Wear of Abrasives in Simulated Hot Grinding

Abstract

Chemical interaction between the work material and the abrasive plays an important role in grinding. This will be more so in hot grinding. In this paper a novel experimental setup to study the wear and performance of various abrasives in hot grinding (up to ≈ 1000° C) is described. An oxy-acetylene torch under the work material is used as the heat soruce. Initial results on the performance of two commonly used abrasives, namely aluminum oxide and silicon carbide in simulated hot grinding of a cobalt base superalloy at 1000° C are presented using a scanning electron microscope. The results are compared with similar ones obtained at room temperature for the same combination of work material and abrasive. The results indicate that while silicon carbide wears more than aluminum oxide at room temperature, the reverse was found to be the case at high temperature. Also, the mode of wear and the nature of buildup were found to be different. In hot grinding, wear of aluminum oxide was found to involve the continuous release of micron sized crystallites while the formation of whiskers of silicon carbide was associated with the wear of silicon carbide. Buildup on aluminum oxide as metal was invariably found at room temperature while a uniform reaction product was present at high temperature.