarser grains and (210) [001] texture.Ni-Fe alloy types. bal.000 bei tp = 50 µs Pulse transformers. The Magnifer 53 F variant has a flat hysteresis loop and thus a high unipolar flux density swing. A special variant (RG S) which lie between the RG and TG can be produced by taking account of the conditions of downstream processing requirements. At 1. which are adjusted by means of targeted rolling and annealing processes (see section on "Textures of medium-nickel alloys"). the saturation polarization of Magnifer 50 with 48 % Ni is the highest achievable within the nickel-iron alloy system. Typical applications include rotor and stator plates. for example.55 T.5 T.000 and coercive Material Magnifer ® 53 1) 55 % Ni. The alloy is used exclusively for toroidal strip wound cores (see section "Annealing under a longitudinal magnetic field") and is manufactured in a number of variants (Table 6).000 (Figure 31) to longitudinal field annealing. Figures 30. variant RG forms an isotropic. Fe Magnifer® 53 MG 60 1) Characteristic properties Magnetic properties Magnifer 53 F Strip thickness 0. ∆B in mT 100 10 1 10 100 1000 ˆ H. Applications For toroidal strip wound BS = 1. Further information is contained in the Magnifer® 53 data sheet and in the material tables. force of HC ≤ 5 A/m. thyristor choke coils Magnifer® 54 F 1) High pulse permeability For further quality grades see appropriate material data sheets and/or tables. After final annealing. transverse field annealing generates a particularly flat hysteresis loop and thus high pulse permeability. Magnifer 53 MG 60.5 T cores only. These are distinguished by their varying microstructures. choke coils and transformer cores for residual current circuit breakers and shielding (Table 7. Table 6: Alloys with 55 % nickel. The alloy is produced in several variants (Table 7). owes its high permeability of µ4 = 60. relatively fine-grained microstructure with initial permeabilities of µ4 ≥ 8. bal. This alloy is used for integrating current transformers in residual current circuit breakers with pulsed current sensitivity (Figures 33 and 35). . 25 Magnifer 53 with approximately 55 % Ni has a saturation polarization of 1. 34). This alloy is mainly used for magnetic cores in pulse transformers and thyristor choke coils (Figure 36). This gives the alloy very good permeabilities in the rolling direction. annealed under a magnetic field Highest permeability Flat loop µ4 > 60. Ni-Fe alloys with a medium nickel content. 33. This alloy is used for transducer cores and integrating current transformers in residual current circuit breakers (Figures 30 and 33).10 mm strip) current transformers for residual current circuit breakers Magnifer® 53 F ∆Bstat ≥ 200 mT for integrating current trans∆Hstat = 50 mA/cm2) formers for residual current circuit breakers with pulsed current sensitivity µp > 4. ∆H in mA/cm Figure 35: Magnetic flux density – Magnetic field strength curves for Magnifer® 53 F (55 % Ni. with µ4 ≥ 14 000 (Table 7).000 (50 Hz) Transducers.10 mm 10 000 1 000 ˆ Bsin ∆Bstat ∆Bdyn ˆ B. Fe). toroidal strip cores for LF transformers. toroidal strip anisotropic (50 Hz. humid/ dry cold Toroidal strip wound cores for chokes. storage chokes. Table 7: Alloys with 48 % nickel. 0. stepped motors. fine-grained isotropic microstructure Special variant between 50 RG and 50 TG µ4 > 8. Further information is contained in the Magnifer® 50 datasheet and in the material tables. microstructure transducers.000 ( ≥14. Fe Magnifer ® 50 RG 1) Characteristic properties Magnetic properties BS = 1. stator plates. Fe Characteristic properties High resistivity of 0. Remanence ratio rectangular hyste.20 mm strip) HC < 5 A/m Toroidal strip wound cores. clocks and watches.8 T HC < 5 A/m µmax > 100. . µ4 ≥10.000 (DC) Applications Stamped parts for relays.95 ris loop (0.BR/BM > 0. shieldings Table 8: Alloys with 40 % nickel. shielding Magnifer ® 50 RG S Properties improved over 50 RG Figure 36: Chokes and transformers. integrating current transformers Cubic texture. Magnifer ® 50 TG 1) Transformer grade. bal. clocks and watches. Material Magnifer® 4008 48 % Ni. Figure 37: Relay parts in Magnifer® alloys.000 (DC) corrosion resistant in cyclic climate conditions warm.20 mm strip) wound cores for LF transformers. 8 % Cr bal. stepped motors. memory cores.10 mm strip) Solid material HC < 8 A/m (< 5 A/m) µ4 >100.000 (50 Hz) (0.26 Material Magnifer ® 50 48 % Ni. pulse transformers Stamped parts for relays.000 (DC) HC < 2 A/m µmax < 160. inductive rotary sensors and electrovalves Magnifer ® 50 T Magnifer ® 50 MH 1) Magnifer® 50 B So 1 1) For further quality grades see appropriate material data sheets and/or tables. integrating current transformers for residual current circuit breakers Rotor.96 Ω mm2/m Magnetic properties BS = 0. laminations for LF transformers.55 T Applications Rotor grade.000) Laminations. 35 mm Bd. Table 9: Alloys with 36 % nickel. Variant MH is manufactured as a solid material. inductive rotary sensors for the automotive industry (ABS) and in electrovalves (Figures 37 and 38). Material Magnifer® 36 36 % Ni. Magnifer 4008 with approx. Figures 37 and 38) is another alloy that is produced as a solid material. At 0. toroidal strip wound cores for LF transformers. for armatures and magnetic yokes in relays as well as for stepped motors in photo cameras. in turn. On the other hand.300 ± 200 (50 Hz) Laminations. The ratio of the remanence to the saturation flux density is greater than 0. pole shoes. It is used for stamped parts for relays.3 T Applications Magnifer®36 K 1) Small permeability increase µ16 = 2.75 Ω. In addition the alloy is used for manufacturing transducer cores. 22]. It is used in the watches and clocks industry. its saturation flux density is comparable to that of highnickel alloys. 0. The yoke and armature are made from nickel-iron alloys. Alloy Magnifer 36 with 36 % nickel has a saturation polarization of 1. Variant B So1 features improved corrosion resistance in a climate cycling test with alternating warm and humid / cold and dry phases [21. e. clocks and watches. and stepped motors. shielding transducer cores Magnifer®36 W 1) higher permeability For further quality grades see appropriate material data sheets and/or tables. The second variant has higher permeabilities and lower coercive forces (Figure 31). toroidal strip small permeability wound cores for LF transforincrease between mers. Further information is contained in the Magnifer® 36 data sheet and in the material tables. Magnifer 4008 is much more favourably priced than a high-nickel alloy. for speedometers. 40 % Ni and approx. Typical applications are laminations for LF transformers. With the first variant. as well as strip and sheet for shielding. 1) Figure 38: Stepped motors in analog quartz watches. chokes ˆ H = 4 to 80 mA/cm µ4 ≥ 5. although its magnetic properties are somewhat reduced. pole shoes.) HC < 15 A/m Laminations. leads to rectangular hysteresis loop. and chokes.27 In variant T the final anneal produces a marked cubic texture which.95 (Table 7). bal. .3 T and a high resistivity of ρ = 0.8 T. solid components for relays. the increase in permeability ˆ in the magnetic field strength range of H = ˆ 4 mA/cm to H = 80 mA/cm is very small. 8 % Cr (Table 8.g. Fe Characteristic properties high resistivity 75 Ω mm2/m Magnetic properties BS = 1. It is available in two variants (Table 9).000 (50 Hz. Major applications include solid components for relays. punching and deep drawing are possible. laminations.2 in N/mm2 630 750 600 700 800 900 Elongation A5 in % 5 4 5 4 Hardness HV5 200 200 270 350 Magnifer ® 75 860 76 % Ni. 2 % Cr Magnifer ® 7904 80 % Ni. Condition: hard rolled with strain ≥ 50 %. intermediate annealing may be necessary. the hot strip is cold rolled. Following this. The best welding process is usually resistance spot welding. The alloys are melted in air or under vacuum conditions and then continuously cast into billets. . 5 % Cu. Depending on the final strip thickness and final strain. processing and final annealing. bending. Material (bal. The strip can be rolled down to foil thicknesses as small as 20 µm. The mechanical properties of Ni-Fe alloys are listed in Tables 10 to 12. The strip serves as starting material for the production of toroidel strip wound cores. drilling. relay components and shielding. These are hot rolled to approximately 4 mm thick strip which is pickled and then surface ground if required. Fe) Magnifer ® 36 36 % Ni Magnifer ® 50 48 % Ni Tensile strength Yield strength Rm in N/mm2 RP0.28 Alloy production. although in principle other processes are also applicable. milling. 5 % Mo 1 000 Table 10: Mechanical properties (approximate values) of Ni-Fe alloys. All forming processes including turning. 2 % Cr Magnifer ® 7904 80 % Ni. Metallurgical measures such as deoxidation. Material (bal. Non-magnetic inclusions such as slag particles and oxides must be avoided at all cost. Depending on the intended application.2 in N/mm2 Rm in N/mm2 200 530 580 580 220 220 250 Elongation A5 in % 40 40 40 40 Hardness HV5 90-110 100-120 110-130 110-130 Table 12: Mechanical properties (aproximate values) of Ni-Fe alloys. To reduce the number of dislocations and grain boundaries. a magnetic field annealing may be necessary. Fe) Magnifer ® 36 36 % Ni Magnifer ® 50 48 % Ni Magnifer ® 75 76 % Ni.2 in N/mm2 440 530 600 750 290 280 290 310 Elongation A5 in % 30 40 40 40 Hardness HV5 130-150 120-130 140-160 140-160 After processing. a high annealing temperature should be chosen (grain growth) and the greatest possible care should be applied during the cooling phase and when handling the finalannealed material.e. elements such as O. S. C. Table 11: Mechanical properties (aproximate values) of Ni-Fe alloys.g. Ni-Fe alloys require a (final) recrystallization anneal. 5 % Cu. Fe) Magnifer ® 36 36 % Ni Magnifer ® 50 48 % Ni Magnifer ® 75 76 % Ni. Condition: finish-annealed. . After the final annealing. stirring with argon and degassing under vacuum allow a high degree of purity to be achieved in the material at melt stage. Subsequently. Lattice defects should be kept to an absolute minimum throughout all manufacturing and processing steps. e. Mg should be limited to the smallest possible amounts. 5 % Mo Tensile strength Yield strength Rm in N/mm2 RP0. Condition: deep-drawable and bendable. 2 % Cr Magnifer ® 7904 80 % Ni. Al. by placing the parts in a protective container (avoidance of deformation and internal stresses). this is carried out at temperatures between 750 to 1300 °C in cracked ammonia or pure hydrogen with a dewpoint < -40 °C or – better – < -60 °C. 5 % Mo Tensile strength Yield strength RP0. i. 5 % Cu. stresses leading to plastic deformation must be avoided since this would lead to a considerable loss in magnetic properties.29 Material (bal. Depending on the sensitivity of the residual current circuit breaker. Magnifer 7904 is used for rated leakage currents of 30 mA and 10 mA due to its high permeability. The inductive impedance of the release relay and the integrating current transformer is therefore compensated with the aid of a condenser. In addition. Figure 39: Design of a residual current circuit breaker (according to [24]).30 Applications. Since a current integrating transformer should react not only to sinus-shaped currents but also to pulsed currents. and the release relay connected up to the secondary circuit activates the latch. it requires a core with a flat hysteresis loop (see section "Flat hysteresis loop"). As a result. S R W T L R C T Latch release relay Integrating current transformer Test key All the currents from all the current-carrying lines in the electrical installations are passed through the integrating current transformer. Under normal. depending on the release circuit design. voltage is induced in the secondary winding. for example. the sum of all incoming and outgoing currents is equal to zero. Circuit breakers with 300 mA or 500 mA rated leakage current. are made from Magnifer 53 or Magnifer 50. The energy needed for activating the release relay is provided directly by the leakage current. which is then magnetized accordingly. low temperature dependence between -25 °C and 80 °C is important. trouble-free operating conditions. It consists of an integrating current transformer for recording leakage currents. A residual current circuit breaker protects people and equipment in electrical installations. Any current that leaks into the earth due to an insulation defect is missing in the integrating current transformer. . a release relay. and a latch (Figure 39) [24]. various materials can be used for the core of the integrating current transformer. Residual current circuit breakers. to get optimal sensitivity. 000 250. low coercive force and high saturation flux density. FM . Table 13 below lists the alloys used for this application.5 0. This circuit is premagnetized by a permanent magnet so that the armature is kept in position on the yoke. Polarized relays are used [4. i. The material must maintain stable properties for an extended period of time.2 mW). The electric energy input is increased by a factor through the spring's energy storage (Figure 40). field generated by permanent magnet HU resultant field with release current HU HP H AFe cross sectional area µ0 magnetic field constant Figure 41: B(H) curve of the soft magnetic circuit of a relay. d = Total air gap I Fe = Length of the magnetic circuit µ = Permeability of the material This means very small air gaps in the range of approx. the magnetic holding force FM must be smaller than the holding force FF of the spring [26]. ® ® BS in T 1. Pulled-in armature B 1 Hysteresis loop 2 Released armature 4 3 H P D. components such as residual current circuit breakers operating independently of the mains voltage require a relay with very low release current (e. B = µoµ*H 1/µ* = 1/µ + d/l Fe need not pass through it. a low releasing sensitivity is required. The permanent magnet (low permeability) is therefore by passed via a shunt. In addition. In addition. 25. This also serves to obviate the risk of demagnetizing or remagnetizing the permanent magnet. 26] in most cases.e. approx. With the armature pulled in.g. the armatures is released (state 3). relays are made of pure iron or Fe with 3 % Si for economic reasons.1 to 0. it must be mechanically hard enough to ensure that the pole surfaces are not deformed during switching. Another essential prerequisite is that such a material must be sufficiently resistant to corrosion in cyclic climate conditions as per DIN VDE 664. Here. nickel-iron alloys are used.000 . At the same time. It follows that the magnetic circuit must have the highest possible effective permeability µ*. 31 1 A relay is an electromechanical switch that changes a low release current into mechanical movement. the current – and thus the leakage current – is interrupted (state 4). which means a small release current I a ~ H P – H U. the relay is in state 1 as shown in Figure 41. 1 µm and high permeabilities for the armature and yoke material. In other words. 0.7 HC in A/m <5 <1 <2 µmax (DC. a large ∆B must be generated with an appropriately small HP – HU (Figure 41).74 0. and so the release magnetic flux Material Magnifer 50 MH or B So 1 Magnifer 7904 Magnifer ® 77 TiNb So Table 13: Relay materials. The armature and the yoke require a material with high permeability. FM = B AFe/2µ0 2 Pin Klappanker armature Coil current Ia Coil Yoke Spring Nebenschluss Permanent magnet Figure 40: Schematic illustration of a polarized relay. the magnetic flux density B and the difference ∆B to the current-carrying state should be as big as possible. A polarized relay consists of a soft-magnetic circuit formed by an armature and a yoke.000 350. The coil current Ia reduces the magnetic field strength down to H U (state 2). However. A coil current Ia weakens the magnetic flux in the permanent magnet so that the armature – and thus the relay – is released. For many applications. To cause the relay to open.FF must be big enough to avoid the relay being susceptible to vibrations and external fields. 1mm) 100. Relays for residual current circuit breakers.Applications. C. Magnifer 75 is frequently also used in combination with Fe 3 % Si. Magnifer 75 and Magnifer 53 have proved most successful. losses and the actual load. Transducers of the type shown in Figure 42 can only measure alternating currents. In modern converter connections of the type used. This Hall voltage is used for triggering an electronic amplifier which feeds a current I2 to an additional winding on the core. I2 = n1 I1/n2 is fulfilled. The required accuracy must be ensured in the conversion of the values to be measured. for example. a voltage is excited that is proportional to the magnetic field within the probe. In reality. the current ratio is in inverse proportion to the turns ratio. in drive technology and electric heating systems. the core operates close to the coercive force level that causes an offset. High-permeability toroids in high-nickel Ni-Fe alloys are therefore particularly well-suited to this application. In a magnetized Hall probe. High permeability and high saturation flux density make a compact design possible. Scattering can be reduced through the use of toroidal strip wound cores. Such currents are measured using current measuring modules (Figure 44) [28. this means that the dependence of the permeability on the flux density should be reasonably constant in order to achieve linear conversion behaviour and thus high accuracy. In this case.UB I2 Figure 43: Current measuring module with Hall probe and compensation winding. As a result. For this application. The magnetic field generated by this current is then compensated to zero by the amplifier. Ni-Fe cores ensure the highest permeability at small signals while Fe 3 % Si cores ensures high signals. the ratio will be smaller because account has to be taken of scattering. Transducers. mixed currents occur which comprise both DC and AC components. Figure 44: Current-measuring module.32 Applications. “ I1 n1 I2 n2 Transducers are required for converting currents or voltages in energy distribution systems into values that can be measured by LF measuring equipment [27]. . Current-measuring module RM Submodule IH R 3 6 4 5 +U B 2 _ + I1 1 R . Since the flux density is compensated to zero. For the magnetic material used. For the ideal transducer. n2/n1 = I1/I2 (see Figure 42) A n2 n1 = I1 I2 Figure 42: Design of a transducer. 29] which incorporate a Hall probe (Figure 43). a large flux density swing permits the use of cores with a small cross section and/or a small number of turns and this ensures compact design. The following holds [27]: . For this purpose. In the magnetic core magnetic flux density swing ∆B starts from the remanent flux density. Normally unipolar square wave voltage pulses have to be transformed. Materials for pulse transformers must have a large usable magnetic flux density swing and high pulse permeability.n2 AFe B(t) = ∫ U dt where n2 = U = AFe = t = Number of turns in the secondary winding Secondary voltage Cross sectional area Time With a given voltage-time integral. such as Magnifer 54 F with a very flat hysteresis loop. Pulse transformers. 29]. They transform the trigger voltage pulses to the required level while ensuring potential separation between the control and power components [28. . high pulse permeability is advantageous. At the same time.Applications. very low coupling capacity and leakage inductance are also achieved . 2 Figure 45: Circuit board with pulse transformers in Magnifer® alloys. The main inductance LH of the transformer is then calculated as: LH = n2 µ0 µP AFe / lFe where µP = Pulse permeability lFe = Length of magnetic circuit The number of turns n2 in the secondary winding for the specified voltage-time integral must be large enough to permit the main inductance to be set to a minimum value.an indispensable condition if the gate trigger current is to rise steeply. 33 Thyristors in power electronics are triggered by pulse transformers (Figure 45). Low-distortion transformer in modems. measured on a transformer core package ED-8 (strip thickness 0. Signal distortion can be reduced by measures such as the use of small strip thicknesses and low magnetic flux densities. for example THD values smaller than -80 dB at 200 Hz are required.40 . However. The total harmonic distortion (THD) of a signal is the logarithm of the sum of the powers of all harmonics frequencies above the fundamental frequency to the power of the fundamental frequency. Low-distortion in this context means. For modems with transmission rates of 56 kBaud. Low-distortion transformers are made from highnickel alloys.20 mm).80 . that a sinus signal to be transformed should have a very low harmonic content. Figure 46 shows a typical curve of total harmonic distortion as a function of the frequency for Magnifer 7904. 0 .60 .120 10 100 1 000 Frequency (Hz) 10 000 100 000 Figure 46: Typical curve of "Total Harmonic Distortion" as a function of frequency for Magnifer® 7904. . THD= 10 log (P harmonics/ P fundamental waves) Total harmonic distortion (dB) .34 Applications. This calls for special lowdistortion transformers.100 A modem allows computers to communicate over ordinary analogue telephone lines. the limited frequency range of the analogue network means transmission rates higher than 2400 Baud can only be achieved with special coding techniques.20 . In cases like this. The shielding effect is based on the magnetic flux flowing via the highly permeable and thus magnetically conductive material. 35 Ha Hi Ha Hi Figure 47: Field lines for a cylindrical shield in the case of high frequencies. d exp ( ) 2 2 µδ δ 8 δ= 2 2nfµµ0 κ κ = electric conductivity δ is the skin depth of the field into the shield. the shielding effect is based on the eddy currents induced by the interference field. Fe 150 80 % Ni. Material Magnifer ® 36 Magnifer ® 50 Magnifer® 7904 Chemical composition 36 % Ni. H i is homogeneous and parallel to the interference field H a. Shielding factors for Magnifer 36. especially nickel-iron alloys. bal. measured in the transverse field at 200 A/m on cylinders (length 300 mm. S = | Ha / Hi | Hi = Field in the interior of the shield Ha = Interference field before the shield (In [32] the reciprocal Q or aS = -ln |Q| is used. bal. Shielding. good electric conductivity is essential for the shield.) The function of a magnetic shield is explained in the following using an (ideally. Equipment that generates or is susceptible to interference signals must be shielded. Typical applications for shielding in nickel-iron alloys include sound recording heads. The shielding effect increases along with the permeability. Inside the cylinder they run almost parallel to the cylinder surface. which is why copper or aluminium are used for shielding highfrequency fields. The interference field Ha runs vertical to the cylinder axis (transverse field). b) Frequency f ≈ 0 (or d << δ). without a shield present. Fe 60 48 % Ni. diameter 80 mm) with a wall thickness of 0. . Figure 47 shows the field lines. Figure 48: Field lines for a cylindrical shield in the case of a DC field. infinitely long) round cylinder with the radius R and wall thickness d (Figures 47 and 48). 5 % Mo. In this case. and µ >> 1 Now S can be described by approximation as: S = 1 + 1/2 µ d/R The field lines are shown in Figure 48. microphones.Applications. Inside. they displace the interference field from within the shield. The shielding property is described by the shielding factor S [32]. At high frequencies. R . Magnifer 50 and Magnifer 7904 are set out in Table 14. sensors and electron beam tubes. highly permeable materials are used. Two borderline cases will be described: a) Frequency f ¡ (or d >> δ ) S can be described by approximation as: S= 1 . The measurements were taken on cylinders with a wall thickness of 0. bal. Because µ >> 1 the outer field lines run almost vertically into the shielding cylinder. The materials are also used for cladding complete examination rooms in hospitals where highly sensitive measuring equipment is used.35 mm.35 mm. Fe S 60 150 1 000 Tabelle 14: Shielding factor S of some soft magnetic materials. shielding. storage chokes. magnetic heads . inductive rotary sensors. approximately 5 % molybdenum and the balance iron. . and Magnifer 75 with 76 % nickel. and their most important representatives are Magnifer 7904 with 80 % nickel. balance iron.stamped and bent parts for relays.36 Summary. electrovalves. and thyristor choke coils.laminations for LF transformers. low-distortion transformers in modems . There are two main groups of soft magnetic nickel-iron alloys: The first group comprises medium-nickel alloys whose most important representatives are Magnifer 50 with 48 % nickel. They are used for: . stator sheets.toroidal strip wound cores in integrating current transformers in residual current circuit breakers. electronic differential current switches. 5 % copper and the balance iron. The second group is made up of high-nickel alloys. stepped motors. 2 % chromium. balance iron and Magnifer 53 with approximately 55 % nickel. transducers . rotor sheets. mA/cm A/m A/m A/m A/m weight 1 T = Vs/m2 1mT = 0.List of variables and units used.001 T 1 Hz = 1/s 1 A/m = 10 mA/cm A/m A/m A/m A ampere A ampere A ampere J T tesla 1 T = Vs/m2 . 37 Variable Concentration Unit % Note Unless otherwise specified. data given in percent indicate the percentage per mass a A A5 B BS BM BO BR ˆ B ˆ Bsin ∆B ∆Bstat ∆Bdyn d E Ek Eu Eσ F f H ˆ H ˆ sin H ∆Hstat ∆Hdyn HV5 HC Hi Ha I I1 I2 IA J Lattice constant Cross sectional area Elongation Magnetic flux density or induction Saturation flux density < Magnetic flux density ≈ BS Magnetic flux density in vacuum Remanent magnetic flux density Peak value of magnetic flux density Peak value of magnetic flux density in a sinus-shaped field Flux density swing in a pulsed magnetic field Flux density swing in a half-wave rectified sinus-shaped field Flux density swing in a full-wave rectified sinus-shaped field Air gap or wall thickness Energy Crystal anisotropy energy Uniaxial anisotropy energy Stress anisotropy energy Force Frequency Magnetic field strength H = n1 I1 /lFe Peak value of magnetic field strength Peak value of magnetic field strength in a sinus-shaped field Magnetic field strength swing of a half-wave rectified sinus-shaped field Magnetic field strength swing of a full-wave rectified sinus-shaped field Vickers hardness at 49 N test force Coercive force Field in a shielding's interior Interference field before shielding Electric current Primary current Secondary current Exchange integral Magnetic polarization (induction) m metre m2 % T tesla mT T T T T T T T T T m J joule J J J N newton Hz hertz A/m. K2 Crystal anisotropy constants KU l Uniaxial anisotropy constant(s) Length ∆l l0 lFe L n n1 n2 P Q r R Rm Rp0.38 Variable Saturation polarization JS k Bolzmann's constant K Anisotropy constant.38054 10-23 J/°C 1 J/m3 = 106 Ws/cm3 1 J/m3 = 106 Ws/cm3 1 cm = 0.001s δ κ m.600 s 1 µs = 0.01m 1 mm = 10-3 m 1 µm = 10-6 m 1 H = 1 Tm2/A = 1 Vs/A 1W = 1 VA = 1 J/s according to JIS G 0555 m N/mm2 MPa megapascal MPa megapascal h hour s second s second µs °C °C °C °C V volt m3 cubic metre J 1 MPa = 106N/m2 1 h = 3. single or total K1. µm 1/Ωm .2% S S t tP T TC TE TM THD U V wA αi Change in length Initial length Length of magnetic circuit Inductivity L = n2 µ0 µ AFe /lFe Number of winding turns Number of turns in primary winding Number of turns in secondary winding Power Reciprocal of shielding factor S Degree of purity (reciprocal of the volume in % taken up by inclusions) Radius Tensile strength 0.2 % Proof stress Spin quantum number Shielding factor S = | Ha / Hi | Time Pulse duration Temperature Curie temperature Withdrawal temperature Measuring temperature Total harmonic distortion THD = 10 log ( Pharmonics/Pfundamental waves) Electric voltage Unit volume Exchange energy Cosine of the angle enclosed between the magnetizing direction and the cube edges Bloch wall thickness or depth of penetration Conductivity Unit T tesla J/°C J/m3 Ws/cm3 J/m3 Ws/cm3 J/m3 m metre cm centimetre mm millimetre µm micrometre m m m H henry W watt - Note 1 T = Vs/m2 1. 39 Variable λ Magnetostriction constant λ100 Magnetostriction constant in the cube edge directions Magnetostriction constants in the direction λ111 of body diagonals Mean magnetostriction constant λS µ Relative permeability Magnetic field constant µ0 Amplitude permeability = B/µ0 H µa Initial permeability = amplitude permeability µi ˆ for H → 0 Amplitude permeability at 4 mA/cm µ4 µ* Effective permeability of magnetic circuit (incl. pulse interval >>tP µ∆ Permeability differential = dB/µ0dH φ Angle between two neighbouring magnetic moments or angle between the preferred direction and the magnetizing direction ρ Resistivity σ Tensile stress Unit Tm/A - Note 1. air gaps) Maximum permeability µmax Pulse permeability = ∆B/µ0∆H for an HµP pulse of the duration tP.257·10-6 Tm/A 1/µ* = 1/µ + d/lFe Ω mm2/m N/m2 . Radeloff. p. Gottstein. 816 et seq. 22) H. H. p. p. Erpenbeck. ThyssenKrupp VDM 32) H. Pfeifer. 120 et seq. Verfahren zur Messung der magnetischen Eigenschaften von isotropen weichmagnetischen Nickel-Eisen-Legierungen der Typen E1. JMMM 112 (1992). Puzei. Baer. J. 592 ff. Schulze. Dissertation. Pfeifer. Philips Res. Materials and Corrosion 48 (1997). Berlin Göttingen Heidelberg. Bozorth. Relation between texture and magnetic annealing of a 55 % Ni-Fe alloy. Kolb-Telieps. Magnetismus Vol. 14) G. Metallkunde 57 (1966). A. 190 et seq.W. Berlin/Göttingen/Heidelberg (1962) 3) IEC 404-6 oder DIN IEC 68(CO) 39 (1984). p. 295 et seq. Morgenthaler. p. Springer Verlag.C. 29 (1910). W. Hall.E. p.R. J. 29 et seq. E4 4) C. J. Arch.M. 240 et seq. Appl. Ferromagnetismus. ThyssenKrupp VDM 15) G. Hütig Verlag. Florida 2) E. Berichte der AG Magnetismus (1959) (AG Magnetismus. 1.H. Ser. Erpenbeck. Magnetische Werkstoffe und ihre Anwendung. 190 et seq. Kramer. Physics of Magnetism. p. ThyssenKrupp VDM 30) Datenblatt Impulsübertrager. p. Heck. Fizika Metallov. C.M. Rev.. etc Elektronische Zeitung 113 (1992). Springer Verlag. Rep 4 (1949). p. 20) H. Solleder. nat. 624 et seq. 6) K. 29 (1958).T. H.G. Chikazumi. 252 et seq. 26) H. p. Phys. Krieger-Verlag.M. Kramer. R. Relaisteil-Lexikon. JMMM 19 (1980).und Nickel-Legierungen. Heidelberg. Thesis. A 48 % Ni-Fe alloy of low coercivity and improved corrosion resistance in a cyclic damp heat test. 535 et seq. 17) G. 10 – 17 25) A. Hütig Verlag. 18) E. 7) R. Kaden..G. Hattendorf. Universität Duisburg. (1967) 5) F. FH . Hegg. Hattendorf.E. (1993) 10) I. Metallphysik. p. Seminar on Soft magnetic materials. Akademie Verlag Berlin (1974). Hattendorf.F. 9) R. Fiz. B. phys. Phys. 1) S. E3. p. 12) F. 19) F. 22 (1958). New York (1970) p. Rathenau. Deutsche Gesellschaft für Metallkunde (1984). pp. Z. Custers. B. Küpfmüller. 24) G. 1244 et seq. W. JMMM 231 (2001). Ferguson.Dortmund (1990) 31) Datenblatt Speicherdrosseln. 23) E. TAW 1996 29) Datenblatt Strommessmodul. Weichmagnetische Nickel-Eisen-Werkstoffe in induktiven Bauelementen für die Leistungselektronik. 241 et seq. Nickel. Izvestijie Akademie Nauk SSR. (1959) . Volk. 13) F. Heitbrink. Schreyer. Metallkunde 57 (1966). Walker. 30 (1959). Phys. 21) B. H. (1984) 28) W. 55 et seq. 11) F. Gehrmann. Appl. p. Springer-Verlag. Z. Sci. Pfeifer. 15 et seq. 16) B. L29 et seq.V. L. Sauer. i. 686 et seq. Puzei. Düsseldorf 1960). FehlerstromSchutzschalter für eine zukunftssichere Schutztechnik. Einführung in die theoretische Elektrotechnik. p.40 Literature. J. Springer Verlag. 8) I. Pfeifer. Molotilov. p. Metallovedenie 11 (1961). Adler. Verlag Stahleisen Düsseldorf (1983). Kneller. Heidelberg (1985) 27) K. Berlin. Rekristallisation metallischer Werkstoffe. 89 (1953). Wirbelströme und Schirmung in der Nachrichtentechnik. Berlin Heidelberg New York. Wegerle in Berichte der Arbeitsgemeinschaft. Malabar. Corrosion behaviour of soft magnetic iron-nickel alloys. 30 (1910). p. Möttgen. ) Coercivity class µ4 µmax MF 6 6000 70000 ≤8 MF 8 8000 70000 ≤8 MF 10 10000 80000 ≤5 MH 12 ≤ 12 MH 8 – – ≤8 MG 6 6000 70000 – MG 10 10000 80000 – Strip thickness ~ 0. residual current circuit breakers. max. pulse transformers.8 400 8.3926 1.1 mm with cubic texture 1.7 500 9.05 max. Typical applications 1) 8. relay and shielding components. 0.3910 Ni 36 17445 A 753 1.2 500 10.2 300 5. 0.05 max. 0.3911 RNi 24 17405/17445 1.3 – 0.3 max. relay and shielding components. For further DIN material numbers see special material data sheet. toroidal strip cores. 41 ThyssenKrupp VDM alloy Specification D Material No. Soft magnetic alloys.3927 Ni 48 RNi 12 RNi 8 E 31 17745 17405 17405 DIN IEC 740-2 K94840 / A 753 (F3) (41301) Chemical composition in % Nickel Chromium Iron Carbon Manganese Silicon Aluminium Other elements Mechanical values (N/mm2.3 250 + 20 Quality Permeability (min. . Transformer.0 – 37.5 – bal.02 Mg max. 0. 2) AC values after optimum heat treatment. residual current circuit breakers. 0. 1. 0. max. transducers.0 8. transducers.0 – 48.2 600 290 Rm 630 ≥ 440 A50 5 30 HV 200 140 Rp 0. DIN designation DIN standard UNS / ASTM Magnifer 361) Magnifer 501) USA 1.Material tables.0 max. 0.2 700 280 Rm 750 530 A50 4 30 HV 200 125 35.5 75 140 100 1. laminations.25 500 15 45 164 100 9.2 200 2. %) Rp 0.3 max.1 1450 – good good 1440 – good good Low coercive force.01 50% cold worked deep-drawing Magnetic properties 2) Quality class MD 1 MD 1a MD 3 MD 5 Permeability (min.01 47.2 mm MT strip thickness 0.55 470 + 25 Physical properties at room temperature Density (g/cm3) Specific heat (J/kgK) Thermal conductivity (W/mK) Resistivity (µΩ cm) Modulus of electricity (kN/mm2) Expansion coefficient from 20°C to (10-6/K) Processing Melting point (°C) Max.0 – bal. 0. 0.5 400 8. memory cores. stepped motors. magnetic switches. good permeability with low hysteresis losses at high frequencies.3 mm 1.1 515 12. High saturation induction. working temperature (°C) Formability Weldability Material characteristics High resistivity.) µ16 µmax 2000±200 – 2300±200 – 2900 µ4 5000 20000 25000 Coercivity – – ≤ 16 ≤ 12 Saturation induction Curie temperature Saturation magnetostriction (T) (°C) (10-6) Strip thickness 0.02 Mg max.5 max. DC values on request.8 200 9. Transformer. good permeability with low hysteresis losses.2 300 8.3922 1. max.4595 2.42 ThyssenKrupp VDM alloy Specification D Material No.3 500 16.05 0.0 – 6. high saturation induction.4596 NiFe16CuCr (E3) (E4) RNi 2 RNi 5 E 11 17745 (41301) (41301) 17405 17405 DINIEC740-2 (E DIN40006) N14076 / A 753 Chemical composition in % Nickel Chromium Iron Carbon Manganese Silicon Aluminium Other elements Mechanical values (N/mm2. toroidal strip wound cores. working temperature (°C) Formability Weldability Material characteristics High permeability. max. max. 0. 0.) µ4 µmax 40000 115000 60000 140000 80000 175000 – – Coercivity – – – ≤2 Saturation induction Curie temperature Saturation magnetostriction (T) (°C) (10-6) Strip thickness 0.05 max. 1. residual current circuit breakers. transformer. DC values on request. Transducers.3 0.) µ4 µmax 40000 100000 60000 130000 Coercivity 2 1.4420 NiFe 44 17745 – USA 2. %) Rp 0.0 max.0 max.5 – 2. DIN designation DIN standard UNS / ASTM Magnifer 531) Magnifer 751) 2.5 530 + 25 Strip thickness 0.2 – – Rm – – A50 – – HV – – Rp 0. low coercive force.1 mm 1. Transducers. 0. Typical applications 1) 8.8 8.4592) 2.0 – 17.3 – Cu 4. 2) AC values after optimum heat treatment. transformer. .6 460 17 55 – 100 12.5 15.7 400 10.5 0.0 – 56.5 45 – 100 10. relay and shielding components.2 Quality class ME 4 ME 6 ME 8 MH 2 Permeability (min. 50% cold worked deep-drawing Magnetic properties 2) Quality class MG 40 MG 60 Permeability (min.7 500 10. 1.0 max. toroidal strip wound cores for special applications.6 200 10.6 300 10. For further DIN material numbers see special material data sheet.005 – bal.5 1445 – good ~ 1450 – good good High permeability.8 400 +1 Physical properties at room temperature Density (g/cm3) Specific heat (J/kgK) Thermal conductivity (W/mK) Resistivity (µΩ cm) Modulus of electricity (kN/mm2) Expansion coefficient from 20°C to (10-6/K) Processing Melting point (°C) Max.4501 (2.0 – bal. residual current circuit breakers.4591) (2.2 800 290 Rm 860 600 A50 5 40 HV 270 150 54. 0. laminations.0 – 2.0 – 5. Transducers.43 ThyssenKrupp VDM alloy Specification D Material No. transformers.5 – Mo 4.0. memory cores.0 200 12.0 2. max. 2) AC values after optimum heat treatment. Ti 0.2 900 310 Rm 1000 750 A50 4 40 HV 350 150 Quality class – – – – – – – Permeability (min. Typical applications 1) High initial permeability and maximum permeability with minimum hysteresis losses. stepped motors. 0.2 1030 1210 250 Rm 1050 1240 640 A50 3 1 40 HV 300 350 140 Rp 0. DIN designation DIN standard UNS / ASTM Magnifer 77 TiNb Magnifer 79041) USA Chemical composition in % Nickel Chromium Iron Carbon Manganese Silicon Aluminium Other elements Mechanical values (N/mm2. Stamped parts for relays. toroidal strip wound cores.8 max.06 mm 0.7 200 – 300 – 400 – 500 – Strip thickness 0.0 50% cold worked 80% cold worked deep-drawing Magnetic properties 2) Rp 0. pulse transformer. 0. For further DIN material numbers see special material data sheet.3 – – – – ~ 1440 – good good Precipitation-hardenable alloy with good corrosion behaviour.0 mm – – – – 8. %) – – – – – 77. . DC values on request. working temperature (°C) Formability Weldability Material characteristics Strip thickness 1.2.5 – – – – – – Quality class MP 130 MP 160 MP 200 MP 240 MP 280 Permeability (min. magnetic heads. Nb 1. 0.5 – Cu 4.05 – max.7 460 17 55 – 100 12. chokes.7 – 25 40 – 100 12.0 – bal.4545 NiFe 15 Mo 17745 N14080 / A 753 79.5 – bal.0 – 6. residual current circuit breakers.5 – 1. 0.05 max. max.) µ4 µmax 130000 275000 160000 300000 200000 350000 240000 400000 280000 420000 Coercivity – – – – – Saturation induction Curie temperature Saturation magnetostriction (T) (°C) (10-6) Physical properties at room temperature Density (g/cm3) Specific heat (J/kgK) Thermal conductivity (W/mK) Resistivity (µΩ cm) Modulus of electricity (kN/mm2) Expansion coefficient from 20°C to (10-6/K) Processing Melting point (°C) Max.8 300 13.6 500 14. Mo max.0 – 78.8 410 +1 8. 0.) µ16 µmax 65 000 250 000 – – – – – – – – – – – – Coercivity 1.0 400 13.5 – 81.0. 0 – 6.55 mm 0.) µ4 µmax 100000 200000 Coercivity 1 Saturation induction Curie temperature Saturation magnetostriction (T) (°C) (10-6) Strip thickness 0.0 200 300 400 500 Typical applications Stamped parts and housings for magnetic heads.7 – 17 60 – 100 12. working temperature (°C) Formability Weldability Material characteristics Negative magnetostriction. DIN designation DIN standard ASTM Magnifer 8105 USA – – – – Chemical composition in % Nickel Chromium Iron Carbon Manganese Silicon Aluminium Other elements Mechanical values (N/mm2.0 – 82. 0. ~ 1450 – good good 8.0 50% cold worked deep-drawing Magnetic properties 2) Quality class Permeabilität (min.72 420 -1 Physical properties at room temperature Density (g/cm3) Specific heat (J/kgK) Thermal conductivity (W/mK) Resistivity (µΩ cm) Modulus of electricity (kN/mm2) Expansion coefficient from 20°C to (10-6/K) Processing Melting point (°C) Max.0 – bal. – max.44 ThyssenKrupp VDM alloy Specification D Material No. . %) Rp 0.8 – – Mo 5.2 1250 310 Rm 1250 700 A50 3 30 HV 350 140 – 180 80. 0 (3. pay-off packs.0106 – ≤ 0. relay parts. on spools and spiders Welded tube and pipe Welded tubes and pipes are obtainable from qualified manufacturers using ThyssenKrupp VDM semi-fabricated products.16 – 14 3) 0.) 3) Wider widths up to 730 mm (29 in.01 – 12.140 2) 1) 2) inches 0. Dimension on demand. square (a) Bar.5 mm (0.008 > 0. laminations and other stamped parts.) Maximum thickness: bright annealed – 3 mm (0. square (a) Bar.60 – 30 4) /16 – 4 /16 – 11 /2 – 2 /2 1 10 not standard (3/8 – 3/4) x (11/4 – 31/8) ≤2 (3/16 – 3/4) x (43/4 – 24) 1 1.) Bar.20 – 30 4) 0. Toroidal strip wound cores. in coils.0 mm (0.0008 – ≤ 0.120 2) ≤ 0.25 Width mm 14 – 200 3) 14 – 350 3) 14 – 750 4) 16 – 750 4) 18 – 750 4) 15 – 750 4) Coil I.16 – 8 3) inches 12 12 16 16 16 16 16 16 16 20 20 20 20 20 20 24 24 24 24 24 Bar.10 > 0.Forms supplied.20 > 0.080 > 0. hexagonal (s) 1) Strip1) Conditions: cold rolled.0246 – ≤ 0.0046 – ≤ 0.). mm 300 300 400 400 400 400 400 400 400 500 500 500 500 500 500 600 600 600 600 600 Rolled1) mm 8 – 100 15 – 280 (5 – 20) x (120 – 600) 13 – 41 inches 5 Drawn1) mm 12 – 65 not standard (10 – 20) x (30 – 80) ≤ 50 inches 1 > 0.) subject to special enquiry 4) Wider widths subject to special enquiry Wire Conditions: bright drawn. thermally treated and pickled or bright annealed 2) Thickness mm > 0. D.20 – ≤ 0. D.47 in. machined.010 > 0.120 in.) diameter. flat (a x b) ≤ 24 15/8 – 24 (15/8 – 31/8) x (8 – 24) Bar.16 – 30 4) 0.10 – ≤ 0.60 > 0. D.00 – ≤ 3.0004 – 0.004 > 0. bright annealed Dimensions: 0. 1/4 hard to hard.02 – ≤ 0.0 > 2.040 > 0.00 – ≤ 2. cold rolled only – 3.0 > 1.0806 – ≤ 0.024 > 0. 45 Availability Soft magnetic NiFe base alloys are available in the following standard product forms: Rod & bar Conditions: forged.00 – 30 4) 15/8 – 31/8 /2 – 15/8 other sizes and conditions subject to special enquiry Cut-to-length available in lengths from 250 to 4000 mm (10 to 158 in. hexagonal (s) 0. .25 – ≤ 0.5) 2) 25 – 750 4) inches > 0.0086 – ≤ 0. drawn.140 in.0406 – ≤ 0. descaled or pickled. flat (a x b) Forged1) mm ≤ 600 40 – 600 (40 – 80) x (200 – 600) 40 – 80 inches Rod (O.) Bar. rolled.60 – ≤ 1. thermally treated. peeled or ground Product Rod (O.32 – 30 4) 0. thyssenkruppvdm.de Germany Berlin ThyssenKrupp VDM GmbH Wittestraße 49 13509 Berlin Tel. GR-15410 Psychico (Athens) Tel.O.dk Finland Oy Cronimo Ab Karhutie 6 FIN-01900 Nurmijärvi Tel. Stationsweg 4 NL-3311 JW Dordrecht P. +31 (78) 6 31 69 66 Fax +31 (78) 6 31 58 57 E-Mail: info@tks-vdmnl. Germany Head Office ThyssenKrupp VDM GmbH Plettenberger Straße 2 Postfach 1820 58778 Werdohl Tel. 14 Bte 34 Résidence Saturne B-1410 Waterloo Tel. +32 (2) 3 54 29 00 Fax +32 (2) 3 54 36 26 E-Mail: thyssenkruppvdm@ skynet.com Dresden ThyssenKrupp VDM GmbH Oskar-Röder-Straße 3 01237 Dresden Tel. P. Pambouki Str. Ltd. Avenue du Champ de Mai. +45 (43) 95 07 21 Fax +45 (43) 95 07 01 E-Mail: wg@thyssen. thyssenkrupp.central@kruppvdm. 111. Box 65060 8.O. thyssenkrupp. +30 (10) 6 83 95 35 Fax +30 (10) 6 83 95 36 Europe Great Britain ThyssenKrupp VDM U. thyssenkrupp.V.com Italy ThyssenKrupp VDM Italia Srl Via Milanese 20 I-20099 Sesto San Giovanni (Mi) Tel. +49 (0911) 6 63 26 00 Fax +49 (0911) 6 63 26 01 E-Mail:
[email protected] Stuttgart ThyssenKrupp VDM GmbH Am Ostkai 15 70327 Stuttgart Tel. Hare Lane Claygate-Esher. thyssenkrupp. Surrey KT10 OQY Tel. +49 (02392) 55-2790 Fax +49 (02392) 55-2526 E-Mail: rpechan@tks-vdm. +49 (0711) 9 32 88-36 Fax +49 (0711) 9 32 88-37 E-Mail: hstegmaier@tks-vdm. +49 (0351) 2 52 28 06 Fax + 49 (0351) 2 52 28 07 E-Mail: rsimmchen@tks-vdm. +49 (02392) 55-0 Fax +49 (02392) 55-2217 E-Mail: info@tks-vdm. +49 (02392) 55-2376 Fax +49 (02392) 55-2526 E-Mail: jleonhardt@tks-vdm. thyssenkrupp. 26 BG-1000 Sofia Tel.A. +47 (51) 81 85 00 Fax +47 (51) 81 86 00 Austria/Central and Eastern Europe ThyssenKrupp VDM Austria GmbH Tenschertstraße 3 A-1230 Wien Tel. +39 (02) 2 41 04 61 Fax +39 (02) 24 10 46 29 E-Mail: cquva@tin. +33 (1) 41 39 04 20 Fax +33 (1) 47 16 78 20/14 E-Mail: s. +43 (1) 6 15 06 00 Fax +43 (1) 6 15 36 00 E-Mail: office@krupp-vdm. +44 (1372) 46 71 37 Fax +44 (1372) 46 63 88 E-Mail: info@tks-vdmuk. thyssenkrupp. Bd Bellerive F-92566 Rueil Malmaison CEDEX Tel. Box 750 NL-3300 AT Dordrecht Tel.com Norway A/S Stavanger Roerhandel Gamle Forusvei 53 P. +49 (030) 4 32 40 36 Fax +49 (030) 4 35 29 68 E-Mail: sdueren@tks-vdm. +358 (9) 2 76 42 10 Fax +358 (9) 2 76 42 21 50 E-Mail:
[email protected] Bulgaria ThyssenKrupp VDM Austria GmbH Parensov Str. thyssenkrupp.com www.com Nuremberg ThyssenKrupp VDM GmbH Dieselstraße 55 90441 Nürnberg Tel.46 ThyssenKrupp VDM sales offices.com Europe Belgium/Luxembourg S.fr Greece INTERAG Ltd.V. ThyssenKrupp VDM Belgium N. Box 184 N-4033 Forus Tel.at .it Netherlands ThyssenKrupp VDM Nederland B.com Werdohl – Northern Office ThyssenKrupp VDM GmbH Plettenberger Straße 2 Postfach 1820 58778 Werdohl Tel.fi France ThyssenKrupp VDM SARL 30. 31 DK-2670 Greve Tel. thyssenkrupp. +359 (2) 9 89 16 77 9 88 65 22 Fax +359 (2) 9 89 16 77 E-Mail:
[email protected] Denmark ThyssenKrupp Materials Denmark A/S Agenavej. thyssenkrupp.com Werdohl – Western Office ThyssenKrupp VDM GmbH Plettenberger Straße 2 Postfach 1820 58778 Werdohl Tel. subsidiaries and representations. +58 (2) 284-24 96 Fax +58 (2) 978-12 85 E-Mail: gunz-mse@etheron. Ontario L3R 9T8 Tel. Of. +51 (1) 440 49 53 Fax +51 (1) 442 12 33 Uruguay Fierro Vignoli S.I.com Turkey Akkurt A. Bulevard Manuel Avila Camacho No.za . Lebanon Square Giza/Cairo Tel. Box 3374 3792 Festac Town Tel. +20 (2) 350-21 12 Fax +20 (2) 378-31 15 Nigeria Betcy Investment Limited Betcy House Block 14. Inc.ec Peru AMSET E.3. Suite 203 11 Allstate Parkway Markham.com Brazil IMS DO BRASIL LTDA. 1. de C. +34 (93) 2 00 90 11 Fax +34 (93) 2 00 22 54 E-Mail: info@tks-vdmes. 2da.6886 E-Mail: sergio. +55 (11) 5054 . N. El Ayoubi P. Amuwo Odofin/Festac Access Road P.ro Russian Federation ThyssenKrupp AG Repräsentanz in der Russischen Föderation Krasnopresnenskaja nab 12 Internationales Handelszentrum (CMT) Büro 1209 GUS-123610 Moskau Tel.br Chile ACERIMPEX Huérfanos 1160 Oficina 1013 Santiago – Centro Tel.H. Santa Rosa Oe7-178 y Pasaje Herrera Quito Tel. Edf. 2002/2003 04523-001 Sáo Paulo-SP Tel. 10. +52 (55) 57-14 71 Fax +52 (55) 57-14 76 E-Mail: kruppvdm@prodigy. Piso 9.net North and Middle America Canada ThyssenKrupp VDM Canada Ltd.ch Spain/Portugal ThyssenKrupp VDM Ibérica Calvet.net Africa Egypt OSAB Trade Dr.net. Box Maadi 191 House 30. Ahmediye Köyü TR-34904 B. Cekmece-Istanbul Tel. Box 8027 S-16308 Spanga/Stockholm Tel.A.mx South America Argentina Walvoss S. 306 Columbia Turnpike Florham Park.L. 726 – Cjs.co. 07932 Tel.com Mexico ThyssenKrupp VDM de México S. +27 (11) 626-3370-306 Fax +27 (11) 626-2191 E-Mail: heath@intecom. Torre B.roth@ thyssenkruppvdm.R.ru Sweden ESMA AB Domnarvsgatan 8 P. +54 (11) 43 04 87 70 Fax +54 (11) 43 05 06 91 E-Mail: wvsponte@pinos. El Nil El Abiad St.O. de México C. Av. +56 (2) 688 82 72 Fax +56 (2) 699 03 19 E-Mail: rubenreyesd@terra. Crucible Road Heriotdale 2094 Johannesburg 2000 Tel.L.S. Plot 241.andersson@ esma. Caracas 1060 Tel. Humberto 1° 1333 C 1103 ADA Buenos Aires Tel. 208 Medellin Tel.J. +57 (4) 266-17 37/17 57 Fax +57 (4) 268-61 92 Ecuador Importadora Schiller Cia. José Maria Eguren (Chumbiongo) 107.a E-08021 Barcelona Tel.O.47 Europe Romania ThyssenKrupp VDM Austria GmbH Str. +41 (61) 2 05 84 88 Fax +41 (61) 2 05 84 15 E-Mail: raoul. Transversal. Macuco.se Switzerland ThyssenKrupp VDM (Schweiz) AG Lange Gasse 90 P. +90 (212) 8 87 14 15 – 17 Fax +90 (212) 8 87 10 79 E-Mail: akkurt@ibm. 302 Miraflores (Lima 18) Tel. P.O. Sector 1 RO-010593 Bukarest Tel. 90-B. Ltda. +20 (2) 303 46 33 Fax +20 (2) 346 08 00 Samir L. +1 (973) 236-1664 Fax +1 (973) 236-1960 E-Mail:
[email protected]. thyssenkrupp. O. +1 (905) 477-2064 Fax +1 (905) 477-2817 E-Mail:
[email protected]. Urugay 1274/76 Montevideo Tel. CRA 43 A No. +234 (1) 589 05 52/53 Fax +234 (1) 588 29 69 E-Mail:
[email protected]@ims group. 80 PH-A Lomas de Sotelo Naucalpan Edo. +598 (2) 91 45 60 Fax +598 (2) 92 12 30 South America Venezuela GUNZ S.ca USA ThyssenKrupp VDM USA. 1 Sur-31. Av..R.10 Et.A. Av c/c 1ra. 2°. Ap.com. +593 (2) 2 54 77 60 Fax +593 (2) 2 56 27 88 E-Mail: schiller@interactive. Abbas 6. Box CH-4002 Basel Tel. 53390 México Tel.V.6992 Fax +55 (11) 5054 . Stanislas Cihoschi.net.cl Colombia HERGUT Ltda. Los Palos Grandes. +46 (8) 4 74 42 00 Fax +46 (8) 4 74 42 60 E-Mail: angelika. Dpto. +7 (502) 2 58 20 74 Fax +7 (502) 2 58 20 76 E-Mail:
[email protected]. +40 (21) 6 10 77 05 Fax +40 (21) 2 11 99 44 E-Mail:
[email protected]. Street 11 Maadi-Cairo Tel. Urb.L. Nr.net South Africa ThyssenKrupp VDM SA (PTY) LTD 36. 30-32. La Pradera. net. District 1 Ho Chi Minh City Tel. Ltd. Rooms 715-737.vnn.com.48 Middle East Israel Middle East Metals Ltd.sg South Korea ThyssenKrupp VDM Korea Co. 301.. +63 (2) 631 1775-85 Fax +63 (2) 631 4028 635 0036 E-Mail: mescophil@skyinet. +886 (2) 26 95 30 33 Fax +886 (2) 26 95 07 66 E-Mail: sales@fea. Beijing Representative Office Unit 8A. Bundang-gu Sungnam-si Kyunggido 463-020 Tel.. +66 (2) 216 57 47. No. #12 13. +82 (31) 711 15 83 Fax +82 (31) 717 15 83 E-Mail: michoi@tks-vdmkr. Mumbai – 400018 Tel.vn Peoples Republic of China ThyssenKrupp VDM Hongkong Ltd.com. Ltd. P. 16 Chaoyangmenwai Avenue Chaoyang District Beijing 100020 Tel.vsnl.net Singapore.O.net.th Vietnam ThyssenKrupp AG Representative Office Vietnam Hanoi Office Suite 503. Box 3489 Tourist Club Area Abu Dhabi Tel.com. 20/F. Korazin St.O. Box 870 53583 Givatayim Tel. Fukide Build. +84 (8) 910 24 38 Fax +84 (8) 910 24 40 E-Mail: thyssenkrupp@hcm. Hyundai Office B/D 9-4 Sunai-dong.com. 22/F. +61 (3) 95 61 13 11 Fax +61 (3) 95 61 44 65 E-Mail: cnicola@vdm. +86 (10) 85 25 29 99 Fax +86 (10) 85 25 21 61 E-Mail:
[email protected] Taiwan Far East Alloy Corporation 2F-2. Kakad Chambers 132. Eastern Union Corporation P.com. +972 (3) 571 53 74/69 Fax +972 (3) 571 53 71 E-Mail: isbrildo@netvision. Box 95 02 79 Amman Tel. +852 25 41 00 00 Fax +852 28 54 19 42 E-Mail: desmond@fordley. Payatai Plaza Building Payatai Road Bangkok 10400 Tel. +65 68 46 88 22 Fax +65 68 46 88 33 E-Mail: Daniel. thyssenkrupp.il Jordan International Technical Construction Co.tw Asia Thailand Sahakol Trading Co.cn Asia Peoples Republic of China and Hongkong Fordley Development Ltd Rm 705-707. 724 Springvale Road P. 7F 1-13 Toranomon 4-chome Minato-ku Tokyo 105-0001 Tel. 128/113 9th FL.O. Box 271 Mulgrave. +84 (4) 934 70 43 Fax +84 (4) 934 70 46 E-Mail: doan@thyssenkrupp. 1. 29-1. China Life Tower No. Metro Manila Tel. Ltd No. E.O.hk Australia ThyssenKrupp VDM Australia Pty.jp Philippines MESCO Inc.shanghai@ thyssenkrupp. P.8 Fax +66 (2) 216 57 21 E-Mail:
[email protected] ThyssenKrupp AG Representative Office Ho Chi Minh R. Wanchai Hong Kong Tel.beijing@ thyssenkrupp.ocn. +971 (2) 78 24 62 Fax +971 (2) 77 19 58 India Variety (Agents) Private Ltd. 5th Floor Hanoi Central Office Building 44B Ly Thuong Kiet Street Hoan Kiem District Hanoi Tel. +962 (6) 551 49 63 Fax +962 (6) 553 70 69 E-Mail: itcc@go. +91 (22) 24 93-26 91 Fax +91 (22) 24 95-05 78 E-Mail:
[email protected]. thyssenkrupp. S Floor. Ltd.in Asia Hongkong ThyssenKrupp VDM Hongkong Ltd.jo U.com Japan ThyssenKrupp VDM Japan
[email protected]. 906. China Merchants Tower 161 Lujiazui Dong Road. 10 Ubi Crescent #07-11 Ubi TechPark Singapore 408564 Tel.K. com.au . +81 (3) 5472 2651 Fax +81 (3) 5472 1564 E-Mail: vdmj-t. Victoria 3170 Tel. Indonesia Firsttech Distribution Pte. +852 31 81 78 00 Fax +852 25 27 20 45 E-Mail: info@tks-vdmhk. thyssenkrupp. MESCO Building Reliance Corner Brixton Streets 1603 Pasig City. Pu Dong Shanghai 200120 Tel. Annie Besant Road Worli.com.cn ThyssenKrupp VDM Hongkong Ltd. Yu Sung Boon Building 107-111 Des Voeux Road Central Hong Kong Tel. Shih-Chih City Taipai Hsien Tel. Malaysia. +86 (21) 38 78 47 00 Fax +86 (21) 58 82 95 89 E-Mail: vdm. Saigon Trade Centre 37 Ton Duc Thang. Dr. Sun Hung Kai Centre 30 Harbour Road. Shanghai Representative Office Unit 2009. 7/F. Lane 169 Kang Ning St. A. 27 Soft magnetic Ni-Fe base alloys Published by: ThyssenKrupp VDM GmbH Plettenberger Strasse 2 58791 Werdohl P.com The information and recommendations in this brochure are based on practical experience and our own research and development results at the time of going to press. Product deliveries and services are subject exclusively to our General Terms and Conditions. we do not guarantee that it is accurate.thyssenkruppvdm. VDM Report No.thyssenkrupp. Box 1820 58778 Werdohl Germany Phone: +49 (2392) 55-0 Fax: +49 (2392) 55-2217 Email:
[email protected]. June 2004 . They may be changed at any time in the interest of the ongoing improvement and further development of our materials. While every care has been taken to ensure that the technical information in this brochure is correct and up to date.Imprint.com www. 0 Fax: +49 (23 92) 55 .ThyssenKrupp VDM GmbH Plettenberger Strasse 2 58791 Werdohl P.wüpodvkwdpßokvüßkwdvüßk .com mvpfwmpfkwpkfgvpkwrpvkwd vd.22 17 E-Mail:
[email protected]. Box 18 20 58778 Werdohl Germany Phone: +49 (23 92) 55 .com www.vdüwdpölvüwpldvüplwüldv .