【摘要】 在流动N2保护下,对高压烧结制备的AlN(Y2O3)陶瓷进行了热处理,研究了热处理对AlN陶瓷显微组织及导热性能的影响。结果表明:在970℃热处理2 h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,析出相均位于晶界处或者三角晶界区域,热导率从77.3 W/(m.K)提高到了156.7 W/(m.K)。但是,将热处理时间延长到4 h,AlN陶瓷的气孔增大,出现了反致密化现象,热导率也降低到92.6 W/(m.K)。更多还原

【Abstract】 AlN ceramics prepared at high pressure with Y2O3 as a sintering aids were heat treated in a nitrogen flow atmosphere.The effects of heat treatment on microstructure and thermal conductivity of AlN ceramics were studied.The results show that the grain size of the AlN ceramics heat-treated at 970 ℃ for 2h is significantly increased,and the actual crystal is more perfect and the second phases are almost present at the grain boundaries and triple junctions compared with the samples without heat treatment,and its thermal conductivity increases to 156.7 W/(m.K) from 77.3 W/(m.K) of the un-treated ceramics.However,the pore size of AlN ceramics is increased and the phenomenon of anti-densification is observed while the heat treatment time is extended to 4 h.The thermal conductivity of AlN ceramics heat-treated at 970 ℃ for 4 h is reduced to 92.6 W/(m.K).更多还原