Evolution mechanisms of the primary alpha and beta phases during alpha/beta deformation of an alpha/beta titanium alloy TC8
Evolution mechanisms of the primary alpha and beta phases during alpha/beta deformation of an alpha/beta titanium alloy TC8
复制标题
α/β钛合金TC8的α/β变形过程中初生α相和β相的演化机制
DOI：
10.1016/j.matchar.2016.08.028
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发表时间：
2016
影响因子：
4.7
通讯作者：
Liu Qing
中科院分区：
文献类型：
--
作者：
Wang Ke;Li Miaoquan;Liu Qing
在820-940 °C两相区以10-50 s-1的应变速率对TC 8钛合金进行等温压缩，利用光学显微镜（OM）和透射电子显微镜（TEM）研究初生α和β相的演变机制，包括晶粒形貌、动态回复（DRV）和动态再结晶（DRX）。金相分析表明，变形温度对合金相含量和晶粒形貌的影响比对应变速率的影响更为显著。由于β相中的DRX，β晶粒仅在940 °C下实现细化。透射电镜观察到初生α相的动态再结晶晶粒、亚晶、亚晶界和位错形貌随温度和应变速率的显著变化，并与动态再结晶和动态再结晶有关。初生α相的动态再结晶在860 °C的中温下最强，而在940 °C的中温下，初生α相的动态再结晶占主导地位。随着温度的升高，在β相中的主要机制由DRV转变为DRX。最后，基于初生α相的动态再结晶和动态再结晶以及β相扩散的共同作用，揭示了变形参数对初生α晶粒形貌的影响机制。
A TC8 titanium alloy was isothermally compressed at the strain rates of 10–50 s− 1in the two-phase region of 820–940 °C, and the evolution mechanisms of the primary α and β phases, including grain morphology, dynamic recovery (DRV) and dynamic recrystallization (DRX), were investigated by optical microscopy (OM) and transmission electron microscopy (TEM). OM reveals that the phase content and grain morphology are more significantly influenced by the deformation temperature than the strain rate. The β grains achieve refinement only at 940 °C due to DRX in the β phase. TEM reveals the remarkable variations of the DRX grains, subgrains, sub-boundaries and dislocations morphology with temperature and strain rate related to DRV and DRX in the primary α phase. The DRX in the primary α phase appears most strongly at a middle temperature of 860 °C, and DRV dominates in the primary α phase at 940 °C. While the dominant mechanism varies from DRV to DRX in the β phase as the temperature increases. Finally, the influence mechanism of deformation parameters on the primary α grain morphology is revealed based on the combined effect of DRV and DRX in the primary α phase and diffusion of the β phase.