An experimental study of deformation mechanism and microstructure evolution during hot deformation of Ti–6Al–2Zr–1Mo–1V alloy
An experimental study of deformation mechanism and microstructure evolution during hot deformation of Ti–6Al–2Zr–1Mo–1V alloy
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DOI：
10.1016/j.matdes.2012.09.045
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发表时间：
2013-04
影响因子：
8.4
通讯作者：
D. He;Jingchuan Zhu;Z. Lai;Yuyan Liu;Xuesong Yang
中科院分区：
文献类型：
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作者：
D. He;Jingchuan Zhu;Z. Lai;Yuyan Liu;Xuesong Yang
采用等温拉伸试验研究了Ti-6Al-2 Zr-1 Mo-1V钛合金在750-850°C温度范围和0.001-0.1s-1应变速率范围内的变形机制和组织演变。基于动力学速率方程计算了变形激活能，探讨了热变形机制。利用电子背散射衍射（EBSD）分析了热变形后试样的显微组织，探讨了热变形工艺参数对组织演变和再结晶机制的影响。结果表明，变形机制随变形条件的不同而不同：在中温（800°C）和高温（850°C）下，变形分别以位错蠕变和自扩散机制为主。组织球化机制也与变形温度有关：在750 ~ 800°C温度范围内，大角度晶界主要通过位错聚集或亚晶界滑动和亚晶旋转形成;而在850°C高温下，再结晶是主要机制。特别是首次在TA 15钛合金中观察和研究了再结晶机制随变形温度的演变规律。
Isothermal tensile tests have been performed to study the deformation mechanisms and microstructure evolution of Ti–6Al–2Zr–1Mo–1V titanium alloy in the temperature range 750–850°C and strain rate range 0.001–0.1s−1. The deformation activations have been calculated based on kinetics rate equation to investigate the hot deformation mechanism. Microstructures of deformed samples have been analyzed by electron backscatter diffraction (EBSD) to evaluate the influences of hot deformation parameters on the microstructure evolution and recrystallization mechanism. The results indicate that deformation mechanisms vary with deformation conditions: at medium (800°C) and high (850°C) temperature, the deformation is mainly controlled by the mechanisms of dislocation creep and self-diffusion, respectively. The microstructure globularization mechanisms also depend on deformation temperature: in the temperature range from 750 to 800°C, the high angle grain boundaries are mainly formed via dislocation accumulation or subgrain boundaries sliding and subgrains rotation; while at high temperature of 850°C, recrystallization is the dominant mechanism. Especially, the evolution of the recrystallization mechanism with the deformation temperature is first observed and investigated in TA15 titanium alloy.