1、Designation: B 571 97 (Reapproved 2003)Standard 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 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This practice describes simple, qualit
3、ative tests forevaluating the adhesion of metallic coatings on various sub-stances.1.2 This 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
4、determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 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 controv
5、er-sial subject. If more than one test is used, failure to pass anyone test is considered unsatisfactory. 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 su
6、bsequentlyformed would suggest a draw or a bend test; an article that isto be soldered or otherwise 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 test
7、s are limited to specific types ofcoatings, thickness ranges, ductilities, or compositions of 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
8、 substrate is greater than the cohesive strengthof either. Such adhesion is usually obtained 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
9、 to separate the coatingfrom the substrate. This may be prying, hammering, bending,beating, 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 adh
10、esion is required, it may be desirableto use one or more of the following tests. These tests 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 gu
11、ideline is used for acceptance inspection,the method or methods to be used must be specified. 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 t
12、he designated test, equivalent test panels may beappropriate. If permitted, test panels shall 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. Ben
13、d Tests3.1 Bend the part with the coated surface away over amandrel until its two legs are parallel. 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 substra
14、te,which is evidence of poor adhesion. If the coating fractures orblisters, a sharp blade may be used to attempt to lift off thecoating. With hard or brittle coatings, cracking usually occursin the bend area. Such cracks may or may not propagate intothe substrate. In either case, cracks are not indi
15、cative 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-ration or peeling of the coating. Pryin
16、g with a sharp blade willindicate unsatisfactory adhesion by lift off of the coating.1These test methods are under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and are the direct responsibility of SubcommitteeB08.10 on Test Methods.Current edition approved May 10, 2003. P
17、ublished July 2003. Originallyapproved in 1979. Last previous edition approved in 1997 as B 571 97.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Burnishing Test4.1 Rub a coated area of about 5 cm with a smooth-endedtool for appr
18、oximately 15 s. A suitable tool is a steel rod 6 mmin diameter with a smooth hemispherical 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 sati
19、s-factorily.5. Chisel-Knife Test5.1 Use a sharp cold chisel to penetrate the coating on thearticle 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 substit
20、uted for the chisel with or withouthammering or light tapping. If it is possible to remove 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
21、 38 mm in diameter, to a depth up to18 mm, through the use of a set of adjustable dies in 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 deta
22、chment from the substrate. Ifthere is peeling or flaking of the coating or if it can bedetached, 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
23、the coated specimen and inspect it fordetachment at the deposit/substrate interface. Apply 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 unsatisfactor
24、y adhesion.7.2 This technique is not suitable for thin or soft coatings.8. 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 d
25、irection that 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
26、sufficient timefor it to reach the temperature shown in Table 2. Maintain the2Romanoff, F. P., Transactions, 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
27、Appropriate for Various CoatingsAdhesion TestCoating MaterialACadmium Chromium CopperLead andLead/TinAlloyNickelNickel andChromiumPalladium Rhodium SilverTin andTin/LeadAlloyZinc GoldBend +Burnish + Chisel/knife + +Draw +File + +Grind andsaw+ +Heat/quench +Impact + +Peel +Push + +Scribe + A+ Appropr
28、iate; not appropriate.TABLE 2 Temperature Test GuideSubstrateCoating MaterialChromium,Nickel, Nickel +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 185Z
29、inc alloys 150 150 150 150 150 150 150Copper andcopper alloys250 150 150 150 250 350 185Aluminum andaluminum alloys220 150 150 150 220 220 185B 571 97 (2003)2temperature of the oven within 10C of the nominal. Coatingsand substrates that are sensitive to oxidation should be heatedin an inert or reduc
30、ing atmosphere or a suitable liquid. Thenquench the part in water or other suitable liquid at 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 o
31、r pores which are bridged by the deposit. If thedeposited coating cannot be peeled or lifted 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
32、bond strength of electrodeposits. In some cases, abrittle layer may be created by the materials 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 notcr
33、eate unwanted effects on parts.10. Impact Test10.1 Use a hammer or impact device coupled with 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 a
34、nd the impact head contour is in the form of a5-mm diameter ball, shock loaded by a falling 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.
35、10.2 This test is sometimes difficult to interpret. Soft andductile coatings are generally not 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-
36、backed tapemay be considered as a possible alternative. Heat curing of theadhesive may be used, 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 stan
37、dardized. Failure inthe coating/substrate interface is evidence of inadequate adhe-sion.11.2 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
38、a blind hole 0.75 cm in diameter from theunderside until the point of the drill tip comes within 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 pu
39、nch 0.6 cm in diameter until a button sampleis pushed out.3Exfoliation or peeling of the coating 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 paralle
40、l lines or a rectangular gridpattern on the article using a hardened steel tool ground to asharp (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 throug
41、h the coating to the substrate ina single stroke. If any portion of coating between the linesbreaks 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
42、firm finger pressure onto aclean grid area. Make sure that any loose coating particles fromscribing 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
43、the tape has deposit adhering to itthat comes from the area between the scribed lines. Depositcontinuous 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
44、lines of the scribed area.13.3 Generally, thick deposits are not suitable for evaluationunless 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 test
45、s for a variety of coatingsystems are given in Table 1.15. Precision and Bias15.1 No statement 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,
46、Vol 52,October 1965, pp. 9821000.4Permacel 99, a product of and manufactured by Permacel, New Brunswick, NJ08903, is reported to be a suitable product for this purpose.B 571 97 (2003)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any it
47、em mentionedin this standard. Users of this standard are expressly advised that determination 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 com
48、mittee and must be reviewed every five years andif not revised, either reapproved or withdrawn. 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
49、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 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the
