HfB2-ZrB2-SiC改性C/C复合材料的制备及性能  

Preparation and properties of HfB2-ZrB2-SiC modified C/C composites

作　　者：向秋玲 汤振霄 彭可[1] 易茂中[1] XIANG Qiuling;TANG Zhenxiao;PENG Ke;YI Maozhong(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2020年第2期118-124,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：湖南省自然科学基金资助项目(2017JJ2320)。

摘　　要：将HfB2和ZrB2陶瓷粉按体积比1:1混合制成高固相含量的浆料,通过料浆浸渍结合聚碳硅烷先驱体的浸渍裂解,制备密度为3.37 g/cm^3的C/C-HfB2-ZrB2-SiC复合材料,研究材料的显微组织、力学性能及抗烧蚀性能。结果表明:料浆浸渍法引入的HfB2和ZrB2陶瓷颗粒主要分布在C/C多孔复合材料的网胎层及针刺区,聚碳硅烷裂解产生的SiC主要分布在陶瓷颗粒及纤维束间,这3种陶瓷相都均匀地填充于材料内部。C/C-HfB2-ZrB2-SiC复合材料的抗弯强度和断裂韧性分别为382.6MPa和11.2MPa·m^1/2,表现出明显的假塑性断裂特征。C/CHfB2-ZrB2-SiC复合材料在烧蚀过程中生成HfO2-ZrO2复相氧化膜阻止氧进入材料内部,提高抗烧蚀性能。在2 500℃/120 s的烧蚀条件下表现出优异的抗烧蚀性能,其线烧蚀率和质量烧蚀率分别为0.71μm/s和0.53 mg/s。C/C-HfB2-ZrB2-SiC composites with a density of 3.37 g/cm^3 were prepared by high-solid-loading slurry impregnation and densified by polycarbosilane precursor infiltration and pyrolysis process,and the high-solid-loading slurry consist of HfB2 and ZrB2 ceramic powders with a volume fraction of 1:1.The microstructure,mechanical properties and ablation resistance of the composites were investigated.The results show that HfB2 and ZrB2 ceramic particles introduced by slurry impregnation method are mainly distributed in short cut fiber web layer and needle-punched area of C/C composites.SiC obtained by polycarbosilane precursor infiltration and pyrolysis process mainly distributes between ceramic particles and fiber bundles.HfB2,ZrB2 and SiC are uniformly filled in the materials.The bending strength and fracture toughnes of the C/C-HfB2-ZrB2-SiC composites are 382.6 MPa and 11.2 MPa·m^1/2 respectively,showing obvious pseudoplastic fracture characteristics.In the process of ablation,the formation of HfO2-ZrO2 mixed layer preventes oxygen from entering into the composites,which improves the ablation resistance of the material.C/C-HfB2-ZrB2-SiC composites exhibit good ablation resistance at 2500℃.The linear and mass ablation rates after ablation for 120 s are 0.71μm/s and 0.53 mg/s.

关 键 词：C/C-HfB2-ZrB2-SiC复合材料 料浆 微观结构 力学性能 抗烧蚀性能 

分 类 号：TB332[一般工业技术—材料科学与工程]