真空热压法制备Ti_(2)AlNb/TA15叠层复合材料的微观组织及其高温拉伸性能

Microstructure and high-temperature tensile properties of Ti_(2)AlNb/TA15 laminated composites prepared by vacuum hot pressing

为改善Ti_(2)AlNb合金的本征脆性且不牺牲其高温性能,将其与高温钛合金TA15进行复合,采用真空热压法制备了Ti_(2)AlNb/TA15叠层复合材料,研究了不同热压温度对其微观组织及其拉伸性能的影响。研究结果表明:界面层的孔洞缺陷随热压温度的升高逐渐减少,热压温度在1050℃及以上时可以获得无缺陷冶金结合界面。界面反应层厚度随热压温度的升高而增加,且在1050℃及以上的扩散温度条件下,反应区和Ti_(2)AlNb层间形成了一定宽度的过渡层,提升了界面结合性能。拉伸实验结果表明,相较于Ti_(2)AlNb合金,Ti_(2)AlNb/TA15叠层复合材料的室温和高温拉伸性能均有显著的提升。其中1050℃热压温度条件下的叠层复合材料具有较好的综合性能,650℃高温抗拉强度和应变分别为667.85 MPa和16.2%。

In order to improve the intrinsic brittleness of Ti_(2)AlNb alloy without sacrificing its high-temperature performance,a composite material was prepared by combining it with high-temperature titanium alloy TA15 using vacuum hot pressing.The effects of different hot pressing temperatures on the microstructure and tensile properties of Ti_(2)AlNb/TA15 laminated composite materials were investigated.The results show that the pore defects in the interface layer gradually decrease with the increase of the hot pressing temperature.A defect-free metallurgical bonding interface can be achieved at temperatures of 1050℃and above.The thickness of the interface reaction layer increases with the rise of the hot pressing temperature.Under the diffusion conditions at 1050℃and above,a transition layer of certain width formed between the reaction zone and the Ti_(2)AlNb layers,which improve the properties of the interface bonding.Tensile tests indicate that the room and high-temperature tensile properties of the Ti_(2)AlNb/TA15 laminated composite material are significantly improved compared with Ti_(2)AlNb alloy.The laminated composite material under the hot pressing temperature condition of 1050℃exhibits excellent comprehensive performance,with a high-temperature tensile strength and strain of 667.85 MPa and 16.2%,respectively.