多晶硅炉热场用C/C复合材料的硅化腐蚀失效机理  

Silicon corrosion failure mechanism of C/C composite for polysilicon furnace heat field

作　　者：贾林涛 王梦千 李艳[3] 李爱军 Jia Lin-tao;Wang Meng-qian;Li Yan;Li Ai-jun(College of Sciences,Shanghai University,Shanghai 200444,China;Eighth Research Institute of Nuclear Industry,Shanghai 201800,China;Xi’an Aerospace Composites Research Institute,Shaanxi Xi’an 710025,China;Shaoxing Institute of Technology,Shanghai University,Zhejiang Shaoxing 312000,China)

机构地区：[1]上海大学理学院,上海200444 [2]核工业第八研究所,上海201800 [3]西安航天复合材料研究所,陕西西安710025 [4]上海大学绍兴研究院,浙江绍兴312000

出　　处：《炭素技术》2023年第1期15-19,28,共6页Carbon Techniques

摘　　要：以2D叠层炭布为增强体的炭/炭(C/C)复合材料作为多晶硅炉用热场盖板,对其在硅液/硅蒸汽共同作用下的硅化腐蚀失效机理进行了研究。通过多功能密度测试仪、扫描电子显微镜(SEM)和X射线衍射仪(XRD)分析了硅化作用对C/C复合材料致密度、微观结构及物相组成的影响,并对侵蚀后的C/C复合材料失效机理进行了分析。结果表明:硅化侵蚀后的C/C复合材料致密度高,存在大量的Si元素,生成了大量的β-SiC,且微观缺陷较多,层间开裂严重,呈现脆性断裂模式。理论分析发现,高温下单位摩尔质量的热解炭和单位摩尔质量的硅发生反应生成单位摩尔质量的SiC后,总体积膨胀约为单位摩尔热解炭体积的6.3倍,不同物相间的热失配导致热应力集中,引起C/C复合材料变形开裂失效,裂纹产生的扩散通道加剧了硅液/硅蒸汽对C/C复合材料的硅化侵蚀作用。Carbon/carbon(C/C) composites reinforced by 2D laminated carbon cloth were used as the heat field cover plate of polysilicon furnace.The mechanism of siliconization corrosion of C/C composite under the action of silicon liquid and silicon vapor was investigated.The effects of silicification on the density,microstructure and phase composition of C/C composites were investigated by multifunctional density tester,scanning electron microscope(SEM) and X-ray diffraction(XRD),and the failure mechanism of corroded C/C composites was analyzed.The results show that the silicified C/C composites contain a large number of Si elements and β-SiC,with many micro-defects,and possess high density,serious interlayer cracking and brittle fracture mode.The theoretical analysis shows that the total volume expansion of SiC per molar mass is about 6.3 times of that of the pyrolysis carbon per molar mass.The thermal mismatch between different phases leads to the concentration of thermal stress,resulting in the deformation and cracking failure of the C/C composite. The diffusion channel generated by crack intensifies the silicification erosion of C/C composites by silicon liquid/silicon vapor.

关 键 词：多晶硅炉 C/C复合材料 硅化侵蚀 热失配 扩散通道 

分 类 号：TB332[一般工业技术—材料科学与工程] TQ174[化学工程—陶瓷工业]