In this study, the hot deformation behavior of an as-cast and hot rolled β21S alloy (Ti–15Mo–3Al–3Nb–0.2Si) was investigated. Based on the hot compression tests, which were conducted at high temperatures (800–1200 °C) using different strain rates (10^-2 –10 s⁻¹), a processing map and energy efficiency (η) value were obtained for the alloy. Furthermore, the deformation activation energy of the alloy was calculated and the tensile properties of the alloy after the thermal treatment were analyzed. The processing map results revealed that plastic instability occurred at a temperature of 900 °C and a strain rate of 10 s^-1. Over the entire temperature range the hot deformation mechanisms indicated an activation energy of 269 kJ/mol and the ln Z values, calculated by the Zener-Holloman parameter, varied between 17 and 32 s^-1, in which the stable flow was associated with dynamic recovery and dynamic recrystallization. Likewise, this study revealed that dynamic recovery is the dominant deformation mechanism in the β21S alloy at temperatures lower than 1000 °C, while dynamic recrystallization is prevalent at higher temperatures. Finally, the tensile properties of the β21S alloy depend significantly on the post-processing heat treatment. The rapid grain-growth phenomenon observed at 1200 °C suggests that the practical alloy rolling conditions may differ from that used for hot compression tests performed in the laboratory. These results demonstrate that the process optimization is significantly dependent on sample size which affects soaking time.

在这项研究中，研究了铸态和热轧β21S合金（Ti–15Mo–3Al–3Nb–0.2Si）的热变形行为。根据在高温（800–1200°C）下使用不同的应变速率（10 ^-2 –10 s ^-1）进行的热压缩测试，获得了该合金的工艺图和能效（η）值。此外，计算了合金的变形活化能，并分析了热处理后合金的拉伸性能。加工图结果表明，在900°C的温度和10 s ^-1的应变速率下发生了塑性不稳定性。。在整个温度范围内，热变形机制表明活化能为269 kJ / mol，由齐纳-霍洛曼参数计算得出的ln Z值在17到32 s ^-1之间变化，其中稳定的流动与动态恢复和动态重结晶有关。同样，这项研究表明，在低于1000°C的温度下，动态恢复是β21S合金的主要变形机制，而在较高温度下，动态再结晶是普遍的。最后，β21S合金的拉伸性能显着取决于后处理热处理。在1200°C观察到的快速晶粒长大现象表明，实际的合金轧制条件可能与实验室中进行的热压缩试验所采用的条件不同。这些结果表明，工艺优化在很大程度上取决于影响浸泡时间的样品量。