TiAl合金与C/SiC复合材料钎焊接头界面组织和性能

Microstructure and mechanical property of vacuum brazed TiAl and C/SiC joint

摘要: 采用AgCu箔片对TiAl合金和C/SiC复合材料进行钎焊,研究了接头界面组织的形成及演化过程,分析了界面组织对接头性能的影响.结果表明,TiAl合金的溶解量对接头界面组织的影响较大,当钎焊温度为900℃,保温10 min时,TiAl侧观察到团块状AlCu2Ti相,并伴随少量的条状AlCuTi相和AlCu₄相,靠近复合材料侧焊缝存在大量的AgCu共晶组织和富银区,TiC反应层的生成实现了复合材料的可靠连接.钎焊温度为900℃,保温25 min时,生成的团块状AlCu₂Ti相弥散分布在整个焊缝,强化了接头,接头的抗剪强度达到74 MPa.

Abstract: TiAl alloy and C/SiC composites were vacuum brazed with AgCu foils.The formation and evolution of interfacial structure and its effects on shear strength of the joints were studied in this paper.The results showed that the dissolution of TiAl substrate had a strongly effect on interfacial structure.When the brazing temperature was 900℃ for 10 min,AlCu₂Ti blocks accompanied with a small number of AlCuTi and AlCu₄ phases were observed at TiAl side.There were a lot of AgCu eutectic and silver-rich areas close to the composites and TiC reaction layer was formed between C/SiC composite and AgCu eutectic or silver-rich area.Due to the reinforcing effect of the massive AlCu2Ti phases which dispersed in the whole interlayer,the joint shear strength reached 74 MPa when brazing temperature was 900℃ for 25 min.