ZrB_(2)超细粉体改性C/C-SiC-ZrC复合材料的微观结构和烧蚀性能  

Microstructures and ablation properties of ZrB_(2)ultrafine powder modified C/C-SiC-ZrC composites

作　　者：汤磊 尹健[1] 熊翔[1] 张红波[1] 汪帅 左劲旅 TANG Lei;YIN Jian;XIONG Xiang;ZHANG Hongbo;WANG Shuai;ZUO Jinlü(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Hunan Boyun New Materials Co.Ltd.,Changsha 410205,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]湖南博云新材料有限公司,湖南长沙410205

出　　处：《中南大学学报（自然科学版）》2024年第8期3093-3104,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(U19A2099)。

摘　　要：为进一步提升C/C-SiC-ZrC复合材料的抗烧蚀性能,采用反应熔渗法(reactive melt infiltration,RMI)制备ZrB_(2)超细粉体改性C/C-SiC-ZrC复合材料,考察ZrB_(2)超细粉体含量对改性复合材料的微观结构和烧蚀性能的影响。研究结果表明:相较于未改性的C/C-SiC-ZrC复合材料,ZrB_(2)超细粉体的引入使C/C-SiC-ZrC复合材料的密度由2.25 g/cm^(3)增至2.40~2.48 g/cm^(3);ZrB_(2)主要分布在ZrC基体中,且分布均匀;ZrB_(2)超细粉体的添加显著提升了复合材料的抗烧蚀性能;电火花等离子体烧蚀120 s后,当ZrB_(2)超细粉体摩尔分数为2%时,复合材料的质量烧蚀率和线烧蚀率最低,分别为6.90 mg/s和2.26μm/s;在烧蚀过程中,氧化生成的ZrO_(2)黏附在材料表面,与具有一定流动性的SiO_(2)形成龟壳状的ZrO_(2)-SiO_(2)氧化层,该氧化层减少了烧蚀过程中等离子体向基体的扩散和热传递,有效提升了改性复合材料的抗烧蚀性能。To furtherly improve the ablation resistance of C/C-SiC-ZrC composites,ZrB_(2)ultrafine powder-modified C/C-SiC-ZrC composites were prepared by the reactive melt infiltration(RMI)method.The effects of ZrB_(2)ultrafine powder contents on the microstructure and ablation properties of modified composites were investigated.The results show that the introduction of ZrB_(2)ultrafine powder significantly increases the density of C/C-SiC-ZrC composites from 2.25 g/cm^(3)to 2.40−2.48 g/cm^(3),compared to the unmodified C/C-SiC-ZrC composites.ZrB_(2)is mainly observed in the ZrC matrix and exhibits uniform distribution.The addition of ZrB_(2)ultrafine powder significantly improves the ablation resistance of the composites.After 120 s of spark plasma ablation,the composites exhibites the lowest mass and linear ablation rates of 6.90 mg/s and 2.26μm/s,respectively,when the ZrB_(2)ultrafine powder mole fraction is 2%.During the ablation process,the oxidized ZrO_(2)adheres to the composites'surface,forming a tortoiseshell-like ZrO_(2)-SiO_(2)oxide layer with SiO_(2),which exhibits a certain degree of fluidity.The oxide layer reduces the diffusion and heat transfer of plasma to the matrix during the ablation process,which effectively improves the ablation resistance of modified composites.

关 键 词：ZrB_(2) C/C-SiC-ZrC 反应熔渗 微观结构 抗烧蚀性能 

分 类 号：TB332[一般工业技术—材料科学与工程]