Comparative study of the microstructure of Ti-6Al-4V titanium alloy sheets under quasi-static and high-velocity bulging
Comparative study of the microstructure of Ti-6Al-4V titanium alloy sheets under quasi-static and high-velocity bulging
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DOI：
10.1007/s12206-016-0843-9
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发表时间：
2017-03
影响因子：
1.6
通讯作者：
Fenqiang Li;Jun Zhao;J. Mo;Jianjun Li;Liang Huang
中科院分区：
文献类型：
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作者：
Fenqiang Li;Jun Zhao;J. Mo;Jianjun Li;Liang Huang
为了揭示Ti-6Al-4V钛合金板材高速变形的机制，采用扫描电镜/电子背散射衍射（SEM/EBSD）和透射电镜（TEM）对动态和准静态下的变形行为和微观组织演变进行了比较。结果表明，显微硬度分布不均匀。原因被确定为不均匀的材料流动和动态载荷。Ti- 6Al-4V钛合金板材的晶粒尺寸在两种条件下几乎相同，但与准静态成形相比，动态加载下的晶粒被拉长。在高速胀形过程中，Ti-6Al-4V钛合金在小变形量时的塑性变形机制主要是位错滑移。随着应变的增加，除了位错胞结构之外，孪生现象也被激活。孪晶面确定为（10 11）面。
In order to reveal the high-velocity deformation mechanisms of Ti-6Al-4V titanium alloy sheets, the dynamic deformation behavior and the microstructure evolutions were compared with those under quasi-static case employing Scanning electron microscopy/Electron back-scattered diffraction (SEM/EBSD) and Transmission electron microscopy (TEM). The results indicated that the distribution of microhardness was uneven. The cause was determined to be the non-uniform material flow and dynamic loading. The grain sizes of the Ti- 6Al-4V titanium alloy sheet were nearly the same under two conditions, but the grains were elongated under the dynamic loading compared with that observed in quasi-static forming. In high-velocity bulging, dislocation slip was the principle mechanism of plastic deformation of Ti-6Al-4V titanium alloy when deformation was small. As the strain increased, the twinning phenomenon was activated in addition to the dislocation cell structure. The twinning plane was determined to be the (10 11) plane.