Porous SiC ceramics were prepared from sodium borate,SiC,and activated carbon sintering at temperatures as low as 700-850℃ in air.The bonding behavior,mechanical strength,porosity,and firing shrinkage of the composites were investigated as a function of the sintering temperature and the content of C.The structural morphology and phase compositions were investigated.During the sintering process,the SiC particles were bonded by a glassy phase transformed from the sodium borate.