Pressureless sintered 3Y-TZP/20%Al2O3 composite ceramic

Nanometer 3Y-TZP/20% Al2O3 (mass fraction) composite powders prepared by the chemical coprecipitation method were pressureless sintered at 1550 degreesC for 2 h. Effects of calcining temperatures at 800 degreesC, 1 000 degreesC, and 1 200 degreesC on phase structure, relative density, and Vicker's hardness of the sintered bodies were studied. The results show that 1 000 degreesC was the optimal calcining temperature,and the powder calcined was composed of tetragonal zirconia with the Scherrer crystalline size of 6.3 nm. The relative density was up to 98.5% under pressureless sintering, and the sintered body was t-ZrO2 (without m-ZrO2) + alpha -Al2O3 with the average size of 0.4 mum.