AlN ceramics synthesized by carbothermal reduction of mechanical activated Al2O3

AlN ceramics synthesized by carbothermal reduction using the mechanical activated Al2O3 were investigated. The results show that, using the commercial Al2O3 not milled, the temperature was higher than 1600 deg C when the carbothermal reduction reaction was completed, but, if the Al2O3 was milled by high-energy ball mill for 20 h, the carbothermal reduction reaction occurred below 1100 deg C and completed thoroughly at 1250 deg C, and all of Al2O3 transformed to AlN. These AlN powders can be sintered at about 1600 deg C, and the mechanical properties of these AlN ceramics are as good as that of commercial AlN powders sintered at 1800 deg C.