Flow behavior and plasticity of Ti-6Al-4V under different electrically assisted treatments
Flow behavior and plasticity of Ti-6Al-4V under different electrically assisted treatments
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不同电辅助处理下Ti-6Al-4V的流动行为和塑性
DOI：
10.1088/2053-1591/3/12/126505
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发表时间：
2016-12-01
影响因子：
2.3
通讯作者：
Lai, Xinmin
中科院分区：
文献类型：
--
作者：
Jiang, Tianhao;Peng, Linfa;Lai, Xinmin
进行电辅助拉伸（EAT）和电辅助预处理拉伸（EAPT）以比较对提高Ti-6Al-4V变形抗力和延展性的不同效果。结果发现，与 EAT 相比，EAPT 明显提高了 Ti-6Al-4V 的延展性。为了将热效应与电塑性效应解耦，还进行了热辅助张力（TAT）以及热辅助预处理张力（TAPT）。结果表明，当电流占空比小于20%时，Ti-6Al-4V中具有h.c.p晶体结构的α相的变形机制对电流不敏感。然而，当电流占空比高于 20% 时，仅升高温度不足以解释 EAT 和 EAPT 中观察到的初始屈服应力中的额外应力下降。根据对原始状态、TAPT和EAPT处理样品的XRD研究，发现电流比升高温度更有效地加速Ti-6Al-4V中α相的湮灭和β相的形成，这种微观结构的演变也为实验和理论上观察到的EAPT中流变应力和延展性的改善提供了线索。
Both electrically assisted tension (EAT) and electrically assisted pre-treatment tension (EAPT) were conducted to compare different effects on improving deformation resistance and ductility of Ti-6Al-4V. It is found EAPT obviously enhanced the ductility of Ti-6Al-4V compared with that obtained in EAT. In order to decouple the thermal effect from electro-plastic effect, thermally assisted tension (TAT) as well as thermally assisted pre-treatment tension (TAPT) were also conducted. The result indicates deformation mechanism of alpha phase with h.c.p crystal structure in Ti-6Al-4V was insensitive to electric current when current duty is less than 20%. However, the elevated temperature alone is insufficient to account for additional stress drop in the initial yielding stress observed in EAT and EAPT when current duty is higher than 20%. According to XRD investigation on specimens treated in original state, TAPT and EAPT, it is found electric current accelerates the annihilation of alpha phase and formation of beta phase in Ti-6Al-4V more effectively than the rising temperature does and such microstructure evolution also throws light on the improvement of flow stress and ductility observed in EAPT both experimentally and theoretically.