Development of Constitutive Models and Hot Working Processing Map for Al-12Ce-0.4Sc Alloy

The current study investigates the hot deformation behavior of Al-12Ce-0.4Sc alloy through an isothermal hot compression test in the range of 300-450°C/0.001-1 s^(-1). The flow curves exhibit typical dynamic recovery (DRV) and slight flow softening behavior. Additionally, an-overlapping of flow curves attributed to the dynamic strain aging (DSA) phenomenon in the range of 400-450℃/0.01-0.1 s^(-1). The two different constitutive models were developed using the experimental data for the 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) were determined to be 14.25 and 209.58 kJ 〖mol〗^(-1), respectively. The hot working processing map shows the optimal processing condition at 400°C/1 s^(-1) with a maximum power dissipation efficiency of 22%. The stable and instable domains indicated by the processing map were correlated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron backscatter diffraction (EBSD) characterization techniques. Instability domains were primarily associated with pro-eutectic Al11Ce3 intermetallic fracture and interfacial cracks between the α-Al and the pro-eutectic Al11Ce3.