1、Designation: B 607 91 (Reapproved 2008)Standard Specification forAutocatalytic Nickel Boron Coatings for Engineering Use1This standard is issued under the fixed designation B 607; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 Nickel boron coatings are pr
3、oduced by autocatalytic(electroless) deposition from aqueous solutions. These solu-tions contain either an alkylamineborane or sodium borohy-dride as a reducing agent, a source of nickel ions, a buffer,complexant, and control chemicals.1.2 This specificationdescribes the requirements for coat-ings o
4、f autocatalytic nickel boron deposited from aqueoussolutions onto substrates for engineering use. The specificationclassifies these coatings into two types:1.2.1 Type 1 coatings have a boron content of 0.1 to lessthan 3.5 mass percent with the balance nickel.1.2.2 Type 2 coatings have a boron conten
5、t of 3.5 to 6 masspercent and a minimum of 90 mass percent nickel.1.3 The coatings are hard and uniform in thickness, even onirregular shaped parts, and used in a wide range of applications.1.4 Process solutions formulated with an alkylamineboraneusually produce coatings that contain 0.1 to 3.5 % bo
6、ron. Thincoatings of this type provide bondability and solderability onelectronic components such as lead frames, electrical contacts,and headers. To maintain solderability, these coatings aregenerally not heat treated.1.5 Process solutions formulated with sodium borohydrideare strongly alkaline and
7、 are frequently used to plate steel andtitanium parts to impart surface hardness and wear resistanceproperties. Deposits produced from these processes can contain3 to 5 % boron and thallium or other metals which are used tostabilize the plating solution and modify the coating properties.1.6 The phys
8、ical and mechanical properties of these depos-its such as density, hardness, stress, and melting point will varywith the boron content. The variation of boron content alsoaffects the quantity and structure of nickel boride precipitatedduring heat treatment. In the as-plated condition the depositcons
9、ists of a predominantly amorphous mixture of nickel andboron with a hardness of about 700 HKN. When the deposit isheated above 300C the nickel crystallizes, forming nickelclusters of Ni (111) and boron precipitates as nickel boride,Ni3B (211) and (311), increasing the hardness to greater than1000 HK
10、100for Type 2 coatings.1.7 The nickel boron coatings are microporous and offerlimited corrosion protection. Their columnar structure, how-ever, is beneficial in reducing wear because it provides a meansof trapping lubricants within the surface of the coated part.1.8 This document describes only auto
11、catalytic nickel boroncoatings that have been produced without use of externalelectric sources.1.9 The following hazards caveat pertains only to the TestMethods section of this specification: This standard does notpurport to address the safety problems associated with its use.It is the responsibilit
12、y of the user of this standard to establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.NOTE 1The following AMS standards are not requirements. They arereferenced for information only: AMS 2399 and AMS 2433.2. Referenced Documents2.1 A
13、STM Standards:2B 374 Terminology Relating to ElectroplatingB 487 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination of CrossSectionB 567 Test Method for Measurement of Coating Thicknessby the Beta Backscatter MethodB 568 Test Method for Measurement of Coatin
14、g Thicknessby X-Ray SpectrometryB 571 Practice for Qualitative Adhesion Testing of MetallicCoatingsB 578 Test Method for Microhardness of ElectroplatedCoatingsB 602 Test Method for Attribute Sampling of Metallic andInorganic Coatings1This specification is under the jurisdiction of ASTM Committee B08
15、 onMetallic and Inorganic Coatings and is the direct responsibility of SubcommitteeB08.08.01 on Engineering Coatings.Current edition approved Aug. 1, 2008. Published October 2008. Originallyapproved in 1991. Last previous edition approved in 2003 as B 607 91 (2003).2For referenced ASTM standards, vi
16、sit 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-
17、2959, United States.B 656 Guide for Autocatalytic (Electroless) Nickel-Phosphorous Deposition on Metals for Engineering andUse3B 667 Practice for Construction and Use of a Probe forMeasuring Electrical Contact ResistanceB 678 Test Method for Solderability of Metallic-CoatedProductsB 697 Guide for Se
18、lection of Sampling Plans for Inspectionof Electrodeposited Metallic and Inorganic CoatingsB 762 Test Method of Variables Sampling of Metallic andInorganic CoatingsD 2670 Test Method for Measuring Wear Properties ofFluid Lubricants (Falex Pin and Vee Block Method)D 2714 Test Method for Calibration a
19、nd Operation of theFalex Block-on-Ring Friction and Wear Testing MachineE39 Methods for Chemical Analysis of NickelF 519 Test Method for Mechanical Hydrogen Embrittle-ment Evaluation of Plating/Coating Processes and ServiceEnvironments2.2 Aerospace Materials Specifications:AMS 2399 Electroless Nicke
20、l-Boron Plating4AMS 2433 Electroless Nickel-Thallium-Boron Plating42.3 U.S. Government Standards:MIL-STD-105 Sampling Procedures and Tables for Inspec-tion by Attributes5MIL-STD-13165 Shot Peening of Metal Parts53. Terminology3.1 Definitions: Many terms used in this specificationaredefined in Termin
21、ology B 374.3.2 Definitions of Terms Specific to This Standard:3.2.1 cold shuta void on the surface which has beenclosed by machining and then partially opened through clean-ing.3.2.2 hot halide stress-corrosion crackinga type of me-chanical failure produced by halogenated solvents that havebeen abs
22、orbed onto titanium and then in the presence of heatcause microcracking, and the loss of mechanical strength.3.2.3 lap cracksa surface imperfection caused by coldworking of steels producing a void which can be duplicated inthe deposit.3.2.4 significant surfacethose substrate surfaces whichthe coatin
23、g must protect and that are essential to the appear-ance.4. Classification4.1 The classification by type of these coatings establishesthe amount of boron in the alloy.4.1.1 Type 1Coatings shall contain 0.1 to less than 3.5mass percent boron with the balance nickel.4.1.2 Type 2Coatings shall contain
24、3.5 to 6 mass percentboron and a minimum of 90 mass percent nickel.4.2 The classification by class of these coatings establishesthe post treatment to be performed on the part(s). The posttreatment steps are designed to reduce the potential forhydrogen embrittlement, increase the adhesion of the coat
25、ingto the substrate, improve the fatigue properties of the part(s),and increase the wear resistance and hardness of the coating:4.2.1 Class 1Parts are supplied as plated with no post heattreatment.4.2.2 Class 2Parts are heat treated after plating to increasehardness. The coating is heat treated at 3
26、65 to 385C for 90min (see 7.2.4).4.2.3 Class 3Parts are heat treated after plating at 180 to200C for 2 to 23 h to improve coating adhesion on steel andfor hydrogen embrittlement relief of steels (see 7.2.4).4.2.4 Class 4Parts are heat treated after plating at 120 to130C for a minimum of1htoimprove a
27、dhesion onheat-treatable (age-hardened) aluminum alloys and carburizedsteels (see 7.2.4).4.2.5 Class 5Parts are heat treated after plating at 365 to375C for a minimum of4htoimprove adhesion on titaniumand titanium alloys (see 7.2.4).4.3 The classification by grade establishes the minimumthickness of
28、 the coating:4.3.1 Grade AParts are plated to a minimum coatingthickness of 0.5 m.4.3.2 Grade BParts are plated to a minimum coatingthickness of 12 m.4.3.3 Grade CParts are plated to a minimum coatingthickness of 25 m.4.3.4 Grade DParts are plated to a minimum coatingthickness of 75 m.5. Ordering In
29、formation5.1 The purchaser should be aware of several processingconsiderations or options available to the processor and whenordering should supply the information described in 5.1.1through 5.1.15 in the purchase order and drawings.5.1.1 Title, ASTM designation, and year of issue of thisspecificatio
30、n.5.1.2 Composition and metallurgical condition of the basismetal, assemblies of dissimilar materials must be identified.5.1.3 Classification of the coating: type, class, and grade forthis specification (see Section 4).5.1.4 Minimum thickness required on the significant sur-face, and any maximum dim
31、ensions or tolerance requirements,if any (see 7.2.2).5.1.5 Method of adhesion testing from Test Method B 571to be used in acceptance requirements (see 8.3).5.1.6 Requirements for certification and test reports (seeSection 11).5.1.7 Requirements for heat treatment of the part(s) forstress relief prio
32、r to plating (see 7.2.4).5.1.8 Optional sampling plan for lot inspection of the part(s)(see 9.1 and 13.1).5.1.9 Increased sampling frequency, if any, for qualificationtests (see 7.3).5.1.10 Supplemental requirements for shot peening of thepart(s) (see 12.1).3Withdrawn. The last approved version of t
33、his historical standard is referencedon www.astm.org.4Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.5Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: N
34、PODS.B 607 91 (2008)25.1.11 Supplemental requirements for wear testing (see 12.2and 12.3).5.1.12 Supplemental requirements for heat treatment invacuum or inert or reducing atmosphere (see 7.2.1 see 9.2) is examined for compliance with the requirements placed on theparts, a relatively small number of
35、 partsthe sampleis selected atrandom and inspected. The inspection lot is then classified as complyingor not complying with the requirements based on the results of theinspection sample. The size of the sample and the criteria of complianceare determined by the application of statistics. The procedu
36、re is known assampling inspection. Test Method B 602, Guide B 697, and Method B 762contain sampling plans that are designed for the sampling inspection ofcoatings.Test Method B 602 contains four sampling plans, three for use with teststhat are nondestructive and one for use with tests that are destr
37、uctive. Thepurchaser and producer may agree on the plan(s) to be used. If they do not,Test Method B 602 identifies the plan to be used.Guide B 697 provides a large number of plans and also gives guidanceon the selection of a plan. When Guide B 697 is specified, the purchaserand producer need to agre
38、e on the plan to be used.Method B 762 can be used only for coating requirements that have anumerical limit, such as coating thickness. The test must yield a numericalvalue and certain statistical requirements must be met. Method B 762contains several plans and also gives instructions for calculating
39、 plans tomeet special needs. The purchaser and producer may agree on the plan(s)to be used. If they do not, Method B 762 identifies the plan to be used.9.2 An inspection lot shall be defined as a collection ofcoated parts that are of the same kind, that have been producedto the same specification, t
40、hat have been coated by a singleproducer at one time or approximately the same time underessentially identical conditions, and that are submitted foracceptance or rejection as a group.9.3 If separate test specimens are used to represent thepart(s) in the test, the number shall be that required in 8.
41、1.TABLE 2 Heat Hardening of Nickel Boron DepositsTemperature, C Time, min375 6 10 90TABLE 3 Post Heat Treatment for Class 4 and 5 CoatingsClass Temperature, C Time, minimum, hClass 4 125 6 51Class 5 370 6 54B 607 91 (2008)410. Rejection and Rehearing10.1 Part(s) that fail to conform to the requireme
42、nts of thisspecificationmay be rejected. Rejection shall be reported to theproducer promptly in writing. In the case of dissatisfactionwith the results of a test, the producer may make a claim for arehearing. Coatings that show imperfections may be rejected.11. Certification11.1 When specified in th
43、e purchase order or contract, thepurchaser shall be furnished certification that the samplesrepresenting each lot have been processed, tested, and in-spected as directed in this specification and the requirementshave been met. When specified in the purchase order orcontract, a report of the test res
44、ults shall be furnished.12. Supplementary Requirements12.1 Shot PeeningWhen specified by the purchaser in theordering information, the part(s) shall be shot peened prior toplating in accordance with MIL-STD-13165.12.2 Abrasive WearWhen specified by the purchaser inthe ordering information, the coati
45、ng shall be tested forabrasion wear resistance using the procedure described inAppendix X2 of this specification. The coating shall meet amaximum wear rate which is specified by the purchaser andagreed to by the producer.12.3 Adhesive WearWhen specified by the purchaser inthe ordering information, t
46、he coating shall be tested foradhesive wear resistance using Test Method D 2714 or D 2670.The wear rate shall be specified by the purchaser and agreed toby the producer.12.4 Inert AtmosphereWhen specified by the purchaser inthe ordering information, the coating shall be heat treated in avacuum or an
47、 inert or reducing atmosphere to prevent surfaceoxidation of the coating.12.5 Contact ResistanceWhen specified by the purchaserin the ordering information, the coating shall be tested forcontact resistance using Practice B 667.12.6 SolderabilityWhen specified by the purchaser in theordering informat
48、ion, the unaged coating shall pass TestMethod B 678.13. Special Government Regulations13.1 SamplingThe producer when plating part(s) for theU.S. government and military use shall use a sampling planfrom MIL-STD-105.13.2 Shot PeeningHigh strength steel part(s) processedfor U.S. government and militar
49、y use shall be shot peened inaccordance with MIL-STD-13165.APPENDIXES(Nonmandatory Information)X1. DENSITY OF NICKEL BORON COATINGSX1.1 Many thickness test methods measure the mass perunit area and display the thickness in linear units. These testmethods require a density factor to calculate the thickness. Fig.X1.1 can be used to determine the density of nickel coatingswith varying boron contents.FIG. X1.1 Density of Nickel Coatings with Varying Boron ContentB 607 91 (2008)5X2. TABER ABRASER WEAR TEST METHODX2.1 ScopeX2.1.1 This test method
