Metallographic Etch

Metallographic Etch's Database FileMaterial: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml cold-saturated (in distilled water) sodium thiosulfate solution and 1g potassiurn metabisulfite. Procedure: Imersion at room temperature for 40-120 s. Remarks: Color etching. Ferrite colored brown. Carbides, phosphides and nitrides remain white, nitrides remain white. Phosphorus rich areas outlined. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g potassium metabisulfite, 1g sulfamic acid, 100 ml distilled water. Procedure: Imersion at room temperature for 30-40 s. Remarks: Color etching. Ferrite colored. Carbides, phosphides and nitrides remain white. Sulfides colored white. Phosphorus rich areas aoutlined. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g potassium metabisulfite and 10 g sodium thiosulfate, anhydrous, in 100 ml distilled water (use after 4 %-picral pre-etch). Procedure: Pre-etch with 4 % picral, 1-2 min. Imersion at room temperature for 2 min (until surface turns bluish red). Remarks: Color etching. Spectacular coloration of ferrite grains as a function of crystallographic orientation. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 2 ml hydrochloric acid (35 %), 0.5 ml selenic acid and 100 ml ethyl alcohol (95 %). Procedure: After polishing, immerse for 5-6 min. If pre-etching in 2 % nital, immersion time is shorter: 2-3 min at room temperature. Remarks: Color etching. Cementite colored red-bright. Ferrite remains bright. Phosphides and silicon colores blue-green. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 1 g sodium molybdate in 100 ml distilled water; acidify to pH 2.5 to 3 with nitric acid (use after nital pre-etch). Procedure: Pre-etch with 2 % nital. Immerse at room temperature for 30-45 s. Remarks: Color etching. Phosphides and cementite colored yeloworange. Sulfides remains light gray. Ferrite remains white. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 1 g sodium molybdate and 100-500 mg ammonium bifluoride in 100 ml distilled water; acidify with nitric acid to pH 2.5 to 3.5 (use after nital pre-etch). Procedure: Pre-etch with 2 % nital. Immersion at room temperature for 30-45 s. Remarks: Color etching. Phosphides and cementite colored blueviolet. Ferrite colored white-yellow. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml reagent (240 g sodium thiosulfate, 24 g lead acetate and 30 g citric acid in 1000 ml distilled water (use after ammonium persulfate pre-etch)) plus 200 mg sodium nitrite. Procedure: Pre-etch in 2 % nital. Immersion at room temperature until surface turns blue-violet. Remarks: Color etching. Phosphides colored yellow-brown. Sulfides appear bright. All other phases colored blue--violet. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 240 g sodium thiosulfate, 30 g citric acid and 20-25 g cadmium chloride in 1000 ml distilled water. Procedure: Pre-etch in 2 % nital. Immersion at room temperature (after filtering sulfur particles) for 20-90 s. Remarks: Color etching. After short immersion time (20-40 s), only ferrite is colored (red or violet). After longer immersion time, all phases are colored: phosphides, brown-orange; ferrite, yellow or light blue; cementite, red-violet or blue. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 37. Material: Carbon steels, alloy steels, tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 1 g sodium metabisulfite; dilute to 100 ml with distilled water. Procedure: Immersion at room temperature for 60-120 s. Remarks: Color etching. Colors lath-type and plate-type martensite in Fe-C alloys. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 47. Material: Carbon steels, alloy steels, tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 30 g acetone sodium bisulfite; dilute to 100 ml with distilled water. Procedure: Immersion at room temperature for up to 120 s. Remarks: Color etching. Colors the martensite in Fe-C alloys. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 47. Material: Carbon steels, alloy steels, tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml cold-saturated (in distilled water) sodium thiosulfate solution and 1g potassiurn metabisulfite. Procedure: Irnmersion at room temperature for 40-120 s. Remarks: Color etching. Colors pearlite and hardened structures of unlloyed steels. Ferrite colored brown-black (dark red-dark violet), carbides, phosphides and nitrides remain white. Reference: E. Beraha and B. Sphigler, Color Metallography, American Society for Metals (ASM), Metals Park, Ohio 440073, USA, 1977. p. 47. 1 1977. Material: Stainless steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g potassium metabisulfite. Immersion at room temperature for 5-8 s. alloy steels. Material: Carbon steels. After nital pre-etching. Sphigler. Sphigler. Carbides colored red to blue. American Society for Metals (ASM). USA. Remarks: Color etching. Ohio 440073. p. Beraha and B. Material: Carbon steels. American Society for Metals (ASM). Immersion at room temperature for 2 min. alloy steels. p. Ohio 440073. Remarks: Color etching. 47. redviolet-blue. Beraha and B. Reveals banded structures. Color Metallography. alloy and manganese steels. Gama iron is colored gray. Reference: E. immerse for shorter time 2-3 min. immersion at room temperature for 5-6 min. Sphigler. ferrite grains. 1977. Colors ferrite grains. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 240 g sodium thiosulfate. American Society for Metals (ASM). Carbides and phosphides remain white. American Society for Metals (ASM). Reference: E. 100 ml distilled water. Metals Park. Procedure: Pre-etch in nital. For carbon and alloy steels and some tool steels. Ohio 440073. For Mn. Procedure: Pre-etch in 2 % nital. Color Metallography. dilute to 100 ml with distilled water. USA. Used in carbon and alloy steels. Ferrite colored white-yellow. Material: Carbon steels. Ferrite remains bright. USA. for step 2: 15 to 35 g sodium metabisulfite. USA. 62. Ohio 440073. Reveals Chemical and physical heterogeneity. p. USA. 47. 1g sulfamic acid. USA. Reference: E. Mn-C. Sphigler. Beraha and B. 1-2 g sulfamic acid 2 . alloy steels. Immerse 4-5 min for "line" etching. American Society for Metals (ASM). phosphides remain white. Bainite is colored red. Material: Stainless steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): For step 1 (pre-etching): 25 ml nitric acid and 75 ml ethyl alcohol (95 %). Reveals the substructure of lath-type martensite. 47. alloy steels. Immersion at room temperature for 2 min or until polished surface turns bluish red. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 1 g sodium molybdate and 100-500 mg ammonium bifluoride in 100 ml distilled water. Remarks: Color etching. Remarks: Color etching. alpha martensite is colored black. Sulfides in free-cutting steels colored white. 47. 47. carbides.5-1 g potassium metabisulfite. Metals Park. Remarks: Color etching. 1977. Metals Park. Procedure: Immersion at room temperature. USA. Immersion at room temperature (after filtering sulfur particles) for 20-90 s. Sphigler. alloy steels. 1977. Beraha and B. Colors ferrite grains. For carbon and alloy steels. Color Metallography. Carbides colored brown-violet.5 ml selenic acid and 100 ml ethyl alcohol (95 %). Remarks: Color etching. For carbon. Tint etchant for Fe-Ni alloys from 5-25 % Ni. For carbon and alloy. Metals Park. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g potassium metabisulfite. American Society for Metals (ASM). Remarks: Color etching. 47. Beraha and B. Color Metallography. Color Metallography. 1977. Material: Carbon steels. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml reagent (240 g sodium thiosulfate. Remarks: Color etching. Reference: E. Sphigler. Material: Carbon steels. p. 47. Material: Carbon steels. Reference: E. Other phases colored: ferrite. Material: Carbon steels. Ohio 440073. acidify with nitric acid to pH 2. Procedure: Pre-etch in 2 % nital. Metals Park. Ohio 440073. American Society for Metals (ASM). Procedure: Immersion at room temperature for 2-3 min. alloy steels. Remarks: Color etching. Reference: E. Colors nitrided zone in nitriding steels. Reference: E. Beraha and B. p. steels and some tool steels. Procedure: After polishing. American Society for Metals (ASM). Ohio 440073. yellow or light blue. American Society for Metals (ASM). in 100 ml distilled water (use after 4 %-picral pre-etch). tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g potassium metabisulfite and 10 g sodium thiosulfate. 47.Material: Carbon steels. 30 g citric acid and 20-25 g cadmium chloride in 1000 ml distilled water. Sphigler. 1977. For carbon. Metals Park. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml cold-saturated (distilled water) sodium thiosulfate solution and 5 g thiosulfate. Immersion at room temperature until specimen surface turns blue-violet. Sphigler. Metals Park. p. alloy and Fe-Mn (5-18 % Mn) steels. Immersion at room temperature for 30-60 s. American Society for Metals (ASM). Mn-Cr steels. Color Metallography. Etching time depends on kind of steel. Ohio 440073. p. Procedure: Pre-etch with 4 % picral for 1-2 min. alloy and tool steels. p. alloy steels. 100 ml of the stock solution plus 0. Sulfides remain bright. anhydrous. Sphigler. Procedure: Step 1: Pre-etch with 25 ml HNO3 + 75 ml ethyl alcohol by immersion for approx 10 s. For carbon and tool steels. USA. 1977. Color Metallography. Ohio 440073. Remarks: Color etching. 1977. USA. 47. alloy steels. 1977.5 (use after nital pre-etch). alloy steels. Procedure: Immersion at room temperature for 30-120 s. Color Metallography. Sphigler. depending on the amount of ammonium bifluoride. nitrides. p. carbides. Metals Park. 0. Colors martensite packets of different orientations to different colors. Material: Carbon steels. Reference: E. Epsilon martensite remains white.) Step 2: Etch with 15 to 35 g sodium metabisulfite diluted to 100 ml with distilled water. Metals Park. Color Metallography. For carbon. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g potassium metabisultite in 100 ml distilled water. Beraha and B. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 2 ml hydrochloric acid (35 %). 24 g lead acetate and 30 g citric acid in 1000 ml distilled water (use after ammonium persulfate pre-etch)) plus 200 mg sodium nitrite. Metals Park. Beraha and B. Beraha and B.5 to 3. 1977. Ohio 440073. All other phases colored blue-violet. Color Metallography. Martensite is colored blue. USA. Beraha and B. tool steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): Stock solution: 1:5 v/v hydrochloric acid (35 %) and distilled water. Reference: E. p. Procedure: 100 cc etchants + 2 g ammonium bifluoride + 1 g potassium metabisulfite. Reference: E. (Caution: HNO3 and ethyl alcohol are dangerous at this concentration. 62. Procedure: (1:1 + addition of 100 ml of 2-10 g ammonium bifluoride). American Society for Metals (ASM). Colors the austenitic matrix. Procedure: Immersion at room temperature.5 v/v hydrochloric acid (35 %) and distilled water. Metals Park. Etching of austenitic stainless steels and welds. Color Metallography. When good coloration is not produced. USA. Beraha and B. Metals Park. Sphigler. Material: Stainless steels (Fe) Type: Microetching Material: Heat-resisting steels and alloys (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): Stock solution: 1:2 or 1:1 or 1:0.5-1 g potassium metabisulfite. Etching of stainless steels. Etching of austenitic stainless steels. use reagent (stock solution: 1:2 or 1:1 or 1:0. General color etching for microstructure of ferritic and martensitic stainless steels. Colors carbides and phase.5 v/v hydrochloric acid (35 %) and distilled water. 1977. Immersion at room temperature for 60-150 s. Ni and Co base heat resisting alloys. Color Metallography.6-1 g potassium metabisuifite. Etching time is 1-2 min. 74.5 g ferric chloride). Metals Park. Material: Stainless steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 20-30 ml hydrochloric acid (35 %).5 v/v hydrochloric acid (35 %) and distilled water. 62. 62. 1. American Society for Metals (ASM). USA. Sphigler. p. p. Color Metallography. 1977. Colors carbides and gamma. When good coloration is not produced and when etching heat-resisting steels. Sphigler. Immerse at room temperature for 1-4 min. USA. 74. p. 1977. Colors martensite blue in martensitic and austenitic stainless steel. Optional addition of 1-3 g ferric chloride or 1 g cupric chloride or 2-10 g ammonium bifluoride. USA. 1977. Ohio 440073. Material: Heat-resisting steels and alloys (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 20-30 ml hydrochloric acid (35 %). austenitic and martensitic stainless steels. Immerse at room temperature for 1-4 min.5 v/v hydrochloric acid (35 %) and distilled water.5-1 g ammoniurn bifluoride in 100 ml distilled water. USA. 1-3 ml selenic acid and 100 ml ethyl alcohol (95 %). p. Leaves carbides and nitrides white (uncolored). Metals Park. Metals Park. Beraha and B. Beraha and B. Colors the matrix. American Society for Metals (ASM).6-1 g potassium metabisulfite. Beraha and B. American Society for Metals (ASM). Method: Chemical etching Etchant (electrolyte): 20 g ammonium bifluoride and 0. 1977.5 g potassium metabisulfite in 100 ml distilled water. Etching of martensitic stainless steel. Remarks: Color etching. Beraha and B. Ohio 440073. USA. Material: Stainless steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): Stock solution: 1:5 v/v hydrochloric acis (35 %) and distilled water. 1977. Ohio 440073. p. Metals Park. Colors the matrix. Leaves carbidcs and nitrides white (uncolored). 74. USA. Remarks: Color etching. Ohio 440073. Etching of Fe. lmmersion at roorn temperature for 60-150 s. Etching of Fe. Reference: E. Sphigler. Procedure: (1:1 + addition to 500 ml of 1-1. 100 ml of stock solution plus 0. Material: Heat-resisting steels and alloys (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): Stock solution: 1:2 or 1:1 or 1:0. Remarks: Color etching. Remarks: Color etching. Ohio 440073. Sphigler. Remarks: Color etching. 100 ml of the stock. Colors the matrix. Leaves the rnatrix white (uncolored). Sphigler.5 v/v hydrochloric acid (35 %) and distilled water. Reference: E. Procedure: Immersion at room temperature for 30-120 s. Color etching of ferritic.and 0. Optional addtions of 1-3 g ferric chloride or 1 g cupric chloride or 2-10 g ammonium bifluoride) (1:1 or 1:0. 100 ml of stock solution plus 0.3 ml selenic acid and and 100 ml ethyl alcohol (95 %). American Society for Metals (ASM). When good coloration is not produced. 1977. Procedure: Immersion at room temperature until coloration is obtained. Ohio 440073. Color Metallography. Procedure: Immersion at room temperature for 60-150 s. 100 ml of stock solution plus 0. Reference: E. use 1:1 or 1:0. Reference: E. Etching of Fe-Ni and Co-base heat-resisting alloys. Beraha and B. Ni and Co base heat-resisting alloys. Color Metallography.5) and a longer etching time.6-1 g potassium metabisuifite. 1977. Ohio 440073. Color Metallography. American Society for Metals (ASM). p. When good coloration is not produced. Etching of Fe. USA.6-1 g potassium metabisuifite. American Society for Metals (ASM). leaving carbides and nitrides white (uncolored). 1-3 ml selenic acid and 100 ml ethyl alcohol (95 %). use longer etching time. Procedure: Clean and wet specimen. Reference: E. Remarks: Color etching. Material: Stainless steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): Stock solution: 1:5 v/v hydrochloric acis (35 %) and distilled water. 62. Ohio 440073. Remarks: Color etching. Material: Stainless steels (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 5-10 ml hydrochloric acid (35 %). Beraha and B. Reference: E. Ohio 440073. Sphigler. use a longer etching time. USA. Immersion at room temperature (22 + 5 C) for 5-8 s. Leaves carbidcs and nitrides white (uncolored). Metals Park. Color Metallography. Remarks: Color etching. Color Metallography. 100 ml of stock solution plus 0. Ni and Co base heat resisting alloys. Remarks: Color etching. American Society for Metals (ASM). Sphigler. Sphigler. Procedure: 100 cc of etchant (electrolyte) + 2 g ammonium bifluoride + 1 g potassium metabisulfite. p. Sphigler. Color Metallography.5. Reveals delta ferrite in welds. Optional addition of 1 -3 g ferric chloride or 1 g cupric chloride or 2-10 g ammonium bifluoride. 1977. Remarks: Color etching. Reference: E. Reveals delta ferrite. Etching of ferritic and martensitic stainless steel. Reference: E. 62. 62.6-1 g potassium metabisuifite.prime phase in and heat-resisting steels. Material: Heat-resisting steels and alloys (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): Stock solution: 1:2 or 1:1 or 1:0. Optional addition of 1-3 g ferric chloride or 1 g cupric chloride or 2-10 g ammonium bifluoride. Reference: E. Keep specimen moving during etching. Metals Park. American 3 . Color Metallography. Procedure: Clean and wet specimen. 100 ml of stock solution plus 0. and a longer etching time. American Society for Metals (ASM). Beraha and B. Keep specimen moving during etching. Procedure: Immersion at room temperature until coloration is obtained. Reference: E. Beraha and B. Keep specimen moving during etching. p. Keep specimen moving during etching. Optional addition of 1 -3 g ferric chloride or 1 g cupric chloride or 2-10 g ammonium bifluoride solution plus 0. Metals Park. 100 ml of the stock or stock solution: 1:2 or 1:1 or 1:0. p. Beraha and B. Procedure: Immersion at room temperature until color is obtained (depends on specimen's chemical compostion). Color Metallography. 20 g sodium sulfate. Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): Acid mixture of 0. If necessary. yellow. Reference: E. p. leaves beta phase bright and contrasting with the colored alpha phase in alpha-beta brass.4 F) and watch color change of specimen surface (yellow. Material: Copper alloys (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 200 g chromic acid. 96. violet. and 17 ml hydrochloric acid (35 %) in 1000 ml distilled water. Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 200 g chromic acid. Material: Copper alloys (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 240 g sodium thiosulfate. 87. Metals Park. In copper or monophase alloys. red. Ohio 440073. Sphigler. Color Metallography. p. blue and finally silvery bright). 1977. blue. Sphigler. Metals Park. Reference: E. or phase FeNiAl9 colored brown. Sphigler. USA. Coloring of the matrix grains. 20 g sodium sulfate. Metals Park. p. Colors nickel-rich phases brown and heavily darkens the !vIg2Si phase. 87. Procedure: Immersion at room temperature for 5-30 s. The aluminum matrix remains uncolored. American Society for Metals (ASM). In cast aluminum alloys having a high Ni and Fe content. Metals Park. Detects the susceptibility of wrought aluminum alloys to intergranular corrosion by black coloring of grain boundaries. Procedure: Immersion for approx. Procedure: Pre-etch:10 % NaOH followed by 50 % HNO3 in H2O. leaves the aluminum matrix uncolored. Copper and monophase alloys should be removed from the solution when the surface turns red or violet. Color Metallography. Etching of cast aluminum alloys. silvery bright consutively).5 % nitric acid in aqueous solution. Beraha and B. Reference: E. 24 g lead acetate and 30 g citric acid in 1000 ml distilled water (use after ammonium persulfate pre-etch). Ohio 440073. USA. Metals Park. Color Metallography. Procedure: Immersion for approx 30 s at 70 C (150 F). Etching of cast aluminum alloys. USA. Metals Park. Slightly colors the CuAl2 phase. Polyphase alloys must be removed before reaching silvery bright color. p. Rinse and dry. Remarks: Color etching.Society for Metals (ASM). Sphigler. Rinse in water and immediately dip in etchant (electrolyte) for 1-5 s. Reference: E. 87. Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 20 % sulfuric acid in aqueous solution. 87. Color Metallography. Ohio 440073. Procedure: Immersion at room temperature. Beraha and B. Remarks: Color etching. Rinse in water and dry. Ohio 440073. 1977. Metals Park.2 ± 37. repeat. Reaching silvery bright color should be avoided. USA. Immerse at room temperature (24 ± 3 C) (75. Polyphase alloys usually show violet. and 17 ml hydrochloric acid (35 %) in 1000 ml distilled water. Remarks: Color etching. Iron or iron-rich phases remain bright. 1977.5 ml hydrofluoric acid plus 100 rnl distilled water. p. and 17 ml hydrochloric acid (35 %) in 1000 ml distilled water. Etching should be interrupted when the surface turns violet-blue or blue. The aluminum matrix and silicon remain uncolorcd. American Society for Metals (ASM). USA. Sphigler. FeSiAl3 phase colored brown-blue. Procedure: Immersion at room temperature. Remarks: Color etching. 87. p. Time required for color metallography is longer than for usual etching (15-60 s). Colors AICu-Fe-Mn rich phases brown. Remarks: Color etching. 1977. Beraha and B. 0. USA. 1977. pure nickel is colored gray-brown. Ohio 440073. Agitate slowly for 2-20 s. Metals Park. 87. American Society for Metals (ASM). green or blue beta phase and white iron and iron rich particles. Total etching time should 4 . Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 2-3 g sodium molybdate. American Society for Metals (ASM). In more complex brasses or bronzes. Beraha and B. The gamma phase (CuBe) in berylliumcopper alloys will appear bright against the blue or violet matrix. Procedure: Pre-etch in 10 % ammonium persulfate solution. 74. Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 10 % sodium hydroxide in aqueous solution.Fe-Mn phase. Sphigler. Color Metallography. Remarks: Color etching. American Society for Metals (ASM). 1977. outlines other phases. 1977. Color Metallography. Ohio 440073. violet. Remarks: Color etching. Reference: E. p. Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 200 g chromic acid. USA. 5 ml hydrochloric acid (35 %) and 1-2 g ammonium bifluoride in 100 ml destilled water. 87. American Society for Metals (ASM). American Society for Metals (ASM). FeNiAl9 intermetallic compound is colored blue-violet.4 F) and watch color changes of specimen surface (red. improves contrast and clearly outlines inclusions and insoluble particles. Colors CuAl2 and MglSi phases brown. orange. Colors differently grains and twins in monophase alloys. aluminum matrix remains bright (uncolored). USA.5 ml selenic acid and 300 ml ethyl alcohol (80-85 %) (use after ammonium persulfate pre-etch). Material: Copper alloys (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 2 ml hydrochloric acid (35 %).5 % hydrofluoric acid plus 1. strong coloration occurs: pure iron is colored green. Color Metallography.5 % hydrochloric acid and 2. 96. gamma phasc (CuBe) in beryllium copper is colored differently from alpha phase. Reference: E. Remarks: Color etching. Sphigler. blue or green alpha phase. Remarks: Color etching. NiAl. differential coloration enables the identification of different phases. USA. American Society for Metals (ASM). Metals Park. p. Procedure: Pre-etch in (A) 10 % amononium persulfate solution or (B) with ammonium persulfate/ammonia solution. Reference: E. 1977. Ohio 440073. Sphigler. Immerse at 24 ± 3 C (75. Darkens the Mg2Si phase. red. Material: Aluminum alloys (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 0. the matrix grains and twins (and sometimes inclusions and undissolved particles also) are differently colored. Beraha and B. Ohio 440073. Reference: E. Color Metallography. Procedure: Immersion at room temperature. p. 5 s at 70 C (150 F). 1977. Beraha and B.2 ± 37. p. Ohio 440073. American Society for Metals (ASM). USA. Reference: E. outlines AI-Cu. Etching time approx 5-25 s. 1977. Beraha and B. 20 g sodium sulfate. Beraha and B. Sphigler. Al-Cu-Fe-Mn script colored blue. Metals Park. Beraha and B. Etching of cast aluminum alloys. Ohio 440073. 8 A/cm2. p.be 1-5 min. temperature: 20-25 C (68-77 F). 37. immersion at room temperature for a few sonds. Metallographic Etching. Procedure: 30 s to 2 min. Material:Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): A: 100 ml distilled water. USA. Procedure: For pure titanium. 15-60 s. Reference: G. 1978. p. Air blowing improves both oxidation rate and time and specimen's temperature control. p. Metals Park. 400-600 C (752-1112 F). Alpha titanium grains are differently colored. USA. 111. 1977. Material: Uranium alloys (U) Type: Micro etching Method: Physical etching Etchant (electrolyte): Oxidation in air. American Society for Metals (ASM). Constituents and inclusions may or may not be colored. In titanium-aluminides-based alloys. 112. Possibly without sulfuric acid. 1977. Remarks: Ag and low alloy Ag. Sphigler. Metals Park. 1978. sondary alpha and alpha-prime and various intermetallic phases (such as Ti2Cu) remain white (uncolored) or are evident by coloring. 1977. Sphigler. Remarks: Color etching for uranium alloys. ASM (American Society for Metals). 112.Titanium alpha matrix is colored blue or green.5 A/cm2. Heating is done in a stainless steel or tungstenfilament basket in air. Remarks: Color etching. Reference: E. USA. 5 . last polishing stage should be carried out in. USA.). current density: 0. Sphigler. Procedure: Up to 1 min. American Society for Metals (ASM). American Society for Metals (ASM). 111. Color Metallography. Reference: G. ASM (American Society for Metals). 2 ml saturated aqueous solution of sodium chloride. temperature: 20-25 C (68-77 F). p. p. Petzow. Ohio 440073. 1977. USA. Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 10 ml sulfuric acid. p. Reference: E. saturated solution of oxalic acid. p. Procedure: Seconds to minutes. Metals Park. Electrolytic etching. Beraha and B. Beraha and B. 100 ml saturated aqueous solution of potassium dichromate. 38. p. Material: Uranium alloys (U) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 420 cc glacial acetic acid. 1978. Metallographic Etching. Color Metallography. 5 ml hydrochloric acid (35 %) and 1-2 g ammonium bifluoride in 100 ml destilled water. USA. American Society for Metals (ASM). Ohio 440073. 60 cc water. Sphigler. ASM (American Society for Metals). Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Color Metallography. p. or with. 38. 1:9 dilution with distilled water. USA. Remarks: Color etching. American Society for Metals (ASM). Procedure: Immersion at room temperature for a few sonds. B: 100 ml dest. Metals Park. 111. 1977. Ohio 440073. Reference: G. Electrolytic polishing with electrolyte. American Society for Metals (ASM). Remarks: Pure Ag and Ag alloys. Color Metallography. sondary phases are evident by coloring. Reference: G. Procedure: Cathode: stainless steel. voltage: 35 V. 111. Procedure: Several minutes. Petzow. 50 g chromic acid. Petzow. Different coloring of the matrix and the various phases is obtained. Ag solders. current density: 0. Beraha and B. voltage: 35 V. TiC is colored yellow or dark brown. Titanium alpha grains and twins are differently colored according to their crystallographic orientation. 1977. Material: Uranium alloys (U) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 420 cc glacial acetic acid. grain contrast. 60 cc water. especially Ag-Ni alloys and Ag-Mg-Ni alloys. 10 ml nitric acid. Sphigler. the TiAl matrix usually appears yellow and brown. 10 g amonium persulfate. Remarks: Color etching. 1977. Material: Titanium alloys (Ti) Type: Microetching Method: Chemical etching Etchant (electrolyte): 5 g ammonium bifluoride in 100 ml distilled water. 1977. 39. Beraha and B. Beraha and B. time: 80 s. Reference: E. Remarks: Color etching. p. Specimen temperature approx. Remarks: Pure Ag and low alloy Ag. 10 g potassium cyanide. Reference: E. Procedure: Cathode: stainless steel.2-0. Sphigler. Etching of as-cast titanium alloys. Color Metallography. Material: Titanium alloys (Ti) Type: Microetching Method: Chemical etching Etchant (electrolyte): 3 g ammonium bifluoridie and 4 ml hydrochloric acid (25 %) in 100 ml distilled water. 50 g chromic acid. Sphigler. Sphigler. Color Metallography. Reference: E. p. Beraha and B. American Society for Metals (ASM). Material: Titanium alloys (Ti) Type: Microetching Method: Physical etching Etchnant: Thermal etching Procedure: The specimen is polished and tinting removed from bakelite holder. 2-11 ml sulfuric acid. water. USA. Color Metallography. Ohio 440073.6-0. Metallographic Etching. 96. ASM (American Society for Metals). Reference: E. Metals Park. American Society for Metals (ASM). Longer etching time required for titanium alloys. Color Metallography. 112. Remarks: Predominantly used for Ag alloys. Remarks: Color etching. Reference: E. Differently colors matrix grains and twins. Metals Park. Beraha and B. 2 g chromium (VI) oxide (concentration variable). Material: Silver (Ag) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 95 ml methanol (95 %). (To obtain good coloring. Mix (A) and (B) before etching in proportion 1:1. Remarks: Color etching. Metals Park. Ohio 440073. Time approx. Petzow. Procedure: Temperature 100-200 C (212-392 F). Metallographic Etching. Ohio 440073. Ohio 440073. Beraha and B. Basket temperature 1200 C (2192 F) approx. Procedure: Immersion at room temperature until specimen surface occurs. and greatly enhances Chemical contrast. p. Ohio 440073. Remarks: Color etching. time: 10-15 s. Reference: E. Material: Titanium alloys (Ti) Type: Microetching Method: Chemical etching Etchant (electrolyte): 2-3 g sodium molybdate. Metals Park. The Ti3Al phase usually appears blue or green. 1978. Metallographic Etching. 1978. ASM (American Society for Metals). ASM (American Society for Metals). p. Petzow. Material: Silver (Ag) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 10 ml distilled water. Petzow. 20 (15) ml hydrochloric acid. 25 ml amonia water. 5. 1978. Procedure: Few seconds to minutes. Procedure: 5-30 s. Hig purity Al. Metallographic Etching. Procedure: 5-15 min. Use fresh!. 10 g citric acid. Remarks: Ag solders. 50 ml hydrogen peroxide (3 %). Grain size. p. ASM (American Society for Metals). p. Metallographic Etching. p. 39. p. Petzow. 1978. time 15 s to 1 min. 5-10 g potassium cyanide. Reference: G. Alloys of Al-Mn. Pure Al. 60-70 C (140-160 F). Procedure: 10-30 s. Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 40. Procedure: 5-15 s. distilled water. Cu-Al alloys. Remarks: Suitable for most types of Al and Al alloys. 5 (10) ml hydrofluoric acid (40 %) (concentration variable). Petzow. Ag solders. Metallographic Etching. Reference: G. Remarks: Ag alloys. p. Ag cathode. 6 . Reference: G. 0. Possibly drops 2-3 drops nitric acid. 40. ASM (American Society for Metals). Ag-Ni alloys. 10 ml hydrofluoric acid (40 %)(Flick's reagent). Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Remarks: For most types of Al and Al alloys. Material: Aluminium (Al) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 75 ml hydrochloric acid . 20 (25) ml ntric acid. Use only fresh!. 15 ml nitric acid. Metallographic Etching. Metallographic Etching. Reference: G. 2 g iron (III) chloride. Mg-Al and Mg-Si-Al alloys. 10-20 g sodium hydroxide. Remarks: Al alloys containing Cu. Metallographic Etching. 1978. 1978. 1978.Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml amonia water. 39. Reference: G. Material: Aluminium (Al) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 20 (50) ml distilled water. 15 ml hydrochloric acid. Grain boundaries. 1978. Metallographic Etching. Remarks: Surface imperfections of pure Al. Remarks: Al base materials in general. Petzow. 15 ml hydrofluoric acid (40%). 1978. 39. Welded joints. 39. ASM (American Society for Metals). Ag-W carbides. 5 ml hydrofluoric acid (40 %). Petzow. p. 41. Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 10 ml aqueous solution of sodium (10 %). Petzow. Reference: G. 5 (10) ml nitric acid. Petzow. Mn-Al. 1978. Remarks: Ag rich Ag-Cd alloys. Metallographic Etching. Procedure: Up to 1 min. Material: Aluminium (Al) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 25 ml distilled water. Also useful for microetching. If attack too rapid dilute 50 % with. 1978. Reference: G. Reference: G. 1978. 40. 25 ml nitric acid. If necessary. Procedure: 10-60 s. 1978. Ag-Cu alloys. Procedure: Few seconds to minute. Use fresh! Remarks: Pure Ag. Material: Aluminium (Al) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Petzow. p. 41. ASM (American Society for Metals). Metallographic Etching. Ag-Pd alloys. Material: Aluminium (Al) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Remarks: For most types of Al and Al alloys. 10 ml acqueous solution of potassium ferrocyanide (30%). Reference: G. 40. 3 (6) ml hydrochloric acid. p. Al cast alloys with high Si content. Procedure: Few seconds to minute. Metallographic Etching. 1978. 1978. Petzow. ASM (American Society for Metals). ASM (American Society for Metals). Al-Mg-Mn and Al-Mg-Si. ASM (American Society for Metals). Metallographic Etching. 50 ml hydrogen peroxide (3 %). ASM (American Society for Metals). Remarks: Ag-Mo alloys. Petzow. 39. Use fresh!. Material: Aluminium (Al) Type: Macroetching Method: Microetching Etchant (electrolyte): 90 ml distilled water. Petzow. Reference: G. Remarks: Pure Ag and Ag composites with other metals. ASM (American Society for Metals). Procedure: Several seconds. Rolling direction. Ag-W alloys. p. ASM (American Society for Metals). slip lines in high purity Al. Si and Ti. Exception: Al alloys with high Si content. Metallographic Etching. Remarks: Al base matrials in general. Use fresh! Remarks: High purity Al. Reference: G. Rinse in warm water. AlMg. increase of hydrofluoric acid to 10 ml. p. 39. 39. 45 ml hydrochloric acid. Petzow. p. Alternative polishing and etching. minutes to 1 h. p. Si-Al. Reference: G. Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 25 ml distilled water. Procedure: 5 s to 3 min. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 190 (190) ml distilled water. p. Procedure: Up to 11 min.5 ml sulfuric acid. More concentrated solutions work also at room temperature.5 ml hydrofluoric acid (40 %). ASM (American Society for Metals). Procedure: 6 V dc. Possibly diluted with 25 ml distilled water. Metallographic Etching. 40. Petzow. Material: Silver (Ag) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml amonia water. Reference: G. Procedure: 1-3 min. Reference: G. Mn. 2 (4) ml hydrofluoric acid (40 %). ASM (American Society for Metals). Reference: G. Do not wipe during rinsing.43. 1-8 V dc. 10 min. Material: Aluminium (Al) Type: Microetching Method: Electro etching Etchant (electrolyte): 200 ml distilled water. and Zn-Al. grain boundaries. 42 Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Procedure: 2 min. ASM (American Society for Metals). p. or stainless steel. Material: Aluminium (Al) Type: Microetching Method: Electro etching Etchant (electrolyte): 90 ml distilled water. Al-Mg-Si. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 60 ml distilled water. Reference: G. Metallographic Etching. ASM (American Society for Metals). Metallographic Etching. 1978. Petzow. Metallographic Etching. Material: Gold (Au). Reference: G. rinse in water approx. ASM (American Society for Metals). 1978. Al-Cu. Remarks: Pure Al. Al-Mg-Si alloys. ASM (American Society for Metals).5-25 g sodium hydroxide. 34 ml nitric acid. 6 V dc. 25 ml nitric acid. 43. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Al-Mn. Metallographic Etching. Pt alloys and Pd alloys. platinum (Pt). Reference: G. Metallographic Etching. Ti. 42. p. 1978. 5-10 s. Petzow. ASM (American Society for Metals). Fe. 1978. Be. 42. Mn. Metallographic Etching. Remarks: Especially for Cu-Al alliys (also useful in macroetching). respectively. Remarks: For most of AL and Al alloys. Metallographic Etching. Al-Mn. Al-Zn. Petzow. 1978. 10 ml phosphoric acid. 5 ml ntric acid. p. Procedure: Few minutes. 0. Procedure: Few minutes. stainless steel cathode. ASM (American Society for Metals). Remarks: Au. p. p. 43. Al-Si and Al-Cu alloys. Remarks: Pure Al. ASM (American Society for Metals). Remarks: Precipitates of beta Al8Mg5 or Mg2. 42. Os and Os alloys. palladium (Pd) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 66 ml hydrochloric acid. 50 C (120 F). Mg-Al. Allloys of Cy-Al. Petzow. possibly at 50 C (120 F). 30 ml hydrofluoric acid (40 %). Metallographic Etching. p. ASM (American Society for Metals). 42. Remarks: Differentiantion of intermediate phases in Al with high contents of Cu. Cathode and anode fixtures should be made of high purity Al. Remarks: Precipitates. p. Remarks: Ru and Ru alloys. Al-Mg and Al-Mg-Si alloys. 1g zinc chloride. ASM (American Society for Metals). Rh and Rh alloys. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 25 (20) ml hydrofluoric acid (40 %). Procedure: 1-2 min. Petzow. 42. Metallographic Etching. Petzow. Reference: G. B: Electrolytic. Procedure: Few minutes. 9 g phosphoric acid (crystal). Reference: G. Petzow. 1978. Procedure: 40 s. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 92 ml distilled water. Al2Cu is not colored. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 75 ml distilled water. 10 ml fluoboric acid (35 %). ASM (American Society for Metals). 70 C (160 F). B: Etch 15 min. 42. Material: Ruthenium (Ru). Al-Zn-Mg. p. Al-Mg. 1978. Al-Mn-Mg alloys. Remarks: Pt and Pt alloys. 43. Metallographic Etching. Reference: G. 1978. 1-2 g sodium hydroxide. Metallographic Etching. Remarks: Detection of susceptibility to intercrystaline corrosion of AlMg alloys. Pb. 10 g sodium hydroxide. Fe3Al. ASM (American Society for Metals). 20-40 V dc. Use only fresh!. Procedure: A: 1-3 min. Material: Platinum (Pt) Type: Macroetching Method: Electro etching Etchant (electrolyte): 80 ml saturated aqueous solution of sodium chloride. Rinse in mixture: 95 ml distilled water. p. Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 80 ml distilled water. Petzow. 42 Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 25 (50) ml methanol (95%). p. Procedure: Few seconds to minutes. Use hot and fresh!. Metallographic Etching. 1978. Petzow. especially those containing Cu. ASM (American Society for Metals). Petzow. Reference: G. ASM (American Society for Metals). 1978.Material: Aluminium (Al) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Procedure: Anneal sample to 100 C (212 F) and slow cool before etching. If etching times are short. Remarks: For most types of Al and Al alloys. Reference: G. Reference: G. Petzow. Metallographic Etching. 42. Etch figures. 1978. Shows strain in Al-Mg base alloys. p. Pt cathode. p. Reference: G. 25 (30) ml nitric acid. p. 6 ml nitric acid. 20 ml sulfuric acid. 70 C (160 F). Procedure: 15 s. 20 ml nitric acid. Procedure: A: 5-10 s. Procedure: 10-60 s. 1978. 5 g potassium ferricyanide. 2 ml hydrofluoric acid (40 %). Procedure: 30 min. 7 . Reference: G. Reference: G. Distinct grain boundaries in corrosion sensitive alloys. 20 ml hydrochloric acid. 9 g phosphoric acid (crystal). Remarks: Pure Al. 1978. Procedure: 30 s to 3 min. Remarks: Pure Al. View in polarized light. osmium (Os). Mg-Si-Al. For shrink etching. Petzow. Mg. rhodium (Rh) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 50 ml lactic acid (90 %) or hydrochloric acid. Petzow. Material: Pure gold (Au). 46. Pd alloys with more than 90 % concentration of precious metals. 10 g potassium cyanide. Rh alloys. Petzow. Rh.Reference: G. 3. Procedure: Few minutes. Remarks: Rh bse alloys. p. ASM (American Society for Metals). 0. 1978. Procedure: 30 min to 3 h. Use hot. 45. Procedure: Seconds to minutes. Pt cathode. Material: Palladium (Pd). 20 ml hydrochloric acid. Petzow. ASM (American Society for Metals). palladium (Pd).5 g potassium ferricyanide. graphite cathode. Reference: G. Procedure: 90 s. Reference: G. Reference: G. Procedure: Few seconds to 1 min. graphite or Pt cathode. 10 ml hydrochloric acid. ASM (American Society for Metals). Metallographic Etching. platinum (Pt) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml hydrochloric acid. 1978. 1-5 V ac.2 min. Pd and Pt alloys. Petzow. May require heating. p. Metallographic Etching. p. 5 (10) ml nitric acid. platinum (Pt) Type: Microetching Method: Chemical etching Etchant (electrolyte): 30 (50) ml distilled water. palladium (Pd) and rhodium (Rh) Type: Microetching Method: Chemical etching Etchant (electrolyte): 40 (1) ml nitric acid.Petzow. 1978. 1978. Procedure: 1. 8 . Material: Platinum (Pt). 1978. 1978. p. ASM (American Society for Metals).44. Petzow. Ir. rhodium (Rh). pure Pd and Pd alloys. Petzow. Remarks: For Au alloys with high content of precious metals. 45. 45 Material: Osmium (Os). Remarks: Pt and Pt alloys. ASM (American Society for Metals). Reference: G. 1978. Metallographic Etching. graphite cathode. 6 V ac. Petzow. 45. Remarks: Pt alloys. 1978. Reference: G. 1 min.05-0. 10 V dc. Pt-Au alloys. Metallographic Etching. Petzow. 0. Ru base alloys. platinum (Pt). Remarks: Os base alloys. 45. 5 g potassium cyanide. Pt-10% Rh alloys. Procedure: 30 s to 2 min.5 V ac. Petzow. 25 (100) ml hydrochloric acid. Petzow. Material: Iridium (Ir) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 90 ml distilled water. Reference: G. p. 1-5 V ac. 1978. Petzow. 5-10 ml hydrochloric acid. Metallographic Etching. Petzow. Material: Ruthenium (Ru) Type: Microetching Method: Chemical etching Etchant (electrolyte): 80 ml distilled water. Metallographic Etching. p. Procedure: 25 s. Procedure: 1-5 min. Material: Rhodium (Rh).!. iron (III) chloride. 20 V ac. 45. iridium (Ir) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 80 ml distilled water. ASM (American Society for Metals). Ir. White gold. 1 min. Reference: G. p. 10 ml hydrochloric acid. iridium (Ir) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 65 ml distilled water. 25 g sodium chloride. Material: Gold (Au). 5-20 V ac. p. palladium (Pd). 1. gold (Au) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. 45. ASM (American Society for Metals). 46 Material: Platium (Pt). 1-5 g chromium (VI) oxide. 10 V ac. 4 g ammonium chloride. 45. Especiallt with large grain size. palladium (Pd). Procedure: Few minutes. ASM (American Society for Metals). iridium (Ir) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 90 ml ethanol (96 %). Au-Pd. Remarks: Au alloys with less thn 90 % content of precious metals. gold (Au) and platinum (Pt) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Remarks: Ru rich alloys and Ru-Mo alloys. Procedure: Few seconds to minutes. Metallographic Etching. Proportions in parentheses especially useful for Pt. Metallographic Etching. Remarks: Iridium Reference: G. Remarks: Pure Au and Au-rich alloys.1 A/cm2. ASM (American Society for Metals). 46. Remarks: Pure Au and Pd.. Material: Au-Cu-Ag alloys (Au) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Reference: G. 43. Procedure: 30 s to 2 min. 1g sodium hydroxide.2 A/cm2. pure Pt and Pt alloys. Ir alloys. Au alloys. ASM (American Society for Metals). p. Metallographic Etching. Pd and Pd alloys.5 A/cm2. Material: Palladium (Pd). 0. Material: Beryllium (Be) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 90 ml distilled water. Reference: G. p.5-1. 45. Metallographic Etching. Metallographic Etching. Remarks: Os and Os-W alloys. 1978. 60 (10) ml hydrochloric acid. p. p. Reference: G. 1 min. Petzow. ASM (American Society for Metals). p. 20 ml hydrochloric acid. 1978. 1978. gold (Au) and platinum (Pt) Type:: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Immerse or swab. Remarks: Pure Pt and Pd. Metallographic Etching. Reference: G. 1978. 1978. ASM (American Society for Metals). Metallographic Etching. graphite or Pt cathode. Au and Au alloys. 100 ml hydrogen peroxide (3 %). 20 ml sulfuric acid. ASM (American Society for Metals). Remove precipitate of gold chloride with ammonia water. Reference: G. Remarks: Technical types of Be. 1978. 1 ml hydrogen peroxide (3 %). Material: Osmium (Os) Type: Microetching Method: Chemical etching Etchant (electrolyte): 150 ml distilled water. Use only fresh!. Reference: G. 1-2 min. Petzow. Metallographic Etching. 45. Material: Gold (Au). ASM (American Society for Metals). p. Metallographic Etching. 10 g ammonium persulfate. Remarks: For Au-Cu-Ag alloys. Procedure: Up to 1h. p. Petzow. ASM (American Society for Metals). Procedure: Few minutes. Petzow. 30 ml ethanol (96 %). 48. Material: Beryllium (Be) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml phosphoric acid. p. 10 ml butyl glycol. Reference: G. 1978. B: 400 ml distilled water. ASM (American Society for Metals). Metallographic Etching. 50 V dc. p. 2 g picric acid. cool (10 C. Toxic. Bi-Sn alloys. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water or ethanol (96 %). Metallographic Etching. Material: Bismuth (Bi). 59 g chromium (VI) oxide (possibly some distilled. Reference: G. ASM (American Society for Metals). ASM (American Society for Metals). 1978. Petzow. Procedure: 30-45 s. Remarks: Precipitates. Metallographic Etching. Repeat etching with B. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. 46. Metallographic Etching. Petzow. Remarks: For most types of Be and Be alloys. 1 ml galcial acetic acid. p. Remarks: Technically pure Sb. 1-2 h. 10 g oxalic acid. Procedure: 6 min. Remarks: Be and Be alloys. Procedure: First with A at 40 C (100 F). Procedure: Few seconds to minutes. Petzow. Reference: G. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Metallographic Etching. 40 ml nitric acid. Reference: G. 30 ml glycerol. Metallographic Etching. 2. Use only fresh. Metallographic Etching. Remarks: Be-Ag and Be-Al-Ti alloys. Sb-Bi alloys. Reference: G. 50 F). ASM (American Society for Metals). 1978. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): Saturated solution of copper (II) sulfate in distilled water. p. 5 ml sulfuric acid. 10 ml perchloric acid (10 %). Procedure: Few seconds to minutes. Petzow. p. p. Reference: G. 50 ml nitric acid. 45 g ammonium molybdate. 1978. 47.Material: Beryllium (Be) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 90 ml distilled water. Reference: G. Immerse or swab. Remarks: Grain boundary etch. p. Reference: G. Material: Bismuth (Bi). ASM (American Society for Metals). 1978. grain boundary etch. Remarks: Technical types of Be. 48. Procedure: Few seconds to minutes. ASM (American Society for Metals). stainless steel or Mo cathode. 1978. Metallographic Etching. 13-20 V dc. Remarks: Be alloys. 4 ml hydrochloric acid. Metallographic Etching. Reference: G. 48. p. 1978. ASM (American Society for Metals). 48. Procedure: Few seconds to minutes. Material: Beryllium (Be) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 25 ml sulfuric acid. Procedure: 30 s. 16 min. Petzow. 1978. Procedure: 2 min. p. Metallographic Etching. Material: Bismuth (Bi). Repolish until surface has become bright. Petzow. Reference: G. 1978. Material: Beryllium (Be) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 35 ml ethanol (96 %). 1978. 49. ASM (American Society for Metals). Also used to increrase contrast in polarized light. Reference: G. Metallographic Etching. 47. Metallographic Etching. 45 C (110 F). Procedure: Approx. Remarks: Precipitates. Crystal arrangement. ASM (American Society for Metals). Reference: G. 50 ml hydrochloric acid (40 %). p. Remarks: Be. HF content may be raised to 15 ml. Petzow. 1978. Petzow. Rapid attack. p. 47. 5 ml hydrofluoric acid (40 %). Be-Nb. Equal amounts of A and B are mixed before use. srainless steel cathode. Toxic. Petzow. Metallographic Etching. 2 g ammonium chloride. Procedure: Few seconds to minutes. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml lactic acid (90 %). antimony (Sb) Type: Macroetching Method: Chemical etching Etchant (electrolyte): A: 160 ml distilled water. 155 s. ASM (American Society for Metals). p. water). ASM (American Society for Metals). below 35 C (95 F). grain boundary. 47. Remarks: Be and Be alloys. 1978. 1978. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): 25 ml glycerol. Petzow. 30 ml glacial acetic acid. 3 ml nitric acid. Toxic. Toxic. ASM (American Society for Metals). 500 ml phosphoric acid. 3 ml hydrogen peroxide (30 %). Remarks: Be-U. stainless steel cathode. p. Low alloy Be. 30 C (85 F). Procedure: 1-15 s. Especially with large grain size.5 ml sulfuric acid. 47. Procedure: Few minutes. Metallographic Etching. 10 ml hydrochloric acid. 80 ml nitric acid. Petzow. antimony (Sb) Type: Macroetching Method: Chemical etching Etchant (electrolyte): A: 220 ml distilled water. 47. 46. Procedure: 1 min. Reference: G. Remarks: Sb-Pb. Remarks: Be and Be alloys. 47. Reference: G. Petzow. 2 ml nitric acid. ASM (American Society for Metals). Petzow. 25 V dc. toxic. 2-10 ml hydrofluoric acid (40 %). 20 ml ammonia water. Material: Beryllium (Be) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. B: 300 ml distilled water. antimony (Sb) Type: Macroetching 9 . Material: Beryllium (Be) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 294 ml ehylene glycol. 1978. Be-Y and Be-Zr alloys. Boiling. ASM (American Society for Metals). p. Petzow. 49. ASM (American Society for Metals). 15 ml hydrochloric acid. Procedure: 5-10 min. p. Procedure: 5-10 s. p. Material: Bismuth (Bi). Metallographic Etching. Reference: G. 10 ml hydrogen peroxide (30 %). Petzow. Material: Bismuth (Bi) Type: Microetching Method: Chemical etching Etchant (electrolyte): 95 ml ethanol (96 %). 10 . ASM (American Society for Metals). 1978. Procedure: Few seconds to minutes. 1978. Reference: G. p. 50. In. p. Procedure: 1-10 min. 1978. Low alloy Sb. Metallographic Etching. Material: Antimony (Sb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 30 ml glacial acetic acid. 1978. Remarks: Cd. 49. p. antimony (Sb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. 50. Pb-Sb. antimony (Sb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Reference: G. Petzow. antimony (Sb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 70 ml distilled water. p. Material: Cadmium (Cd). Material: Cadmium (Cd). Metallographic Etching. Remarks: Bismuth Reference: G. 51. p. 49. ASM (American Society for Metals). Reference: G. ASM (American Society for Metals). 1978. Procedure: Few seconds to minutes. Metallographic Etching. 200 ml glycerol. 50 ml hydrochloric acid. p. Metallographic Etching. 51. 1g picric acid. 49. 2 g iron (III) oxide. Remarks: Sb and Sb alloys. 49. Reference: G. 5 ml hydrogen peroxide (30 %). Remarks: Sb and Sb alloys. 49. Reference: G. Procedure: Few seconds to minutes. Remarks: For pure and technically pure types of Sb. Tl. 5 ml nitric acid. 5 g silver nitrate. Metallographic Etching.Petzow. Reference: G. Tl. Remarks: Bi-Sn eutectic. 25 g citric acid. 1978. p. Grain contrast etch.50. Material: Bismuth (Bi). 1978. Metallographic Etching. p. Metallographic Etching. ASM (American Society for Metals). Metallographic Etching. thallium (Tl). 1978. Metallographic Etching. Petzow. 3 ml acqueous solution of chromium (Vi) oxide (Czichralski's reagent). Reference: G. Reference: G. Procedure: Add chromium (VI) oxide shortly before use.Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Bi-Cd alloys. Petzow. 1978. Procedure: Few seconds to minutes. 1978. In-Sb and In-As alloys. Procedure: Few seconds to minutes. 1978. 30 ml hydrochloric acid. Petzow. Procedure: Few seconds to minutes. 25 (9) ml nitric acid. 10 ml hydrochloric acid (40 %). ASM (American Society for Metals). 49. Metallographic Etching. 1978. ASM (American Society for Metals). p. Procedure: Few seconds to minutes. Petzow. Remarks: Sb alloys. Toxic. Remarks: Cd and solder alloys containing Cd. ASM (American Society for Metals). Bi and their alloys. 200 ml phosphoric acid. Petzow. p. Reference: G. Remarks: Sb-Pb alloys. p. thallium (Tl) Type: Microetching Method: Chemical etching Etchant (electrolyte): 98 ml ethanol (96 %). Toxic. Remarks: Sb. 2 ml nitric acid. Material: Cadmium (Cd). Material: Bismuth (Bi) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. ASM (American Society for Metals). thallium (Tl) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilledwater. 25 (9) ml glacial acetic acid. Remarks: Cd. Metallographic Etching. Material: Indium (In) Method: Microetching Type: Chemical etching Etchant (electrolyte): 100 ml ethanol (96 %). ASM (American Society for Metals). Petzow. 30 ml hydrochloric acid. Bi-Sn and Bi-Cd alloys. p. 1978. 10 g ammonium molybdate. 50 ml acqueous solution of sodium thiosulfate (16 %). 49. Procedure: Few seconds to minutes. In. ASM (American Society for Metals). 50. ASM (American Society for Metals). Reference: G. ASM (American Society for Metals). Reference: G. indium (In) Type: Microetching Method: Chemical etching Etchant (electrolyte): 40 ml distilled water. 5 ml hydrochloric acid. Metallographic Etching. 10 ml hydrogen peroxide (30 %). Tl. Petzow. Petzow. Petzow. Petzow. Petzow. Metallographic Etching. ASM (American Society for Metals). ASM (American Society for Metals). Procedure: 1-10 min. Remarks: Crystal arrangement. Procedure: Few seconds to minutes. 10 g chromium (VI) oxide. Remarks: Cd-Sn and Cd-Zn eutectics. Material: Antimony (Sb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 30 ml distilled water. 25 ml hydrochloric acid. Metallographic Etching. Chromium (VI) oxide content can be raised. 8-9 V dc. Remarks: In and In rich alloys. Reference: G. Casting imperfection in Sb and Bi. Material: Antimony (Sb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 (100) ml glycerol. Remarks: Cd and Cd alloys. 1978. p. Reference: G. Cd cathode. Material: Bismuth (Bi). Material: Cadmium (Cd). Procedure: Few seconds to minutes. thallium (Tl Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. 49. 8 g iron (III) chloride. 1978. Material: Cadmium (Cd) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Petzow. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Toxic. stainless steel cathode. Alloys used for Co base cutting tools. Remarks: Pure and low alloy Co. Metallographic Etching. 50 ml nitric acid. Material: Cobalt (Co) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. 7g iron (III) chloride. Remarks: Pure Co. 100 ml hydrochloric acid. Rinse in hot water. Remarks: WC-TiC-TaC-Co and WC-NbC-Co type cemented carbides. Immerse or swab. WC-TiC-NbC-Co type cemented carbides. 52. Metallographic Etching. Reference: G. Procedure: 10-15 s.Material: Cobalt (Co) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. 52. p. p. 52. 50 ml hydrochloric acid. and CoMn alloys. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 75 ml hydrochloric acid. ASM (American Society for Metals). 1978. Remarks: Co-Cr alloys. Petzow. Magnetic alloys. Supperalloys. p. Co-Pt alloys. 1 ml nitric acid. 1978. Reference: G. p. Remarks: WC-TiC-NbC-Co type cemented crabides. Use fresh only. 400-450 C (750-850 F). Metallographic Etching. Procedure: 10 s. 53. Remarks: Cemented carbides and other Co base alloys. Rinse in warm water. 5 ml nitric acid. 1978. ASM (American Society for Metals). Reference: G. Metallographic Etching. 1978. Nb)C-Co tye cemented carbides. Reference: G. 52. 20-30 g ammonium persulfate. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml hydrochloric acid. Procedure: Few seconds. Procedure: Few seconds to minutes. 53. Reference: G. Procedure: 90 s. Petzow. ASM (American Society for Metals). Co-21Cr-20Ni. ASM (American Society for Metals). 60 ml hydrochloric acid. ASM (American Society for Metals). 15 ml nitric acid. Material: Cobalt (Co) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 25 ml distilled water. Metallographic Etching. 25 ml nitric acid. ASM (American Society for Metals). Material: Cobalt (Co) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Petzow. 50 ml hydrochloric acid. 5 ml hydrogen peroxide (30 %). 51. Reference: G. Procedure: 30 min. 10 g potassium hydroxide. Wait at least 1 h before use. Procedure: Swab. WC-TiC-TaC-Co type cemented carbides. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 2 g copper (II) chloride. Procedure: Few seconds. p. Metallographic Etching. p. Procedure: Few seconds to minutes. 1978. ASM (American Society for Metals). Metallographic Etching. Reference: G. Petzow. High temperature alloys. ASM (American Society for Metals). Toxic. 1-100 ml nitric acid. Procedure: 5-30 s. Remarks: Cemented carbides with Co binder phase. Reference: G. 1978. 1978. Procedure: Few seconds to minute. Metallographic Etching. 1978. ASM (American Society for Metals). ASM (American Society for Metals). 1978. Reference: G. 2 g sodium carbonate. p. Metallographic Etching. Reference: G. p. 53. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml methanol (95 %). Petzow. 25 ml nitric acid. Carbide phase are easily distinguishable fom binder phase by differences in colors. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 3 V dc. ASM (American Society for Metals). Remarks: Co-Fe alloys. Procedure: Few seconds to minutes. Procedure: 30-60 min. 52. 1978. ASM (American Society for Metals). 51. Increase of sodium carbonate content increase removal rate of WC phase. Use only fresh. hot. Toxic. Remarks: Co-Ga alloys. ASM (American Society for Metals). 200 ml methanol (95 %). p. p. p. Remarks: Co-25Cr-10Ni-8W. Petzow. 53. Co-Fe alloys. 1978. 52. Material: Cobalt (Co) Type: Microetching Method: Physical etching Etchant (electrolyte): Hot etching in air. Co-B alloys. 10 g potassium ferricyanide. Petzow. 52. p. 1978. Petzow. Reference: G. 1978. Toxic. Metallographic Etching. Remarks: WC-TiC-(Ta. 15 ml glacial acetic acid. 3 g potassium hydroxide. also Stellite. Remarks: Wear resistant alloys. Petzow. Petzow. 1 ml glacial acetic acid. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Co-Ti alloys. 10 g iron (III) oxide. Metallographic Etching. Toxic. Petzow. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 15 ml distilled water. 1978. Metallographic Etching. other stellites. ASM (American Society for Metals). Petzow. and Co-3Cr-3Mo-1Nb alloys. Reference: G. Material: Cobalt (Co) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Deposit removed with diluted hydrochloric acid. Grain boundary etch. Reference: G. Metallographic Etching. Remarks: Co-Sm alloys. 51. 11 . Metallographic Etching. 50 ml hydrochloric acid. Petzow. Procedure: Few seconds to minutes. Reference: G. Remarks: Co-Ni-Fe base alloys. 10 ml nitric acid. p. p. Proportions in perenthses for Nb an its alloys Reference: G. stainless steel cathode. molybdenium (Mo) Type: Microetching Method: Chemical etching Etchant (electrolyte): 10 (10) ml hydrofluoric acid. W-Th alloys. 1978. Proportions in perenthses for Ta and Nb and alloys. p. 3 V dc. Procedure: 14-20 s. Metallographic Etching. Metallographic Etching. Petzow. Petzow. Remarks: Stellite up to 70 % Co. Procedure: 10 s. Metallographic Etching. Reference: G. tungsten (W). Petzow. Procedure: 2-10 s. Procedure: 10-20 min. Reference: G. 1978. Remarks: Cr. Material: Tantalum (Ta). 53. 12 . Remarks: Ta and Ta base alloys. Material: Cobalt (Co) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. Use fresh only. 50 ml hydrfluoric acid (40 %). p. 1978. niobium (Nb). Mo-Cr alloys (up to 80 % Cr). Remarks: Co base wear resistant alloys and materials used for cutting tools. 55. 1978. p. stainless steel cathode. 60 (30) ml lactic acid. Procedure: 2-20 s. graphite cathode. For Mo and W . Toxic. ASM (American Society for Metals). Co silicides. Superalloys. Co-Al alloys. vanadium (V)). Material: Chromium (Cr). 1978. Petzow. Reference: G. Remarks: Ta. rhenium (Re). vanadium (V) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 75 ml distilled water. Nb. p. 1978. Remarks: Pure Co. Do not store. Nb. Mo. Remarks: Cr and Cr base alloys. Material: Cobalt (Co) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water or hydrochloric acid. 55. 2-10 g chromium (VI) oxide. p. Material: Molybdenum (Mo). 53. Toxic. 3 V dc. Remarks: Mo and Mo-Ni alloys. Procedure: Few seconds to minutes. 56. 53. Co base superalloys. Re and Re base alloys. ASM (American Society for Metals). Toxic. Procedure: Approx. ASM (American Society for Metals). Procedure: 3-5 s. Material: Tantalum (Ta). p.Material: Cobalt (Co) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. p. tungsten (W) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 (50) ml distilled water. 10 g potassium hydroxide. p. Petzow. ASM (American Society for Metals). Reference: G. Remarks: Cr. 1978. Reference: G. 55. Metallographic Etching. Remarks: Cr Reference: G. molybdenum (Mo). Petzow. Petzow. niobium (Nb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 20 ml nitric acid. 60 ml hydrochloric acid. ASM (American Society for Metals). Cr and Cr silicide. 50 (5) ml hydrofluoric acid. tungsten (W). Material: Molybdenum (Mo). Procedure: Few seconds to minutes. Ta and their alloys. Toxic. ASM (American Society for Metals). boiling. ASM (American Society for Metals). 1978. 10 min boiling. stainless steel cathode. Metallographic Etching. tungsten (W) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 (70) ml distilled water. Metallographic Etching. 1978. 54. Mo-Fe alloys. 15 ml hydrofluoric acid (40 %). Material: Cobalt (Co) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml hydrochloric acid. Reference: G. Petzow. Procedure: Few seconds to minutes. Metallographic Etching. Material: Chromium (Cr). Remarks: Nb. niobium (Nb). Toxic. 30 (10) ml nitric acid. Material: Chromium (Cr) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 90 ml distilled water. ASM (American Society for Metals). p. p. 56. 1978. 1978. W and W alloys. Metallographic Etching. rhenium (Re) Type: Microetching Method: Chemical etching Etchant (electrolyte): A: 100 ml distilled water. 5 ml hydrochloric acid. ASM (American Society for Metals). 60 ml hydrofluoric acid. 1978. 10 g potassium ferricyanide. 55. 1978. Toxic. Mo-Re alloys. 50 (20) ml hydrogen peroxide (30 %). Reference: G. Ta. ASM (American Society for Metals). 53. Material: Chromium (Cr) Type: Microetching Method: Chemical etching Etchant (electrolyte): 20 ml nitric acid. Metallographic Etching. Metallographic Etching. W and W base alloys. Reference: G. Petzow. Metallographic Etching. Material: Tantalum (Ta) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. 10 g iron (III) chloride. p. V. Procedure: Few seconds. ASM (American Society for Metals). 54. Remarks: Pure Co. ASM (American Society for Metals). Material: Molybdenum (Mo). and their alloys. p. 6 V dc. Metallographic Etching. Petzow. 10 ml sulfuric acid. Do not store. Procedure: 2-5 min. tungsten (W). Equal amounts of A and B. Petzow. p. 5-10 ml hydrochloric acid. Remarks: Mo. chromium (Cr). ASM (American Society for Metals). 50 (25) ml nitric acid. Reference: G. 4 ml hydrogen peroxide (30 %). and alloys. Toxic. Reference: G. 35 ml nitric acid. Petzow. 56. Co base superalloys. 10 s. 54. W. 50 (10) ml ammonia water. 15 ml nitric acid. Reference: G. p. Metallographic Etching. sodium hydroxide and sodium ferricyanide may alse be used. 4 V dc. ASM (American Society for Metals). Procedure: 5-60 s. Toxic. 30 ml hydrofluoric acid. Re silicide. Nb. W and V. tantalum (Ta) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 30 ml hydrochloric acid. niobium (Nb). 1978. Petzow. Metallographic Etching. Procedure: 15-60 s. Mo and their alloys. Reference: G. Petzow. Remarks: Mo. B: 100 ml distilled water. Remarks: Mo (grain contrast). niobium (Nb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml glacial acetic aicd. Mo-Ti alloys. Procedure: Up to 5 min. p. Remarks: Pure Ta. Remarks: Ta base alloys. Fe-Cr alloys and V. Material: Tungsten (W). 1978. Metallographic Etching. Ta. 45 ml glycerol. 56. 2 g picric acid. 10 (20) ml nitric acid. Petzow. 10 g sodium hydroxide. W component turns black. 1978. Material: Tantalum (Ta) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. p. Remarks: W and W base alloys. Material: Chromium (Cr) Type: Microetching Method: Chemical etching Etchant (electrolyte): 30 ml hydrochloric acid. chromium (Cr). ferrovanadium. 57. 56. Petzow. Reference: G. vanadium (V).56. molybdenum (Mo) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 (0) distilled water. Reference: G. Reference: G. Metallographic Etching. ASM (American Society for Metals). 57. 10 g oxalic acid. Remarks: Mo. Petzow. Ta na Ta base alloys. ASM (American Society for Metals). niobium (Nb). 20 ml nitric acid. 1978. 5-10 V dc. Metallographic Etching. Remarks: Eutectic W-Co alloys. 20 ml nitric acid. 25 g sodium hydroxide. Procedure: Few seconds to minutes. Metallographic Etching. Material: Vanadium (V). 30-50 V dc. ASM (American Society for Metals). Metallographic Etching. Remarks: Ta base and Nb base alloys. Alloys of high Cr content. 56. chromium (Cr). Procedure: 15 s. ASM (American Society for Metals). Petzow. p. 5 ml hydrochloric acid. 56. 56. Procedure: 30-90 s. Cr and Cr base alloys. 1978. Material: Molybdenum (Mo). p. ASM (American Society for Metals). Procedure: 30-90 s. 1978. Mo-Cr-Fe alloys. Metallographic Etching. tantalum (Ta) Type: Microetching Method: Chemical etching Etchant (electrolyte): 10-20 ml glycerol. stainless steel or Pt cathode. tantalum (Ta) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. 1978. Remarks: Cr and Cr alloys. Reference: G. vanadium (V)). Nb. Petzow. Remarks: W-Co alloys containing 10-70 % W. 57. stainless steel cathode. Material: Vanadium (V). 1 ml hydrogen peroxide (30 %). Toxic. Material: Tantalum (Ta). Toxic. ASM (American Society for Metals). Metallographic Etching. p. p. Nb-Cr alloys. Reference: G. ASM (American Society for Metals). Petzow. galvanic Cr layers. Reference: G. Material: Tungsten (W) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Pure V and V base alloys. Ta-Nb alloys. Petzow. niobium (Nb) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml glacial acetic acid. Petzow. stainless steel cathode. p. stainless steel cathode. Procedure: 10-30 s. p. 13 . Reference: G. Reference: G. Procedure: Few seconds to minutes. Metallographic Etching. 1978. Petzow. p. 1978. Petzow. 10 ml nitric acid. Remarks: W and W base alloys. 10 g sodium hydroxide. Remarks: W and W abse alloys. ASM (American Society for Metals). Material: Molybdenum (Mo).Material: Tantalum (Ta). 56. Procedure: Few seconds to minutes. Metallographic Etching. Cr silicides. p. chromium (Cr) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 95 ml glacial acetic acid. Reference: G. Remarks: Ta and Ta base alloys. ASM (American Society for Metals). Metallographic Etching. 15 ml nitric acid. U-Nb alloys. Material: Tantalum (Ta). Petzow. Boiling. ASM (American Society for Metals). Reference: G. Metallographic Etching. 56. Remarks: Cr and Cr base alloys. Nb and Nb base alloys. p. Procedure: Few seconds to minutes. Metallographic Etching. ASM (American Society for Metals). Metallographic Etching. 1978. p. Reference: G. Petzow. Procedure: Few seconds to minutes. Toxic. Procedure: 10-30 s. ASM (American Society for Metals). 57. Toxic. Material: Tungsten (W) Type: Microetching Method: Chemical etching Etchant (electrolyte): 10 ml hydrochloric acid. Material: Tungsten (W) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 1 ml hydrogen peroxide (30 %). niobium (Nb). 5 ml hydrofluoric acid (40 %). Boiling. Procedure: 15 s. p. 10 ml hydrogen peroxide (30 %).5-6 V dc. 1978. 10 ml hydrofluoric acid (40 %). Reference: G. Boiling. Remarks: V and V base alloys. rhenium (Re) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml distilled water. 5 ml hydrofluoric acid (40 %). Pure V and V base alloys. 1978. 1978. Nb base alloys. Reference: G. molybdenum (Mo) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 95 ml distilled water. Procedure: 2-5 s. Petzow. ASM (American Society for Metals). 15 (50) ml sulfuric acid. p. Petzow. 1978. 56. Mo and Mo alloys. 56. Procedure: Few seconds to minutes. Material: Tungsten (W) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 6 V dc. ASM (American Society for Metals). 1. 5 ml perchloric acid (60 %). 1978. Re and Re allloys (etching time is 1 min). 20 (20) ml hydrofluoric acid (40 %). Mo and Mo alloys. Reference: G. Metallographic Etching. Toxic. Reference: G. 58 Material: Copper (Cu) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 90 ml distilled water. Metallographic Etching. 10 g ammonium persulfate. 58. Toxic. 1978. Toxic. Metallographic Etching. 5 ml sulfuric acid. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 80 ml distilled water . Procedure: 30 s. Petzow. Material: Copper (Cu) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. Use only fresh. p. dilute with distilled water. p. p. Metallographic Etching. Mo. Procedure: Few minutes. Alpha-beta brass. Procedure: Few seconds to minutes. p. Reference: G. Remarks: Brasses. Metallographic Etching. ASM (American Society for Metals). Toxic. Petzow. 5 ml sulfuric acid. Material: Copper (Cu) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 120 (100) ml distilled water or ethanol (96 %). Al brass. p. German silver. ASM (American Society for Metals). molybdenum (Mo) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 65 ml distilled water. Petzow. ASM (American Society for Metals). 50-60 V dc.5 g ammonium chloride. V and V base alloys. Bronzes. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100-120 ml distilled water or ethanol (95 %). Metallographic Etching. ASM (American Society for Metals). Remarks: W and W base alloys. p.Material: Tungsten (W). 1 ml hydrofluoric acid (40 %). Formation of dendrites in alpha alloys. 58. bronzes. Cu welds. 1 g mercury (II) nitrate. 60. Petzow. Grains and cracks. Al bronze with eutectoid. ASM (American Society for Metals). Pt cathode. Toxic. Especially brasses containing Co. 57. Petzow. Petzow. Remarks: Verification of stresses in brass. p. 59. ASM (American Society for Metals). German silver. ASM (American Society for Metals). 5-10 ml iron (III) chloride. Metallographic Etching. For alpha and beta 14 . 40 g chromium (VI) oxide. 1978. Material: Copper (Cu) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 1 ml nitric acid. Si bronzes. Material: Tantalum (Ta). Reference: G Petzow. Material:Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 17 ml hydrofluoric acid (40 %). Remarks: All types of Cu. 12-30 V dc. Add ammonia water. Remarks: T and Ta base alloys. Brasses (colors beta brass). 1978. CuNi. p. 1978. Reference: G Petzow. Possibly heated. 1978. ASM (American Society for Metals). 58. 7. 50 ml nitric acid. Metallographic Etching. Procedure: Few seconds to minutes.Petzow. Remarks: Color and grain contrast etchant for Cu. Immediately before use. Reference: G. Reference: G. Reference: G. Procedure: Few seconds to minutes. Grain contrast. p. Remarks: Cu and all types of brasses. Procedure: 5-60 s. Metallographic Etching. Reference: G. Remarks: Pure Nb. 10 g copper (II) ammonia chloride. Metallographic Etching. 10 (20) g iron (III) chloride. add two drops of hydrochloric acid. Remarks: Cu. 1978. 1978. Metallographic Etching. Samples with stresses negin to crack after some time. Cu-Cr. 10 ml hydrochloric acid. Remarks: Cu. Petzow. brasses. Procedure: Few seconds to minutes. Grain contrast. Material: Niobium (Nb). Procedure: 10-20 s. Remarks: Cu and all types of brasses. 50 ml nitric acid. 60. Al bronzes. 1978. stainless steel cathode. Time until sample begins to crack is indication of stress. 8 ml sulfuric acid. 10-60 ml nitrioc acid. 10 g sodium or potassium dichromate. ASM (American Society for Metals). 60. Cu-Ni and Cu-Ag alloys. molybdenum (Mo). 30 (6) ml hydrochloric acid. 1978. Reference: G. 58. 17 ml nitric acid. stainless steel cathode. Cu-Be. Cu-Mn. Reference: G. Procedure: Few seconds to minutes. 1978. Red cast bronze. 20-25 ml hydrochloric acid. Petzow. ASM (American Society for Metals). German silver. Reference: G. Remarks: Cu and brasses. Procedure: Few minutes. Also useful for macroetching. 57. ASM (American Society for Metals). Petzow. 30 V dc. Mo and Mo base alloys. Procedure: 3-30 s. Petzow. p. Procedure: Few minutes. Cu-Sn alloys. Toxic. Metallographic Etching. 10 ml sulfuric acid. Special brass. molybdenum (Mo) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 100 ml methanol (95 %). Remarks: Brasses containing Si. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml saturated acqueous solution of sodium thiosulfate. Reference: G. Cu-Si alloys. 25 ml hydrochloric acid. 1978. German silver. Metallographic Etching. B: 100 ml distilled water. Procedure: 6-9 min. 58. 25 g ammonium persulfate. p. Material: Copper (Cu) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. precipitate dissolves. 5 g potassium metabisulfite. Special bronzes. Material: Copper (Cu) Type: Macroetching Method: Chemical etching Etchant (electrolyte): A:100 ml distilled water. If dissolution too severe. ASM (American Society for Metals). Procedure: Mix A and B in equal amounts. Verification of (100) rolling texture in Cu (increase ammonia persulfate to 20 g). Reference: G. Remarks: Brasses. 1978. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 120 ml distilled water. ASM (American Society for Metals). 1978. Cu-Be alloys. p. Metallographic Etching. Alpha bronze. p. Grain contrast of alpha brasses. vanadium (V) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 75 ml methanol (95 %). Mo and Mo base alloys. Material: Copper (Cu) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 90 ml distilled water. Procedure: Few seconds to minutes. Use only fresh. 6. 1978. imerse in warm. Metallographic Etching. p.1 A/cm2. Material: Iron. 525 ml hydrogen peroxide (30 %). 13 ml nitric acid. Reference: G. Reference: G. 10 ml phosphoric acid. Procedure: Up to 15 s. 62. Reference: G. Petzow.6 ml hydrochloric acid (40 %). Reference: G. 1978. Remarks: Most types of Cu and Cu alloys. Al cathode. Deep etching. Metallographic Etching. Petzow. p.brass use 1 g potassium meta bisulfite (Klemm's reagent) and etching time 3 min. 1978. p. Metallographic Etching. 1978. Remarks: Most types of Cu and Cu alloys. 60. ASM (American Society for Metals). Proportions in parentheses for Cu-Ga alloys. Metallographic Etching. 60. dendrites. 1978. ASM (American Society for Metals). ASM (American Society for Metals). 6 V dc. 1. 100 ml ethanol (96 %). or decarburized zones. p. Remarks: Color etchnat and grain size contrast of bronzes. 60.German silver. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. 5 ml cold saturated acqueous solution of sodium thiosulfate. Petzow. Metallographic Etching. good polish and etch for Cu and Cu with oxide and sulfide inclusions. Cu cathode. Petzow. Also useful for microetching. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. Reference: G. Remarks: Al bronzes which are difficult to etch otherwise. Petzow. 1978. Remove film under running water. 9 g chromium (VI) oxide. p. 5 ml potassium metabiosulfite. Material: Copper (Cu) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): Aqueous solution of chromium (VI) oxide (1 %). 10 g iron (III) nitrate. 61. 15 g iron (III) sulfate. useful for Fe and steel. 1978. Al-Si bronzes. 61. cast irons (Fe) Type: Macroetching 15 . P. steels. Depth of nitriding. stainless steel cathode. 1978. Petzow. Cu-Ag solder layers. Metallographic Etching. Material: Copper (Cu) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 480 ml distilled water. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. 20 % acqeous solution of nitric acid. Monel and Cu-Ni alloys. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 50 ml distilled water. Deep etchant fot surface control and segregation. 25 ml ammonia water. 2 g sodium hydroxide. hardness indentations. Procedure: Attack polishing with out adding abrasive on velvet. Toxic. Remarks: Beta brasses. 1978. 1978. ASM (American Society for Metals). 5 V dc. Porosity. Petzow. Procedure: Few seconds to minutes. Possibly addition of 1-5 ml solution of potassium hydroxide (20 %). 1978. up to 80 C (180 F). Tombac. Petzow. p. ASM (American Society for Metals). 25 ml saturated solution of copper (II) sulfate (Marble's reagent). Remarks: All types of Cu. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 25 ml distilled water. Procedure: 1-5 min. 50 ml nitric acid. 10 (25) ml nitric acid. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 30 (100) ml distilled water. Metallographic Etching. 10 ml nitric acid. ASM (American Society for Metals). Reference: G. Reference: G. For corrosion resistant steels. steels. Remarks: Austenite and high temperature steels. 61. Bronzes. Material: Iron. ASM (American Society for Metals). Remarks: Fast. p. ASM (American Society for Metals). Flow lines in brass. Reference: G. Delta phase. p. Material: Copper (Cu) Type: Microetching Method: Electrolytic etching Etchant (electrolyte): 950 ml distilled water. steels. p. Procedure: 3-5 min. Remarks: Versatile etchant for alloyed and unalloyed steels. 61. Petzow. More addition of hydrogen peroxide etch to grain contrast. Cu cathode. 61. 8-10 V dc. 62. Mn. factures inclusions. Material: Iron. Remarks: Al bronzes. Material: Iron. Metallographic Etching. Procedure: 3-6 s. 60. Metallographic Etching. Remarks: Versatile. ASM (American Society for Metals). Metallographic Etching. 62. Reference: G. 1978. Petzow. 50 ml hydrochloric acid. p. Petzow. Cu-Be alloys. Procedure: 5-10 s. ASM (American Society for Metals). Reference: G. flow lines. 15 ml hydrofluoric acid (40 %). p. Easily machinable brasses. p. Fe-Cr-Ni cast alloys. 1-8 V dc. 61. Metallographic Etching. p. Procedure: Few seconds to minutes. Procedure: 30 s. Little addition of hydrogen peroxide etch to grain boundaries. Procedure: Few minutes. Material: Copper (Cu) Type: Microetching Method: Chemical etching Etchant (electrolyte): 45 ml distilled water. Remarks: Multiple constituent Sn bronzes. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 90 ml ethanol (96%). 1978. 960 ml phosphoric acid. ASM (American Society for Metals). ASM (American Society for Metals). Metallographic Etching. ASM (American Society for Metals). Petzow. ASM (American Society for Metals). 1978. Petzow. Reference: G. Metallographic Etching. Procedure: 10-30 min. Cartridge brass. Segregation. steels. Carburized. Reference: G. p. 61. Petzow. 10 (8) ml hydrochloric acid. Metallographic Etching. ferrite. Reference: G. 50 ml sulfuric acid. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 50 ml hydrochloric acid. Be. Reference: G. Muntz metal. Remarks: Brasses. Procedure: Few seconds to minutes. Prior etching. Method: Chemical etching Etchant (electrolyte): 100 ml methanol (95 %). and gray cast iron. heat at 150-200 C (300-400 F) for 5-30 min. 5 ml sulfuric acid (Baumann print). Metallographic Etching. 1978. 64. 64. Cu precipitates wiped with water. Metallographic Etching. Material: Iron. ASM (American Society for Metals). Reference: G. 63. Petzow. Reference: G.. ASM (American Society for Metals). Primary structure. ASM (American Society for Metals). and gray cast iron. 20 g copper (II) ammonium chloride (Heyn's reagent). 1-10 ml nitric acid (Nital). p. Petzow. Material: Iron. Remarks: ost common etchant for pure iron. Procedure: Few seconds to minutes. Metallographic Etching. Remarks: Verification. p. p. Reference: G. ASM (American Society for Metals). 500 ml ethanol (96 %). Material: Iron. 1g potassium metabisulfite (Klemm's reagent). Metallographic Etching. p. 42 ml hydrochloric acid. p. and neutralize in ammonia water. Microstion must be polished. steels. Remarks: Flow lines in low carbon N2 steels. Caution: not to exceed 10 % solution. High temperature steels. Remarks: Steels and special steels. cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml ethanol (96 %). Blowhole segregation. rinse in water. 1978. steels. alloy steels. steels. Petzow. immerse in conc. Fe3C stained light yelow. 45-90 g copper (II) chloride (Fry's regent). 20 ml hydrochloric acid. Segregation can cause ineven attack. Petzow. Procedure: 5-10 min. Metallographic Etching. ASM (American Society for Metals). p. Petzow. 1978. Remarks: Phosphorus segregation in low carbon steels. Fiber orientation.2 ml nitric acid. Sulfide reacts with sulfuric acid. Remarks: Differntiation of cubic and tetragonal martensite. cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml ethanol or methanol (95 %). Procedure: Silver bromide paper is satured with solution. 1978. Procedure: 5-30 min. hydrochloric acid. Possible adition of hydrogen peroxide (30 %). After 1-5 min. Add hydrochloric acid last (Oberhoffer's reagent). steels. Metallographic Etching. Pearlite.5 g tin (II) chloride. 1978. Use fresh only.3 ml picric acid. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 50 ml saturated aqueous solution of thiosulfate. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. low carbon steels. Metallographic Etching. ASM (American Society for Metals). p. steels. ASM (American Society for Metals). 0. 0. 64. Grain contrast. Primary structure. arrangemnet. Procedure: Few seconds to minutes. p. froming hydrogen sulfide which combines to darkish silver sulfide with the silver from the silver bromide in the photographic paper. Metallographic Etching. Petzow. Remarks: Most common etchant for pure iron. 1978. Fe-enriched areas appear dark. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 120 ml distilled water. ASM (American Society for Metals). Remarks: Phosphorus distribution in cat steel and cast iron. 30 g iron (III) chloride. steels. After etching. Fiber orientation. 1978. low carbon steels. 1978. Petzow. Toxic. steels. ASM (American Society for Metals). Petzow. 62. 64. Reference: G. Ni containing Cr steels. cast irons (Fe) Type: Macroetching Method: Chemical etching Etchant (electrolyte): 500 ml distilled water. Reference: G. Uniform etching. Material: Iron. Reference: G. Reference: G. Material: Iron. Procedure: Few seconds to minutes. Petzow. cast irons (Fe) Type: Microetching Method: Chemical etching Etchant (electrolyte): 100 ml methanol or ethanol (96 %). Procedure: Few seconds to minutes. 63. and firmly pressed against the prepared surface. Metallographic Etching. Remarks: Generally used for iron and heat treated steels. martensite and bainite. even with segregations. p. steels. Material: Iron. Welding zones. 63. 120-180 ml hydrochloric acid. 1978. rinse in a 4:1 mixture of ethanol and hydrochloric acid. Reference: G. and distribution of Fe and Mn sulfide inclusions. 0. wash and dry. rinse fic (6 g sodium thiosulfate in 100 ml water). Material: Iron. Procedure: Few seconds to minutes. 2-4 g picric acid (Picral). Reference: G.Method: Chemical etching Etchant (electrolyte): 100 ml distilled water. alloy steels. Procedure: 2-10 min. cast irons (Fe) Type: Microetching 16 . 63. Material: Iron. Explosive. Thomas steel. After etching.