The critical assessment of data for Al-Fe based intermetallic phases formed during solidification of aluminium alloys

Abstract

An understanding of the thermodynamic properties and phase diagram is fundamental to the control of the microstructure and the phases formed during solidification. This is particularly important as regards the control of harmful impurities such as iron during the solidification of commercial aluminium alloys where it is desirable to select conditions and compositions to avoid the precipitation of phases which cause deleterious mechanical properties. Calculations using critically assessed thermodynamic data to predict changes in phase constitution as an alloy solidifies offer a way to achieve the required control. This relies on the availability of high quality critically assessed thermodynamic datasets for the component binary and ternary systems, reliable models to extrapolate these data into systems with more components, and software which can then use these data to calculate the necessary phase equilibria. This paper will be concerned with the critical assessment of data for systems containing multicomponent intermetallic phases containing iron which are important for the required control of impurities during solidification of aluminium alloys.