Cementing hard carbide particles to substrates - using slag or alloy binder, applying by flame spraying on a tacky surface and fusing binder

摘要

Particles are cemented by a hard carbide to the surface of a metallic substrate by applying a layer of gangue or a metallic binder, free of copper to the surface in the molten state, the m.pt. of the material being about 1100 degrees C and below that of the particles and the substrate, and onto the binder is applied a layer of a sticky organic non-metallic adhesive which can volatise completely in a furnace in a non-oxidising atmosphere. The particles are spread over the adhesive layer to form a layer held in place by the adhesive, and the substrate, so covered, is heated in a non-oxidising atmosphere in a furnace, to a temp. below the m.pt. of the substrate, but high enough to volatilise the adhesive and melt the binder so that it attaches the particles to the substrate on subsequent solidification. Method is used in mfr. of abrasive and cutting tools, giving improved bonding between particles and substrate.