Insights of texture and microstructure evolution in the short time annealing of Al-Cu-Mg alloy at large temperature range

Abstract

Texture and microstructure evolution of the 2524 Al-Cu-Mg cold rolled sheet in the annealing at 140–560 °C (for 1 h), was investigated carefully using X-ray diffraction, scanning electron microscopy, and electron backscatter diffraction. The characteristic texture transition rate spectral curve (CTTS), texture index, and orientation streamline approach were utilized to study the successive rules and unknown micro-mechanisms. The results demonstrated that the CTTS could precisely obtain the rule, tendency, and abnormal region of texture evolution within a large temperature range. An abnormal valley zone of texture evolution was observed at 380–440 °C, which is related to the rotation of Cube texture, and huge pinning force from the second phase. The orientation streamline approach effectively revealed the potential evolutional mechanisms of the texture, including α55° {φ1 = 55°, φ = 45°, φ2 = 0°}, Cu35° {φ1 = 35°, φ = 90°, φ2 = 45°}, and F {φ1 = 90°, φ = 55°, φ2 = 45°}. The content of ∑3 twin grain boundary and texture index FCGB weaken each other in the temperature ranges of 320–400 °C and 440–560 °C.