Abstract
Al2O3 based ceramics is considered to be useful for high speed cutting of steel and low machinability material because of its higher chemical and thermal stabilities than those of coated cemented carbides or cermets. However, it has many problems to be solved in the mechanical properties which is necessary for the cutting tool.
This study is concerned with the improvements of mechanical properties and cutting performance of the Al2O3 ceramics. After the cutting performance of Al2O3-TiC ceramic tools having 10-50mass%TiC and various grain size was investigated, the strengthening of TiC-free white ceramics which has excellent wear resistance in high speed cutting was studied. The flank wear in the turning test of gray cast iron decreased with decreasing TiC content and increasing TiC grain size. The tool having 20-30mass%TiC and finer TiC grain size showed a superior resistance to flaking and flank wear in the turning test of alloy tool steel. The room temperature transverse-rupture strength of the fine grained white ceramics reached about 1.3GPa in contrast to 0.7-0.9GPa of conventional one.
