烧蚀型面结构对CVI+HPIC工艺制备针刺C/C喉衬等离子烧蚀性能的影响  

Effect of Ablation Surface Microstructure on Plasma Arc Ablation Properties of C/C Throat Insert Fabricated via CVI+HPIC Methods

作　　者：吴小军[1] 杨杰[1] 郑蕊[1] 张兆甫 杨毅[1] WU Xiaojun;YANG Jie;ZHENG Rui;ZHANG Zhaofu;YANG Yi(Xi’an Aerospace Composites Research Institute,Xi’an 710025,China)

机构地区：[1]西安航天复合材料研究所,西安710025

出　　处：《无机材料学报》2020年第6期654-660,共7页Journal of Inorganic Materials

基　　金：国家自然科学基金(21676163);中国航天青年拔尖人才项目(2019.1-2021.12)。

摘　　要：以碳纤维无纬布/碳纤维网胎叠层针刺预制体为增强体,经化学气相渗透(CVI)联合沥青高压碳化(HPIC)工艺制备了热解碳+沥青碳双元基针刺C/C喉衬材料,利用X射线断层扫描(μ-CT)和扫描电镜(SEM)表征了材料的微观结构,采用等离子烧蚀试验考察了针刺喉衬材料X-Y纤维铺层面(0°)、Z向针刺面(90°)以及两者间过渡层面(23°、45°和68°)的烧蚀性能。结果表明,采用CVI+HPIC组合工艺能使针刺材料达到高致密态,获得了孔隙率仅为4%的C/C材料,材料内部孔隙呈离散态分布,其中98%的孔隙为小于20μm的小孔。烧蚀结果显示,针刺C/C材料不同区域的烧蚀性能存在差异,从X-Y层面(0°)到Z向针刺面(90°),其耐烧蚀性能呈先增强后减弱的趋势,68°层面耐烧蚀性能最好,线、质量烧蚀率分别为0.056 mm/s、0.050 g/s。烧蚀面纤维的排布是影响烧蚀性能的关键因素,68°层面因形成的尖端烧蚀模式占比较高,表现出最佳的耐烧蚀性能。The C/C composite was prepared by chemical vaper infiltration(CVI)followed by pitch impregnation and high pressure carbonization(HPIC)using needled non-woven carbon fiber felt preform.The microstructure of composites was characterized by micro-computed tomography(μ-CT)and scanning electron microscope(SEM).The ablation resistance at different cross sections was evaluated using plasma ablation test.Typical cross sections of the experiment were X-Y section(0°,perpendicular to needing direction),Z section(90°,parallel to needing direction)and cross sections(23°,45°,68°)of composites,respectively.The results presented that the porosity of the C/C composites was as low as 4%,and 98% of the internal pores was smaller than 20μm.The ablation resistance at different cross sections improved first and then decreased from X-Y section(0°)to Z section(90°).The cross section at 68°showed the best ablation resistance,at which the mass and linear ablation rates were 0.050 g/s and 0.056 mm/s,respectively.The best ablation resistance is attributed to the icicle-like ablation mode of carbon fiber,which indicates that fiber arrangement at the cross section has significant impact on ablation resistance of C/C composites.

关 键 词：针刺预制体 C/C复合材料 烧蚀率 微观结构 

分 类 号：TB332[一般工业技术—材料科学与工程]