Effects of heating rate on the alloy element partitioning and mechanical properties in equiaxed α-β Ti-6Al-4V alloy
Effects of heating rate on the alloy element partitioning and mechanical properties in equiaxed α-β Ti-6Al-4V alloy
复制标题
加热速率对等轴αβTi-6Al-4V合金合金元素分配及力学性能的影响
DOI：
10.1016/j.jmst.2021.02.061
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发表时间：
2021-05-29
影响因子：
10.9
通讯作者：
Yang, Rui
中科院分区：
文献类型：
--
作者：
Zhang, Jinhu;Ju, Hongtao;Yang, Rui
通过实验和相场模拟，研究了加热速度对固溶处理的Ti-6Al-4V合金中α&β相变过程中合金元素分配和力学性能的影响，揭示了非平衡态组织和成分的演变规律，较好地验证了实验结果。具体结果表明，在较低的升温速率下，用电子探针(EPMA)测得的成分接近于溶液温度对应的平衡成分。加热至目标固溶温度时，随着加热速度的提高，初生α(α(P))相中的Al含量减少，V含量增加，α(P)相的体积分数增加，α(P)和β相之间的成分梯度变陡。详细讨论了体系的扩散、组成、溶液温度和自由能之间的相互关系。此外，提高加热速度(类似于20.0K/min)可通过在加热到固溶温度的过程中主要调整α(P)/β(T)体积分数、α(P)颗粒尺寸和二次α(S)尺寸来改善合金的力学性能。这些结果对基于知识的热处理工艺路线优化具有一定的参考价值。(C)爱思唯尔有限公司代表中国金属学会出版的《2021》。
The effects of heating rate on the alloy element partitioning and mechanical properties during the phase transformation of alpha ->beta in Ti-6Al-4 V alloy under solution treatment have been investigated by the experiments and phase field simulations, which reveal the evolutions of microstructure and compositions at the non-equilibrium state and well verify the experimental results. The specific results indicate that the compositions measured through electron probe micro-analysis (EPMA) under a lower heating rate are close to the equilibrium ones corresponding to the solution temperature. Heating up to the target solution temperature, as the heating rate increases, the Al content decreases and V increases in the primary alpha (alpha(p)) grain with a larger size, the volume fraction of alpha(p) increases and the composition gradient between alpha(p) and beta phases gets steeper. The interrelated relationship among the diffusion, compositions, solution temperature and free energy of the system has been discussed in detail. Moreover, increasing the heating rate (similar to 20.0 K/min) may help to improve the mechanical properties of the alloy by mainly adjusting the alpha(p)/beta(t) volume fractions, alpha(p) particle size and secondary alpha (alpha(s)) size during the process of heating up to the solution temperature. These results may shed some light on the optimization of the knowledge-based heat treatment route. (C) 2021 Published by Elsevier Ltd on behalf of Chinese Society for Metals.