Possesses the high intensity and high tenacity the aluminum oxide basic ceramic make cutting tool

摘要

PURPOSE:To improve the strength of the ceramic by mixing the powder of the oxide of a specified metal or rare-earth element, the powder of the carbide, nitride and oxide of a group 4a metal and Al2O3 powder, compacting the mixture, sintering the green compact and then heat-treating the compact. CONSTITUTION:The Al2O3 powder having =0.6mum average particle diameter, 0.05-2wt.% of the powder of the oxide of a metal consisting of =1 kind among Y, Mg, Cr, Ni, Co and rare-earth elements and having =1mum average particle diameter and 5-50wt.% of the powder of the carbide, nitride and oxide of a group 4a metal consisting of =1 kind among the carbide, nitride, carbonitride, carboxide, nitrooxide and carbonitrooxide of Ti, Zr and Hf, having =1.5mum average particle diameter and in which the content of the particles having =0.3mum diameter is controlled to =10% are mixed, and the mixture is compacted to obtain the green compact. The compact is sintered at 1680-1830 deg.C for 10-40min in the Ar or gaseous mixture of Ar and an inert gas kept at 0.8-5atm, and then held at 1300-1450 deg.C for 2-10hr in the Ar or gaseous mixture of Ar and an inert gas kept at 100-2000atm to obtain an Al2O3 ceramic having high strength and toughness and in which the particle diameter of the hard dispersed phase in the Al2O3 base is controlled to =0.3mum.