A study on the hot deformation behavior of Mg-1Al-12Ho alloy based on experiments and multiscale simulations

Through experiments and multi-scale simulations, the high-temperature thermal deformation behavior of Mg-1Al-12Ho alloy is systematically examined. Models using Materials Studio show that Ho atoms preferentially occupy surface positions in the Mg matrix. A Support Vector Regression (SVR) model, developed from experimental flow stress data, exhibited excellent predictive accuracy across varying strain rates and temperatures (R² = 0.9995). The resulting hot processing map, combined with microstructural observations, indicated that twinning and dynamic recovery are the primary causes of flow instability. Dynamic recrystallization (DRX) dominates the softening effect, while at high strain rates, dynamic recovery and dislocation climb lead to an increase in the proportion of low-angle grain boundaries (LAGBs). At 400–450 °C, extensive DRX effectively reduced stored strain energy and LAGBs. Moreover, discontinuous DRX weakened basal texture, whereas continuous DRX produced recrystallized grains with orientations similar to the parent grains. These findings demonstrate that the SVR model effectively captures the nonlinear strain–temperature–strain rate–stress relationship, providing a theoretical foundation for the accurate prediction of hot deformation behavior in Mg–Al–Ho alloys.