Huang Feng, Xu Jiaguo, Zhan Zihao, Cheng Zhe, Liu Yanxiong
State Key Laboratory of Light Superalloys, Wuhan University of Technology, Wuhan, 430070, China.
Hubei Longzhong Laboratory, Xiangyang, 441022, China.
Sci Rep. 2025 Aug 11;15(1):29433. doi: 10.1038/s41598-025-15339-4.
In this paper, the microstructure and mechanical properties of a high Nb-TiAl alloy with different carbon contents were characterized and measured, and the influence mechanisms of carbon addition were discussed. The results indicate that, the added carbon was first dissolved in alloy matrix and caused lattice distortion in α₂-TiAl and γ-TiAl. Exceeding its solid solubility, which was proved to be about 0.6 at%, the extra carbon was precipitated in the form of TiAlC. In addition, with the increasing of carbon content, the volume fractions of the α₂ phase and TiAlC enhancement phase increased, while the relative contents of γ phase and B2 phase decreased. Under the synergistic effects of phase composition, C solid solution strengthening, TiAlC precipitation strengthening and fine crystal strengthening, the high Nb-TiAl-0.6 C alloy exhibits the best overall performance, especially the high temperature compression performance. Compared with the original alloy without carbon addition, at 800 °C, its compressive stress increases from 900 MPa to 1074 MPa and compressive strain corresponding to the maximum compressive stress increases from 11.3 to 12.5% respectively.
本文对不同碳含量的高铌钛铝合金的微观组织和力学性能进行了表征与测试，并探讨了碳添加的影响机制。结果表明，添加的碳首先溶解于合金基体中，导致α₂-TiAl和γ-TiAl晶格畸变。超过其固溶度（约为0.6原子%）后，多余的碳以TiAlC形式析出。此外，随着碳含量的增加，α₂相和TiAlC增强相的体积分数增加，而γ相和B2相的相对含量降低。在相组成、C固溶强化、TiAlC析出强化和细晶强化的协同作用下，高铌钛铝-0.6C合金表现出最佳的综合性能，尤其是高温压缩性能。与未添加碳的原始合金相比，在800℃时，其压缩应力从900MPa增加到1074MPa，对应最大压缩应力的压缩应变分别从11.3%增加到12.5%。
