中文摘要：

热处理是AlN陶瓷调整结构、改善性能的有效手段.利用国产六面顶压机,在5.0GPa高压条件下,对高压烧结制备的AlN（Y2O3）陶瓷进行了热处理,研究了高压热处理对AlN陶瓷显微结构及导热性能的影响.结果表明：经5.0GPa/970℃/2h高压热处理后的AlN陶瓷材料与未热处理的试样相比,晶粒尺寸显著增大,晶粒形状越发规整,第二相均位于晶界处或者三角晶界区域,热导率达到了173.2W/（m.K）,是未经过热处理试样的2.2倍.但是,将高压热处理时间延长到4h,AlN陶瓷的气孔增大,出现了反致密化现象,热导率也降低到80.9W/（m.K）.

英文摘要：

The thermal annealing is an effective means of structural adjustment and performance improvement for AlN ceramics.AlN ceramics prepared at high pressure with Y2O3 as sintering additive,were annealed at high-pressure（5.0GPa） in a chinese cubic anvil ultra high-pressure and high-temperature device.The effects of high pressure annealing on microstructure and thermal conductivity of aluminum nitride ceramics were studied.The results show that the grain size of the AlN ceramics annealed at 5.0GPa and 970℃ for 2h is significantly increased,the actual crystal morphology is realistic and the second phases are almost present at the grain boundaries or triple pockets compared with the samples before annealing at high pressure.Its thermal conductivity reaches 173.2W/（m·K）,which is 2.2 times of the samples without heat annealing at high pressure.However,while the annealing time is extended to the 4h,the pore size of AlN ceramics is increased with anti-densification.And the thermal conductivity of AlN ceramics annealed at 5.0GPa and 970℃ for 4h is reduced to 80.9W/（m·K）.