Fabrication of SiC_w/SiC–Si–Y composites and their resistance to water-oxygen corrosion at 1500 °C

The thermos-structural materials with high strength and high temperature water-oxygen corrosion resistance are urgently needed in aero-space fields. SiC whisker reinforced SiC matrix (SiC_w/SiC) composites are the ideal candidate materials for their excellent mechanical properties and thermostability. However, the poor resistance to water-oxygen corrosion ability of SiC matrix limits their further application. In this work, a novel SiC_w/SiC–Si–Y composites were first prepared by infiltrating silicon-yttrium (Si–Y) alloy into SiC_w/C preform via reactive melt infiltration method. The as-obtained composites not only show the excellent mechanical properties (σ_F = 363 MPa, K_ⅠC = 9.14 MPa m^1/2), and more importantly after water-oxygen corrosion of 20 h at such temperature as high as 1500 °C, the strength and toughness retention of the composites can reach 106.1% and 103.6%, respectively. The SiC_w/SiC–Si–Y composites developed in this paper have a great potential as a new high-performance thermos-structural material for aero-space applications.