以直接氮化法合成的AlN微米粉为原料,添加3%(质量分数)的CaC2为烧结助剂,在5GPa的压力下烧结30min,考察不同烧结温度对AlN陶瓷热导率的影响。用阿基米德排水法、XRD、SEM等技术手段对AlN烧结体进行性能检测。研究表明,在1500~1800℃范围内,温度的升高能促使AlN陶瓷内部晶粒长大,晶型饱满,尺寸均一,晶界相减少,实现烧结致密化,利于热导率的提高。
This article aims to study the effects of the temperature on the thermal conductivity of the aluminum nitride ceramics,under the condition of 5GPa/30min,using AlN powder produced by geuther process as starting material and CaC2(3wt%) powder as sintering additive.The sintered AlN bodies were tested by XRD and SEM.The results show that the rise of the temperature(during 1500-1800℃) has important effects on the AlN ceramics,i.e.promoting the growth of the crystal grains inside the AlN ceramics,making full crystal grains with quidimensional size,decreasing the grain boundary phases,acquiring high-density AlN ceramics,and increasing the thermal conductivity of the AlN ceramics.