Hot Deformation Behavior and Microstructural Evolution of As-Extruded 2195 Aluminum Alloy
摘要
In this study, hot compression tests were conducted on the as-extruded 2195 aluminum alloy at 350-500 °C and 0.01-10 s−1. A dual-corrected, strain-compensated Arrhenius constitutive model was established, and the mechanisms of microstructural evolution were revealed utilizing electron backscatter diffraction (EBSD). The results indicate that the established model exhibits satisfactory prediction accuracy, yielding a correlation coefficient (r) of 0.9819 and an average absolute relative error (AARE) of 7.55%. Regarding the microstructural evolution, the degree of dynamic recrystallization (DRX) generally increases with rising temperature. At 500 °C, DRX is highly extensive, achieving a volume fraction of 78.6% and an average grain size refined to 7.22 μm. Notably, at 450 °C, intensive dynamic recovery (DRV) promotes dislocation annihilation and reduces the overall deformation stored energy, thereby weakening the driving force for DRX and resulting in a lower DRX fraction accompanied by grain coarsening. Furthermore, an extremely low strain rate of 0.01 s−1 is highly conducive to the full progression of DRX, whereas high strain rates ranging from 1 to 10 s−1 provide a robust driving force for nucleation via high dislocation density, thereby significantly refining the grains. The softening mechanisms of the as-extruded 2195 aluminum alloy during hot deformation are DRV and continuous dynamic recrystallization (CDRX). This study provides a solid theoretical foundation for the precise regulation of hot forming processes for this alloy.