ASTM B867-1995(2018) Standard Specification for Electrodeposited Coatings of Palladium-Nickel for Engineering Use.pdf

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1、Designation: B867 95 (Reapproved 2018)Standard Specification forElectrodeposited Coatings of Palladium-Nickel forEngineering Use1This standard is issued under the fixed designation B867; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi

2、on, the year of last 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 CompositionThis specification covers requirementsfor electrodeposited palladium-nickel coatings contai

3、ning be-tween 70 and 95 mass % of palladium metal. Compositecoatings consisting of palladium-nickel and a thin gold over-plate for applications involving electrical contacts are alsocovered.1.2 PropertiesPalladium is the lightest and least noble ofthe platinum group metals. Palladium-nickel is a sol

4、id solutionalloy of palladium and nickel. Electroplated palladium-nickelalloys have a density between 10 and 11.5, which is substan-tially less than electroplated gold (17.0 to 19.3) and compa-rable to electroplated pure palladium (10.5 to 11.8). This yieldsa greater volume or thickness of coating p

5、er unit mass and,consequently, some saving of metal weight. The hardnessrange of electrodeposited palladium-nickel compares favorablywith electroplated noble metals and their alloys (1, 2).2NOTE 1Electroplated deposits generally have a lower density thantheir wrought metal counterparts.Approximate H

6、ardness (HK25)Gold 50250Palladium 75600Platinum 150550Palladium-Nickel 300650Rhodium 7501100Ruthenium 60013001.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety con

7、cerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with

8、 internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:

9、3B183 Practice for Preparation of Low-Carbon Steel forElectroplatingB242 Guide for Preparation of High-Carbon Steel for Elec-troplatingB254 Practice for Preparation of and Electroplating onStainless SteelB281 Practice for Preparation of Copper and Copper-BaseAlloys for Electroplating and Conversion

10、CoatingsB322 Guide for Cleaning Metals Prior to ElectroplatingB343 Practice for Preparation of Nickel for Electroplatingwith NickelB374 Terminology Relating to ElectroplatingB481 Practice for Preparation of Titanium and TitaniumAlloys for ElectroplatingB482 Practice for Preparation of Tungsten and T

11、ungstenAlloys for ElectroplatingB487 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination ofCross SectionB488 Specification for Electrodeposited Coatings of Goldfor Engineering UsesB489 Practice for Bend Test for Ductility of Electrodepos-ited and Autocatalyti

12、cally Deposited Metal Coatings onMetalsB507 Practice for Design of Articles to Be Electroplated onRacksB542 Terminology Relating to Electrical Contacts and TheirUse1This specification is under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and is under the direct responsibi

13、lity of Subcom-mittee B08.03 on Engineering Coatings.Current edition approved June 1, 2018. Published June 2018. Originallyapproved in 1995. Last previous edition approved in 2013 as B867 95 (2013).DOI: 10.1520/B0867-95R18.2The boldface numbers in parentheses refer to the list of references at the e

14、nd ofthis specification.3For referenced 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.Copyright ASTM International, 100 Bar

15、r Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recomm

16、endations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1B558 Practice for Preparation of Nickel Alloys for Electro-platingB568 Test Method for Measurement of Coating Thicknessby X-Ray SpectrometryB571 Practice for Qualitative Adhesion Testing of MetallicCoatings

17、B602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB697 Guide for Selection of Sampling Plans for Inspectionof Electrodeposited Metallic and Inorganic CoatingsB741 Test Method for Porosity In Gold Coatings On MetalSubstrates By Paper Electrography (Withdrawn 2005)4B748 Test Met

18、hod for Measurement of Thickness of Metal-lic Coatings by Measurement of Cross Section with aScanning Electron MicroscopeB762 Test Method of Variables Sampling of Metallic andInorganic CoatingsB765 Guide for Selection of Porosity and Gross Defect Testsfor Electrodeposits and Related Metallic Coating

19、sB798 Test Method for Porosity in Gold or Palladium Coat-ings on Metal Substrates by Gel-Bulk ElectrographyB799 Test Method for Porosity in Gold and PalladiumCoatings by Sulfurous Acid/Sulfur-Dioxide VaporB809 Test Method for Porosity in Metallic Coatings byHumid Sulfur Vapor (“Flowers-of-Sulfur”)B8

20、27 Practice for Conducting Mixed Flowing Gas (MFG)Environmental TestsB845 Guide for Mixed Flowing Gas (MFG) Tests for Elec-trical ContactsB849 Specification for Pre-Treatments of Iron or Steel forReducing Risk of Hydrogen EmbrittlementB850 Guide for Post-Coating Treatments of Steel for Reduc-ing the

21、 Risk of Hydrogen EmbrittlementD1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterD3951 Practice for Commercial Packaging3. Terminology3.1 Definitions: Many terms used in this specification aredefined in Terminology B374 or B542.3.2 Definitions of Terms Specific to This Standard

22、:3.2.1 overplating, na coating applied onto the topmostpalladium-nickel coating. The thickness of an overplating or“flash” is usually less than 0.25 m.3.2.2 significant surfaces, nthose surfaces normally vis-ible (directly or by reflection) or which are essential to theserviceability or function of

23、the article; or which can be thesource of corrosion products or tarnish films that interfere withthe function or desirable appearance of the article. The signifi-cant surfaces shall be indicated on the drawings of the parts, orby the provision of suitably marked samples.3.2.3 underplating, na metall

24、ic coating layer or layersbetween the basis metal or substrate and the palladium-nickelcoating. The thickness of an underplating is usually greaterthan 1 m, in contrast to a strike which is thinner.4. Classification4.1 Orders for articles to be plated in accordance with thisspecification shall speci

25、fy the coating system, indicating thebasis metal, the thicknesses of the underplatings, the type andthickness class of the palladium-nickel coating, and the gradeof the gold overplating according to Table 1, Table 2, and Table3. See Section 7.5. Ordering Information5.1 In order to make the applicati

26、on of this specificationcomplete, the purchaser shall supply the following informationto the seller in the purchase order or other governing document:5.1.1 The name, designation, and date of issue of thisspecification;5.1.2 The coating system including basis metal, composi-tion type, thickness class

27、 and gold overplate grade (see 4.1 andTable 1, Table 2, and Table 3);5.1.3 Presence, composition, and thickness of underplating(see 3.2.1). For nickel underplating see 6.5.1;5.1.4 Significant surfaces shall be defined (see 3.2.3);5.1.5 Requirements, if any, for porosity testing (see 9.6);5.1.6 (Stee

28、l parts only) Stress relief if required (see Speci-fication B849);5.1.7 (Steel parts only) Hydrogen embrittlement relief (seeB850 );5.1.8 Sampling plan employed (see Section 8); and,5.1.9 Requirement, if any, for surface coating cleanliness(absence of residual salts). See Appendix X6.6. Manufacture6

29、.1 Any process that provides an electrodeposit capable ofmeeting the specified requirements will be acceptable.6.2 Substrate:6.2.1 The surface condition of the basis metal should bespecified and should meet this specification prior to the platingof the parts.6.2.2 Defects in the surface of the basis

30、 metal, such asscratches, porosity, pits, inclusions, roll and die marks, laps,cracks, burrs, cold shuts, and roughness may adversely affectthe appearance and performance of the deposit, despite theobservance of the best plating practice. Any such defects onsignificant surfaces should be brought to

31、the attention of thesupplier and the purchaser.6.2.3 Clean the basis metal as necessary to ensure a satis-factory surface for subsequent electroplating in accordancewith Practices B183, B242, B254, B281, B322, B343, B481,B482, and B558.6.2.4 Proper preparatory procedures and thorough cleaningof the

32、basis metal are essential for satisfactory adhesion andperformance of these coatings. The surface must be chemically4The last approved version of this historical standard is referenced onwww.astm.org.TABLE 1 Composition TypeType Nominal Composition (Mass %) Range (Mass% Pd)I 75 % Pd/25 % Ni 7080 % P

33、dII 80 % Pd/20 % Ni 7585 % PdIII 85 % Pd/15 % Ni 8090 % PdIV 90 % Pd/10 % Ni 8595 % PdB867 95 (2018)2clean and continuously conductive, that is, without inclusionsor other contaminants.The coatings must be smooth and as freeof scratches, gouges, nicks, and similar imperfections aspossible.NOTE 2A me

34、tal finisher can often remove defects through specialtreatments such as grinding, polishing, abrasive blasting, chemicaltreatments, and electropolishing. However, these may not be normal in thetreatment steps preceding the plating, and a special agreement is indicated.6.3 If required (see 5.1.6), st

35、eel parts with a hardness greaterthan 1000 MPa (31 HRC) shall be given a suitable stress reliefheat treatment prior to plating in accordance with SpecificationB849. Such stress relief shall not reduce the hardness to a valuebelow the specified minimum. Avoid acid pickling of highstrength steels.6.3.

36、1 Apply the coating after all basis metal preparatory heattreatments and mechanical operations on significant surfaceshave been completed.6.4 Racking:6.4.1 Position parts to allow free circulation of solution overall surfaces. The location of rack or wire marks in the coatingshould be agreed upon be

37、tween the producer and supplier.6.5 Plating Process:6.5.1 Nickel UnderplatingApply a nickel underplatingbefore the palladium-nickel when the product is made fromcopper or copper alloy. Nickel underplatings are also appliedfor other reasons. See Appendix X5.NOTE 3In certain instances where high frequ

38、ency analog signals areemployed, such as wave guides, the magnetic properties of nickel mayattenuate the signal. Palladium-nickel itself is non-ferromagnetic when thenickel content is less than 14 mass %.NOTE 4In applications where forming or flaring operations are to beapplied to the plated compone

39、nt, a ductile nickel electrodeposit should bespecified.6.5.2 StrikesGood practice suggests the use of a palla-dium strike to follow any underplate or substrate (other thansilver or platinum) immediately prior to applying thepalladium-nickel.6.5.3 PlatingGood practice calls for the work to beelectric

40、ally connected when entering the palladium-nickelsolution.NOTE 5Some palladium-nickel electroplating solutions attack copper.This can result in codeposition of copper impurity. The situation is furtheraggravated when low current densities are utilized. Copper can beremoved from solutions by low curr

41、ent density electrolysis (0.1 to 0.3mA/cm2).6.5.4 Gold OverplatingApply a thin gold overplating afterthe palladium-nickel in any application in which palladium-nickel plated electrical connectors are mated together in acontact pair. This process is necessary to preserve the perfor-mance of the conta

42、ct surface. See Appendix X1 for otherreasons for using a gold overplate.NOTE 6When using Type 1 gold, the thickness of the gold overplateshall not exceed 0.12 m (5 in.) due to increased risk of degradingdurability and increasing the coefficient of friction.6.5.5 Residual SaltsFor rack and barrel pla

43、tingapplications, residual plating salts can be removed from thearticles by a clean, hot (50 to 100C) water rinse. A minimumrinse time of 2.5 min (racks) or 5 min (barrel) is suggested.Best practice calls for a minimum of three dragout rinses andone running rinse with dwell times of 40 s in each sta

44、tion whenrack plating and 80 s when barrel plating. Modern high-velocity impingement type rinses can reduce this time to a fewseconds. This is particularly useful in automatic reel-to-reelapplications where dwell times are significantly reduced. SeeAppendix X6.7. Coating Requirements7.1 Nature of Co

45、atingThe palladium-nickel deposit shallhave a minimum purity of 70 mass % palladium.7.2 CompositionThe composition of the palladium-nickelelectrodeposit shall be within 65 mass % of the specified type.7.3 AppearancePalladium-nickel coatings shall becoherent, continuous, and have a uniform appearance

46、 to theextent that the nature of the basis metal and good commercialpractices permit.7.4 ThicknessEverywhere on the significant surface (see5.1), the thickness of the palladium-nickel coating shall beequal to or exceed the specified thickness. The maximumthickness, however, shall not exceed the draw

47、ing tolerance.NOTE 7The coating thickness requirement of this specification is aminimum requirement, that is, the coating thickness is required to equal orexceed the specified thickness everywhere on the significant surfaceswhile conforming to all maximum thickness tolerances given in theengineering

48、 drawing.Variation in the coating thickness from point to pointon a coated article is an inherent characteristic of electroplating processes.The coating thickness at any single point on the significant surface,therefore, will sometimes have to exceed the specified value in order toensure that the th

49、ickness equals or exceeds the specified value at all points.Hence, most average coating thicknesses will be greater than the specifiedvalue. How much greater is largely determined by the shape of the article(see Practice B507) and the characteristics of the plating process. Inaddition, the average coating thickness on products will vary from articleto article within a production lot. If all of the articles in a production lotare to meet the thickness requirement, the average coating thickness forthe production lot as a whole will be greater than t