Evaluation of Mechanical Properties of SiC Whisker Reinforced In-Situ Composites Prepared by Carbothermal Reduction of Silicate Minerals

Abstract

Al2O3-SiCx, and ZrO_-SiCx, composite powders were prepared by carbothermal reduction of alumino-silicate minerals (kaoline and silimanite) and zircon respectively. The powders were hot pressed at 175011C and 40 MPa pressure in argon atmosphere.Test specimens (4 x 6 x 30 mm3) were made out of hot pressed discs for mechanical properties evaluation. The physical properties i.e. bulk density (B.D.), apparent porosity (A.P.) were measured by Archimedes principle. Young's modulus, fracture toughness and bending strength were measured by resonance frequency response, SENB technique and 4-point bend test respectively. Mechanical properties were found to be better in the case of composites prepared from silimanite and zircon due to optimum whisker content.