The effects of microstructure morphology on corresponding tensile mechanical properties of Ti–5Al–5Mo–5V–1Cr–1Fe alloy controlling by three different heat treatment conditions (solution, single-step and two-step aging) were investigated in the present paper. The results show that the solution temperature exhibited an important impact on the precipitation behavior of secondary-α phase (α_s) during aging, in which the content of α_s gradually increased with the increase of solution temperature. When the alloy was single-step aged at 500–600 ​°C, the needle-like α_s precipitated from matrix, as well as the content of α_s decreased and coarsened corresponding to the increase of aging temperature. Compared with single-step aging, the α_s slightly increased when the alloy was subjected to two-step aging heat treatment. The tensile results show that the α_s is the main strengthening phase in the alloy. Moreover, its content as well as the intensity of the precipitation mode directly affects the strength, whereas inevitably with an accompanying penalty on ductility. In general, the higher solution temperature and the lower first-step aging temperature result in a more intensive α_s and then lead to the higher strength. Meanwhile, $\left\{10\overline{1}2\right\}$ and $\left\{10\overline{1}1\right\}$ twins were found in two-step aged tensile samples, which may impart twinning-induced plasticity (TWIP). Overall, this study demonstrates that the alloy can be heat treated to achieve an excellent match between strength and ductility and to provide sufficient stress and optional ductility (ultimate strength of 978–1439 ​MPa and elongation of 8.25–18.9%).

本文通过三种不同的热处理条件（固溶、单步和两步时效）研究了显微组织形态对 Ti-5Al-5Mo-5V-1Cr-1Fe 合金相应拉伸力学性能的影响。结果表明，固溶温度对时效过程中次生α相(α _s )的析出行为有重要影响，其中α _s的含量随着固溶温度的升高而逐渐增加。当合金是老化在500-600℃下单步，针状α_小号沉淀从矩阵，以及α的含量_小号降低，粗大化对应于老化温度的升高。与单步老化相比，α当合金进行两步时效热处理时，_s略有增加。拉伸结果表明，α _s是合金中的主要强化相。此外，它的含量以及沉淀模式的强度直接影响强度，而不可避免地伴随着对延展性的惩罚。一般来说，较高的固溶温度和较低的第一步时效温度会导致更强烈的α _s，从而导致更高的强度。同时，$\left\{10\overline{1}2\right\}$ 和 $\left\{10\overline{1}1\right\}$在两步时效拉伸样品中发现了孪晶，这可能会产生孪晶诱导塑性 (TWIP)。总的来说，这项研究表明，该合金可以进行热处理，以实现强度和延展性之间的完美匹配，并提供足够的应力和可选的延展性（最终强度为 978-1439 MPa，伸长率为 8.25-18.9%）。