Interfacial microstructure and mechanical properties of TiAl and C/SiC joint brazed with TiH2–Ni–B brazing powder
Interfacial microstructure and mechanical properties of TiAl and C/SiC joint brazed with TiH2–Ni–B brazing powder
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DOI：
10.1016/j.matchar.2013.02.010
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发表时间：
2013-05
影响因子：
4.7
通讯作者：
Zhenwen Yang;Lixia Zhang;Xiaoyu Tian;Yuzhang Liu;P. He;Jicai Feng
中科院分区：
文献类型：
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作者：
Zhenwen Yang;Lixia Zhang;Xiaoyu Tian;Yuzhang Liu;P. He;Jicai Feng
采用机械球磨法制备了(TiH_2-66Ni)1−xBX(x=3wt.%)钎焊粉。用该钎料在1180℃保温10min，成功地实现了TiAl合金和C/SiC复合材料的钎焊。研究了钎焊接头的显微组织和力学性能。接头的典型组织分为三个特征区，即与C/SiC复合材料相邻的TiC反应层、TiB晶须增强中心区和TiAl合金相变的β层。原位合成的TiB晶须起到了有效的增强相作用，降低了接头的残余应力，提高了接头的剪切强度。接头室温强度达到105 Mpa，随着碳纤维的拔出，裂纹主要在C/SiC基材中扩展，部分在TiC层和τ3相中扩展。接头强度随试验温度的升高略有下降，在600℃试验时仍保持在70 Mpa。600℃试验时，裂纹扩展路径由TiC反应层转向τ-3相。
(TiH2–66Ni)1−xBx(x=3wt.%) brazing powder was fabricated by mechanical milling of a TiH2, Ni and B mixture with the milling time ranged from 30 to 180min. TiAl alloy and C/SiC composite were successfully brazed using this filler metal at 1180°C for 10min. The microstructure and mechanical properties of the brazed joints were investigated. The typical microstructure of the joint was divided into three characteristic zones, including the TiC reaction layer formed adjacent to C/SiC composite, the TiB-whisker reinforced central zone, and the β layer transformed from TiAl alloy. The in situ synthesized TiB whiskers acted as an effective reinforcement phase aid to decrease the residual stress and improve the shear strength of the joints. The joint strength reached 105MPa at room temperature, and cracks primarily propagated in the C/SiC substrate with the pull-out of carbon fibers and partially in the TiC layer and τ3phase. The joint strength decreased slightly with the testing temperature increased to 500°C, and remained at 70MPa when tested at 600°C. The crack propagation path diverted from the TiC reaction layer to the τ3phase when the joint was tested at 600°C.