GB1025897A - Process of metal plating - Google Patents

Abstract

In a thermal decomposition process of metal coating a substrate, the substrate is heated to above the decomposition temperature of a carbon containing metal plating compound which is dissolved in an organic solvent and contacted with the substrate. The substrate may be contacted with the solution either before or preferably after being heated and it may also be reheated after contact which is preferably effected by dipping or spraying. The temperature of the solution is controlled and the process may be carried out under vacuum or an inert atomosphere of N2, H2, CO or CH4. The metals of the plating compounds are those in Groups NB to VA of Deming's Periodic Chart namely: Ti, Zr, Hf, V, Nb, Ta, Cx, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Bi. The carbon containing compounds are preferably those containing up to 40 carbon atoms such as alkyl amine complexes of aluminium hydride, organometallics, inorganic metal carbonyls, nitrosyl substituted metal carbonyls and organic metal chelates: A large selection of these compounds is included in the specification. The organic solvents are those next to the plating compounds and preferably those with up to 25 carbon atoms e.g. alkanes, aromatics, cycloalkanes, fused ring aromatics, ethers, fluorocarbons, silicone oils, alcohols and ketones. A large selection of typical solvents is given. The preferred weight ratio of plating compound to solvent is from 1 : 10 to 7 : 10. The preferred substrates to be plated are aluminium, steel, magnesium, cobalt-nickel base alloys, spun glass, "Pyrex" (Registered Trade Mark) ceramics, refractories and graphite. The preferred temperature range for the plating process is 100 DEG -500 DEG C. and in one embodiment gases may be bubbled through the plating compound to introduce Alloying or hardening constituents into the plating. Furthermore the solvent may be so chosen that it breaks down and supplies carbon for forming metal carbides in the plating. A large number of different examples are included in the Specification.