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采用磁控溅射先驱丝法并结合真空热压技术制备SiC_f/TC17复合材料,并在973,1023,1073和1123 K进行长时热暴露实验.结果表明,在热压和热暴露过程中,界面附近的元素扩散形式主要为化学反应和浓度梯度导致的界面互扩散,以及基体相变扩散.化学反应扩散是C和Ti扩散的主要动力,也是反应层形成和长大的原因;原于浓度梯度使Si,Al,Mo,Cr,Zr和Sn在C层/反应层界面进行下坡扩散,但扩散程度有限;基体相变扩散使Al向α相偏聚,Mo和Cr向β相偏聚,Sn向Ti_3AlC偏聚,同时使这些元素的界面互扩散受到抑制.界面热稳定性研究表明,SiC_f/TC17复合材料的反应层长大激活能为138 kJ/mol,该材料界面在973 K及以下温度是长时稳定的.
The SiC_f / TC17 composites were prepared by magnetron sputtering precursor wire method combined with vacuum hot pressing technique, and long time thermal exposure tests were carried out at 973, 1023, 1073 and 1123 K. The results showed that during hot pressing and heat exposure, The diffusion of elements in the vicinity of the interface is mainly due to the interdiffusive interfacial diffusion caused by chemical reaction and concentration gradient and the matrix phase change diffusion.The chemical reaction diffusion is the main driving force for the diffusion of C and Ti and the reason for the formation and growth of the reaction layer, Gradient makes Si, Al, Mo, Cr, Zr and Sn downhill diffusion at the C layer / reaction layer interface, but the degree of diffusion is limited. Phase transformation and diffusion make the Al to α phase segregation, Mo and Cr to β phase segregation , The segregation of Sn into Ti_3AlC and the interfacial interdiffusion of these elements are inhibited.The thermal stability of the interface shows that the activation energy of the reaction layer of SiC_f / TC17 composites is 138 kJ / mol, the interface of the material is at 973 K and The following temperature is long-term stability.