Effect of molding pressure on structural and densification behavior of microwave‐sintered ceramic tool material

Abstract

AbstractThe die‐pressed Al2O3‐based ceramic compacts for microwave sintering were prepared using uniaxial molding pressure. Effect of molding pressure on density distribution, microstructure, and mechanical properties of both green and sintered compacts were studied by simulation and experiments. The results suggested that the density distribution of green compact showed obvious stratification phenomenon as the pressure increased. High pressure could increase the density of green compact but led to large density variation. Cracks were formed within the sintered compact due to the severe stress concentration at high molding pressure. Better mechanical properties were obtained at the pressure of 200‐300°MPa. The optimal mechanical properties of Al2O3/Ti(C,N) ceramic tool were obtained at 1550°C with the soaking time of 10 minutes, which were as high as that of conventional sintering, but the sintering period was sharply shortened.