استاندارد میکرواچینگ فلزات و آلیاژهای آن ASTM E 407 – 99

Standard Practice for Microetching Metals and Alloys1 ASTM E 407 – 99

 لطفا تجربیات مثبت ومنفی خود را در زیر مطلب ارسال نمایید

فایل زیر را دانلود کنید

با ما تماس بگیرید

TABLE 2 Numerical List of Etchants
Etchant Composition Procedure
1 1 mL HF (a) Swab with cotton for 15 s. 200 mL water (b) Alternately immerse and polish several minutes. (c) Immerse 3–5 s. (d) Immerse 10–120 s.
2 3 mL HF (a) Swab 10 s to reveal general structure. 100 mL water (b) Immerse 15 min, wash 10 min in water to form film with hatching which varies with grain orientation.
3 2 mL HF (a) Immerse 10–20 s Wash in stream of warm water. Reveals general structure. 3 mL HCl (b) Dilute with 4 parts water-colors constituents—mix fresh. 5 mL HNO3 190 mL water
4 24 mL H 3PO4 Electrolytic: Use carbon cathode raising d-c voltage from 0–30 V in 30 s. Total etching time 3 min 50 mL Carbitol (diethylene glycol monoethyl ether) with agitation. Wash and cool. Repeat if necessary. 4 g boric acid 2 g oxalic acid 10 mL HF 32 mL water
E 407
6
TABLE 2
Continued
Etchant Composition Procedure
5 5 g HBF4 200 mL water
Electrolytic: Use Al, Pb, or stainless steel cathode. Anodize 1–3 min, 20–45 V d-c. At 30 V, etch for 1 min.
6 25 mL HNO3 75 mL water
Immerse 40 s at 70°C (160°F). Rinse in cold water.
7 10–20 mL H2SO4 80 mL water
Immerse 30 s at 70°C (160°F). Rinse in cold water.
8 10 mL H 3PO4 (a) Immerse 1–3 min at 50°C (120°F). 90 mL water (b) Electrolytic at 1–8 V for 5–10 s.
9 3–4 9 sulfamic acid 5 drops HF 100 mL water
Use just prior to the last polishing operation. It is not intended as a final etchant. The specimen is examined as polished under polarized light.
10 10 mL HF 90 mL methanol (90 %)
Immerse 10–30 s.
11 2 mL HF 100 mL water
Immerse or swab few seconds to a minute.
12 20 mL HNO3 60 mL HCl
Use hood. Do not store. Immerse or swab 5–60 s.
13 10 g oxalic acid 100 mL water
Electrolytic at 6 V: (a) 10–15 s. (b) 1 min. (c) 2–3 s. Use stainless steel cathode and platinum or Nichrome connection to specimen.
14 10 mL HNO3 90 mL methanol (95 %)
Immerse few seconds to a minute.
15 15 mL HNO3 15 mL acetic acid 60 mL HCl 15 mL water
Age before use. Immerse 5–30 s. May be used electrolytically.
16 5–10 mL HCl 100 mL water
Electrolytic at 3 V for 2–10 s.
17 5 mL HCl 10 g FeCl3 100 mL water
Electrolytic at 6 V for few seconds.
18 2–10 g CrO3 100 mL water
Electrolytic at 3 V for 2–10 s.
19 A
8 g NaOH 100 mL water
B
Saturated aqueous solution of KMnO4
Immerse in freshly mixed SolutionsA+B(1:1) for 5–10 s. If surface activation is necessary, first use Etch #18, then rinse in water. While still wet, immerse in Solutions A + B (1:1). Mixture of solutions A + B has15-min useful life.
20 5 mL H2O2(30 %) 100 mL HCl
Use hood.
M i x f r e s h .
Immerse polished face up for few seconds.
21 1 g CrO3 140 mL HCl
Use hood. To mix, add the HCl to CrO3. Electrolytic at 3 V for 2–10 s.
22 100 mL HCl 0.5 mL H2O2 (30 %)
Use hood. Do not store. (a) Immerse or swab 1⁄2 –3 min. Add H2O2 dropwise to maintain action. (b) Electrolytic, 4 V, 3–5 s.
23 5 mL HCl Electrolytic at 6 V for 10–20 s. 95 mL ethanol (95 %) or methanol (95 %)
24 5 mL HNO3 200 mL HCl 65 g FeCl3
Use hood. Immerse few seconds.
25 10 g CuSO4 50 mL HCl 50 mL water
Immerse or swab 5–60 s. Made more active by adding few drops of H2SO4 just before use.
E 407
7
TABLE 2
Continued
Etchant Composition Procedure
26 5 g FeCl3 10 mL HCl 50 mL glycerol 30 mL water
Swab 16–60 s. Activity may be decreased by substituting glycerol for water.
27 1 g KOH 20 mL H2O2(3 %) 50 mL NH4OH 30 mL water
Dissolve KOH in water, then slowly add NH4OH to solution. Add 3 % H2O2 last. Use fresh—immerse few seconds to a minute.
28 1 g FeNO3 100 mL water
Swab or immerse few seconds to a minute.
29 1 g K 2Cr2O7 4 mL H 2SO4 50 mL water
Add 2 drops of HCl just before using. Swab few seconds to a minute.
30 25 mL NH4OH 25 mL water 50 mL H2O2(3 %)
Mix NH4OH and water before adding H2O2. Must be used fresh. Swab 5–45 s.
31 10 g ammonium persulfate (a) Swab or immerse to 5 s. 100 mL water (b) Immerse to 2 min to darken matrix to reveal carbides and phosphides. (c) Electrolytic at 6 V for few seconds to a minute. (d) Immerse 3–60 s. Can be heated to increase activity.
32 60 g CrO3 100 mL water
Saturated solution. Immerse or swab 5–30 s.
33 10 g CrO3 Add HCl just before use. Immerse 3–30 s. Phases can be colored by Nos. 35, 36, 37. 2–4 drops HCl 100 mL water
34 5 g FeCl3 50 mL HCl 100 mL water
(a) Immerse or swab few seconds to few minutes. Small additions of HNO3 activate solution and minimize pitting.
(b) Immerse or swab few seconds at a time. Repeat as necessary.
35 20 g FeCl3 5 mL HCl 1 g CrO3 100 mL water
Immerse or swab few seconds at a time until desired results are obtained.
36 25 g FeCl3 25 mL HCl 100 mL water
Immerse or swab few seconds at a time until desired results are obtained.
37 1 g FeCl3 10 mL HCl 100 mL water
Immerse or swab few seconds at a time until desired results are obtained
38 8 g FeCl3 25 mL HCl 100 mL water
Swab 5–30 s.
39 5 g FeCl3 10 mL HCl 1 g CuCl2 0.1 g SnCl2 100 mL water
Immerse or swab few seconds at a time until desired results are obtained.
40 5 g FeCl3 16 mL HCl
Immerse or swab few seconds to few minutes.
60 mL ethanol (95 %) or methanol (95 %)
41 2 g K 2Cr2O7 8 mL H 2SO4 4 drops HCl 100 mL water
Add the HCl just before using. Immerse 3–60 s.
42 10 g cupric ammonium chloride Add NH4OH to solution until neutral or slightly alkaline. Immerse 5–60 s. 100 mL water NH4OH
E 407
8
TABLE 2
Continued
Etchant Composition Procedure
43 20 mL NH4OH 1 g ammonium persulfate 60 mL water
Immerse 5–30 s.
44 50 mL NH4OH 20–50 mL H2O2(3 %) 0–50 mL water
Use fresh. Peroxide content varies directly with copper content of alloy to be etched. Immerse or swab to 1 min. Film on etched aluminum bronze removed by No. 82.
45 1 g CrO3 100 mL water
Electrolytic at 6 V for 3–6 s. Use aluminum cathode.
46 15 mL NH4OH 15 mL H2O2 (3 %) 15 mL water 4 pellets NaOH
When mixing, add NaOH pellets last. For best results use before pellets have dissolved.
47 5 g NaCN or KCN 5 g (NH4)2S2O2 100 mL water
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact.
48 10 g NaCN 100 mL water
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Electrolytic at 6 V: (a) 5 s for sigma. (b) 30 s for ferrite and general structure. (c) to 5 min for carbides.
49 3 g FeSO4 0.4 g NaOH 10 mL H2SO4 190 mL water
Electrolytic at 8–10 V (0.1 A) for 5–15 s.
50 5 mL acetic acid 10 mL HNO3 85 mL water
Use hood. Do not store. Electrolytic at 1.5 V for 20 to 60 s. Use platinum wires.
51 2 g FeCl3 5 mL HCl 30 mL water 60 mL ethanol or methanol
Immerse few minutes.
52 1 g sodium dichromate 1 g NaCl 4 mL H 2SO4 250 mL water
Swab few seconds.
53 1–5 mL NH4OH 100 mL water
Immerse 5–60 s.
54 1 g ammonium acetate 3 g sodium thiosulfate 7 mL NH 4OH 1300 mL water
Electrolytic at 0.3 A/cm2 for 5–30 s.
55 1 mL H2SO4 15 mL HNO3 10 mL acetic acid 5 mL H 3PO4 20 mL lactic acid
Swab gently 10–15 s. Rinse with methanol and blow dry. Helps to chemically polish. If final etch is too mild, follow with No. 98.
56 30 mL HNO3 10 mL H3PO4 20 mL acetic acid 10 mL lactic acid
Swab gently 5–15 s. Rinse with ethanol or methanol and blow dry.
57 75 mL acetic acid 25 mL H2O2(30 %)
Immerse 6–15 s.
58 25 mL HF 25 mL HNO3 5 mL water
Swab 3–20 s.
59 2 g AgNO3 40 mL water 40 mL HF 20 mL HNO3
Mix AgNO3 and water, then add HF and HNO3. Swab 1⁄2 –2 min.
E 407
9
TABLE 2
Continued
Etchant Composition Procedure
60 25 mL HNO3 15 mL acetic acid 15 mL HF 5–7 drops bromine
Use hood. Let stand 1⁄2 h before using. Swab 3–20 s.
61 60 mL HCl 40 mL HNO3
Use hood. Immerse few seconds to a minute.
62 1–5 g CrO3 100 mL HCl
Vary composition of reagent and aging of reagent after mixing to suit alloy. Swab or immerse few seconds to a minute.
63 0.1 g CrO3 10 mL HNO3 100 mL HCl
Swab few seconds to a minute.
64 5 mL HNO3 (a) Immerse 1–5 min. 25 mL HCl 30 mL water (b) Use hot. Will form chloride film on gold alloys if much silver is present. Ammonia will remove film.
65 A
10 g ammonium persulfate 100 mL water
B
10 g KCN 100 mL water
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Mix 1 + 1 mixture of Solutions A and B just before use. (A mixture of 5 drops of each will cover the surface of a 1 in. dia. mount.) Immerse 1⁄2 – 2 min.
66 30 mL HF 15 mL HNO3 30 mL HCl
Swab 3–10 s or immerse to 2 min.
67 10 mL perchloric acid 10 mL 2-butoxyethanol 70 mL ethanol (95 %) 10 mL water
Precaution—Keep cool when mixing and use. Electrolytic at 30–65 V for 10–60 s.
68 3 mL perchloric acid 35 mL 2-butoxyethanol 60 mL methanol (absolute)
Precaution—Keep cool when mixing and use. Electrolytic at 60–150 V for 5–30 s.
69 5 mL perchloric acid 80 mL acetic acid
Precaution—Keep cool when mixing and use. Electrolytic at 20–60 V for 1–5 min.
70 5 mL HF 2 mL AgNO3(5 %) 200 mL water
Swab for 5–60 s.
71 5 mL HF 95 mL water
Add 5–10 drops of this solution on the final polishing wheel which has been charged with the polishing solution. The specimen is polished on this wheel until the surface turns black. Distilled water is then slowly added to the wheel and polishing continued until the surface is bright. At this time the specimen should be ready for examination via polarized light. Note—Use inert substance between cloth and wheel to prevent attack of the wheel. Wear gloves.
72 10 mL HF 45 mL HNO3 45 mL water
Swab for 5–20 s.
73 20 mL HCl Electrolytic etch—use carbon cathode and platinum wire connection to specimen. 25 g NaCl (a) 6 V ac for 1 min. 65 mL water (b) 5 V–20 V ac for 1–2 min. (c) 20 V ac for 1–2 min. For etch-polishing, use shorter times. After etching, water rinse, alcohol rinse, and dry.
74 1–5 mL HNO3 Etching rate is increased, sensitivity decreased with increased percentage of HNO3. 100 mL ethanol (95 %) or methanol (95 %) (a) Immerse few seconds to a minute. (b) Immerse 5–40 s in 5 % HNO3 solution. To remove stain, immerse 25 s in 10 % HClmethanol solution. (c) For Inconels and Nimonics, use 5 mL HNO3 solution—electrolytic at 5–10 V for 5–20 s. (d) Swab or immerse several minutes. (e) Swab 5–60 s. HNO3 may be increased to 30 mL in methanol only depending on alloy. (Ethanol is unstable with over 5 % HNO3.) Do not store.
75 5 g picric acid 8 g CuCl2 20 mL HCl 200 mL ethanol (95 %) or methanol (95 %)
Immerse 1–2 s at a time and immediately rinse with methanol. Repeat as often as necessary. (Long immersion times will result in copper deposition on surface.)
E 407
10
TABLE 2
Continued
Etchant Composition Procedure
76 4 g picric acid 100 mL ethanol (95 %) or methanol (95 %)
Composition given will saturate with picric acid. Immerse few seconds to a minute or more. Adding a wetting agent such as zepherin chloride will increase response.
77 10 g picric acid 5 drops HCl 100 mL ethanol (95 %) or methanol (95 %)
Composition given will saturate the solution with picric acid. Immerse few seconds to a minute or more.
78 10 g potassium metabisulfite Immerse 1–15 s. Better results are sometimes obtained by first etching lightly with No. 76 or 74. 100 mL water
79 40 mL HCl 5 g CuCl2 30 mL water 25 mL ethanol (95 %) or methanol (95 %)
Swab few seconds to a minute.
80 5 mL HCl 1 g picric acid 100 mL ethanol (95 %) or methanol (95 %)
Immerse or swab few seconds to 15 min. Reaction may be accelerated by adding a few drops of 3 % H2O2. Optional (for prior austenite grain boundaries)—temper specimen at 600–900°F prior to preparation.
81 2 g picric acid Composition given will saturate the solution with picric acid. 1 g sodium tridecylbenzene sulfonate. (a) Immerse few seconds to a minute. 100 mL water (b) Immerse to 15 min with occasional swabbing for heavy grain boundary attack.
82 5 g FeCl3 5 drops HCl 100 mL water
Immerse 5–10 s.
83 10 g CrO3 100 mL water
(a) Electrolytic at 6 V for 5–60 s. Attacks carbides. (b) Electrolytic at 6 V for 3–5 s.
84 10 mL H2SO4 10 mL HNO3 80 mL water
Precaution—Add H2SO4 slowly to water and cool, then add HNO3. Immerse 30 s. Swab in running water. Repeat three times and repolish lightly.
85 2 g picric acid 25 g NaOH 100 mL water
Immerse in boiling solution for 5 min. Precaution—Do not boil dry—anhydrous picric acid is unstable and highly explosive. Alternative: Electrolytic at 6 V for 40 s (room temperature). Use stainless steel cathode.
86 3 g oxalic acid 4 mL H 2O2(30 %) 100 mL water
Solution solution be freshly prepared. Immerse 15–25 min when specimens or parts cannot be given usual metallographic polish. Multiple etching may be required.
87 10 mL HNO3 20–50 mL HCl 30 mL glycerol
Use hood—Can give off nitrogen dioxide gas. Precaution—Mix HCl and glycerol thoroughly before adding HNO3. Do not store. Discard before solution attains a dark orange color. Immerse or swab few seconds to few minutes. Higher percentage of HCl minimizes pitting. A hot water rinse just prior to etching may be used to activate the reaction. Sometimes a few passes on the final polishing wheel is also necessary to remove a passive surface.
88 10 mL HNO3 20 mL HCl 30 mL water
Use hood—Can give off nitrogen dioxide gas. Precaution—Discard before solution attains a dark orange color. Immerse few seconds to a minute. Much stronger reaction than No. 87.
89 10 mL HNO3 10 mL acetic acid 15 mL HCl 2–5 drops glycerol
Use hood. Do not store. Immerse or swab few seconds to few minutes.
90 10 mL HNO3 20 mL HF 20–40 mL glycerol
Immerse 2–10 s.
91 5 mL HNO3 5 mL HCl 1 g picric acid 200 mL ethanol (95 %) or methanol (95 %)
This etchant is equivalent to a 1 + 1 mixture of No. 80 and No. 74 (5 % HNO3). Swab for 30 s or longer.
92 10 mL HCl 100 mL ethanol (95 %) or methanol (95 %)
Immerse 5–30 min or electrolytic at 6 V for 3–5 s.
93 concentrated HNO3 Use hood. Electrolytic at 0.2 A/cm2 for few seconds.
94 2 g CuCl2 40 mL HCl 40–80 mL ethanol (95 %) or methanol (95 %)
Submerged swabbing for few seconds to several minutes. Attacks ferrite more readily than austenite.
E 407
11
TABLE 2
Continued
Etchant Composition Procedure
95 2 g CuCl2 40 mL HCl 40–80 mL ethanol (95 %) or methanol (95 %) 40 mL water
Immerse or swab few seconds to few minutes.
96 85 g NaOH 50 mL water
Electrolytic at 6 V for 5–10 s.
97 45 g KOH 60 mL water
Composition of solution is approximately 10 N. Electrolytic at 2.5 V for few seconds. Stains sigma and chi yellow to red brown, ferrite gray to blue gray, carbides barely touched, austenite not touched.
98 10 g K3Fe(CN)4 Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Use fresh. 10 g KOH or NaOH (a) Immerse or swab 15–60 s. Stains carbides and sigma. (To differentiate, No. 31 electrolytic at 4 V will attack sigma, but not carbides. If pitting occurs, reduce voltage.) 100 mL water (b) Immerse in fresh, hot solution 2–20 min. Stains carbides dark, ferrite yellow, sigma blue. Austenite turns brown on overetching. (c) Swab 5–60 s. (Immersion will produce a stain etch). Follow with water rinse, alcohol rinse, dry.
99 25 mL HCl 3 g ammonium bifluoride 125 mL water few grains potassium metabisulfite
M i x f r e s h . (For stock solution, mix first three items. Add potassium metabisulfite just before use.) Immerse few seconds to a few minutes.
100 10 g FeCl3 90 mL water
Immerse few seconds.
101 2 g CrO3 20 mL HCl 80 mL water
Immerse 5–60 s. (CrO3 may be increased up to 20 g for difficult alloys. Staining and pitting increase as CrO3 increased.)
102 concentrated NH4OH Use hood. Electrolytic at 6 V for 30–60 s. Attacks carbides only.
103 20 mL HNO3 4 mL HCl 20 mL methanol (99 %)
Immerse 10–60 s.
104 5 mL HNO3 45 mL HCl 50 mL water
Immerse 10 min or longer.
105 5 mL H2SO4 3 mL HNO3 90 mL HCl
Use hood. Precaution—add H2SO4 slowly to HCl with stirring, cool; then add HNO3. Discard when dark orange color. Swab 10–30 s.
106 7 mL HNO3 25 mL HCl 10 mL methanol (99 %)
Use fresh to avoid pitting. Immerse or swab 10–60 s.
107 10 mL H3PO4 50 mL H2SO4 40 mL HNO3
Use hood. Precaution—Mix H3PO4 and HNO3 thoroughly, then add H2SO4 slowly with stirring. Use fresh, but allow to cool. Electrolytic at 6 V for few seconds. Brown discoloration will form at edges of specimen. To slow reaction, add water (to 100 mL) very carefully with stirring. Attacks bakelite mounts.
108 3–10 mL H2SO4 100 mL water
Electrolytic at 6 V for 5–10 s. Tends to pit with longer times.
109 50 mL HCl 25 mL HNO3 1 g CuCl2 150 mL water
Make fresh but allow to stand 30 min to avoid plating out copper. Immerse few seconds to a few minutes.
110 10 mL HCl 5 mL HNO3 85 mL ethanol (95 %) or methanol (95 %)
Immerse to several minutes until deeply etched. Follow with light repolish.
111 5 mL H2SO4 8 g CrO3 85 mL H3PO4
Electrolytic at 10 V (0.2 A/cm2) for 5–30 s. Reveals Ti- and Cb-rich areas at a faster rate than grain boundaries.
E 407
12
TABLE 2
Continued
Etchant Composition Procedure
112 60 mL acetic acid 30 mL H2O2(30 %)
Immerse 8–15 s.
113 15 mL acetic acid 15 mL HNO3 60 mL glycerol
Do not store. Use fresh solution at 80°C (176°F).
114 15 mL acetic acid 20 mL HNO3 80 mL water
Use fresh solution at 40–42°C (104–108°F). Immerse 4–30 min depending on depth of worked metal layer. Clean with cotton in running water.
115 100 mL acetic acid 10 mL H2O2(30 %)
Immerse 10–30 min depending on depth of worked metal layer. Clean in HNO3 if necessary.
116 5–10 g AgNO3 90 mL water Swab.
117 10 mL HCl 90 mL water
(a) Immerse for 1⁄2 –5 min. Follow with electrolytic etch at low current density in same solution. If specimen has considerable surface flow, immerse in concentrated HCl for a few seconds, then follow above procedure. (b) Immerse for 1⁄2–2 min.
118 1 mL HNO3 75 mL diethylene glycol 25 mL water
Swab 3–5 s for F and T6, 1–2 min for T4 and O temper.
119 1 mL HNO3 20 mL acetic acid 60 mL diethylene glycol 20 mL water
Swab 1–3 s for F and T6, 10 s for T4 and O temper.
120 10 mL HF 90 mL water
Immerse with gentle agitation 3–30 s.
121 0.7 mL H3PO4 4 g picric acid 100 mL ethanol (95 %) or methanol (95 %)
Composition critical. (a) Immerse with gentle agitation 10–30 s. (b) To increase staining immerse and withdraw with a meniscus layer. Lightly apply etchant over surface until dark stain develops.
122 2 g oxalic acid 100 mL water
Swab.
123 60 mL H3PO4 100 mL ethanol (95 %)
Electrolytic: Use stainless steel cathode. Space electrodes 2 cm apart. Start at 3 V dc. After 30 s maintain at 11⁄2 V.
124 5 mL acetic acid 10 mL water 6 g picric acid 100 mL ethanol (95 %) or methanol (95 %)
Immerse with gentle agitation 10–60 s.
125 10 mL acetic acid 6 g picric acid 100 mL ethanol (95 %) or methanol (95 %)
Immerse with gentle agitation 15–30 s.
126 30 mL acetic acid 15 mL water 6 g picric acid 100 mL ethanol (95 %) or methanol (95 %)
Immerse with gentle agitation 1–30 s.
127 20 mL acetic acid 20 mL water 3 g picric acid 50 mL ethanol (95 %) or methanol (95 %)
Immerse with gentle agitation 5–30 s.
128 8 mL HF 5 mL HNO3 200 mL water
Immerse with gentle agitation 5–15 s.
129 10 mL HF 30 mL HNO3 60 mL lactic acid
Swab 10–20 s. Vary HF to increase or decrease activity.
130 25 mL HCl 75 mL methanol
Caution—Keep below 24°C (75°F). Electrolytic at 30 V for 30 s.
E 407
13
TABLE 2
Continued
Etchant Composition Procedure
131 5 mL H2SO4 1 mL HF 100 mL methanol (95 %)
Electrolytic at 50–60 V for 10–20 s.
132 5 mL HF 10 mL HNO3 50 mL lactic acid
Use fresh. (a) Swab with heavy pressure for 5–10 s. Water rinse, alcohol rinse, dry, then etch with No. 98c. (b) Swab for 5–30 s.
133 50 mL HNO3 50 mL acetic acid
Use hood. Do not store.
M i x f r e s h .
Immerse or swab 5 to 30 s. Will chemically polish with longer times. Sulfidized grain boundaries etched before normal grain boundaries.
134 70 mL H3PO4 30 mL water
Electrolytic 5–10 V for 5–60 s. (Polishes at high currents.)
135 80 mL HNO3 3 mL HF
Use hood. Warm specimen in boiling water prior to immersion for 10 to 120 s.
136 20 mL H3PO4 80 mL water
Electrolytic at 10–20 V for 10–15 s.
137 10 g NaNO3 100 mL water
Electrolytic, 0.2 A/cm2, 1 min.
138 5 g FeCl3 2 mL HCl 100 mL ethanol (95 %) or methanol (95 %)
Swab 10–60 s.
139 5 g KCN 100 mL water 0.5 mL H2O2(3 %)
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Immerse 10–100 s.
140 50 mL acetic acid 50 mL HNO3 50 mL acetone
Use hood. Do not store. Decomposes with possible explosion on standing. Immerse 10–30 s.
141 3 g NH4Cl 3 g CrO3 10 mL HNO3 90 mL water
Swab 5–30 s. Do not store.
142 5 mL HF 10 mL glycerol 85 mL water
Electrolytic at 2–3 V for 2–10 s.
144 A
10 g sodium thiosulfate 100 mL water
B
10 mL HCl 90 mL water
Electrolytic in Solution A: specimen is cathode, 10 V, 5–10 s. Then electrolytic in Solution B: specimen is anode, 10 V, 5–10 s.
145 2 mL H2SO4 100 mL water
Electrolytic at 3–10 V for 5–15 s. Use platinum wires. H2SO4 may be increased to 20 mL for deeper attack.
146 10 mL HF 100 mL HNO3
Immerse 30 s–3 min.
147 20 mL HNO3 80 mL HCl
Immerse 5–30 s.
148 5 mL HNO3 100 mL water
Immerse 10–30 s.
149 50 mL HCl 2 mL H 2O2(30 %) 50 mL water
Immerse 10–30 s. Do not store.
150 60 mL HCl 20 mL HNO3 40 mL glycerol
Use hood. Do not store. Swab few seconds to a minute. Discard when solution turns dark yellow.
151 10 mL HF 25 mL HNO3 150 mL water
Swab 5–30 s.
E 407
14
TABLE 2
Continued
Etchant Composition Procedure
152 85 mL NH4OH 15 mL H2O2(30 %)
Immerse 5–15 s. Do not store—Decomposes.
153 10 mL HNO3 50 mL HCl 60 mL glycerol
Use hood. Do not store. Add HNO3 last. Discard when dark yellow. Immerse 10–60 s. Preheating specimen in boiling water hastens reaction.
154 50 mL HCl 50 mL ethanol (95 %) or methanol (95 %)
Immerse 10–100 s.
155 3 mL selenic acid 10 mL HCl 100 mL ethanol (95 %) or methanol (95 %)
Immerse 1–15 min. (Up to 30 mL of HCl may be used for more vigorous action.) Stable for 3–90 days, depending on HCl concentrations.
156 1 g thiourea 1 mL H 3PO4 1000 mL water
Electrolytic, 0.005–0.01 A/cm2, 1–2 min.
157 25 g CrO3 150 mL HCl 50 mL water
Immerse 5–20 s.
158 10 mL HF 10 mL HNO3 20 mL glycerol
Swab 5–15 s.
159 5 mL HF 20 mL HNO3 50 mL acetic acid
Swab 10–30 s.
160 20 mL HF 15 mL H2SO4 5 mL HNO3 50 mL water
Immerse to 5 min.
161 25 mL HNO3 5 mL HF
Immerse 5–120 s.
162 A Swab 1–3 min in Solution A (acts as etch polish). To etch, swab with Solution B for 5 s. Repeat if necessary. The HF may be varied to give more or less etching. 50 mL lactic acid 30 mL HNO3 2 mL HF B 30 mL lactic acid 10 mL HNO3 10 mL HF
163 30 mL H2SO4 30 mL HF 3–5 drops H2O2(30 %) 30 mL water
Immerse 5–60 s. Use this solution for alternate etch and polishing.
164 50 mL HNO3 30 g ammonium bifluoride 20 mL water
Use hood. Swab 3–10 s.
165 10 mL HCl 90 mL ethanol
(a) Electrolytic at 10 V for 30 s. Use carbon cathode and platinum wire connection to specimen. For etch-polishing, use shorter time. (b) Electrolytic at 6 V for 10 s. Use stainless steel cathode and platinum or Nichrome wire contact to specimen.
166 A
20 g ammonium persulfate 90 mL water
B
20 g KCN 90 mL water
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Mix 1 + 1 ratio of Solution A and B just before use. (A mixture of 5 drops of each will cover the surface of a 1 in. dia mount.) Immerse to several minutes.
167 5 g NaCN 100 mL water
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Electrolytic at 1–5 V ac for 1–2 min. Use platinum cathode.
168 20 mL HCl 35 g NaCl 80 mL water
Composition given will saturate the solution with NaCl. Electrolytic at 11⁄2 V ac for 1 min.
E 407
15
TABLE 2
Continued
Etchant Composition Procedure
169 5 mL HNO3 50 mL ethylene glycol 20 mL ethanol (95 %) or methanol (95 %)
Electrolytic at 0.05 A/cm2 for 2 min. Use stainless steel cathode.
170 1 mL HF (a) Swab 5–30 s. Follow with water rinse, alcohol rinse, dry. 30 mL HNO3 30 mL lactic acid (b) Swab for 10 s intervals. Increase HF to exaggerate grain boundaries.
171 concentrated HCl Use hood. Electrolytic at 5 V ac for 1–2min. For etch-polishing, use shorter times. Follow with water rinse, alcohol rinse, and dry.
172 A
5 g ammonium persulfate 100 mL water
B
5 g KCN 100 mL water
Use hood—Can give off extremely poisonous hydrogen cyanide. Precaution—Also poisonous by ingestion as well as contact. Prepare 1 + 1 mixture of Solutions A and B just before use. (A mixture of 5 drops of each will cover the surface of a 1 in. dia mount.) Immerse 1–2 min.
173 50 mL NH4OH 10–30 mL H2O2 (50 %)
Immerse few seconds to a minute.
174 A Prepare 1 + 1 mixture of Solutions A and B. Apply with camel’s hair brush. Nonadherent film of silver chromate should form. If film adheres, add more of Solution A, if none forms, add Solution B. 25 mL HNO3 1gK 2Cr2O7 1000 mL water B 40 g CrO3 3 g Na 2SO4 200 mL water
175 1 g CrO3 1 mL H 2SO4 1000 mL water
Immerse to 1 min.
176 2 g FeCl3 100 mL water
Immerse 5–30 s.
177 10 g NaOH 100 mL water
Swab or immerse 5–15 s.
178 20 mL HF 20 mL HNO3 60 mL lactic acid
Swab for 5–20 s.
179 A Use hood—Mix Solution B very slowly. Solution A is used as a chemical polish, though some etching will occur. Swab 2 or more minutes for desired surface. If surface is insufficiently etched use Solution B electrolytically at 1⁄2 –1 V/in.2 of specimen. Use carbon cathode and platinum wire connection to specimen. Discard Solution B after 1 hr. 10 mL HF 10 mL HNO3 30 mL lactic acid B 10 mL HF 90 mL H2SO4
180 10 mL HNO3 30 mL acetic acid 50 mL glycerol
Immerse for 1⁄2 –10 min at 38 to 42°C (100–108°F).
181 2 mL HCl 100 mL ethanol (95 %) or methanol (95 %)
Swab for 1–3 min.
182 10 mL HNO3 10 mL acetic acid 80 mL glycerol
Immerse for 1⁄2 –10 min at 38 to 42°C (100–108°F).
183 2 drops HF 1 drop HNO3 25 mL glycerol
Immerse for 1 min.
E 407
16
TABLE 2
Continued
Etchant Composition Procedure
184 10 g FeCl3 2 mL HCl 100 mL water
Immerse for 1⁄2 –5 min.
185 10 mL HF 10 mL HNO3
Swab for few seconds.
186 10 mL HF 5 mL HNO3 85 mL water
Swab 3–20 s.
187 10 mL HF 30 mL HNO3 50 mL water
Swab 3–20 s.
188 1 mL HF 2 mL HNO3 50 mL H2O2 (30 %) 50 mL water
Swab until stain is removed.
189 10 mL HF 25 mL HNO3 45 mL glycerol 20 mL water
Swab 3–20 s.
190 8 g KOH 10 mL H2O2(30 %) 60 mL water
Swab 3–20 s.
191 25 mL HF Swab 3–20 s. 18 g benzalkonium chloride 35 mL methanol (95 %) 40 mL glycerol
192 1–3 mL HF 2–6 mL HNO3 100 mL water
Swab 3–10 s or immerse 10–30 s. (HF attacks and HNO3 brightens the surface of titanium. Make concentration changes on this basis.)
193 2 drops HF 1 drop HNO3 3 mL HCl 25 mL glycerol
Swab 3–20 s.
194 20 mL HF 20 mL HNO3 60 mL glycerol
Immerse 5–30 s.
195 30 mL H3PO4 30 mL ethylene glycol 50 mL ethanol (95 %)
Electrolytic at 18–20 V (0.03 A/cm2) for 5–15 min.
196 18 g CrO3 75 mL acetic acid 20 mL water
Dissolve CrO3 in hot water and cool before adding acetic acid. Keep solution below 2°C (35°F) during use. Electrolytic at 80 V for 5–30 min. Do not store.
197 5 g oxalic acid 100 mL water
Electrolytic at 6 V for 5–20 s.
198 30 mL HF 30 mL HNO3 30 mL glycerol
Swab for 60 s.
199 2 mL HF 5 g AgNO3 100 mL water
Swab for 5 s.
200 A Immerse in Solution A with gentle agitation for several seconds. Rinse in Solution B. 40 g CrO3 3 g Na 2SO4 200 mL water B 40 g CrO3 200 mL water
E 407
17
TABLE 2
Continued
Etchant Composition Procedure
201 A Immerse in Solution A with gentle agitation for several seconds. Rinse in Solution B. 40 g CrO3 1.5 g Na 2SO4 200 mL water B 40 g CrO3 200 mL water
202 A Immerse in Solution A for 2–5 s. Rinse in Solution B. 10 g CrO3 1 g Na 2SO4 200 mL water B 40 g CrO3 200 mL water
203 20 g CrO3 100 mL water
Electrolytic at 0.2 A/cm2 for 5 s.
204 10 mL perchloric acid 10 mL glycerol 70 mL ethanol (95 %) 10 mL water
Precaution—Keep cool when mixing and use. Electrolytic at 15–50 V for 15–60 s.
205 5 mL HF 2 mL AgNO3(5 %) 100 mL water
Swab vigorously for 10–60 s. Wet cotton frequently.
206 5 mL HF 10 mL HNO3 100 mL glycerol
Precaution—Discard after use. Solution decomposes on standing. Electrolytic at 9–12 V for 1–10 min.
207 30 mL HNO3 30 mL acetic acid 30 mL water
Swab for 5–30 s.
208 1 mL NH4OH 3 g ammonium persulfate 100 mL water
Immerse or swab few seconds to a minute.
209 15 mL HNO3 3 mL HF 80 mL water
Immerse 5–60 s.
210 50 mL water (cold) saturated with sodium thiosulfate 1 g potassium metabisulfite
First ingredient in stock solution. Add potassium metabisulfite before use. Solution good for several days, or longer. Immerse face up, gently agitate until coloration begins, allow to settle. Stop etch when surface is red-violet. Etch time varies with material. Colors matrix phases.
211 3 g potassium metabisulfite 10 g sodium thiosulfate 100 mL water
Use fresh solution. Immerse specimen face up, gently agitate solution until coloration begins, allow to settle. Stop etch when surface is red-violet. Etch time varies with material. Colors matrix phases.
212 10–50 % HCl in water 0.5–1.0 g potassium metabisulfite per 100 mL of aqueous HCl solution Optional: 1 g CuCl2 1–3 g FeCl3 2–10 g ammonium bifluoride
For more corrosion resistant alloys. Increase the HCl and potassium metabisulfite contents. Use optional ingredients to improve coloration, if needed. Colors matrix phases. Use by immersion only.
213 2–10 mL HCl 0.5–3 mL selenic acid 100 mL ethyl alcohol (95 %)
For more corrosion resistant alloys, increase the HCl and selenic acid content. For highly corrosion-resistant alloys, use 20–30 mL HCl. Colors second phase constituents. Use by immersion only.
214 1 g sodium molybdate 100 mL water
Add nitric acid to lower the pH to 2.5–3. Add 0.1–0.5 g ammonium bifluoride for carbon steels. Use by immersion only. Colors carbides. Immerse about 15 s.
215 240 g sodium thiosulfate 30 g citric acid 24 g lead acetate 1000 mL water
Mix in order given. Store in a dark bottle at least 24 h before use at 20°C. Lightly pre-etch specimen before use. Use small portion of stock solution for 4 h max. Pre-etch steel specimens with nital before tinting the MnS (add 0.2 g sodium nitrite to 100 mL of etch) white. Colors phosphides in cast iron. Colors matrix of Cu alloys.
216 8–15 g sodium metabisulfite 100 mL water
Do not store. Mix fresh. Immerse specimen face up. Agitate solution gently until coloration begins, allow to settle. Stop when surface is dark. Use crossed polarized light and sensitive tint to improve coloration.