Effect of La2O3 Content on Mechanical Properties and Toughened Mechanics of SiC Nanowires Toughened Cw/SiC Composites
In this paper, micrometers long and 20–100nm diameter SiC nanowires had been synthesized in the Cw/SiC composites by annealing treatment. The present work demonstrated that it is possible to fabricate in-situ SiC nanowires toughening Cw/SiC composites. La2O3 had a significant effect on the morphology and distribution of the SiC nanowires in the Cw/SiC composites. The excess lanthanum resulted in the growth of SiC nanowires with an increasing growth rate in the longitudinal direction and a decreasing growth rate in radial direction. The addition of La2O3 would improve the mechanical properties in the room-temperature. The vapor–liquid-solid growth mechanism of the SiC nanowires along <111> direction was proposed. The combination of grain bridging, crack deflection, whisker debonding and SiC nanowires can improve fracture toughness.
Yafang Han, Tianmin Wang and Shaoxiong Zhou
Y. L. Zhang et al., "Effect of La2O3 Content on Mechanical Properties and Toughened Mechanics of SiC Nanowires Toughened Cw/SiC Composites ", Materials Science Forum, Vol. 650, pp. 119-125, 2010