Thermal and Mechanical Properties of Alumina Matrix Composite with SiC Nanowires

Abstract

A very small amount (0.035, 0.1, 0.2 wt%) of β-SiC/SiO₂ core-shell nanowires (SiCNWs) were mixed with alumina powder, followed by hot-pressing at 1400^oC in argon atmosphere with 85 MPa applied pressure. Alumina specimens containing SiC nanopowder were also prepared for comparison. Full-dense specimens were obtained. Hardness was increased by 18% with decreasing grain sizes of alumina matrix composite. SiCNWs-contained specimens showed higher thermal conductivity than SiC nanopowder-contained ones. Furthermore, microstructure and SiCNWs distribution were observed by electron microscope, and fracture toughness of composites measured by indentation fracture method was also evaluated.