AlN powders were synthesized by both ordinary and modified processes of carbothermal reduction and nitridation in an Al O C N system. In the ordinary process, the AlN phase appeared at 1300℃ for 6h and the...AlN powders were synthesized by both ordinary and modified processes of carbothermal reduction and nitridation in an Al O C N system. In the ordinary process, the AlN phase appeared at 1300℃ for 6h and the nitridation was completed at 1600℃ for 6 h. The particle size of the ordinary AlN powders was about 1 μm and the specific surface area was 1 1 5m 2/g. In the modified process, the nitridation began and was completed at a temperature lower than that for the ordinary process by more than 100K. The particle size was much finer, 0 1 0 2 μm, and the specific surface area was about 20m 2/g. At some conditions, the AlN whiskers appeared in the powders. The nitridation rate was a function of the temperature and N 2 flow rate as well as the reaction period. The results are used to discuss some aspects of the mechanism.展开更多
文摘AlN powders were synthesized by both ordinary and modified processes of carbothermal reduction and nitridation in an Al O C N system. In the ordinary process, the AlN phase appeared at 1300℃ for 6h and the nitridation was completed at 1600℃ for 6 h. The particle size of the ordinary AlN powders was about 1 μm and the specific surface area was 1 1 5m 2/g. In the modified process, the nitridation began and was completed at a temperature lower than that for the ordinary process by more than 100K. The particle size was much finer, 0 1 0 2 μm, and the specific surface area was about 20m 2/g. At some conditions, the AlN whiskers appeared in the powders. The nitridation rate was a function of the temperature and N 2 flow rate as well as the reaction period. The results are used to discuss some aspects of the mechanism.
