METHOD OF FORMING A HARD LAYER ON A SUBSTRATE

摘要

A method of forming a hard layer on a substrate (18) involves rubbing particles of boron nitride (20) across the surface of the substrate at a high speed and under sufficiently high pressure to cause a layer of boron nitride to adhere to the surface. A mop of carbon fibre (10) rotating at a speed of about 15 000 rpm is held against a substrate such as polished stainless steel, with a slight interference between the periphery of the mop and the substrate. Particles of cubic boron nitride with a size distribution between zero and 0.5 microns are applied to the interface between the mop and the substrate, and the substrate is driven back and forth slowly underneath the mop, until a layer of boron nitride builds up on the surface of the substrate. Experimental coatings had a thickness of approximately 0.3 microns, and had good wear characteristics.