CUTTING OF ALUMINA CERAMICS BY SINGLE-CRY STAL DIAMOND

Alumina-ceramic materials have been used instead of metals as structur al components for aircraft, space craft and automotives. These materia ls are highly brittle, superhard and difficult to machine, Therefore,t he cost of machining alumina-ceramic materials is considerably higher than that of metals. As a result a new cutting method has been develop ed to achieve lower-cost processing of the alumina ceramic materials. In this cutting process, the corner of single-crystal octahedral diamo nds in native state is used as the cutting edge, The applicability of this method to practical uses was evaluated by measuring the finished surface roughness and the tool life, and the strength characteristics of the materials, cut using this method, were investigated by the bend ing test. The cutting tool life is longer in the wet cutting method as compared with that in the dry cutting process, Moreover, when the abr asion side position of the diamond crystal edge cor responded to (100) of the crystallographic orientation, the cutting tool life tended to be longer, The maximum roughness of the finished surface was about 18 mu m and the material strength after cutting was decreased by about 15 % compared to that before cutting.