High temperature oxidation and ablation behaviors of HfB_(2)-SiC/SiC coatings for carbon/carbon composites fabricated by dipping-carbonization assisted pack cementation  

作　　者：Lei Zhou Jiaping Zhang Dou Hu Qiangang Fu Wuqing Ding Jiaqi Hou Bing Liu Mingde Tong 

机构地区：[1]State Key Laboratory of Solidification Processing,Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials,Northwestern PolytechnicalUniversity,Xi’an 710072,China

出　　处：《Journal of Materials Science & Technology》2022年第16期88-98,共11页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51872239,52061135102,52002321);the Creative Research Foundation of Science and Technology on Thermostructural Composite Materials Laboratory(No.5050200015);the Fundamental Research Funds for the Central Universities(No.G2020KY05125);the Xi’an Association for Science and Technology"Young Talent Support Project"(No.095920211338)。

摘　　要：To improve the uniformity and the content of HfBin Hf B-Si-based ceramic coating and alleviate the damage of substrate,and then enhance the high-temperature(1700°C)oxidation and cyclic ablation resistances of carbon/carbon composites,a close-knit double layer HfB_(2)-SiC/SiC coatings with a mosaic structure and high content of HfBwere prepared by a novel dipping-carbonization assisted pack cementation methods(DPC–HS/S).In contrast,a HfB_(2)-SiC/SiC coatings were also fabricated by pack cementation(PC–HS/S).Results revealed that the oxidation and ablation protective performances of the DPC–HS/S coatings were superior to those of PC–HS/S coatings.After 30 thermal cycles between 1500°C and room temperature,the mass gain of the coated sample was 0.78%,and the mass loss was 1.65%after oxidation at 1700°C for 156 h.Moreover,under an oxyacetylene torch ablation for 180 s(3 cycles),the linear ablation rate of the DPC–HS/S coated specimen was 1.62μm/s,which was much lower than that of PC–HS/S coated specimen(3.08μm/s).

关 键 词：C/C composites HfB2 Oxidation resistance Cyclic ablation resistance 

分 类 号：TB332[一般工业技术—材料科学与工程]