ASTM B481-68 pdf free.Standard Practice for Preparation of Titanium and Titanium Alloys for Electroplating.
Electroplate 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 umfollowed by the desired final metal.The adhesion of the electrodeposit is mechanicaland, therefore,although of a relatively high order of magni-tude， it may be less than adequate. If a higher degree ofadhesion is desired, use nickel as an intermediate coating andheat treat.This causes interdiffusion of the nickel and titaniumand produces a metallurgical bond. The heat treatment can beperformed after all electroplating is applied or immediatelyafter the nickel electroplating.This later approach is used incertain cases,for example,when undesirable diffusion canoccur between the nickel and the subsequent deposit.
Heat treat in an inert gas atmosphere (for example,argon) for 1 to 4 h at 540 to 800°C.The exact time andtemperature should be selected by subjecting electroplated testpieces to adhesion or performance tests or both.
If the heat treatment is performed before applyingthe subsequent deposit, the nickel will have to be activatedbefore continuing the electroplating. Methods of activation aregiven in Practice B 343.The water content must not be too high; therefore,less concentrated grades of hydrofluoric acid cannot be substi-tuted for the 71 % grade. The solution or part should be mildlyagitated.The cathodes may be carbon, nickel, copper, or othermaterials not attacked by the solution.Remove the part while the current is still on.5.2.4.4 Excessive current densities will produce electropol-ishing and inadequate current densities will permit localchemical attack.Both conditions will result in lack of adhesionof the electroplating.Electroplate with copper from an acidbath or copper from a cyanide bath preceded by a cyanidecopper strike, with cadmium from a cyanide bath, with silverfrom a cyanide bath,or with nickel from a Watts bath.ASTM B481 pdf download.