DECORATIVE CHROMIUM PLATING - COPPER, NICKEL,
GM DS0008348MaterialsI737-and Processes- MetalsIDECORATIVE CHROMIUM PLATING - COPPER, NICKEL, CHROMIUM TYPEGM4372MGM4373M1 SCOPE.These specifications cover basic requirementsfor electroplated parts of the copper-nickel-chromium type asused on steel, zinc die cast, copper based alloys, and plasticcomponents, and wrought, die-cast or forged aluminum andaluminum alloys, excluding wheels.1.1 GM4372M and GM4374M are intended for exterior partsand provide 2 levels of corrosion protection. GM4374M provides corrosion protection for severe service conditions thatinclude likely damage from denting, scratching and abrasivewear in addition to corrosive environments such as encountered by automotive bumpers and related components. Thisspecification differs from GM4372M in that it requires alonger corrosion (CASS) exposure. GM4372M provides corrosion protection for corrosive environments which receive littleadditional mechanical abuse. Both specifications require theuse of discontinuous chromium plate in addition to a multiplelayer nickel system.GM4374Mis used between the semibright and bright nickel layers, thenthe semibright thickness shall be a minimum of 40%.3.1.3 Minimum thickness and corrosion resistance performance requirements for textured finishes (matte, vapor blast,brush, etc.) apply after texturing.3.1.4 Exceptions to the minimum plating thickness are generally shown as a detail on the part drawing by eitherdesignating plating checkpoint(s) or by indicating in an appropriate view the area(s) with deviated thickness(es) allowed.These exceptions must still meet the specified number of corrosion test hours.POTENTIALELECTROCHEMICAL3.2 NICKEL(GM4372M AND GM4374M ONLY). Determine potentialdifference following ASTM B764.1.2 GM4373M is intended for interior applications. It doesnot require the use of discontinuous chromium or multiplelayer nickel systems.3.2.1 The bright nickel layer shall exhibit an anodic electrochemical potential difference of 100 mV minimum to semibright nickel on all significant surfaces. Conformance to thisrequirement shall be determined with 99% confidence (3sigma) using appropriate statistical charting techniques on aroutine quality control basis.1.3 When specifying chromium plating on aluminum, a coating must be applied to all of the non-significant surfaces whichdo not receive a full complement of plate and are exposed tosevere corrosive environments. Aluminized wax or other corrosion protective coatings are recommended,3.2.2 The maximum electrochemical potential differencebetween the microparticulate nickel layer and the bright nickelon all significant surfaces of all substrates is 20 mV.2REFERENCED STANDARDS.GM4260PGM9071PASTM B36833.3 DISCONTINUOUS CHROMIUM.Shall be performedby either the copper deposition (Dubpemell) method or by thedetermination of active corrosion sites after corrosion testing.Both are described in the appendix of ASTM B456. In the caseof an active sites determination, compare the viewed sample at100X to the pore density charts shown in Appendix A of thisspecification to determine pore count.ASTM B456ASTM B487ASTM B571ASTM B7643.3.1 The microdiscontinuous chromium surface shall exhibita minimum of 10 000 pores/cm2 as determined by copper deposition or 2000 pores/cm2 as determined by active sites.REQUIREMENTS.3.1 PLATING THICKNESS. Shall be determined by themicroscopic method (ASTM B487) or the electrochemicalmethod of GM4260P In case of disagreements between purchaser and supplier, the microscopic method shall be thepreferred method.3.1.1 Minimum plate thickness as specified in Table 1 isintended to apply to all low current density and high currentdensity areas of significant surfaces as specified on appropriatepart drawings or as otherwise agreed upon between purchaserand supplier. Such surfaces are those normally visible directly or by reflection - on the fished part when assembledin car position, or which can be the source of corrosion deposits that deface visible surfaces on the assembled vehicles.3.1.2 The multiple layer nickel thickness consisting of at least2 layers of electro-deposited nickel shall be a minimum of60% semibright nickel, except when high activity nickel strike0 CopptghtJUNE 1992JUNE 1992 Gmerd3.4 CORROSION RESISTANCE. Shall be determined bythe CASS test, ASTM B368, according to the number of hoursspecified in Table 1.3.4.1 Plated components shall be free of corrosion on all significant surfaces when examined at normal reading distancewith the unaided eye and uniform diffused light.3.5 ADHESION. Plated metallic components shall be subjected to the Saw-Grind Test, ASTM B571, with no evidenceof lifting or peeling either between plated layers or the plateand the substrate.3.5.1 Plated plastic parts shall be subject to the thermalcycling test described below. At the conclusion of the testsequence the plated part shall show no deformation, crazing,blistering, splitting, or loss of adhesion to the substrate or lossof adhesion between individual layers of the plated metal.Motors CorporationPAGE 1All Rights Reserved4372M
G[IGENERALMOTORSGfl4372flENGINEERING92 -STANDARDS900b379I0008349Materials875and Processesm- MetalsIDECORATIVE CHROMIUM PLATING - COPPER, NICKEL, CHROMIUM TYPEGM4372M GM4373M GM4374M3.5.2 The thermal cycling test shall be performed as follows:(4 When corrosion test is specified, expose part for 22 h(b)(clCd)(4(0k)04minimum CASS prior to Step (b). When corrosiontest is not required, completely immerse part in watermaintained at 38 f 1.5”C for 22 h prior to Step (b).Mount part in a restrained position simulating in service usage. One hour maximum is allowed betweenend of Step (a) and start of Step (c).Expose part for 1 h min at -30 f 1.5”C.Expose part for 15 minutes minimum at 25 5 C.Expose part for 1 h min in an air circulating oven at85 f 1.5”C.Expose part for 15 minutes minimum at 25 f 5 C.Steps (c) thru (f) constitute 1 thermal cycle. RepeatSteps (c) thru (f) 3 additional times for a total of 4cycles. Examine part per the requirements in 3.5.2after each cycle.For parts not completely enveloped with electroplate,following the fourth cycle, scribe an X through theplating at the stop off demarcation into the basicmaterial; place pressure sensitive adhesion tape, asdescribed in GM9071P. approximately 20 mm wideover the X (leaving sufficient length of tape to graspbetween fingers for quick removal); quickly pull tapeat approximately 90 degrees to the surface of part toremove entire strip. Examine for evidence of liftingof electroplate.5 INITIAL SOURCE APPROVAL.No shipment shallbe made by any supplier until representative initial productionsamples have been approved by engineering as meeting therequirements of this specification.5.1 Completed copies of the GM Material Safety Data Sheetand Critical Material Register (available from the engineeringdepartment or laboratory), or equivalent, must be submittedwith any new submissions or where a composition change hasoccurred.6 INSPECTION AND REJECTION.All shipments ofmaterial or parts under contract or purchase order manufactured to this specification shall be equivalent in every respectto the initial samples approved by engineering. There shall beno changes in either formulation or manufacturing processespermitted without prior notification and approval by engineering. Lack of notification by the supplier constitutes groundsfor rejection of any shipment. While samples may be takenfrom incoming shipments and checked for conformance to thisspecification, the supplier shall accept the responsibility forincoming shipments meeting this specification without dependence upon purchaser’s inspection.4 SAMPLING.Methods of sampling and resampling,and the basis of rejection, shall be subject to mutual agreementof supplier and purchaser. The number of samples to beselected and the frequency of selection will, in general, dependupon the number of pieces plated.0 Copyight4372MJUNE 1992 General Motors7 APPROVED SOURCES.Engineering qualificationof an approved source is required for this specification. Onlysources listed in the GM Corporate Materials File under thisspecification number have been qualified by engineering asmeeting the requirements of this specification, Sources areavailable through the on-line MATSPC System.8 GENERAL INFORMATION.This standard was firstissued in September 1962. The latest revisions include:Rev.EFCqxmtionPAGE 2Date71894192DescriptionComplete revisionRevision to add Aluminum SubstratesAll Rights Rwa-wdJUNE 1992
GM GM 008350Materials597and Processes- MetalsIDECORATIVE CHROMIUM PLATING - COPPER, NICKEL, CHROMIUM TYPEGM4372M GM4373M GM4374MTABLE 1NOTE 1: For nonwear interior parts, minimum chromium thickness may be 0.13 tmr, if authorized by purchaser.Approval is indicated by addition ofsymbol (B) to the specification numbeq e.g. WM4373M(B).”NOTE 2: Copper may be used but not required. If not used at supplier option, then nickel must be used to meet the total plate thickness requirement.When copper is not used when plating steel substratesto GM4372M or GM4374M requirements,the total minimum thickness is reduced to 30 pm.NOT!? 3: Chromium thickness should be limited to 0.4 pm to preclude overlaying the microparticulate nickel pores if used. The use of chromiumdeposits from trivalent chromium baths is not permitted unless otherwise specified on the detail drawing.NOTE 4: Tin Cobalt alloy may be used in lieu of chromium when symbol (K) is added to the specification number, e.g. “GM4373M(K)“.NOTE 5: For cloisormd type substrates,copper is optional.NOTE 6: Suitable preueatment processesmust be developed for each type of alloy and processesof manufacture of the alloy. All pretreatment ofaluminum processesmust pass all visual adhesion and corrosion resistanceproperties as specified prior to production on each type.of ahoy and eachtype of manufacturing process of aluminum.NOTE 7: All plated components must receive an aluminized wax or other corrosion-resistantcoating on nonsignificant surfaces unless otherwisespecified on the drawing.Q CopyrightJUNE 1992JUNE 1592 Gem-alMotors CorporationPAGE 3All Flights Resemd4372M
GM GM43721I92-GENERAL MOTORS ENGINEERING STANDARDS900b379000835l1423mMaterials and ProcessesI- MetalsIDECORATIVE CHROMIUM PLATING - COPPER, NICKEL, CHROMIUM TYPEGM4372M GM4373M GM4374MAPPENDIX AAPPENDIX - PORE DENSITY CHARTS (lmm BY lmm)1000PORES/cm’AT 100X5000PORES/cm’AT 100X.l.l*l.l.’ l .’ .l.9.PORES/cm’.2000.AT 100Xl.10 000.,*PORES/cm’AT 100X.l -.:.-9’.l.ll.‘9,.l.l.l.l.l. l * .’.4372-AO1(4/92)JUNE 1992.*l.l.4372-AO2(4/92)PAGE44372M
ENGINEERINGSTANDARDSTest MethodGM9684PMaterialsProcedure For Evaluating Parting Lines1 ScopeThis specification covers the evaluation methodfor determining the acceptability of parting lines oninterior trim, visible or customer contact plasticparts.Note: Nothing in this test method supersedesapplicable laws and regulations unless a specificexemption has been obtained.Note: In the event of a conflict between theEnglish and domestic language, the Englishlanguage shall take precedence.2 ReferencesNote: Only the latest approved standards areapplicable unless otherwise specified.5.1 Summary of Test Method. Visually inspectinterior trim, visible or customer contactable partsfor parting line condition.5.2 Test Sample Preparation. Production moldedparts are painted silver by GM Interiors Dept.5.3 Test Procedure. Parts should be viewedinstalled in a vehicle or buck. If a property is notavailable the part may be evaluated by holding itto approximate installed position.6 Evaluation and Rating6.1 Evaluate tool half mismatch, flash and texturelocation. See Figure 1.6.2 On tactile parts no tool half mismatch isacceptable. Tactile surfaces examples are insideremote handles, knobs, switches and buttons.2.2 GM Standards/Specifications.6.3 Tool half mismatch less than or equal to0.05mm or .002 in. is acceptable. Tool halfmismatch greater than 0.05 mm or .002 in. is notacceptable.None.6.4 Flash is not acceptable.2.3 Additional References.6.5 All parts must be texture free on both sides ofthe parting lines for a distance of 0.010 in.2.1 External Standards/Specifications.None.Boundary Sample Process,www.supplypower.comNAO 4425, Styling Verification Form, InteriorDepartment6.6 The part submission and evaluation procedureis repeated until all issues are in agreement.0.25mm3 Test EquipmentParting lineTool Mismatch0.05mm maxDigital Calipers / Feeler GagesSilver paint4 Test Material0.25mmProduction tooled finished molded parts shall beevaluated.Approvals to grain cavities evaluations are basedon injection-molded parts from production toolingnot based on reviews of tooling nor cold pourimpressions from tooling.Stop Texture 0.25mmfrom the Parting LineFigure 1: Parting Line and Tool MismatchRequirements5 Test Method Copyright 2003 General Motors Corporation All Rights ReservedOctober 2003Originating Department: North American Engineering StandardsPage 1 of 2
GM9684PGM ENGINEERING STANDARD7 Report10 Release and RevisionsApproval of textured tool cavities and insertsbased on reviews of production injection moldedparts will be authorized on the Styling VerificationForm (NAO 4425) issued by the Interiordepartment.Boundarysampleswillbemaintained as specified by the Supplier power.com).10.1 Release. This test method originated inOctober 1993 and was approved by IPPCommittee and Midsize Car Division in June 1994.It was first published in July 1994.8 SafetyThis method may involve hazardous materials,operations and equipment. This method does notpropose to address all the safety problemsassociated with its use. It is the responsibility ofthe user of this method to establish appropriatesafety and health practices and determine theapplicability of regulatory limitations prior to use.10.2 Revisions.RevApprovalDateDescription (Organization)AJune 2003Revised acceptance criteriafor interior trim, customerinterface parts to allow noparting line mismatch, offsetor flash based on request byInterior Center to supportPerceived Quality Initiatives.(IPP)9 Coding systemThis material specification shall be given in otherdocuments, drawings, VTS, SSTS, CTS etc. asfollows:Test to: GM9684PWhereGMN Validation Area (NorthAmerican)GMN# Base Test Method Specification Copyright 2003 General Motors Corporation All Rights ReservedPage 2 of 2October 2003
WORLDWIDEENGINEERINGSTANDARDSMaterial SpecificationFinishGMW14668Minimum Performance Requirementsfor Decorative Chromium Plated Plastic Parts2.2 GM Standards/Specifications.1 ScopeThis specification covers basic requirements forcopper-nickel-chromium electroplated plastic parts,including assemblies.1.1 Material Description. Platings to thisspecification are intended for interior (code A) andexterior (code B) application with two levels ofcorrosion protection. For exterior applicationsdiscontinuous chromium plate (microporous (mp)or microcracking (mc)) in addition to a multiplelayer nickel system shall be used. Interiorapplications do not require the use ofdiscontinuous chromium or multiple layer nickelsystems. For interior application non discontinuouschrome (r) is permissible. Exterior plastics plated tothis specification are further subdivided intoapplication types: Type 1 which receives little or nostone chipping exposure on a vehicle, and Type 2which is exposed to significant chipping. Type 2includes significant surfaces of plated plastic partsattached to forward-facing vehicle areas or tovehicle areas subject to self-generated stonechipping (as defined by 15 degree impingementof straight line projection from tire). If no type islisted on detail drawing, Type 2 is assumed.1.2 Symbols. Not applicable.1.3 Typical Applications. This type of finish shallbe principally used for decorative purpose. Brightand other (e.g., satin, brushed, grained)appearances for interior and exterior plasticapplications, as defined by styling and specificappearance standards.1.4 Remarks. Not applicable.2 ReferencesNote: Only the latest approved standards areapplicable unless otherwise specified.2.1 External Standards/Specifications.ASTM B368ASTM B456ASTM B571ASTM D764DIN 50021ISO 1463ISO 2177ISO 3497GMW3001GMW3059GMW3286GMW14458GMW14700GMW148293 Requirements3.1 Requirements on Delivery3.1.1 Chemical Requirements. Not applicable.3.1.2 Physical Requirements. Not applicable.3.1.3 Mechanical Requirements.3.1.3.1 Plating Thickness. Shall be determined bythe microscopic method (ISO 1463) or theelectrochemical method (ISO 2177), or by X-Raymethod (ISO 3497). In case of disagreementsbetween purchaser and supplier, the microscopicmethod shall be the preferred method.3.1.3.1.1 Minimum plate thickness as specified inSummary Table, Table B1 is intended to apply toall low current density and high current densityareas of significant surfaces as specified onappropriate part drawings or as otherwise agreedupon between purchaser and supplier (writtenstatement). Such surfaces are those normallyvisible - directly or by reflection - on the finishedpart when assembled in car position, or which canbe the source of corrosion deposits that defacevisible surfaces on the assembled vehicles. Ifcorrosion products are visible anywhere on afinished & dressed component in vehicle position,this specification is not met.3.1.3.1.2 For systems with a total nickel layerthickness 20 microns, multiple layer nickelthickness consisting of at least 2 layers of electrodeposited nickel shall be as indicated in Table 1.3.1.3.1.3 Exceptions to the minimum platingthickness are generally shown as a detail on thepart drawing by either designating platingcheckpoint(s) or by indicating in an appropriateview the area(s) with deviated thickness(es)allowed. These exceptions must still meet thespecified number of corrosion test hours. Copyright 2007 General Motors Corporation All Rights ReservedFebruary 2007Originating Department: North American Engineering StandardsPage 1 of 7
GMW14668GM WORLDWIDE ENGINEERING STANDARDSTable 1: Nickel ThicknessThickness Relative to TotalNickel ThicknessType of NickelLayerDouble LayerTriple LayerBottombright)60 to 80% Note 150 to 70%Middle (high-S)Not applicable 10%Top (bright)20 to 40% 30%(semiNote1: If the total nickel layer thickness is 20 microns, thesemi bright thickness shall be 50% minimum.3.1.3.1.4 Minimum thickness and corrosionresistance performance requirements for texturedfinishes (matte, vapor blast, brush, etc.) apply aftertexturing.3.1.4 Additional Requirements.3.1.4.1 Substrate / Molded Part.3.1.4.1.1 Substrate type. Only for platingapproved and designed substrates shall be used.Main types see Table 2.Table 2: Substrate TypesSubstrate TypeMax Temp.ABS 90 3 CABS / PC 110 3 CPC, PA6, PA66 - MF (10 to 40) 120 3 CPA6, PA66 - GF (10 to 30) 130 3 C3.1.4.1.2 Substrate Structure. Parts shalldemonstrate no defects like cracks or shrink holes.Parts shall be free of internal tension, which mayinfluence adhesion or appearance of the galvaniccoating.3.1.4.1.3 Surface properties. The surface shall besmooth, free of flow lines, cracks, sink marks,craters or substrate separations, which mayinfluence the appearance. Surface shall alsocontain no oil/fat or any human sweat fromhandling. In the tool no separation agents may beused, also parts may not be mechanically polishedor sanded before plating.3.2 Processing Requirements.3.2.1 Chemical Requirements. Not applicable.3.2.2 Physical Requirements. Not applicable.3.2.3 Mechanical Requirements.3.2.3.1 Nickel Electrochemical Potential (onlyexterior parts). Determination of potentialdifference following ASTM B764.3.2.3.1.1 The bright (or satin) nickel layer shallexhibit an anodic electrochemical potentialdifference of 100 to 200 mV to semi bright nickelon all significant surfaces. The supplier mustdemonstrate the conformance to this requirementby using appropriate statistical charting techniqueson a routine quality control basis.3.2.3.1.2 The micro particulate nickel layer shallexhibit a cathodic electrochemical potentialdifference of 10 to 40 mV to the bright or satinnickel on all significant surfaces of all substrates.3.2.3.1.3 If a micro cracking system is used,usually no microparticulate electrochemicalpotential difference is measurable.3.2.3.1.4 The optional “high activity nickel strike”layer shall exhibit an anodic electrochemicalpotential difference of 15 to 40 mV to the brightnickel layer.3.2.3.2 Discontinuous Chromium, shall beperformed by either the copper deposition(Dubpernell) method or by the determination ofactive corrosion sites after corrosion testing. Bothare described in the appendix of ASTM B456. Inthe case of an active sites determination, comparethe viewed sample at 100X to the pore densitycharts shown in Appendix A of this specification todetermine pore count.3.2.3.2.1 Microporous System (mp). Themicrodiscontinuous chromium surface shall exhibita minimum of 10 000 pores/cm2 as determined bycopper deposition or 2000 pores/cm2 asdetermined by active sites per ASTM B456Appendix X4 or X5.3.2.3.2.2 Microcracking System (mc). Thecracked chromium surface shall exhibit 250 to800 cracks/cm and provide a closed homogenousnetwork in all directions.3.2.4 Additional Requirements. Not applicable.3.3 Performance Requirements.3.3.1 Chemical Requirements. Not applicable.3.3.2 Physical Requirements.3.3.2.1 Adhesion.3.3.2.1.1 Saw Grind Test. Plated plasticcomponents shall be subjected to the Saw-GrindTest, ASTM B571, with no evidence of lifting orpeeling between plated layers. Place pressuresensitive adhesion tape, as described inGMW14829. approximately 10 to 20 mm wide overthe cut edge (leaving sufficient length of tape tograsp between fingers for quick removal); quicklypull tape at approximately 90 degrees to thesurface of part to remove entire strip. Examine forevidence of lifting of electroplate. Copyright 2007 General Motors Corporation All Rights ReservedPage 2 of 7February 2007
GM WORLDWIDE ENGINEERING STANDARDS3.3.2.2 Temperature Storage. All parts shall betemperature tested for 6 0.5 h. Temperatures seebelow. Test pieces shall show no surface changes,adhesion loss or other changes which reduce theperformance and shall comply with specifieddrawing requirements after test.3.3.2.2.1 If not defined separately all parts will betested to the following temperature: 90 3 C3.3.2.2.2 For high temperature application arease.g., engine compartment the substrate has to beselected to suit requirements. Test temperature: 110 3 C. This must be indicated on the drawing.3.3.2.3 Temperature Cycle. All plated plastic partsinterior and exterior shall be subject to the thermalcycling test described below. At the conclusion ofthe test sequence the plated part shall show nodeformation, crazing, blistering, splitting, or loss ofadhesion to the substrate or loss of adhesionbetween individual layers of the metal platinglayers.3.3.2.3.1 Cycle A.The thermal cycling test shall be performed asfollows:a. When corrosion test is specified, expose partfor 24 1 h CASS prior to Step (b). Note forLAAM non export vehicles only, it is optional toreplace 24 1 h CASS with 72 1 h NSS.When corrosion test is not required, completelyimmerse part in water maintained at 38 1.5 Cfor 22 h prior to Step (b).b. Mount part in a restrained position simulatingin service usage. One (1) h maximum isallowed between end of Step (a) and start ofStep (c).c.Expose part for 1 h min at -30 1.5 C.d. Expose part for 15 minutes minimum at 25 5 C.e. Expose part for 1 h minimum in an aircirculating oven at 85 1.5 C.Expose part for 15 minutes minimum at 25 5 C.g. Steps (c) thru (f) constitute 1 thermal cycle.Repeat Steps (c) thru (f) 3 additional times fora total of 4 cycles. Examine part per therequirements in 3.3.2.3 for evidence ofelectroplate adhesion loss after each cycle.h. After completion of thermal cycle step (g),expose part for 24 1 h CASS. Note for LAAMnon export vehicles only, it is optional toreplace 24 1 h CASS with 72 1 h NSS.i. For parts not completely enveloped withelectroplate, following the fourth cycle, scribean X through the plating at the stop offf.GMW14668demarcation into the basic material. Placepressure sensitive adhesion tape, as describedin GMW14829 approximately 20 mm wide overthe X (leaving sufficient length of tape to graspbetween fingers for quick removal). Quicklypull tape at approximately 90 degrees to thesurface of part to remove entire tape strip.Examine for evidence of lifting of electroplate.3.3.2.3.2 Cycle B. The test piece shall besubjected 3 temperature cycles before thecorrosion test one cycle consists of temperatureslisted below.a. 22 1 h at 80 3 C followed byb. 2 h 10 minutes at -20 3 C.Immediately upon removal from the refrigeratortest piece shall be subjected to one of the followingimpact tests:Test pieces having a weight of 440 g shall bedropped in the cold condition from a height of 1m onto a hard (stone-)floor.Test pieces weighing 440 g:A ball of diameter 50 1 mm and a mass of 550 50 g shall be dropped from a height of 80 cmonto the center of the cold test piece, placed on ahard (stone-)floor. In case of curved test piecescare shall be taken that the test piece is supportedon the intended attachment areas.Immediately following to above the first 3 cycles,the test piece shall be further subjected to the testcycle listed below.a. 1 h 5 min at 60 3 C followed byb. 1 h 5 min at -40 3 C.This test cycle shall be repeated two further times,3 cycles total.3.3.2.4 Stone Chipping. Exterior parts (B) & Type2 for component validation only. Significantsurfaces of the plated component shall besectioned. For EU platings the chip resistancetests per GMW14700 is performed followed by athermal cycle (as described under 3.3.2.3) plus 48hours CASS after chip test with no adhesion loss(plating separation from substrate) and noblistering (visible as distorted reflection) larger than5 mm diameter at chip site is allowed. For USplatings CASS and Thermal cycle are performedafter chip testing. This additional test only appliesto adhesion assessment, not to corrosion. Otherperformance criteria in paragraph 3.3.2.3 applyaway from chip sites.3.3.3 Mechanical Requirements.3.3.3.1 Corrosion Resistance. Shall bedetermined by the CASS test, GMW14458 ASTMB368/DIN 50021(CASS), according to the number Copyright 2007 General Motors Corporation All Rights ReservedFebruary 2007Page 3 of 7
GMW14668GM WORLDWIDE ENGINEERING STANDARDSof hours specified in the Summary Table, TableB1. Note for LAAM non export vehicles only, it isoptional to replace the CASS test with the NSStest, GMW3286, according to the number of hoursspecified in the Summary Table, Table B1. Platedcomponents shall be free of any surface defects anfree of corrosion on all significant surfaces whenexamined at normal reading distance 0.5 0.1 mwith the unaided eye and uniform diffused light.3.3.4 Additional Requirements. Not applicable.4 Manufacturing ProcessNot applicable.5 Rules and Regulations5.1 All materials supplied to this standard mustcomply with the requirements of GMW3001, Rulesand Regulations for Material Specifications.5.2 All materials supplied to this standard mustcomply with the requirements of GMW3059,Restricted and Reportable Substances forParts.6 Approved SourcesEngineering qualifications of an approved source isrequired for this specification. Only sources listedin the GM Materials File (i.e., GM Supply Power)under this specification number have beenqualified by engineering as meeting therequirements of this specification.For other GM locations, the responsibleengineering group should be contacted to obtainthe approved source in that individual country.7 Notes7.1 Glossary. Not applicable.7.2 Acronyms, Abbreviations, and Symbols.ABSAcrylonitrile Butadiene StyreneCASSCopper-Accelerated Acetic Acid SaltSprayGFGlass filledmcmicrocrackingMFMineral filledmpmicroporousNSSNeutral Salt SprayPAPolyamide (Nylon)PCPolycarbonate8 Coding SystemThis standard shall be referenced in otherdocuments, drawings, VTS, CTS, etc. as follows:Material per GMW146689 Release and Revisions9.1 Release. This standard originated in October2005, replacing GME 00006. It was first approvedby the Global Finish Team in June 2006. It wasfirst published in February 2007. Copyright 2007 General Motors Corporation All Rights ReservedPage 4 of 7February 2007
GM WORLDWIDE ENGINEERING STANDARDSGMW14668Appendix AFigure A1: Pore Density Charts (1 mm by 1 mm)Applicable to both “Active Sites” and “Copper Deposition” evaluation methods Copyright 2007 General Motors Corporation All Rights ReservedFebruary 2007Page 5 of 7
GMW14668GM WORLDWIDE ENGINEERING STANDARDSAppendix BTable B1: Summary TableCodeCASSNSSPlating ThicknessMinimum MinimumTotalCopperNickelCorrosion CorrosionResistance Resistance(µm)(µm)(µm)(h)(h)minimum minimum minimum(A) InteriorNote 1, 2, 3(B) ExteriorVar 1- Type 1w/o Stone Chip"LowCopper"(GMNA)Note 6Var 2"HighCopper"(GME)-Type 2Var 1with Stone Chip"LowCopper"(GMNA)Note 6Var 2"HighCopper"(GME)Chromium(µm)82418108(r) 0.25 minimum(mp) 0.25 minimum(mc) 0.25 minimum48144351520(mp) 0.25 to 0.548144352515(r) not allowed(mp) 0.25 to 0.5(mc) 0.8 minimum48144351520(mp) 0.25 to 0.548144352515(r) not allowed(mp) 0.25 to 0.5(mc) 0.8 minimumNote 1: For nonwear interior parts, minimum chromium thickness may be 0,15 µm if authorized by purchaser and engineering. Approvalis indicated by addition of symbol (R) to specification number on drawing.Note 2: Tin Cobalt alloy may be used in lieu of chromium when symbol (K) is added to the specification number on the drawing.Note 3: (r) continuous chrome, (mp) microporous chrome, (mc) microcracked chrome.Note 4: Run water immersion per 3.3.2.3.1(a) (instead of first
GM4260P ASTM B456 ASTM B764 GM9071P ASTM B487 ASTM B368 ASTM B571 3 REQUIREMENTS. 3.1 PLATING THICKNESS. Shall be determined by the microscopic method (ASTM B487) or the electrochemical method of GM4260P In case of disagreements between pur-
QQ-C-320 350B CP None . Chromium Plating (Electrodeposited) AMS-QQ-C-320 351 CP None Tank #1 Only Hard Chromium Plating - Class 1 and 2 BAC 5709 353 CP None Tank #1 Only Hard Chromium Plating - Class 4 (QPL) BAC 5709 355 CP None None Copper Plating MIL-C-14550 366 CP None Classes 1 & 2 Electroless Nickel Coatings
Zinc-Nickel Alloys What is Best Ni Composition in Zinc-Nickel Plating? - 4 to 18% Appears to Give Good Corrosion Resistance and Sacrificial Protection to Steel - High % Ni Appears to Create a Non-Embrittling Plating Process What is Best pH for Zinc-Nickel Plating? - Alkaline Plating Appears to Be Easier to Use Bath Easier to Maintain
ance, followed closely by arsenical copper. Phosphorus deoxidized copper, aluminum bronze and 95-5 copper nickel are somewhat better, followed by aluminum brass and 90-10 copper-nickel. Of the copper alloys, 80-20, 70-30 and 60-40 copper-nickel are the most corrosion resistant. Monel alloy 400 (7'½o Ni-Cu) has even higher
NICKEL PLATING Electroplating metals is a crucial step in the manufacturing of many end-user products in industries like automobile, . conductive when it comes to non-conductive surfaces. Many metals can be used for electroplating like chromium, gold, zinc, nickel, etc. but when you need electroless plating, Nickel is always the best choice. .
Iron, zinc plating 2 E3C-S50 (8) E39-L40 Iron, zinc plating 1 Phillips screws M4 25 (with spring and plain washers) Iron, zinc plating 2 E3JK Nuts M4 Iron, zinc plating 2 E39-L41 Iron, zinc plating 2 Phillips screws M3 14 (with spring washers) Iron, zinc plating 4 6 E3C-1 (10) Plain washer M3 Iron, zinc plating 4 E39-L42 Iron, black coating 2
Ready To Use Silver Solution Silver Plating Rhodium Plating Bath 1 Gm Rhodium Plating Bath 2 Gms Pen Plating Solution Black Rhodium Black Ruthenium . Metal Coating, Paint & Powder Coating Stripper Nickel Stripper From Copper And Copper Alloys Nickel Strippe
36 copper tube (a) - high side copper 4a1846-01 1 1 1 1 37 copper tube (b) - high side copper 3a1317-01 1 1 1 1 38 copper tube (c) - high side copper 3a1316g01 1 1 1 1 39 copper tube (d) - high side copper 3a1311g01 1 1 1 1 40 heat exchanger copper 2a1498g01 1 1 1 1 41 strainer - 4a0397-01 1 1 1 1 42 copper tube (a) - hot gas copper 4a1878-01 1 .
24 Plating & Surface Finishing December 2009 December 2009 Plating & Surface Finishing 25 Characterization of a Zinc/Nickel Plating Bath Paulo Vieira, Bart Van den Bossche and Alan Rose* Elsyca, Inc. Newnan, Georgia, USA Zinc/nickel electrodeposits have been seen as a viable replacement for cadmium, which has highly desirable prop-
