1、Designation: E 1558 99 (Reapproved 2004)Standard Guide forElectrolytic Polishing of Metallographic Specimens1This standard is issued under the fixed designation E 1558; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide deals with electrolytic polishing as a meansof preparation of specimens for metallographic purposes.Procedur
3、es are described for polishing a variety of metals.NOTE 1References (1-133)2on electrolytic polishing will provide thereader with specific information beyond the scope of this guide.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theres
4、ponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific safetyprecautions are described in Section 5 and 6.3.1.2. Referenced Documents2.1 ASTM Standards:3E 7 Terminology Relating
5、to MetallographyE 407 Test Methods for Microetching Metals and Alloys3. Terminology3.1 DefinitionsAll terms used in this guide are eitherdefined in Terminology E 7 or are discussed in 3.2.3.2 Definitions of Terms Specific to This Standard:3.2.1 electrolytic polish (electropolish)A method of pol-ishi
6、ng metals and alloys in which material is removed from thesurface by making the metal the anode in an electrolytic bath.4. Significance and Use4.1 Advantages of Electrolytic Polishing:4.1.1 For some metals, a high quality surface finish can beproduced that is equivalent to, or better than, that whic
7、h can beobtained by mechanical methods.4.1.2 Once procedures have been established, satisfactoryresults can be obtained rapidly with reproducibility.4.1.3 There can be a marked saving of time if manyspecimens of the same material are polished sequentially.4.1.4 Electropolishing a selected area on th
8、e surface of arelatively large metal part can be accomplished nondestruc-tively, that is, without the need for sectioning to remove apiece.4.1.5 Soft, single-phase metals, which may be difficult topolish by mechanical methods, may be successfully electropol-ished.4.1.6 The true microstructure of a s
9、pecimen can be obtainedbecause artifacts (such as disturbed metal, scratches, andmechanical twins) produced on the surface, even by carefulgrinding and mechanical polishing operations, can be removed.These features are important in low-load hardness testing,X-ray diffraction studies, and in electron
10、 microscopy, wherehigher resolution puts a premium on undistorted metal sur-faces.4.1.7 After electropolishing is completed, etching can oftenbe accomplished by reducing the voltage (generally to aboutone-tenth that required for polishing) for a short time before itis turned off.NOTE 2Not all electr
11、opolishing solutions produce good etchingresults.4.2 Disadvantages of Electrolytic Polishing:4.2.1 Many of the chemical mixtures used in electropolish-ing are poisonous or dangerous if not properly handled (seeSection 5). These hazards are similar to those involved in themixing and handling of etcha
12、nts, see Test Methods E 407.4.2.2 In multi-phase alloys, the polishing rate of each phasemay be different. The result may be a non-planar surface.4.2.3 Electropolished surfaces may be slightly undulatedrather than perfectly planar and, therefore, may not be suitablefor examination at all magnificati
13、ons.4.2.4 The rate of polishing in areas adjacent to variousinhomogeneities, such as nonmetallic inclusions and voids, isusually greater than that in the surrounding matrix and tends toexaggerate the size of the inclusions and voids.4.2.5 Dimples, pits, and waviness limit applications involv-ing sur
14、face phenomena, coatings, interfaces, and cracks. Edgestend to be attacked preferentially, resulting in edge rounding.4.2.6 Artifacts may be produced by electropolishing.1This guide is under the jurisdiction of ASTM Committee E04 on Metallographyand is the direct responsibility of Subcommittee E04.0
15、1 on Specimen Preparation.Current edition approved June 1, 2004. Published July 2004. Originally approvedin 1993. Last previous edition approved in 1999 as E 1558 99.2The boldface numbers in parentheses refer to the references at the end of thisstandard.3For referenced ASTM standards, visit the ASTM
16、 website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
17、 States.4.2.7 Specimen mounting materials may react with theelectrolyte.4.2.8 The electropolished surfaces of certain materials maybe passive and difficult to etch.4.2.9 Metal removal rates by electropolishing are usuallyquite low, typically about 1 m/min, and all of the priorinduced damage from cut
18、ting and grinding may not be re-moved if preparation is stopped after a 600-grit SiC grind andelectropolishing times are short.4.2.10 A large number of electrolytes may be needed topolish the variety of metals encountered by a given laboratory.Considerable time may be required to develop a procedure
19、 fora new alloy.5. General Safety Precautions5.1 Before using or mixing any chemicals, all product labelsand pertinent Material Safety Data Sheets (MSDS) should beread and understood concerning all of the hazards and safetyprecautions to be observed. Users should be aware of the typeof hazards invol
20、ved in the use of all chemicals used, includingthose hazards that are immediate, long-term, visible, invisible,and with or without odors.5.1.1 Consult the product labels and MSDS for recommen-dations concerning proper protective clothing.5.1.2 All chemicals are potentially dangerous. All personsusin
21、g any electrolyte should be thoroughly familiar with all ofthe chemicals involved and the proper procedure for handling,mixing, and disposing of each chemical, as well as anycombinations of those chemicals.5.1.3 Table 1 includes specific safety precautions for themixing or use of some electrolytes.
22、The user should take careto observe each of these specific precautions.TABLE 1 Electrolytes for ElectropolishingClass Use Formula Cell Voltage Time RemarksGroup I (Electrolytes Composed of Perchloric Acid and Alcohol With or Without Organic Additions)I-1 Al and Al alloys with less than ethanol (95 %
23、) 800 mL 30 to 80 15 to 60 s2 percent Si distilled water 140 mLperchloric acid (60 %) 60 mLsteelscarbon, alloy, stainless 35 to 65 15 to 60 sPb, Pb-Sn, Pb-Sn-Cd, Pb-Sn-Sb 12 to 35 15 to 60 sZn, Zn-Sn-Fe, Zn-Al-Cu 20 to 60 .Mg and high Mg alloys . . nickel cathodeI-2 stainless steel and aluminum etha
24、nol (95 %) 800 mL 35 to 80 15 to 60 sperchloric acid (60 %) 200 mLI-3 stainless steel ethanol (95 %) 940 mL 30 to 45 15 to 60 sperchloric acid (65 %) 60 mLI-4 steel, cast iron, Al, Al alloys, Ni,Sn, Ag, Be, Ti, Zr, U,heat-resisting alloysethanol (95 %)2-butoxy ethanolperchloric acid (30 %)700 mL100
25、mL200 mL30 to 65 15 to 60 s one of the best formulas foruniversal useI-5 steelsstainless, alloy,high-speed; Fe, Al, Zr, Pbethanol (95 %)glycerinperchloric acid (30 %)700 mL100 mL200 mL15 to 50 15 to 60 s universal electrolyte comparable toI-4I-6 Al, Al-Si alloys ethanol (95 %)diethyl etherperchloric
26、 acid (30 %)760 mL190 mL50 mL35 to 60 15 to 60 s particularly good with Al-Si alloysI-7 Mo, Ti, Zr, U-Zr alloy methanol (absolute)2-butoxy ethanolperchloric acid (60 %)600 mL370 mL30 mL60 to 150 5 to 30 sI-8 Al-Si alloys methanol (absolute)glycerinperchloric acid (65 %)840 mL125 mL35 mL50 to 100 5 t
27、o 60 sI-9 vanadium methanol (absolute)2-butoxy ethanolperchloric acid (65 %)590 mL350 mL60 mL30 3 s three-second cycles repeated atleast seven times to prevent heatinggermaniumtitaniumzirconium25 to 3558 to 6670 to 7530 to 60 s45 s15 spolish onlypolish and etch simultaneouslyI-10 aluminum methanol (
28、absolute)nitric acidperchloric acid (60 %)950 mL15 mL50 mL30 to 60 15 to 60 sI-11 steelscarbon, alloy, stainlessTi, high-temperature alloys, Pb,Momethanol (absolute)butylcellosolveperchloric acid600 mL360 mL60 mL3040 560 s good all purpose electropolishI-12 Al and Al alloys ethanol (95 %)perchloric
29、acid1000 mL200 mL10 2 min not good for Al-Cu and Al-Si alloys.Black film forms. Peel off after 11.5min and polish 1 min more.I-13 steel, Al, Ni, Sn, Ti, Bestainless steelAl3Niethanol (95 %)butylcellosolvewaterperchloric acid700 mL100 mL137 mL62 mL20 20 s Mix ethanol and water, addperchloric acid car
30、efully. Then, addbutylcellosolve before use.I-14 Ni, Ag, or Cu alloysCdethanol (95 %)butylcellosolveperchloric acid700 mL100 mL200 mL7080 15 sE 1558 99 (2004)2TABLE 1 ContinuedClass Use Formula Cell Voltage Time RemarksI-15 Mo and Mo alloys methanol (absolute)waterbutylcellosolveperchloric acid600 m
31、L13 mL360 mL47 mL20 s Mix methanol and water, addperchloric acid carefully. Addbutylcellosolve before use.Group II (Electrolytes Composed of Perchloric Acid and Glacial Acetic Acid in Varying Proportions)II-1 Cr, Ti, Zr, U,Fe, steelcarbon, alloy, stainlessacetic acid (glacial)perchloric acid (60 %)9
32、40 mL60 mL20 to 60 1 to 5 min good general-purpose electrolyteII-2 Zr, Ti, U, steelcarbon and alloy acetic acid (glacial)perchloric acid (60 %)900 mL100 mL12 to 70 0.5 to 2 minII-3 U, Zr, Ti, Al, steelcarbon andalloyacetic acid (glacial)perchloric acid (60 %)800 mL200 mL40 to 100 1 to 15 minII-4 Ni,
33、 Pb, Pb-Sb alloys acetic acid (glacial)perchloric acid (60 %)700 mL300 mL40 to 100 1 to 5 minII-5 3 percent Si-Fe acetic acid (glacial)perchloric acid (60 %)650 mL350 mL. 5 min 0.06 A/cm2II-6 Cr acetic acid (glacial)perchloric acid1000 mL5mL3050 23 min can lower voltage to 25 V by adding515 % water.
34、II-7 Hf, steelcarbon and alloy acetic acid (glacial)perchloric acid1000 mL50 mL. . Used to polish Hf wires.Group III (Electrolytes Composed of Phosphoric Acid in Water or Organic Solvent)III-1 cobalt phosphoric acid (85 %) 1000 mL 1.2 3 to 5 minIII-2 pure copper distilled waterphosphoric acid (85 %)
35、175 mL825 mL1.0 to 1.6 10 to 40 min copper cathodeIII-3 stainless, brass, Cu and Cualloys except Sn bronzewaterphosphoric acid (85 %)300 mL700 mL1.5 to 1.8 5 to 15 min copper cathodeIII-4 alpha or alpha plus beta brass,Cu-Fe, Cu-Co, Co, Cdwaterphosphoric acid (85 %)600 mL400 mL1 to 2 1 to 15 min cop
36、per or stainless steel cathodeIII-5 Cu, Cu-Zn waterpyrophosphoric acid1000 mL580 g1 to 2 10 min copper cathodeIII-6 steel diethylene glycol monoethyletherphosphoric acid (85 %)500 mL500 mL5 to 20 5 to 15 min 120FIII-7 Al, Ag, Mg waterethanol (95 %)phosphoric acid (85 %)200 mL380 mL400 mL25 to 30 4 t
37、o 6 min aluminum cathode, 100 to 110FIII-8 uranium ethanol (absolute)glycerin (cp)phosphoric acid (85 %)300 mL300 mL300 mL. .III-9 Mn, Mn-Cu alloys ethanol (95 %)glycerinphosphoric acid (85 %)500 mL250 mL250 mL18 .III-10 Cu and Cu-base alloys distilled waterethanol (95 %)phosphoric acid (85 %)500 mL
38、250 mL250 mL. 1 to 5 minIII-11 stainless steel ethanol (absolute), topyrophosphoric acid1L400 g. 10 min good for all austenitic heat resistantalloys, 100F plusIII-12 Mg-Zn ethanol (95 %)phosphoric acid (85 %)625 mL375 mL1.5 to 2.5 3 to 30 minIII-13 uranium ethanol (95 %)ethylene glycolphosphoric aci
39、d (85 %)445 mL275 mL275 mL18 to 20 5 to 15 min 0.03 A/cm2III-14 Al-Mg alloys waterethanol (95 %)phosphoric acid (85 %)250 mL380 mL400 mL5060 2 minIII-15 Cu-Pb alloys ethanol (95 %)phosphoric acid (85 %)620 mL380 mLgood up to 30 % PbIII-16 Neptunium ethanol (95 %)glycerolphosphoric acid (85 %)400 mL4
40、00 mL800 mLafter 600-grit SiC, use 6-mdiamond on nylon beforeelectropolishing.Group IV (Electrolytes Composed of Sulfuric Acid in Water or Organic Solvent)IV-1 stainless steel watersulfuric acid250 mL750 mL1.5 to 6 1 to 2 minIV-2 stainless steel, Fe, Ni watersulfuric acid400 mL600 mL1.5 to 6 2 to 6
41、minIV-3 stainless steel, Fe, Ni, Mo watersulfuric acid750 mL250 mL1.5 to 6 2 to 10 minMo0.3 to 1 minparticularly good for sinteredMo32 to 80FIV-4 molybdenum watersulfuric acid900 mL100 mL1.5 to 6 0.3 to 2 min particularly good for sinteredMo32 to 80FE 1558 99 (2004)3TABLE 1 ContinuedClass Use Formul
42、a Cell Voltage Time RemarksIV-5 stainless steel waterglycerinsulfuric acid70 mL200 mL720 mL1.5 to 6 0.5 to 5 minIV-6 stainless steel, aluminum waterglycerinsulfuric acid220 mL200 mL580 mL1.5 to 12 1 to 20 minIV-7 molybdenum methanol (absolute)sulfuric acid875 mL125 mL6 to 18 0.5 to 1.5 min 32 to 80F
43、IV-8 Ni-base superalloys methanol (absolute)sulfuric acid800 mL200 mL30 20 s for alloy 625Group V (Electrolytes Composed of Chromic Acid in Water)V-1 stainless steel waterchromic acid830 mL620 g1.5 to 9 2 to 10 minV-2 Zn, brass waterchromic acid830 mL170 g1.5 to 12 10 to 60 sGroup VI (Mixed Acids or
44、 Salts in Water or Organic Solvent)VI-1 stainless steel phosphoric acid (85 %)sulfuric acid600 mL400 mL. .VI-2 stainless steel waterphosphoric acid (85 %)sulfuric acid150 mL300 mL550 mL. 2 min 0.3 A/cm2VI-3 stainless and alloy steel waterphosphoric acid (85 %)sulfuric acid240 mL420 mL340 mL. 2 to 10
45、 min 0.1 to 0.2 A/cm2VI-4 stainless steel waterphosphoric acid (85 %)sulfuric acid330 mL550 mL120 mL. 1 min 0.05 A/cm2VI-5 bronze (to 9 % Sn) waterphosphoric acid (85 %)sulfuric acid450 mL390 mL160 mL. 1 to 5 min 0.1 A/cm2VI-6 bronze (to 6 % Sn) waterphosphoric acid (85 %)sulfuric acid330 mL580 mL90
46、 mL. 1 to 5 min 0.1 A/cm2VI-7 steel waterglycerinphosphoric acid (85 %)sulfuric acid140 mL100 mL430 mL330 mL. 1 to 5 min 1 to 5 A/cm2, 100F plusVI-8 stainless steel waterglycerinphosphoric acid (85 %)sulfuric acid200 mL590 mL100 mL110 mL. 5 min 1 A/cm2, 80 to 120FVI-9 stainless steel waterchromic ac
47、idphosphoric acid (85 %)sulfuric acid260 mL175 g175 mL580 mL. 30 min 0.6 A/cm2, 80 to 120FVI-10 stainless steel waterchromic acidphosphoric acid (85 %)sulfuric acid175 mL105 g460 mL390 mL. 60 min 0.5 A/cm2, 80 to 120FVI-11 stainless and alloy steel waterchromic acidphosphoric acid (85 %)sulfuric aci
48、d240 mL80 g650 mL130 mL. 5 to 60 min 0.5 to A/cm2, 100 to 130FVI-12 tantalum hydrofluoric acidsulfuric acid100 mL900 mL. 9 min graphite cathode, 0.1 A/cm2,90to100FVI-13 stainless steel waterhydrofluoric acidsulfuric acid210 mL180 mL610 mL. 5 min 0.5 A/cm2, 70 to 120FVI-14 zinc waterchromic acidsulfu
49、ric acidsodium dichromateacetic acid (glacial)800 mL100 g46 mL310 g96 mL. . 0.002 A/cm2, 70 to 100FVI-15 stainless steel hydrogen peroxide (30 %)(Caution)hydrofluoric acidsulfuric acid260 mL240 mL500 mL. 5 min 0.5 A/cm2(Caution) DangerousVI-16 stainless steel waterhydrofluoric acidsulfuric acid520 mL80 mL400 mL.12 to 4 min 0.08 to 0.3 A/cm2E 1558 99 (2004)4TABLE 1 ContinuedClass Use Formula Cell Voltage Time RemarksVI-17 stainless steel waterchromic acidnitric acidhydrochloric acidsulfuric acid600 mL180 g60 mL3mL240 mL. .VI-18 bismuth glycer
