1、Designation: B 571 97 (Reapproved 2008)e1Standard Practice forQualitative Adhesion Testing of Metallic Coatings1This standard is issued under the fixed designation B 571; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTEThe units statement in subsection 1.2 was
3、corrected editorially in April 2008.1. Scope1.1 This practice covers simple, qualitative tests for evalu-ating the adhesion of metallic coatings on various substances.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This
4、standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility 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.2. Significance and Use2
5、.1 These tests are useful for production control and foracceptance testing of products.2.2 Interpreting the results of qualitative methods for deter-mining the adhesion of metallic coatings is often a controver-sial subject. If more than one test is used, failure to pass anyone test is considered un
6、satisfactory. In many instances, theend use of the coated article or its method of fabrication willsuggest the technique that best represents functional require-ments. For example, an article that is to be subsequentlyformed would suggest a draw or a bend test; an article that isto be soldered or ot
7、herwise exposed to heat would suggest aheat-quench test. If a part requires baking or heat treating afterplating, adhesion tests should be carried out after such post-treatment as well.2.3 Several of the tests are limited to specific types ofcoatings, thickness ranges, ductilities, or compositions o
8、f thesubstrate. These limitations are noted generally in the testdescriptions and are summarized in Table 1 for certain metalliccoatings.2.4 “Perfect” adhesion exists if the bonding between thecoating and the substrate is greater than the cohesive strengthof either. Such adhesion is usually obtained
9、 if good electro-plating practices are followed.2.5 For many purposes, the adhesion test has the objectiveof detecting any adhesion less than “perfect.” For such a test,one uses any means available to attempt to separate the coatingfrom the substrate. This may be prying, hammering, bending,beating,
10、heating, sawing, grinding, pulling, scribing, chiseling,or a combination of such treatments. If the coating peels,flakes, or lifts from the substrate, the adhesion is less thanperfect.2.6 If evaluation of adhesion is required, it may be desirableto use one or more of the following tests. These tests
11、 havevarying degrees of severity; and one might serve to distinguishbetween satisfactory and unsatisfactory adhesion in a specificapplication. The choice for each situation must be determined.2.7 When this guideline is used for acceptance inspection,the method or methods to be used must be specified
12、. Becausethe results of tests in cases of marginal adhesion are subject tointerpretation, agreement shall be reached on what is accept-able.2.8 If the size and shape of the item to be tested precludesuse of the designated test, equivalent test panels may beappropriate. If permitted, test panels shal
13、l be of the samematerial and have the same surface finish as the item to betested and shall be processed through the same preplating,electroplating, and postplating cycle with the parts they repre-sent.3. Bend Tests3.1 Bend the part with the coated surface away over amandrel until its two legs are p
14、arallel. The mandrel diametershould be four times the thickness of the sample. Examine thedeformed area visually under low magnification, for example,43, for peeling or flaking of the coating from the substrate,which is evidence of poor adhesion. If the coating fractures orblisters, a sharp blade ma
15、y be used to attempt to lift off thecoating. With hard or brittle coatings, cracking usually occurs1This practice is under the jurisdiction of ASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 onTest Methods.Current edition approved April 1,
16、 2008. Published April 2008. Originallyapproved in 1979. Last previous edition approved in 2003 as B 571 97 (2003).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.in the bend area. Such cracks may or may not propagate intothe substra
17、te. In either case, cracks are not indicative of pooradhesion unless the coating can be peeled back with a sharpinstrument.3.2 Bend the part repeatedly, back and forth, through anangle of 180 until failure of the basis metal occurs. Examinethe region at low magnification, for example, 103, for sepa-
18、ration or peeling of the coating. Prying with a sharp blade willindicate unsatisfactory adhesion by lift off of the coating.4. Burnishing Test4.1 Rub a coated area of about 5 cm with a smooth-endedtool for approximately 15 s. A suitable tool is a steel rod 6 mmin diameter with a smooth hemispherical
19、 end. The pressureshall be sufficient to burnish the coating at each stroke but notso great as to dig into it. Blisters, lifting, or peeling should notdevelop. Generally, thick deposits cannot be evaluated satis-factorily.5. Chisel-Knife Test5.1 Use a sharp cold chisel to penetrate the coating on th
20、earticle being evaluated. Alternatively the chisel may be placedin back of an overhang area of the coating or at a coating-substrate interface exposed by sectioning the article with a saw.A knife may be substituted for the chisel with or withouthammering or light tapping. If it is possible to remove
21、 thedeposit, the adhesion is not satisfactory. Soft or thin coatingscannot be evaluated for adhesion by this method.6. Draw Test6.1 Form a suitable sample about 60 mm in diameter into aflanged cap approximately 38 mm in diameter, to a depth up to18 mm, through the use of a set of adjustable dies in
22、anordinary punch press.2Penetration of the male die may becontinued until the cap fractures. The adhesion of the coatingmay be observed directly or evaluated further by techniquesdescribed in Section 5 for detachment from the substrate. Ifthere is peeling or flaking of the coating or if it can bedet
23、ached, the adhesion is not satisfactory.6.2 Results from this technique must be interpreted cau-tiously, because the ductilities of both the coating and substrateare involved.7. File Test7.1 Saw off a piece of the coated specimen and inspect it fordetachment at the deposit/substrate interface.Apply
24、coarse millfile across the sawed edge from the substrate toward thecoating so as to raise it, using an approach angle of approxi-mately 45 to the coating surface. Lifting or peeling is evidenceof unsatisfactory adhesion.7.2 This technique is not suitable for thin or soft coatings.2Romanoff, F. P., T
25、ransactions, Electrochem. Soc., Vol 65, 1934, p. 385;Proceedings, Amer. Electroplaters Soc. Vol 22, 1934, p. 155; Monthly Review,Amer. Electroplaters Soc., Vol 22, April 1935, p. 8.TABLE 1 Adhesion Tests Appropriate for Various CoatingsAdhesion TestCoating MaterialACadmium Chromium CopperLead andLea
26、d/TinAlloyNickelNickel andChromiumPalladium Rhodium SilverTin andTin/LeadAlloyZinc GoldBend +Burnish + Chel/knife+ +Draw +File + +Grind andsaw+ +Heat/quench +Impact + +Peel +Push + +Scribe + A+ Appropriate; not appropriate.TABLE 2 Temperature Test GuideSubstrateCoating MaterialChromium,Nickel, Nicke
27、l +Chromium,Copper,Temperature, CTin,Temperature,CLead,Tin/Lead,Temperature,CZinc,Temperature,CGold andSilver,Temperature,CPalladium,Temperature,CRhodium,Temperature,CSteel 250 150 150 150 250 350 185Zinc alloys 150 150 150 150 150 150 150Copper andcopper alloys250 150 150 150 250 350 185Aluminum an
28、daluminum alloys220 150 150 150 220 220 185B 571 97 (2008)e128. Grind-Saw Test8.1 Hold the coated article against a rough emery wheel sothat the wheel cuts from substrate toward the deposit in a jerkyor bumpy fashion. A hack saw may be substituted for thewheel, making sure to saw in the direction th
29、at tends toseparate the coating from the substrate. Lifting or peeling isevidence of unsatisfactory adhesion.8.2 This technique is especially effective on hard or brittlecoatings but is not suitable for thin or soft coatings.9. Heat-Quench Test9.1 Heat the coated article in an oven for a sufficient
30、timefor it to reach the temperature shown in Table 2. Maintain thetemperature of the oven within 10C of the nominal. Coatingsand substrates that are sensitive to oxidation should be heatedin an inert or reducing atmosphere or a suitable liquid. Thenquench the part in water or other suitable liquid a
31、t roomtemperature.9.2 Flaking or peeling of the deposit is evidence of unsat-isfactory adhesion. Blisters may erupt during the heat andquench test when plating solution is entrapped in substratesurface pits or pores which are bridged by the deposit. If thedeposited coating cannot be peeled or lifted
32、 from the substratein an area adjacent to the blister(s), the appearance of blistersshould not be interpreted as evidence of inferior adhesion.9.3 Diffusion and subsequent alloying of metals may im-prove the bond strength of electrodeposits. In some cases, abrittle layer may be created by the materi
33、als involved causingpeeling as a result of fracture rather than poor adhesion. Thiswould not give a correct indication of the as-plated bondstrength.9.4 This test is nondestructive if the procedure does notcreate unwanted effects on parts.10. Impact Test10.1 Use a hammer or impact device coupled wit
34、h a suitablebacking block to support the article to be tested to deform thesample. Reproducible results are more easily obtained by theuse of a suitably modified impact tester where the force isreproducible and the impact head contour is in the form of a5-mm diameter ball, shock loaded by a falling
35、weight orswinging pendulum weight. The severity of the test may bealtered by changing the load and diameter of the ball. Exfolia-tion or blisters in and around indentations are evidence ofinadequate adhesion.10.2 This test is sometimes difficult to interpret. Soft andductile coatings are generally n
36、ot suited for evaluation.11. Peel Test11.1 Bond a strip of steel or brass about 1.5 mm thick and20 mm wide by solder or suitable adhesive to a properly flatarea of the coated surface of the article. Adhesive-backed tapemay be considered as a possible alternative. Heat curing of theadhesive may be us
37、ed, keeping in mind considerations noted in9.3. The angle of pull shall be 90 to the surface. Forreproducible results, the rate of pull, the thickness and width ofthe strip, and deposit thickness must be standardized. Failure inthe coating/substrate interface is evidence of inadequate adhe-sion.11.2
38、 The tensile and shear strengths of adhesives andsolders limit the range of adhesion strengths that can beevaluated. A quantitative analysis of the factors involved hasbeen published.312. Push Test12.1 Drill a blind hole 0.75 cm in diameter from theunderside until the point of the drill tip comes wi
39、thin approxi-mately 1.5 mm of the deposit/substrate interface on theopposite side. Supporting the material on a ring about 2.5 cmin diameter, apply steady pressure over the blind hole using ahardened steel punch 0.6 cm in diameter until a button sampleis pushed out.3Exfoliation or peeling of the coa
40、ting in thebutton or crater areas is evidence of inadequate adhesion.12.2 Soft, very ductile, and thin deposits are generally notsuited for this technique.13. Scribe-Grid Test13.1 Scribe three or more parallel lines or a rectangular gridpattern on the article using a hardened steel tool ground to as
41、harp (30) point with a distance between the scribed lines ofapproximately ten times the nominal coating thickness, with aminimum distance of 0.4 mm. In scribing the lines, usesufficient pressure to cut through the coating to the substrate ina single stroke. If any portion of coating between the line
42、sbreaks away from the substrate, the adhesion is inadequate.13.2 When apparently satisfactory adhesion is indicated,apply a pressure-sensitive tape, having an adhesion bondstrength of at least 45 g/mm, using firm finger pressure onto aclean grid area. Make sure that any loose coating particles froms
43、cribing do not remain. Shortly thereafter, remove the tape byseizing a free end and pulling it off rapidly (not jerked) backupon itself as close to an angle of 180 as possible. Theadhesion is not adequate if the tape has deposit adhering to itthat comes from the area between the scribed lines. Depos
44、itcontinuous to the scribed lines is not considered.13.2.1 The tape supplier4shall specify that their tape has asufficient adhesion bond strength. The tape shall be wideenough to cover three or more parallel lines of the scribed area.13.3 Generally, thick deposits are not suitable for evaluationunle
45、ss a chisel or other sharp instrument is used to pry theexposed coating/substrate interface, in which case this tech-nique becomes a variant of Section 5.14. Test-Coating Systems14.1 Recommended adhesion tests for a variety of coatingsystems are given in Table 1.15. Precision and Bias15.1 No stateme
46、nt is made about the precision and bias ofthese tests because of their qualitative nature.16. Keywords16.1 adhesion; metallic coatings3Saubestre, E. B., Durney, L. J., Hajdu, J., and Bastenbeck, E., Plating, Vol 52,October 1965, pp. 9821000.4Permacel 99, a product of and manufactured by Permacel, Ne
47、w Brunswick, NJ08903, is reported to be a suitable product for this purpose.B 571 97 (2008)e13ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determinat
48、ion of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withd
49、rawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by
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