1、Designation:B48168(Reapproved 2013)Standard Practice forPreparation of Titanium and Titanium Alloysfor Electroplating1This standard is issued under the fixed designation B481;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year o
2、f last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONFull utilization of the light weight and high strength of titanium is prevented by the tendency it hasto gall and seize
3、and by its lack of corrosion resistance at elevated temperatures.Frequently theselimitations can be overcome by electrodepositing upon the titanium a metal with satisfactoryproperties.Titanium is an active metal that rapidly forms an adherent oxide coating in the presence ofoxygen and water.This coa
4、ting prevents the application of adherent electrodeposits by the morefamiliar preparative processes.For this reason,the special processes described in this practice weredeveloped.1.Scope1.1 This practice describes processes that have been foundto be successful in producing adherent electrodeposits o
5、f goodquality on titanium and certain titanium alloys.Not all of theprocesses that have been reported as successful are described,but rather three basic ones that have had the widest use.Arather complete listing of the published work on electroplatingon titanium is given in the list of references wh
6、ich appear at theend of this practice.1.2 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-bility of regulatory limit
7、ations prior to use.For a specifichazard statement,see 3.1.2.Referenced Documents2.1 ASTM Standards:2B343 Practice for Preparation of Nickel for Electroplatingwith Nickel3.Reagents3.1 Purity of ReagentsAll acids and chemicals used in thispractice are technical grade.Acid solutions are based upon the
8、following assay materials(WarningUse hydrofluoric acidwith extreme care.):Hydrochloric acid37 mass%,density 1.184 g/mLHydrofluoric acid60 mass%,density 1.235 g/mLHydrofluoric acid71 mass%,density 1.260 g/mLHydrofluoric acid100 mass%,density 1.0005 g/mLNitric acid69 mass%,density 1.409 g/mL3.2 Purity
9、 of WaterUse ordinary industrial or potablewater for preparing solutions and rinsing.4.Process No.14.1 CleaningRemove oil,grease,and other soil by appro-priate conventional processes such as vapor degreasing,alka-line cleaning,grinding,or blasting.4.2 ActivatingActivation may be done by chemical ore
10、lectrochemical etching or liquid abrasive blasting.It is pos-sible that all three processes will work equally well on puretitanium and all common alloys;however,only those for whicheach process has been demonstrated to be successful are givenhere.The suitability of a process for an alloy not listed
11、shouldbe experimentally determined before committing productionparts.4.2.1 Chemical Etch:4.2.1.1 The following procedure is suitable for commer-cially pure titanium and for 6Al-4V,4Al-4Mn,and 3Al-5Cr.4.2.1.2 PickleImmerse in the following solution,at roomtemperature,until red fumes are evolved:1This
12、 practice is under the jurisdiction of ASTM Committee B08 on Metallicand Inorganic Coatingsand is the direct responsibility of Subcommittee B08.02 onPre Treatment.Current edition approved Dec.1,2013.Published December 2013.Originallyapproved in 1968.Last previous edition approved in 2008 as B48168(2
13、008).DOI:10.1520/B0481-68R13.2For 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 Barr
14、 Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 HF(60 mass%)1 volume andHNO3(69 mass%)3 volumes4.2.1.3 Rinse.4.2.1.4 EtchImmerse in the following aqueous solutionfor 20 min(Note that a special formulation is recommended for3Al-5Cr alloy).Standard3Al-5CrNa2Cr2O72H2O250 g/L390
15、 g/LHF(60%mass)48 mL/L25 mL/LTemperature82 to 100C82 to 100CNOTE1For platinum electroplating on commercially pure titanium,etching may be done by immersion for 5 min in hot(94C min)concentrated hydrochloric acid followed by rinsing and platinum electro-plating(1)34.2.2 Rinse.4.2.3 ElectroplateElectr
16、oplate with chromium,with cop-per from an acid bath,or with nickel from either a Watts orsulfamate bath,or deposit nickel in an autocatalytic bath.If adeposit of some metal other than these three is desired,firstapply a nickel coating with a minimum thickness of 1 mfollowed by the desired final metal.4.2.4 Heat Treat:4.2.4.1 The adhesion of the electrodeposit is mechanicaland,therefore,although of a relatively high order ofmagnitude,it may be less than adequate.If a higher degree ofadhesion is d