Microstructure and Mechanical Properties of SiC_w/BAS Glass-Ceramic Composites

The BAS glass-ceramic composites reinforced with different volume fractions of SiC whiskers were successfully studied by a hot-pressing method. The results show that the BAS matrix is composed of BaAl2Si2O8 and mullite. The incorporation of SiC whiskers can significantly increase the fiexural strength and fracture toughness of BAS glass-ceramics. The flexural strength and fracture strength of 30vol%SiCw/BAS composites can increase 128% and 190% compared to the unreinforced BAS matrix. The main toughening mechanisms are crack deflection, whisker pullout and bridging. The results of TEM observations show that SiC whiskers are directly bonded to the BAS matrix grains with no interfacial glass larer or reaction layer. In addition, the BAS composites also have good elevated temperature mechanical properties.