Abstract:

SiC-diamond ceramics were prepared using SiC and diamond as raw materials,alumina and yttrium oxide as sintering agents,and pressureless firing at 1 850 ℃ for 1 h.Effect of diamond addition (0,0.25%,0.5%,1.0%,2.5%,and 5%,by mass) on properties of the SiC-diamond ceramics was researched.The results show that with the diamond addition increasing from 0.25% to 5%,the density of SiC-diamond ceramics decreases gradually,while the grain size increases first and then decreases.With 0.25% diamond,the ceramics perform the best properties,the density of 90.3%,the thermal conductivity of 83.2 W·m^-1·K^-1,and the specific heat capacity of 0.71 J·g^-1·K^-1.

Key words: silicon carbide, diamond, thermal conductivity, density

摘要：

以碳化硅(SiC)和金刚石为原料,以氧化铝和氧化钇为烧结助剂,在1 850 ℃保温1 h无压烧结制备了SiC-金刚石陶瓷。研究了金刚石含量(质量分数分别为0、0.25%、0.5%、1.0%、2.5%、5%)对SiC-金刚石陶瓷性能的影响。结果表明:随金刚石含量(0.25%~5%(w))的增加,SiC-金刚石陶瓷的致密度逐渐下降,晶粒尺寸先增大后减小。当添加0.25%(w)的金刚石时,试样性能最好,其致密度、热导率和比热容分别为90.3%、83.2 W·m^-1·K^-1和0.71 J·g^-1·K^-1。

关键词: 碳化硅, 金刚石, 热导率, 致密度