Oxidation resistance behavior of SiC nanowires/Si layer on the C/SiC composites

To reduce Si layer delamination or spallation caused by volume change of the layer during thermal cycle and improve the oxidation resistance of Si layer, the SiC-nanowire-reinforced Si layer (SiCnws-Si layer) was prepared in situ on carbon/silicon carbide (C/SiC) composites though the chemical vapor reaction route and atmospheric plasma spray (APS). The SiC nanowires was conducive to fabricate a dense and homogeneous layer. The SiC nanowires was introduced to improve the bonding strength between Si layer and C/SiC composites, enhance the toughness of Si layer and relieve the thermal stress caused by volume change. Therefore, the results of thermal cycling and the tensile strength tests showed that the weight loss of the SiCnws-Si-coated C/SiC composites was 8.3%-60.9% lower than that of Si layer after suffering 12 times thermal cycles between room temperature and 1673 K. Moreover, due to the bridging effect of SiC nanowires on the interface, the tensile strength of the SiCnws-Si-coated C/SiC composites was higher than 3.9 MPa.

Automated summary

To reduce delamination or spallation of the Si layer during thermal cycles and enhance its oxidation resistance, a SiC-nanowire-reinforced Si layer (SiCnws-Si layer) was prepared on carbon/silicon carbide (C/SiC) composites using chemical vapor reaction and atmospheric plasma spray (APS). The introduction of SiC nanowires improved the bonding strength, toughness, and thermal stress relief of the Si layer. Results showed that the SiCnws-Si-coated C/SiC composites had lower weight loss (8.3%-60.9%) than Si layer after 12 thermal cycles between room temperature and 1673 K, and the tensile strength of the SiCnws-Si-coated C/SiC composites exceeded 3.9 MPa due to the bridging effect of SiC nanowires on the interface.