超微粉（AlN＋Al）的添加对AIN的烧结和导热的影响

EFFECT OF ADDITION OF ULTRAFINE POWDER(AlN+Al)ON SINTERING AND THERMAL CONDUCTIVITY OF FINE AlN POWDER

将混合超微粉（ＡｌＮ＋Ａｌ）添加到ＡｌＮ细粉中，在不同温度下进行了常压烧结试验。测定了烧结体的导热系数，进行了Ｘ射线衍射分析和电镜观察。结果表明：当烧结温度≤２０２３Ｋ时，超微粉的添加使ＡｌＮ的烧结密度和导热率提高；当烧结温度升至２１２３Ｋ时，超微粉的添加反而引起ＡｌＮ的烧结密度和导热率的下降。讨论了超微粉对ＡｌＮ的烧结和导热的作用条件和机理。

Mixed ultrafine powder of AlN+Al was produced by arc plasma method. This ultrafine powder wasmixed wlth fine AlN powder,obtained by carbonthermal reduction method and then sintered at 1973,2023 2073 and 2123K respectively.The experiment results,such as X ray diffrection,electron mi-croscopy,thermal conductivity analysis and so on,show that the density and themal conductivity of the sin-tered samples increase with the addition of the ultrafine powder when sintering temperature is under2123K,and decrease inversely when the temperature comes up to 2123K. In this paper,the condition andmechanism of the effects of addition of the ultrafine powder on the sintering and thermal conduction of thefine AlN powder are discussed.