In situ synthesis of SiC nanowire porous layer on carbon/carbon composites

Abstract

AbstractSiC nanowire porous layer was synthesized in situ by a simple two‐step technique involving slurry painting and high temperature heat‐treatment without catalyst assist. The proposed method is effective and low‐cost, which can prepare plentiful and high‐purity SiC nanowires (SiCNWs). The microstructure of SiCNWs and the effects of heat‐treatment temperatures on the synthesis of SiCNWs were investigated in detail. Results show that the as‐synthesized NWs consisted of 3C–SiC, with the length of up to several hundred micrometers and the diameter of 50‐100 nm at 1500°C. Meanwhile, the diameter of SiCNW increases with the increasing of heat‐treatment temperature. The growth process of the SiCNWs can be controlled by the vapor‐solid growth mechanism. After introducing SiCNWs into the SiC coating prepared by pack cementation, the elastic modulus of the nanowire‐toughened SiC coating was increased by 35% compared to SiC coating without SiCNWs.