温压固化结合CVI增密制备石墨基复合材料的微观结构与性能  

Microstructure and properties of graphite-based composites prepared by warm-pressure curing combined with CVI densification

作　　者：张洋[1] 李国栋[1] 韩前武 姜毅 王洋[1] ZHANG Yang;LI Guodong;HAN Qianwu;JIANG Yi;WANG Yang(National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China)

机构地区：[1]中南大学轻质高强结构材料国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2021年第3期211-218,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：轻质高强结构材料国家重点实验室基金资助项目。

摘　　要：以天然鳞片石墨粉、中间相沥青粉以及短炭纤维为原料,采用温压固化结合化学气相渗透(chemical vapor infiltration,CVI)的方法制备石墨基复合材料。通过X射线衍射分析、扫描电镜和偏光显微镜以及力学性能与导热性能测试等手段,研究CVI沉积热解炭(pyrolytic carbon,PyC)对石墨基复合材料微观结构与性能的影响。结果表明:与单纯掺杂短炭纤维的石墨基复合材料相比,通过CVI增密在复合材料内部引入PyC,材料的抗弯强度从22.5 MPa显著提高到55.9 MPa,同时复合材料的微晶尺寸增大,石墨化度提高,从而使材料的导热性能提高,热导率由213.24 W/(m·K)提高到242.80 W/(m·K)。Using natural flake graphite powder,mesophase pitch powder and short carbon fiber as raw materials,graphite-based composites are prepared by the method of warm-pressure curing combined with chemical vapor infiltration(chemical vapor infiltration,CVI).The influence of CVI deposited pyrolytic carbon(PyC)on the microstructure and properties of graphite-based composites was studied through X-ray diffraction analysis,scanning electron microscopy and polarized light microscopy,as well as mechanical performance and thermal conductivity testing.The results show that the bending strength of the composites after CVI densification is improved compared with the graphite-based composites doped with short carbon fibers.By introducing PyC into the composite material through CVI,the bending strength of the graphite-based composites increases from 22.5 MPa to 55.9 MPa.Besides,the average grain size of the material and the degree of graphitization increase,which thereby improves the thermal conductivity of the material from 213.24 W/(m·K)to 242.80 W/(m·K).

关 键 词：石墨基复合材料 化学气相渗透 显微结构 力学性能 导热性能 

分 类 号：TB331[一般工业技术—材料科学与工程]