高压扭转变形的Al-Zn-Mg-Cu-Zr合金显微组织及织构

摘要

在380℃变形条件下对不同高径比的Al-Zn-Mg-Cu-Zr合金试样进行高压扭转实验,借助于EBSD和XRD技术分析变形Al-Zn-Mg-Cu-Zr合金的显微组织、第二相粒子和织构的演变规律.结果表明:在高压扭转过程中,大量第二相粒子从过饱和Al基体中脱溶析出,显微组织明显细化,在部分三叉晶界处出现了细小的动态再结晶组织;材料织构强度随着高径比的减小而减弱;当高径比为0.20时,晶粒的择优取向方向也发生了明显变化,晶粒在<102>、<111>方向上出现了择优取向.%Al-Zn-Mg-Cu-Zr alloys with different height-diameter ratios were deformed by high pressure torsion at 380℃. The evolution of microstructures, second-phase particles and textures were studied by electron backscattered diffractometry (EBSD) and X-ray diffractometry (XRD). The results show that a large number of second-phase particles precipitate from supersaturated Al matrix, the microstructures are significantly refined, fine dynamic recrystallization structure occurs at the trigeminal grain boundaries. The density of textures reduces with height-diameter ratios decreasing. When the height-diameter ratio decreases to 0.20, the preferred orientation direction of grains has also undergone a significant change, it occurs on the direction of<102> and<111>.