Primary solidification of ternary compounds in Al-rich Al–Ce–Mn alloys

Abstract

Primary solidification of ternary compounds Al20Mn2Ce and Al10Mn2Ce were analyzed through the coupling of the thermodynamic modeling and classic nucleation theory. Thermodynamic models of Al20Mn2Ce and Al10Mn2Ce were developed using the CALPHAD approach based on first-principles calculated enthalpy of formation and experimental data obtained from this work and the literature. The analysis suggested that despite the larger thermodynamic driving force for nucleation of Al10Mn2Ce, nucleation is preferred for the Al20Mn2Ce phase in the highly undercooled liquid due to its smaller interfacial energy. Therefore, manufacturing methods with rapid cooling rates will favor primary solidification of Al20Mn2Ce for Al-rich Al–Ce–Mn alloys.