Patent GB-984366-A (GB)
Title: Chemical vapour plating process
IPC: C04B41/45
Filed: 1961-09-04
Abstract: In a chemical vapour plating process a heated substrate is simultaneously contacted with a vaporized chemical vapour-plating material and moving solid particles which are non-reactive under the process conditions.  The solid particles are smaller than 1 inch in diameter with less than 50% finer than 325 mesh, preferably 45 to 0.25 inch, and they may be particles of Al2O3, ZrO2, ThO2 or SiO2 or preferably particles of the material to be deposited. They are either suspended in a gas-fluidized bed maintained by the plating gas stream or by an inert gas, or they are subjected to mechanical vibration or agitation by rotation of the plating chamber or they may be suspended in the plating gas stream or an inert gas which is directed against the substrate.  Chemical vapour plating reactions utilized may be a thermal reduction process such as hydrogen or metal reductions of a halide and reactions of halides with a gas containing C, N, B, Si or oxygen compounds, thermal decomposition of halides, oxygen compounds, carbonyls and hydrides.  The materials deposited may be Cu, Al, Ti, Zr, Hf, Th, Ge, Pb, Sn, V, Nb, Ta, As, Sb, Bi, Cr, Mo, W, U, Re, Fe, Co, Ni, Ru, Rh, Os, Ir, Pt and alloys of these metals, carbon and carbides such as those of B, Si, Ti, Zr, Hf, Th, V, Nb, Ta, Cr, Mo, W, U, nitrides of Zr, Ti, Ta, Nb and Hf, boron and borides of Al, Th, V, Nb, Fe and Ni, silicon and silicides of Ti, Zr, V, Nb, Ta, Mo, W, Pt, Fe, Co and Ni, and oxides of Al, B, Si, Zr, and Cr. The substrate may be Cu, Ni, Ta, Mo, W, Fe, graphite, porcelain, Al2O3, fused SiO2, boro-silicate glass and sintered carbides.  Various examples are given of the deposition of N6, Ta and W on a steel substrate heated to 600-1000 DEG  C. by the reduction of the vaporized halide of the metal with hydrogen, Al2O3 particles being maintained as a fluidized bed by the gas.  Alternatively, two gas streams are used, one containing the halide and an inert gas and the other stream being hydrogen. Glass is also coated with Cr, or Mo by hydrogen reduction of the chloride using particles of SiO2.  Ta and W are deposited on Mo from the chloride using Ta particles and Ni is deposited on steel by decomposition of the carbonyl.ALSO:In a chemical vapour plating process, a heated substrate is simultaneously contacted with a vaporized chemical vapour plating material and moving solid particles which are non-reactive under the process conditions.  The solid particles are smaller than 1 inch in diameter with less than 50% finer than 325 mesh, preferably 45 microns to 0.25 inch, and they may be particles of Al2O3, ZrO2, ThO2 or SiO2 or preferably particles of the material to be deposited.  They are either suspended in a gas fluidized bed maintained by the plating gas stream or by an inert gas, or they are subjected to mechanical vibration or agitation by rotation of the plating chamber or they may be suspended in the plating gas stream or an inert gas which is directed against the substrate.  Chemical vapour plating reactions utilized may be a thermal reduction process such as hydrogen or metal reductions of a halide and reactions of halides with a gas containing C, N, B, Si, or oxygen compounds, thermal decomposition of halides, oxygen compounds, carbonyls and hydrides.  The materials deposited may be Cu, Al, Ti, Zr, Hf, Th, Ge, Pb, Sn, V, Nb, Ta, As, Sb, Bi, Cr, Mo, W, U, Re, Fe, Co, Ni, Ru, Rh, Os, Ir, Pt, and alloys of these metals, carbon and carbides such as those of B, Si, Ti, Zr, Hf, Th, V, Nb, Ta, Cr, Mo, W, U, nitrides of Zr, Ti, Ta, Nb, and Hf, boron and borides of Al, Th, V, Nb, Fe, and Ni, silicon and silicides of Ti, Zr, V, Nb, Ta, Mo, W, Pt, Fe, Co, and Ni, and oxides of Al, B, Si, Zr, and Cr.  The substrate may be Cu, Ni, Ta, Mo, W, Fe, graphite, porcelain, Al2O3, fused SiO2, borosilicate glass and sintered carbides.  Various examples are given of the deposition of Nb, Ta and W on a steel substrate heated to 600-1000  DEG C. by the reduction of the vaporized halide of the metal with hydrogen, Al2O3 particles being maintained as a fluidized bed by the gas.  Alternatively two gas streams are used, one containing the halide and an inert gas and the other stream being hydrogen. Glass is also coated with Cr, or Mo by hydrogen reduction of the chloride using particles of SiO2. Ta and W are deposited on Mo from the chloride using Ta particles, and Ni is deposited on steel by decomposition of the carbonyl.