Abstract

In present work, a novel SiC_f reinforced (Al₃Ti + Al₃Ni)-based metallic–intermetallic laminate (Ti–(Al₃Ti + Al₃Ni)/SiC_f-MIL) composite without centerline defect was prepared using Ti, Al foils, NiTi wires and SiC fibers by vacuum hot pressing sintering method. Electron backscatter diffraction was employed to characterize the microstructure and phase constituents of Ti–(Al₃Ti + Al₃Ni)/SiC_f-MIL composite during various stages of preparation process. The elimination mechanism of intermetallic centerline was discussed. Besides, quasi-static compressive performance and fracture toughness of the synthesized composite were investigated. The experimental results indicated that as reaction time increasing, the NiTi/Al interfacial reaction occurred prior to the Ti/Al interfacial reaction to form an Al₃Ti/Al₃Ni zone. Then, the oxides gathered at the front of Ti/Al interfacial reaction layer were dispersed in the intermetallic layer rather than being pushed together to generate the centerline due to the Al₃Ti/Al₃Ni zone. After reaction, there were no residual NiTi phases and intermetallic layers mainly consisting of Al₃Ti and Al₃Ni phases were obtained in this composite. In addition, high angle grain boundaries in Al₃Ti grains occupied a large proportion, conversely, low angle grain boundaries dominated in Al₃Ni grains. Furthermore, stress concentration appears at the interface between layers instead of along the middle plane of intermetallic layer. Moreover, both compressive strength and fracture toughness of the composite are superior in comparison with SiC_f reinforced Ti–Al₃Ti metallic–intermetallic laminate composite (Ti–Al₃Ti/SiC_f-MIL) ascribed to the elimination of centerline.

Graphic Abstract

中文翻译：

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SiC f增强（Al 3 Ti + Al 3 Ni）基金属-金属间层合复合材料的组织演变和力学性能

摘要

在目前的工作中，使用Ti制备了没有中心线缺陷的新型SiC _f增强（Al ₃ Ti + Al ₃ Ni）基金属-金属间层合物（Ti-（Al ₃ Ti + Al ₃ Ni）/ SiC _f -MIL）复合材料。 ，铝箔，NiTi丝和SiC纤维采用真空热压烧结法。电子背散射衍射用于表征Ti–（Al ₃ Ti + Al ₃ Ni）/ SiC _f的微观结构和相组成-MIL复合材料在制备过程的各个阶段。讨论了金属间中心线的消除机理。此外，还研究了合成复合材料的准静态压缩性能和断裂韧性。实验结果表明，随着反应时间的增加，NiTi / Al界面反应先于Ti / Al界面反应形成Al ₃ Ti / Al ₃ Ni区。然后，由于Al ₃ Ti / Al ₃ Ni区的缘故，聚集在Ti / Al界面反应层前部的氧化物分散在金属间层中，而不是被推到一起而产生中心线。反应后，没有残留的NiTi相和主要由Al组成的金属间层在该复合物中获得了₃ Ti和Al ₃ Ni相。另外，Al ₃ Ti晶粒中的高角度晶界占很大比例，相反，Al ₃ Ni晶粒中的低角度晶界占主导。此外，应力集中出现在层之间的界面处，而不是沿着金属间层的中间平面。此外，该复合材料的两个压缩强度和断裂韧性都优于在有SiC的比较_˚F增强的Ti-Al系₃的Ti金属的金属间层压复合材料（钛铝₃的Ti /碳化硅_˚F -MIL）归因于消除的中心线。

图形摘要