GB1464375A - Abrading devices - Google Patents

Abstract

1464375 Abrasive devices ASSOCIATED ENG Ltd 22 May 1974 [22 Feb 1973] 8835/73 Heading B3D [Also in Division B2] A method of producing an abrading device, such as a grinding wheel for mechanical or electrolyte grinding, a hand file, or lining for a tumbling machine for de-burring and surface roughing, having an abrasive layer 3 of ceramic material alone on a former 1 affording a substrate, comprises plasma spraying, from a plasma gun, a ceramic material containing at least 50% by weight of alumina, which at least partly melts in the spraying process, so as to fuse to the former and form an abrasive layer on the substrate. In one example, a grinding wheel produced by the method has an annular aluminium wheel 1, a sleeve 2 of synthetic plastics material and a layer 3 of ceramic abrasive material sprayed on to the wheel, the layer consisting entirely of alumina having a grain size of 220 (FEPA). In another example, the wheel is of mild steel, or a mild steel rim is detachably mounted on a wheel, and the layer consists of 75% by weight of alumina plus 25% by weight of titania, the grain size being 360 (FEPA). In a third example, the layer consists of 50% by weight alumina and 50% by weight chrome oxide, the grain sizes being, respectively, 150 and 400. The sprayed alumina may contain at least 40% by weight of gamma phase alumina and, on a former 200 mm. in diameter, may have a thickness up to 10 mm. The former may be of metal, ceramic or high temperature synthetic resin.