Effect of sintering conditions on the properties of Al2O3/Ti(C,N) ceramics

This paper presents a study on the densification and mechanical properties ofAl2O3/Ti(C,N) ceramics processed using a pressureless sintering technique. The Al2O3/Ti(C,N)ceramics containing 10, 20, 30 and 40 wt% Ti(C,N) were sintered in the temperatures ranging from1500 to 1750 °C and in the atmospheres of vacuum, Ar, H2 and N2. It is found that both optimum sintering temperature and Ti C,N) content exist, where the best densification and mechanical properties are achieved. The Al2O3/Ti C,N) properties will decrease when either sintering temperature or Ti(C,N) content moves away from their optimum value. The experimental results also demonstrate that among the four atmospheres, Ar gives best results. To improve further the properties of Al2O3/Ti(C,N) composites, Al2O3 and Al2O3/Ti C,N) powders have used to cover the specimens during sintering, and experiments revealed that covering with Al2O3/Ti(C,N) powder can significantly improve the properties of Al2O3/Ti(C,N) ceramics. Furthermore, the effects of Ti(C,N) content and sintering conditions on densification and mechanical properties are explained in terms of their influences on Al2O3/Ti(C,N) microstructures.