Development of constitutive models and hot-working processing map for Al–12Ce–0.4Sc alloys

The current study investigates the hot deformation behavior of Al–12Ce–0.4Sc alloy with an isothermal hot compression test at 300–450°C/0.001–1 s⁻¹. Results show that the flow curves exhibit typical dynamic recovery (DRV) and slight flow-softening behavior. Additionally, the flow curves overlap owing to the dynamic strain aging (DSA) phenomenon at 400–450°C/0.01–0.1 s⁻¹. Two different constitutive models were developed using the experimental data for hot deformation: (i) strain-compensated Arrhenius model (Method I) and (ii) logistic regression model (Method II). The average stress exponent (n) and apparent activation energy (Q) are 14.25 and 209.58 kJ·mol^–1, respectively. The hot-working processing map shows that the optimal processing condition is 400°C/1 s⁻¹, and the maximum power dissipation efficiency is 22%. Stable and unstable domains indicated by the processing map were correlated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron backscatter diffraction (EBSD) characterization techniques. The unstable domains are primarily associated with pro-eutectic Al₁₁Ce₃ intermetallic fracture and interfacial cracks between α-Al and pro-eutectic Al₁₁Ce₃.