Fabrication, microstructure and mechanical behavior of SiCw-B4C–Si composite

Abstract

SiC whiskers (SiCw) was prepared and SiCw-B4C–Si composites were fabricated by ball milling together with reactive hot press sintering process at the temperature around 1850K and 30MPa. The compositions, morphologies and mechanical properties of the fabricated composites were investigated. The hardness was decreased with the addition of SiCw and Si. The Si additive improved the relative density of B4C, whereas the addition of SiCw did not change the density to much. The addition of SiCw and Si reinforced the composite in fracture toughness and flexural strength due to the formation of laminated flakes and fiber network structures. At the contents of 5wt% SiCw and 10wt% Si, the relative density, hardness, flexural strength and fracture toughness of the composites could reach 96.5%, HRA93.5, 487MPa, 5.78MPam1/2, respectively.