A comparison between conventional abrasives and superabrasives in grinding of SiC-aluminium composites

The subject of this paper is concerned with an experimental study on the grindability of metal matrix composites. Machining by abrasive tools of these materials has been investigated by means of experimental tests carried out with different types of grinding wheels, made with both conventional abrasives and superabrasives. It has been found that the decrease in cutting ability of the grinding wheels is mainly caused by clogging of the active surface due to chip adhesion rather than by flattening of the grits caused by the abrasion of the hard reinforcement. Grinding forces and surface degradation of the wheel, detected during the machining process, and ground surface roughness, assessed out-of-line, have also been analysed. Among the types of grinding wheels employed in experimental tests, the ones manufactured with conventional abrasives and open structure have given better performances than those with superabrasives in terms of low clogging, low grinding forces and better surface finish. The influence of wheel preparation, namely truing and dressing, has been also taken into consideration. (C) 1999 Elsevier Science Ltd. All rights reserved.