Al-Zn-Mg-Cu合金多道次熱變形及固溶處理過程中的晶粒演變

Al-Zn-Mg-Cu合金多道次熱變形及固溶處理過程中的晶粒演變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合金多道次熱變形及固溶處理過程中的晶粒演變。采用Gleeble 1500D熱模擬機進行熱壓縮實驗，采用電子背散射衍射（EBSD）定量表征微觀組織。主要研究變形量、變形道次、變形溫度以及變形速率對平均晶粒尺寸、再結(jié)晶體積分數(shù)、大小角度晶界比例等微觀組織特征的影響。結(jié)果表明：平均晶粒尺寸、再結(jié)晶體積分數(shù)以及小角度晶界比例均隨著變形道次的增加而降低；隨著溫度的升高，大角度晶界比例減小，小角度晶界比例升高；平均晶粒尺寸和大角度晶界比例隨著變形量的增大而減小，而小角度晶界比例的變化則呈現(xiàn)出相反的趨勢。

The grain evolution of Al-Zn-Mg-Cu aluminum alloy was quantitatively investigated during multi-pass hot deformation and solution 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.