金属学报英文版 ›› 2021, Vol. 34 ›› Issue (7): 932-942.DOI: 10.1007/s40195-020-01170-5

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  • 收稿日期:2020-06-10 修回日期:2020-08-24 接受日期:2020-09-10 出版日期:2021-01-02 发布日期:2021-01-02

Tensile Behavior of SiC Fiber-Reinforced γ-TiAl Composites Prepared by Suction Casting

Yingying Shen1,2, Qing Jia1(), Xu Zhang1, Ronghua Liu1, Yumin Wang1, Yuyou Cui1, Rui Yang1()   

  1. 1Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
    2School of Materials Science and Engineering, University of Science and Technology of China, 72 Wenhua Road, Shenyang 110016, China
  • Received:2020-06-10 Revised:2020-08-24 Accepted:2020-09-10 Online:2021-01-02 Published:2021-01-02
  • Contact: Qing Jia,Rui Yang
  • About author:Rui Yang, ryang@imr.ac.cn
    Qing Jia, qjia@imr.ac.cn;

Abstract:

The process of preparing SiC fiber-reinforced γ-TiAl composites by the conventional methods is difficult and complicated due to the high reactivity, high melting point and poor deformability of γ-TiAl alloys. In this work, suction casting, a promising method for preparing SiCf/TiAl composite, had been attempted. In the process, γ-TiAl alloy melt was introduced rapidly into a mold within pre-arranged fibers that were coated with additional layer of titanium alloy. This simple method successfully prevented serious reactions between the alloy melt and the fibers which remained intact during the solidification process. The interfacial reaction layer was observed by optical microscopy, scanning electron microscopy (SEM). The interfacial reaction products were identified by transmission electron microscopy (TEM). Tensile tests of the matrix alloy and composites were performed at room temperature and 800 °C. The results exhibited that the tensile strength of SiCf/γ-TiAl composite was higher than that of the matrix alloy at both room temperature and 800 °C. At room temperature, tensile strength of SiCf/γ-TiAl composite was increased by about 7% (50 MPa), whereas a double increase in tensile strength 14% (100 MPa) was obtained at 800 °C. The titanium alloy coating on the fiber not only prevented the serious interfacial reaction between the γ-TiAl alloy melt and the SiC fiber, but also played a role in delaying the propagation of cracks in the matrix to the fiber at 800 °C. The fracture mechanism of the composite was analyzed by fracture metallographic analysis.

Key words: Suction casting, SiCf/γ-TiAl composite;, Interfacial reaction, Tensile strength, Fracture mechanism