High yield synthesis of SiC nanowires and their mechanical performances as the reinforcement candidates in Al2O3 ceramic composite

Abstract

In this work, SiC nanowires (SiCNWs) has been synthesized through a high yield in-situ carbothermal reduction strategy in all-solid raw materials reaction system. The effect of holding time on the morphology and yield of the as-synthesized SiC nanowires has been investigated in detail at reaction temperature, and the maximum yield of pure SiCNWs is above 70% after purification treatment. The positive performance of SiCNWs as reinforcements with different proportion (1.5 wt%∼7.5 wt%) on the mechanical properties of the alumina ceramic composites have also been explored. The fracture toughness and flexural strength of the ceramic composite display greatly improvement when the addition proportion of the SiCNWs is approximately 6 wt%. Compared with matrix control sample, the fracture toughness and flexural strength of the optimized SiC/Al2O3 ceramic composites were enhanced approximately 21.46% and 18.97% respectively. In addition, the maximum value of 15.6 GPa of Vickers hardness has been achieved for the ceramic composite with SiCNWs proportion of 7.5 wt%. All of these results suggest that SiCNWs exert a significant role in reinforcing ceramic matrix composites as an ideal reinforcement candidate.