控制 β 单相区变形后的组织形态对近 β 钛合金服役性能至关重要。 研究了 TC18 钛合金 β 单相区热变形后的 组 织 演 变 规 律 ， 发现 随 着 应 变 速 率 的 降 低 ， 小角 度 晶 界 (low-angle grain boundaries, LAGBs)分数 会 显 著 降 低 ，锯齿 状 β 晶界 呈 现 平 直 化 趋 势 ，同时 亚 晶 从 晶 界 区 域 向 晶 内 扩 展 且 尺 寸 明 显 粗 化 。 晶粒 取 向 显 示 ，随着 应 变 速 率降低 和 变 形 量 的 增 加 ，{001}织构 体 积 分 数 显 著 增 加 ，而{111}织构 呈 现 相 反 演 化 规 律 。 这是 由 于{112}<111> 滑移系的 择 优 激 活 与 应 变 诱 导 晶 界 迁 移(strain-induced grain boundary migration, SIBM)协同 作 用 导 致 。 此外 ，应变 速 率的降低使得动态再结晶(dynamic recrystallization, DRX)分数随之提高，且 DRX 机制从不连续动态再结晶(discontinuousdynamic recrystallization, DDRX)向连续动态再结晶(continuous dynamic recrystallization, CDRX)过渡，这也导致{001}再 结晶织构组分有所增强。

Controlling the microstructure morphology after deformation in the β single-phase region is crucial for the service performance of near-β titanium alloys. The microstructural evolution of the TC18 titanium alloy after hot deformation in the β single-phase region was investigated. The results show that as the strain rate decreases, the fraction of low-angle grain boundaries (LAGBs) significantly decreases, the serrated β grain boundaries tend to straighten, and subgrains expand from grain boundary regions into grain interiors with noticeable coarsening. The grain orientation analysis reveals that with decreasing strain rate and increasing deformation, the volume fraction of the {001} texture significantly increases, whereas the {111} texture exhibits the opposite trend. This is attributed to the synergistic effect of preferential activation of the {112}<111> slip system and strain-induced grain boundary migration (SIBM). Additionally, lower strain rates lead to an increase in the dynamic recrystallization (DRX) fraction, with the DRX mechanism transitioning from discontinuous dynamic recrystallization (DDRX) to continuous dynamic recrystallization (CDRX), which also enhances the {001} recrystallization texture component.