1、Designation: B659 90 (Reapproved 2014)Standard Guide forMeasuring Thickness of Metallic and Inorganic Coatings1This standard is issued under the fixed designation B659; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the methods for measuring the thick-ness of many metallic and inorganic coatings includingelectrodepos
3、ited, mechanically deposited, vacuum deposited,anodic oxide, and chemical conversion coatings.1.2 This guide is limited to tests considered in ASTMstandards and does not cover certain tests that are employed forspecial applications.1.3 The values stated in SI units are to be regarded asstandard. No
4、other units of measurement are included in thisstandard.1.4 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 determine the applica-bilit
5、y of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B244 Test Method for Measurement of Thickness of AnodicCoatings on Aluminum and of Other NonconductiveCoatings on Nonmagnetic Basis Metals with Eddy-Current InstrumentsB487 Test Method for Measurement of Metal and Ox
6、ideCoating Thickness by Microscopical Examination ofCross SectionB499 Test Method for Measurement of Coating Thicknessesby the Magnetic Method: Nonmagnetic Coatings onMagnetic Basis MetalsB504 Test Method for Measurement of Thickness of Metal-lic Coatings by the Coulometric MethodB530 Test Method fo
7、r Measurement of Coating Thicknessesby the Magnetic Method: Electrodeposited Nickel Coat-ings on Magnetic and Nonmagnetic SubstratesB567 Test Method for Measurement of Coating Thicknessby the Beta Backscatter MethodB568 Test Method for Measurement of Coating Thicknessby X-Ray SpectrometryB588 Test M
8、ethod for Measurement of Thickness of Trans-parent or Opaque Coatings by Double-Beam InterferenceMicroscope TechniqueB681 Test Method for Measurement of Thickness of AnodicCoatings onAluminum and of Other Transparent Coatingson Opaque Surfaces Using the Light-Section Microscope(Discontinued 2001) (W
9、ithdrawn 2001)3B767 Guide for Determining Mass Per Unit Area of Elec-trodeposited and Related Coatings by Gravimetric andOther Chemical Analysis Procedures2.2 ISO Standards:41463 Metal and Oxide CoatingsMeasurement of Thick-ness by Microscopic Examination of Cross Sections2128 Surface Treatment of M
10、etalsAnodization (AnodicOxidation) of Aluminum and Its AlloysMeasurement ofthe Thickness of Oxide CoatingsNondestructive Mea-surement by Light Section Microscope2176 Petroleum Products Lubricating Grease Determinationof Dropping Point2177 Metallic CoatingsMeasurement of CoatingThicknessCoulometric M
11、ethod by Anodic Solution2178 Non-Magnetic Metallic and Vitreous or PorcelainEnamel Coatings on Magnetic Basis Metals, Measurementof Coating Thickness, Magnetic Method2360 Non-Conductive Coatings on Non-Magnetic BasisMetalsMeasurement of Coating ThicknessEddy Cur-rent Method2361 Electrodeposited Nick
12、el Coatings on Magnetic andNon-Magnetic SubstratesMeasurement of CoatingThicknessMagnetic Method3497 Metallic CoatingsMeasurement of CoatingThicknessX-Ray Spectrometric Methods3543 Metallic and Non-Metallic CoatingsMeasurement ofThicknessBeta Backscatter Method1This guide is under the jurisdiction o
13、f ASTM Committee B08 on Metallic andInorganic Coatings and is the direct responsibility of Subcommittee B08.10 on TestMethods.Current edition approved May 1, 2014. Published May 2014. Originallyapproved in 1979. Last previous edition approved in 2008 as B65990(2008)1.DOI: 10.1520/B0659-90R14.2For re
14、ferenced ASTM standards, visit the ASTM 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.3The last approved version of this historical standard is referenced
15、 onwww.astm.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Significance and Use3.1 Most coating spe
16、cifications specify the thickness of thecoating because coating thickness is often an important factorin the performance of the coating in service.3.2 The methods included in this guide are suitable foracceptance testing and are to be found in ASTM standards.3.3 Each method has its own limitations w
17、ith respect to thekind of coating and its thickness.4. Reliability of Methods4.1 All methods covered by this guide are sufficientlyreliable to be used for acceptance testing of many electroplatedand other coatings. That is, each method is capable of yieldingmeasurements with an uncertainty of less t
18、han 10 % of thecoating thickness over a significant range of coating thick-nesses when used by properly instructed personnel.5. Nondestructive Methods5.1 Magnetic MethodsThese methods employ instrumentsthat measure the magnetic attraction between a magnet and thecoating or the substrate or both, or
19、that measure the reluctanceof a magnetic flux path passing through the coating and thesubstrate. These methods, in practice, are limited to nonmag-netic coatings on carbon steel (Test Method B499 and ISO2178) and to electrodeposited nickel coatings on carbon steelor on nonmagnetic substrates (Test M
20、ethod B530 and ISO2361) and to nonmagnetic autocatalytically deposited nickel-phosphorus alloys on carbon steel (Test Method B499 and ISO2176). Coating thickness gages of this type are availablecommercially.5.2 Eddy-Current MethodThis method employs an instru-ment that generates a high-frequency cur
21、rent in a probe,inducing eddy currents near the surface of the test specimen.The magnitude of the eddy currents is a function of the relativeconductivities of the coating and substrate materials and thecoating thickness. Because variation in the electroplatingprocess can change the electrical proper
22、ties of the coating and,hence, instrument response for a given thickness, the use ofeddy-current instruments is usually limited to the measurementof nonconductive coatings on nonmagnetic basis metals (TestMethod B244 and ISO 2360). These instruments are, however,also suitable for the thickness measu
23、rement of high-conductivity metal (for example, copper and silver) coatings onnonconductive substrates. Coating thickness gages of this typeare available commercially.5.3 X-Ray Fluorescence Methods:5.3.1 These methods cover the use of emission and absorp-tion X-ray spectrometry for determining the t
24、hickness ofmetallic coatings up to about 15 m. The upper limit may besignificantly above or below 15 m depending on the coatingmaterial and on the equipment used. When exposed to X rays,the intensity of the secondary radiation emitted by the coatingor by the substrate followed by attenuation by the
25、coating ismeasured. The intensity of the secondary radiation is a functionof the coating thickness.5.3.2 In multiple coatings the X-ray method is generallyapplicable to the final metal coating.5.3.3 Suitable equipment is available commercially (TestMethod B568 and ISO 3497).5.4 Beta Backscatter Meth
26、od:5.4.1 The beta backscatter method employs radioisotopesthat emit beta radiation and a detector that measures theintensity of the beta radiation backscattered by the test speci-men. Part of the beta radiation entering the material collideswith atoms of the material and is scattered back towards th
27、esource. The intensity of the backscattered radiation is afunction, among others, of the coating thickness. A measure-ment is possible if the atomic number of the coating material issufficiently different from that of its substrate and if the betaradiation is of suitable energy and intensity. The me
28、thod can beused for measuring both thin and thick coatings, the maximumthickness being a function of the atomic number of the coating.In practice, high atomic number coatings, such as gold, can bemeasured up to 50 m, while low atomic number coatings,such as copper or nickel, can be measured up to ab
29、out 200 m.5.4.2 Coating thickness gages of this type are availablecommercially (Test Method B567 and ISO 3543).6. Semidestructive Methods6.1 Coulometric Method:6.1.1 Coating thickness may be determined by measuringthe quantity of electricity consumed in dissolving the coatingfrom an accurately defin
30、ed area when the article is made anodicin a suitable electrolyte under suitable conditions. The changein potential occurring when the substrate is exposed indicatesthe end point of the dissolution. The method is applicable tomany coating-substrate combinations (Test Method B504 andISO 2177).6.1.2 Co
31、ating thickness instruments employing this methodare available commercially.6.2 Double-Beam Interference Microscope MethodA stepis formed between the coating surface and the substrate surfaceby dissolving a small area of coating. The height of this step ismeasured with a double-beam interference mic
32、roscope. Themethod is applicable to thin coatings such as usually used fordecorative chromium. It can be used to measure transparentoxide coatings without the need of forming a step (Test MethodB588).7. Destructive Methods7.1 Microscopical MethodIn the microscopical methodthe thickness is measured i
33、n a magnified image of a crosssection of the coating (Test Method B487 and ISO 1463).7.2 Gravimetric Method (Strip and Weigh):7.2.1 The coating mass is determined by weighing thesample before and after dissolving the coating without attack ofthe substrate or by weighing the coating after dissolving
34、thesubstrate without attack of the coating.7.2.2 The coating thickness is given by the equation:t 5m 310d 3A(1)where:B659 90 (2014)2t = thickness, m,d = density of coating material, g/cm3,m = mass of coating, mg, andA = area covered by coating, cm2.7.2.3 Procedures for applying this method to many d
35、ifferentcoatings are given in Guide B767.7.2.4 A variation of this method is to weigh the item beforeand after electroplating or, if the current efficiency is 100 %, tomeasure the coulombs passed during the electroplating todetermine the coating weight.8. Other Methods8.1 Profilometry and multiple-b
36、eam interferometry offerreliable methods of measuring coating thickness provided astep can be formed by removing a portion of the coating.8.2 The light section microscope is used for measuring thethickness of non-opaque coatings on relatively smooth sub-strates (Test Method B681 and ISO 2128).9. Sum
37、mary of Applicability of Coating ThicknessMeasuring Methods9.1 The applicability and limitations of coating gages andother methods of measuring coating thickness are set forth inthe pertinent ASTM and ISO standards, publications on elec-troplating and related finishing technology, and manufacturersi
38、nstructions for the use of coating thickness gages. The X-ray,gravimetric, microscopical, and interference microscopicalmethods are applicable to almost all combinations of substrateand coatings. Table 1 indicates the substrate and coatingcombinations to which the beta backscatter, coulometric,eddy-
39、current, and magnetic methods have been applied.ASTM 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 determination of the validity of any such patent rights,
40、 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 withdrawn. Your comments are invited either for rev
41、ision 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
42、 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
43、obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Applicabilit
44、y of Coating Thickness Measuring MethodsNOTE 1B = Beta backscatter; C = Coulometric; E = Eddy current; and M = Magnetic.CoatingsSubstrates Copper NickelChro-miumAuto-catalyticNickelZincCad-miumGoldPalla-diumRhod-iumSilver Tin LeadTin-LeadAlloysNon-metalsVitreousand Por-celainEnamelsMagnetic steel (i
45、ncludingcorrosion-resisting steel)CM CMACM CBMACM BCM BM BM BM BCM BCM BCM BCCCMBM MNonmagnetic stainless steels CEDCMACCBCBCBBBBCEDBC BC BCCCBE ECopper and alloys C only onbrass andCu-BeCMACCBBBBBBBCBCBCCCBE EZinc and alloys C MA. . .BBBBBBBBCBE .Aluminum and alloys BC BCMABC BCBEA,BBCBCBBBBCBCBCBC
46、CCEEMagnesium and alloys B BMABB BBBBBBBBBCE .Nickel C . C . C BC BBBBCBCBCBCCCBE .Silver B BMAB B B . B . . . . BC BCBE EGlass Sealing Nickel-cobalt-ironalloys UNS No. K94610MCAMCBMAMBMBMBMBMBMBMBCMBACCM BM .Nonmetals BCEDBCMABC BCBBCBCBBBBCBCBCBCCC. .Titanium B BMABCBBEA,BBBBBBBBBBCBE .AMethod is sensitive to permeability variations of the coating.BMethod is sensitive to variations in the phosphorus content of the coating.CMethod is sensitive to alloy composition.DMethod is sensitive to conductivity variations of the coating.B659 90 (2014)3
