Novel method to synthesize SiC nanowires and effect of SiC nanowires on flexural strength of Cf/SiC composite

The graphite fiber toughened silicon carbide (Cf/SiC) composite was annealed at 1500, 1600, 1700, 1750, 1800 and 1850 °C for 30 min and the flexural strength increased first and then decreased as annealing temperature increased. The maximum flexural strength was obtained for the sample annealed at 1750 °C. The microstructure observation indicated that the amount and length of in situ formed SiC nanowires increased as the annealing treatment time increased, which was very favorable to the improvement of flexural strength. The formation of SiC nanowires was attributed to the presence of the metal La and Al. The vapor-liquid-solid growth mechanism of the SiC nanowires along 〈1 1 1〉 direction is proposed. Furthermore, the purpose of this paper is to report novel method to synthesize SiC nanowires.