AlN陶瓷的空心阴极等离子烧结工艺研究

Research on hollow cathode discharge plasma sintering techniques of aluminium nitride

将空心阴极效应运用于AIN陶瓷的烧结,选用自蔓延高温合成的AIN粉体为原料,用Y2O3-Li2O-CaO(YLC)作为烧结助剂,进行了烧结试验,并探讨了工艺参数的影响。结果表明,空心阴极烧结工艺可制备出致密度高,导热性能好的AIN陶瓷。添加质量分数为5.5%的YLC烧结助剂,在1 700℃、保温3h的烧结条件下,获得相对密度为98.9%、热导率为93.8W/(m.K)的AIN烧结体。烧结体断口的SEM照片显示,烧结试样的晶粒生长发育完善,晶粒轮廓清晰,呈尖锐的多面体形状,晶粒大小均匀,孔隙和晶界相少,断裂模式主要为穿晶解理断裂。TEM观测表明,晶界相少,且大部分都缩至三角晶界,AIN晶粒与晶粒接触紧密。

Sintering of AlN powder produced by the method of SHS was investigated with hollow cathode discharge and Y2O3-Li20-CaO as the additive, and effects of processing parameters were discussed. The results show that, AlN ceramics with high performances, high density and excellent conductivity are obtainable. The densities of sampies sintered at 1700℃ reach the highest relative density of 98.9% after holding 3h, with amount of the sintering additive of 5.5wt% and thermal conductivity 93.8W/（m·K）. The SEM photographs on the fractured surface show that the AlN grains grow perfectly with clear, sharpedge and multilateral morphology, grain boundary phase and pores are little, and fracture mode is of intercrystalline fracture. TEM shows that AlN phase is continuous, boundary phase is little and contracted in triangle grain boundary.