GB1275339A - Process of plating by pyrolytic deposition - Google Patents

Abstract

1275339 Pyrolytic deposition GENERAL TECHNOLOGIES CORP 4 June 1970 27009/70 Heading C7F A liquid comprising a pyrolytically decomposable precursor compound is forcibly projected against a substrate as finely divided liquid particles of size 1-1000 Á, the substrate being maintained at at least the temperature at which said precursor compound decomposes to give a reaction product adherent to the substrate. The precursor is a derivative of a metal or metalloid (e.g. Si, B, As) of atomic number 4 to 83, typically an organometallic, hydride, carbonyl, substituted carbonyl, amine, chelate, alkyl, alkylamine, aryl, dienyl or acetylacetonate derivative thereof, specific examples being mesitylene tungsten tricarbonyl, mesitylene molybdenum tricarbonyl, tungsten carbonyl, molybdenum carbonyl, nickel carbonyl, dicumene chromium, IrCl 3 , bischloropentadienyl pentafluorophenyl titanium, trimethylamine borane, trimethylsilane, aluminium acetylacetonates, vanadium carbonyl, and di- and tri-isobutyl aluminium. The precursor, if liquid, may be supplied as such, or in solution, suitable solvents being listed, or in the presence of a catalyst or species with which it may react to give a compound of the metal or metalloid, the said species being either incorporated into the said solution, atomized simultaneously but separately against the substrate or provided as the ambient in the coating vessel, the pressure in the vessel being preferably 0.01 mm Hg to 10 atmospheres. For example, a coating of W and WC may be provided from an atomized solution of W (CO) 6 in heptane, a Ti/TiC coating from a Ti compound in benzene, or a coating of Ni with dispersed SiO 2 from an atomized dispersion of colloidal SiO 2 in Ni carbonyl/CS 2 . The substrate, which may be cleaned by etching, wire brushing, or vapour blasting, is heated to 25-1200‹C. and may be steel, iron alloy, Al, Mg, Cu, Ti, Ni, Co, Be, a refractory metal, glass, quartz, zeolite, zircon, Al 2 O 3 , MgO, plastics, graphite or B, and is generally treated for 5 minutes-6 hours. Two coatings may be applied e. g. nylon may be coated with Ni and then electroplated with Al.