It is now well established that simultaneous application of acoustic energy during deformation results in lowering of stresses required for plastic deformation. This phenomenon of acoustic softening has been used in several manufacturing processes, but there is no consensus on the exact physics governing the phenomenon. To further the understanding of the process physics, in this manuscript, after-deformation microstructure of aluminium samples deformed with simultaneous application of kilohertz range acoustic energy was studied using Electron-Backscatter Diffraction analysis. The microstructure shows evidence of acoustic energy enabled dynamic recovery. It is found that the subgrain sizes increase with an increase in acoustic energy density applied during deformation. A modified Kocks-Mecking (KM) model for crystal plasticity has been used to account for the observed acoustic energy enabled dynamic recovery. Using the modified KM model, predicted stress versus strain curves were plotted and compared with experimental results. Good agreements were found between predictions and experimental results. The manuscript identifies an analogy between microstructure evolution in hot deformation and that in acoustic energy assisted deformation.

现已公认，在变形过程中同时施加声能可降低塑性变形所需的应力。这种声音软化现象已在多个制造过程中使用，但对于控制该现象的确切物理方法尚无共识。为了进一步理解过程物理学，在本文中，使用电子反向散射分析研究了在同时施加千赫兹范围声能的情况下变形的铝样品的变形后微观结构。微观结构显示了声能实现动态恢复的证据。已经发现，亚晶粒尺寸随着变形期间施加的声能密度的增加而增加。修改后的用于晶体可塑性的Kocks-Mecking（KM）模型已用于解决观察到的声能动态恢复问题。使用改进的KM模型，绘制了预测的应力与应变曲线，并将其与实验结果进行了比较。在预测和实验结果之间找到了很好的协议。该手稿确定了热变形和声能辅助变形中的微观结构演化之间的类比。