The effect of strain path changes on texture evolution and deformation behavior of Ti6Al4V subjected to accumulative angular drawing
The effect of strain path changes on texture evolution and deformation behavior of Ti6Al4V subjected to accumulative angular drawing
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DOI：
10.1016/j.msea.2019.138168
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发表时间：
2019-09-09
期刊：
影响因子：
6.4
通讯作者：
Beyerlein, I. J.
中科院分区：
文献类型：
--
作者：
Kawalko, J.;Muszka, K.;Beyerlein, I. J.
Ti-6Al-4V 合金丝在室温下使用累积角拉拔 (AAD) 工艺进行塑性变形，最大对数应变 epsilon 类似于 0.51。使用扫描电子显微镜内的电子背散射衍射技术定量研究钛合金丝的微观结构和微观织构演变以及不均匀性，并与传统线性拉拔后的丝进行比较。变形后观察到适度的晶粒细化。核平均取向误差参数显着增加，表明亚晶结构发生了演化。 AAD 和线性拉拔后屈服应力和极限抗拉强度增加，而在 AAD 和线性拉拔过程的第一道次后观察到硬度下降。然而，AAD 导致了样品横截面硬度值的不均匀性。硬度变化与局部织构不对称参数相关，而硬度和晶粒尺寸之间没有观察到相关性。 Schmid 因子分析表明，AAD 不均匀地引入有利于棱柱形和金字塔形位错滑移的晶粒取向，对 Ti-6Al-4V 合金丝在拉拔过程中的塑性产生积极影响。
The Ti-6Al-4V alloy wires were plastically deformed using the accumulative angular drawing (AAD) process at room temperature with a maximal logarithmic strain epsilon similar to 0.51. Microstructure and microtexture evolution and inhomogeneity of the Ti alloy wires were investigated quantitatively using the electron backscattered diffraction technique within the scanning electron microscope and compared to wires after conventional linear drawing. Moderate grain refinement was observed after deformation. The kernel average misorientation parameter increased significantly, pointing to evolution of subgrain structure. The yield stress and ultimate tensile strength increased after the AAD and linear drawing and decrease in hardness was observed after the first pass of the AAD and linear drawing process. However, the AAD introduced inhomogeneity in hardness values at the sample cross section. Hardness variation correlates with a local texture asymmetry parameter, while no correlation between hardness and grain size was observed. A Schmid factor analysis indicated that the AAD is inhomogeneously introducing grain orientations that are favorable for prismatic and pyramidal dislocation slip, having a positive effect on the plasticity of Ti-6Al-4V alloy wire during drawing.