Realization of (ZrC/SiC)n multilayer alternating coatings prepared by one-step chemical vapor deposition: Mechanical and anti-ablation enhancement

Abstract

Combining ZrC and SiC monolayers to form alternating multilayers on C/C composites allows to achieve advanced properties. Herein, a one-step CVD method was developed to fabricate the (ZrC/SiC)_n multilayer alternating coatings with high fabrication efficiency, high bonding strength and precise control of sublayer thickness and number. The deposition behavior of coating was demonstrated to be the hetero-epitaxial growth at the interface and the preferential growth of SiC and ZrC columnar grains. It brought a pure and tight interface between SiC and ZrC, with high bonding strength (ten times higher than common CVD method). The indentation response, scratch behavior and pullout test of the coating were studied to obtain the strengthen mechanism of one-step deposition. The increase of interfacial bonding strength gave the coating the ability to resist the delamination of sublayers, resulting in the improved mechanical properties and further superior ablation resistance.