Thermal deformation behavior and microstructural evolution of AlZnMgCu/TiB2 alloy

AlZnMgCu/TiB 2 alloy was thermally compressed at temperatures of 390–450 °C and strain rates of 0.001–0.5 s −1 . The flow curves, constitutive equations, 3D processing maps, microstructures, and related mechanisms of the composite were studied, and the results are discussed. The results indicate that TiB 2 ceramic particles have a significant influence on the rheological stress curve of the studied alloy. The true stress–strain curves take the form of a broad flow stress peak at high strain rate deformations (0.1–0.5 s −1 ) due to TiB 2 inducing dynamic equilibrium between dynamic softening and dynamic recrystallization (DRX). A modified strain-compensated Arrhenius constitutive model was constructed that accurately describes the rheological behavior of the alloy. The thermal deformation activation energy Q was evaluated as 123,815 J·mol –1 , which was reduced by the presence of the TiB 2 ceramic particles. Hot-processing map analysis revealed the thermal deformation characteristics of the AlZnMgCu/TiB 2 alloy at 390–450 °C within the strain rate range 0.001–0.5 s −1 . Areas of flow instability were identified. Electron back-scattering diffraction (EBSD) analysis of the AlZnMgCu/TiB 2 alloy under different thermal deformation conditions revealed the microstructure evolution. The processes of dynamic recovery (DRV)/DRX were enhanced with increasing deformation and decreasing strain rate, resulting in sufficient DRX and the distribution of second-phase particles at the subgrain boundaries and recrystallization grain boundaries.