Mullite-modified ZrB2-MoSi2 coating for carbon/carbon composites to withstand long term ablation

作者:Liu, Xuezhang*; Deng, Chunming; Deng, Changguang; Liu, Min; Zhou, Kesong*
来源:Ceramics International, 2018, 44(4): 4330-4337.
DOI:10.1016/j.ceramint.2017.12.025

摘要

There are two prominent challenges when coating carbon/carbon composites with ultra-high temperature ceramics to withstand long term ablation. One is the decrease of coating strength under high ablation temperature, and the other is the volatilization of produced glass phase. Due to excellent creep resistance, mullitemodified ZrB2-SiC coating was here investigated, and coating microstructure, the composition and ablation behavior were studied. Results showed a dense scale was formed on the surface layer and it alleviated the volatilization of glass phase. Meanwhile, the strip-shaped particles of mullite pinned in the middle layer and a firm framework with ZrO2 particles filling in the interspaces was constituted, which prevented the peeling off of the coating. After oxyacetylene flame ablation for 600 s, mass ablation rate of the modified ZrB2-MoSi2 coating was - 1.91 x 10(-3) g/s, which exhibited better ablation resistance compared with a traditional ZrB2-MoSi2 coating.