Microstructure of hot-pressed SiC with AlB2 additive.

Pure SiC powder cannot be densified by normal pressure sinteiring or by hot-pressi and some additives are needed to densify it The studies reported previously showed tha B or B compounds1),2), and Al or Al com pounds3) were the most effective additives. I is well known that B and C additives can sinter SiC powder under normal pressure and that B4C, BP and BN are also effectiv The author have been studying the sinte ing behaviors of SiC by an addition of Al compounds, such as AlB2, AlN and Al4C They have found that a small amount of AlB addition could sinter SiC powder by hot-pres ing. Recently, J. A. Coppola et al.4) reporte a sintering of SiC with AlB2 additive in their