Coating diamond grains with metal (carbide layers - from solid metal/halogen atmosphere or volatile metal cpds

摘要

Natural or synthetic diamond grains are contacted in the dry state, with agitation, with B or Si or one or more transition metals in an opt. diluted halogen contg. atmosphere or alone in an atmosphere of a B or Si halide or hydride or transition metal halide or other volatile transition metal cpds. esp. carbonyls at 0.01-1.5 atm. for 1- several hundred min. depending on required thickness at 400-1100 degrees C. A carbide and/or metal layer is formed on the grains, the coating atmosphere being evacuated and the grains cooled under vacuum or inert gas. When grains used in synthetic resin bound abrasive sheets they bind well to the resin and heat conduction is improved.