Journal of the American Ceramic Society, Vol.83, No.6, 1530-1532, 2000
Al2O3/TiC based metal cutting tools by microwave sintering followed by hot isostatic pressing
The feasibility of producing Al2O3/TiC metal cutting tools by fast microwave sintering followed by hot isostatic pressing was examined. Microwave heating profiles able to ensure near-full densification of Al2O3/TiC ceramic components were determined. Simple-shape specimens could be sintered to a bulk density of 97% theoretical density (TD) while in the case of tool-shaped ones maximal densification levels attained were somewhat lower, i,e,, similar to 95% TD, Temperature uniformization-within the heating chamber-by using a particulate SIC susceptor noticeably reduced tool cracking propensity. Densification levels in the range acceptable for commercial tool manufacturing (greater than or equal to 98% TD) were achieved by hot isostatic pressing of the microwave-sintered parts. The isostatically pressed parts exhibited a Vickers hardness H-nu congruent to 2000 kg/mm(2) and a fracture toughness K-IC similar to 4.3 MPa.m(1/2).