Al-Zn-Mg-Cu合金多道次热变形及固溶处理过程中的晶粒演变

Grain Evolution in Process of Multi-pass Hot Deformation and Solution Heat Treatment of Al-Zn-Mg-Cu Aluminum Alloy

定量研究Al-Zn-Mg-Cu合金多道次热变形及固溶处理过程中的晶粒演变。采用Gleeble 1500D热模拟机进行热压缩实验,采用电子背散射衍射(EBSD)定量表征微观组织。主要研究变形量、变形道次、变形温度以及变形速率对平均晶粒尺寸、再结晶体积分数、大小角度晶界比例等微观组织特征的影响。结果表明:平均晶粒尺寸、再结晶体积分数以及小角度晶界比例均随着变形道次的增加而降低;随着温度的升高,大角度晶界比例减小,小角度晶界比例升高;平均晶粒尺寸和大角度晶界比例随着变形量的增大而减小,而小角度晶界比例的变化则呈现出相反的趋势。

The grain evolution of Al-Zn-Mg-Cu aluminum alloy was quantitatively investigated during multi-pass hot deformation and so-lution heat treatment. The Gleeble 1500D machine was used to carry out the hot compression experiments. The effects of deformation, number of pass, temperature and strain rate on the average grain size, volume fraction of recrystallization and grain boundaries were characterized by electron back-scattering diffraction （ EBSD） . The results show that the average grain size, the volume fraction of small-angle grain boundary and recrystallization decrease with the decrease of number of pass ; the volume fraction of high-angle grain boundary increases, and small-angle grain boundary decreases with the increase of deformation temperature ; and the average grain size and the volume fraction of high angle grain boundary decrease with the increase of deformation ; while an opposite tendency is shown in the change of the ratio of small-angle grain boundary.