低温反应熔渗工艺制备AlN-SiC复相陶瓷及其性能研究  

Fabrication and Properties of AlN-SiC Multiphase Ceramics via Low Temperature Reactive Melt Infiltration

作　　者：孙小凡 陈小武[1,2] 靳喜海 阚艳梅[1,2] 胡建宝 董绍明[1,2] SUN Xiaofan;CHEN Xiaowu;JIN Xihai;KAN Yanmei;HU Jianbao;DONG Shaoming(State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海硅酸盐研究所,高性能陶瓷和超微结构国家重点实验室,上海200050 [2]中国科学院大学材料与光电研究中心,北京100049

出　　处：《无机材料学报》2023年第10期1223-1229,共7页Journal of Inorganic Materials

基　　金：National Natural Science Foundation of China(52172111,51872310);National Key R&D Program of China(2022YFB3707700)。

摘　　要：AlN-SiC复相陶瓷力学性能好、导热性与抗高温氧化性能优异,作为纤维增强陶瓷基复合材料的基体材料具有良好的应用前景。本研究以Si-Al合金为熔渗介质,多孔C-Si_(3)N_(4)为熔渗预制体,对低温反应熔渗制备AlN-SiC复相陶瓷及其性能展开研究。研究发现Si-Al合金形态对反应熔渗过程存在着重要的影响:以Si-Al合金粉末作为熔渗介质时,反应熔渗过程中在Si-Al/C-Si_(3)N_(4)界面处将原位形成一层致密的Al–O阻挡层,从而严重阻碍Si-Al熔体向C-Si_(3)N_(4)预制体内部的渗透,使反应熔渗过程难以进行;以Si-Al合金锭作为熔渗介质时,Si-Al熔体可以深入渗透到多孔C-Si_(3)N_(4)预制体内部,并通过进一步反应,原位形成致密的AlN-SiC复相陶瓷。材料性能测试表明,所得材料的力学和热学性能与其内部残余硅含量关系密切。随着残余硅含量降低,材料强度明显提升,而热导率有所下降。含质量分数4%残余硅的AlN-SiC复相陶瓷,抗弯强度达到320.1 MPa,热导率达26.3 W·m^(–1)·K^(–1),材料的强度几乎与传统反应烧结SiC陶瓷相当,并深入探讨了出现上述现象的本质原因。本研究对低温熔渗工艺制备SiCf/AlN-SiC复合材料具有重要的指导意义。AlN-SiC multiphase ceramics possess robust mechanical strength,high thermal conductivity and good oxidization resistance,and show great potential as the matrix material of fiber reinforced ceramic matrix composites.In this work,AlN-SiC multiphase ceramics were fabricated via low temperature reactive melt infiltration of Si-Al alloy into porous C-Si_(3)N_(4)preforms.Influence of Si-Al source on the melt infiltration process was studied,and impact of residual silicon on the mechanical and thermal properties of the AlN-SiC ceramics was investigated.It was found that an Al–O layer was in-situ formed at the interface between Si-Al melt and C-Si_(3)N_(4)preform,when Si-Al powder was used as the infiltration medium.This seriously retarded the melt infiltration process and made the penetration of Si-Al melt into the C-Si_(3)N_(4)preform hardly possible.However,when Si-Al ingot was used as the infiltration medium,a well infiltration of Si-Al melt into the C-Si_(3)N_(4)preform occurred,which led to the formation of dense AlN-SiC ceramics.Mechanical and thermal property measurements indicated that the strength of the AlN-SiC ceramics was significantly improved as the residual silicon content in it was reduced,while a reverse trend was observed for the thermal conductivity.AlN-SiC ceramics with 4%(in mass)residual silicon showed a high strength of 320.1 MPa,nearly comparable to that of conventional reaction bonded SiC,although its thermal conductivity was modest(26.3 W·m^(–1)·K^(–1)).The fundamental reasons for the above phenomena were discussed.This study is of great significance for the preparation of SiCf/AlN-SiC composites by low temperature reactive melt infiltration.

关 键 词：反应熔渗(RMI) AlN-SiC 机械性能 热导率 

分 类 号：TB484[一般工业技术—包装工程]