1、Designation: B 604 91 (Reapproved 2003)e1Standard Specification forDecorative Electroplated Coatings of Copper Plus NickelPlus Chromium on Plastics1This standard is issued under the fixed designation B 604; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year of 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.e1NOTESections X4.2.2 and X4.3.3 were editorially updated in May 2003.1. Scope1.1 This specif
3、ication covers the requirements for severalgrades and types of electrodeposited copper plus nickel pluschromium coatings on plateable plastic substrates where ap-pearance, durability and resistance to thermal cycling areimportant to service performance. Five grades of coatings areprovided to correla
4、te with the service conditions under whicheach is expected to provide satisfactory performance.1.2 This specification covers the requirements for coatingsapplied subsequent to the application of metal film by auto-catalytic deposition or subsequent to the application of anystrike coatings after auto
5、catalytic deposition.1.3 The following caveat pertains only to the test methodportions of Section 6, Annex A1, and Appendix X2, AppendixX3, and Appendix X4 of this specification. This standard doesnot purport to address all of the safety concerns, if any,associated with its use. It is the responsibi
6、lity of the user of thisstandard to establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:B 368 Method for Copper-Accelerated Acetic Acid-SaltSpray (Fog) Testing (CASS Test)2B 487 Test Method f
7、or Measurement of Metal and OxideCoating Thicknesses by Microscopical Examination of aCross Section2B 489 Practice for Bend Test for Ductility of Electrodepos-ited and Autocatalytically Deposited Metal Coatings onMetals2B 504 Test Method for Measurement of Thickness of Me-tallic Coatings by the Coul
8、ometric Method2B 530 Test Method for Measurement of Coating Thick-nesses by the Magnetic Method: Electrodeposited NickelCoatings on Magnetic and Nonmagnetic Substrates2B 532 Specification for Appearance of Electroplated PlasticSurfaces2B 533 Test Method for Peel Strength of Metal ElectroplatedPlasti
9、cs2B 556 Guide for Measurement of Thin Chromium Coatingsby the Spot Test2B 567 Test Method for Measurement of Coating Thicknessby the Beta Backscatter Method2B 568 Test Method for Measurement of Coating Thicknessby X-Ray Spectrometry2B 602 Test Method for Attribute Sampling of Metallic andInorganic
10、Coatings2B 659 Guide for Measuring Thickness of Metallic andInorganic Coatings2B 727 Practice for Preparation of Plastics Materials forElectroplating2B 764 Test Method for Simultaneous Thickness and Elec-trochemical Potential Determination of Individual Layersin Multilayer Nickel Deposit (STEP Test)
11、2D 1193 Specification for Reagent Water3E 50 Practices for Apparatus, Reagents, and Safety Precau-tions for Chemical Analysis of Metals, Ores, and RelatedMaterials43. Terminology3.1 Definitions:3.1.1 significant surfacesthose surfaces normally visible(directly or by reflection) that are essential to
12、 the appearance orserviceability of the article when assembled in normal positionor that can be the source of corrosion products that defacevisible surfaces on the assembled article.4. Classification4.1 Five grades of coatings designated by service conditionnumbers and several types of coatings defi
13、ned by classificationnumbers are covered by this specification.1This specification is under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and is the direct responsibility of SubcommitteeB08.08.03 on Decorative Coatings.Current edition approved Feb. 10, 2003. Published May
14、2003. Originallyapproved in 1975. Last previous edition approved in 1997 as B 604 91 (1997).2Annual Book of ASTM Standards, Vol 02.05.3Annual Book of ASTM Standards, Vol 11.01.4Annual Book of ASTM Standards, Vol 03.05.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
15、en, PA 19428-2959, United States.4.2 Service Condition Number:4.2.1 The service condition number indicates the severity ofexposure for which the grade of coating is intended, inaccordance with the following scale:SC5extended very severeSC4very severeSC3severeSC2moderateSC1mild4.2.2 Service condition
16、 numbers are further defined inAppendix X1 where they are related to the severity of exposureencountered by electroplated articles.4.3 Coating Classification Number The coating classifi-cation number is a means of specifying the types and thick-nesses of coatings appropriate for each grade and is co
17、mprisedof the following:4.3.1 The symbol for the substrate (PL) indicating it isplateable plastic, followed by a slash mark,4.3.2 The chemical symbol for copper (Cu),4.3.3 A number giving the minimum thickness of the coppercoating in micrometres,4.3.4 A lower-case letter designating the type of copp
18、erelectrodeposit (see 4.4 and 6.3.1),4.3.5 The chemical symbol for nickel (Ni),4.3.6 A number giving the minimum thickness of the nickelin micrometres,4.3.7 A lower-case letter designating the type of nickelelectrodeposit (see 4.4 and 6.3.2),4.3.8 The chemical symbol for chromium (Cr), and4.3.9 A lo
19、wer-case letter or letters designating the type ofchromium (see 4.4 and 6.3.3).4.4 Symbols for Expressing ClassificationThe followinglower-case letters shall be used in coating classification num-bers to describe the types of coatings:a ductile copper deposited from acid-type bathsb single-layer nic
20、kel deposited in the fully-bright conditiond double- or triple-layer nickel coatingsr regular (that is, conventional) chromiummc microcracked chromiummp microporous chromium4.5 Example of Complete Classification NumberA coat-ing on plastic comprising 15 m minimum ductile acid copperplus 15 m minimum
21、 double-layer nickel plus 0.25 mminimum microporous chromium has the classification num-ber: PL/Cu15a Ni15d Cr mp.5. Ordering Information5.1 When ordering articles to be electroplated in accordancewith this standard, the purchaser shall state the following:5.1.1 ASTM designation number.5.1.2 Either
22、the classification number of the specific coat-ing required (see 4.3) or the substrate material and the servicecondition number denoting the severity of the conditions it isrequired to withstand (see 4.2). If the service condition numberis quoted and not the classification number, the manufacturer i
23、sfree to supply any of the types of coatings designated by theclassification number corresponding to the service conditionnumber, as given in Table 1.5On request, the manufacturershall inform the purchaser of the classification number of thecoating applied.5.1.3 The appearance required, for example,
24、 bright, dull, orsatin. Alternatively, samples showing the required finish orrange of finish shall be supplied or approved by the purchaser.5.1.4 The significant surfaces, to be indicated on drawingsof the parts, or by the provision of suitably marked specimens(see 3.1).5.1.5 The positions on signif
25、icant surfaces for rack orcontact marks, where such marks are unavoidable (see 6.1.1).5.1.6 The extent to which defects shall be tolerated onnonsignificant surfaces.5.1.7 The ductility if other than the standard value (see 6.4).5.1.8 The extent of tolerable surface deterioration aftercorrosion testi
26、ng (see 6.6.3).5.1.9 Sampling methods and acceptance levels (See Section7).5.1.10 Whether thermal cycle and corrosion testing shall beconducted individually on separate specimens as described in6.6 and 6.7, or sequentially using the same specimens asdescribed in 6.8, and whether the specimens shall
27、be un-mounted or mounted in a manner simulating assembly whenthese tests are conducted.5.2 The minimum values of the electrochemical potentialdifferences between individual nickel layers as measured inaccordance with Test Method B 764 within the limits given in6.10.6. Product Requirements6.1 Visual
28、Defects:6.1.1 The significant surfaces of the electroplated articlesshall be free of visible defects, such as blisters, pits, roughness,cracks, and uncoated areas, and shall not be stained ordiscolored. On articles where a visible contact mark is un-avoidable, its position shall be specified by the
29、purchaser. Theelectroplated article shall be free of damage and clean.5“Performance of Decorative Electrodeposited Copper-Nickel-Chromium Coat-ings on Plastics” is a final report on programs conducted by ASTM and ASEP toevaluate the coating classification numbers. A copy of the report has been filed
30、 atASTM Headquarters as RR B-8-1003.TABLE 1 Copper Plus Nickel Plus Chromium Coatings onPlasticAServiceConditionNumberClassification NumberEquivalent Nickel Thicknessm mils (approx.)SC 5 PL/Cu15a Ni30d Cr mcPL/Cu15a Ni30d Cr mp30301.21.2SC 4 PL/Cu15a Ni30d Cr rPL/Cu15a Ni25d Cr mcPL/Cu15a Ni25d Cr m
31、p3025251.21.01.0SC 3 PL/Cu15a Ni25d Cr rPL/Cu15a Ni20d Cr mcPL/Cu15a Ni20d Cr mp2520201.00.80.8SC 2 PL/Cu15a Ni15b Cr rPL/Cu15a Ni10b Cr mcPL/Cu15a Ni10b Cr mp1510100.60.40.4SC 1 PL/Cu15a Ni7b Cr r 7 0.3AThe minimum copper thickness may be greater in some applications to meetthermal cycling and othe
32、r requirements.B 604 91 (2003)e126.1.2 Defects in the surface of the molded plastic, such ascold shots, ejection marks, flash, gate marks, parting lines,splay and others, may adversely affect the appearance andperformance of coatings applied thereto despite the observanceof the best electroplating p
33、ractice. Accordingly, the electroplat-ers responsibility for defects in the coating resulting from theplastic-molding operation shall be waived (Note 1).NOTE 1To minimize problems of this type, the specifications cover-ing the items to be electroplated should contain appropriate limitations onthe ex
34、tent of surface defects. Practice B 532 distinguishes between defectsthat arise primarily in molding and those that arise in electroplatingoperations.6.2 PretreatmentsProper preparatory procedures are es-sential for satisfactory performance of electrodeposited coat-ings on plastics. Procedures descr
35、ibed in Practice B 727 maybe followed. In the case of patented processes, the instructionsprovided by the suppliers of those processes shall be followed.6.3 Process and Coating RequirementsFollowing prepa-ratory operations, plastic articles are placed in electroplatingsolutions as required to produc
36、e the composite coating de-scribed by the specific coating classification number or bycoating one of the specified classification numbers listed inTable 1 appropriate for the specified service condition number.6.3.1 Type of CopperDuctile copper shall be depositedfrom acid-type baths containing organ
37、ic additives that promoteleveling by the copper deposit.6.3.2 Type of NickelFor double- or triple-layer nickelcoatings, the bottom layer shall contain less than 0.005 mass %sulfur (Note 2). The top layer shall contain greater than 0.04mass % sulfur (Note 3), and its thickness shall be not less than1
38、0 % of the total nickel thickness. In double-layer coatings, thethickness of the bottom layer shall be not less than 60 % of thetotal nickel thickness. In triple-layer coatings, the bottom layershall be not less than 50 % nor more than 70 %. If there arethree layers, the intermediate layer shall con
39、tain not less than0.15 mass % sulfur and shall not exceed 10 % of the totalnickel thickness. These requirements for multilayer nickelcoatings are summarized in Table 2.6.3.3 Thickness of Chromium DepositThe minimum per-missible thickness of the chromium deposit shall be 0.25 m onsignificant surfaces
40、. The thickness of chromium is designatedby the same symbol as the type instead of by numerals as in thecase of copper and nickel (see 4.4).NOTE 2The sulfur content is specified in order to indicate which typeof nickel electroplating solution must be used. Although no simple methodis yet available f
41、or determining the sulfur content of a nickel deposit on acoated article, chemical determinations are possible using speciallyprepared test specimens. See Appendix X2 for the determination of sulfurin electrodeposited nickel.NOTE 3It will usually be possible to identify the type of nickel bymicrosco
42、pical examination of the polished and etched section of an articleprepared in accordance with Test Method B 487. The thickness of theindividual nickel layers in double-layer and triple-layer coatings, as wellas the electrochemical relationships between the individual layers can bemeasured by the STE
43、P test in accordance with Test Method B 764.6.4 DuctilityThe minimum value of the ductility shall be8 % for copper and for nickel when tested by the method givenin Appendix X3. Greater ductility may be requested but shallbe subject to agreement between the purchaser and the manu-facturer.6.5 Coating
44、 Thickness:6.5.1 The minimum coating thickness shall be as designatedby the coating classification number.6.5.2 It is recognized that requirements may exist for thickercoatings than are covered by this specification.6.5.3 The thickness of a coating and its various layers shallbe measured at points o
45、n the significant surfaces (see 4.2 andNote 4.)NOTE 4When significant surfaces are involved on which the specifiedthickness of deposit cannot readily be controlled, such as threads, holes,deep recesses, bases of angles, and similar areas, the purchaser and themanufacturer should recognize the necess
46、ity for either thicker deposits onthe more accessible surfaces or for special racking. Special racks mayinvolve the use of conforming, auxiliary, or bipolar electrodes, ornonconducting shields.6.5.3.1 The coulometric method described in Test MethodB 504 may be used to measure thickness of the chromi
47、um, thetotal thickness of the nickel, and the thickness of the copper.The STEP test, Test Method B 764, which is similar to thecoulometric method, may be used to determine the thicknessesof individual layers of nickel in a multilayer coating.6.5.3.2 The microscopical method described in Test MethodB
48、 487 may be used to measure the thickness of each nickellayer and of the copper layer.6.5.3.3 The beta backscatter method described in TestMethod B 567 may be used when the total thickness of acopper/nickel/chromium composite coating is to be measured,without any indication of the thickness of each
49、individual layer.6.5.3.4 Other methods may be used if it can be demon-strated that the uncertainty of the measurement is less than10 %, or less than that of any applicable method mentioned in6.4.3. Other methods are outlined in Test Methods B 530 andB 568 and Guides B 556 and B 659.6.6 Corrosion Testing:6.6.1 Coated articles shall be subjected to the corrosion testfor a period of time that is appropriate for the particular servicecondition number (or for the service condition number corre-sponding to a specified classification number) as shown inTa
