Mechanical properties as a function of microstructure in the new Mg–Al–Ca–La alloy solidified under different conditions

This paper aimed the study of the ZAXLa05413 magnesium alloy (Mg–0.5wt%Zn–4wt%Al–1wt%Ca–3wt%La) by analyzing the influence of solidification parameters on mechanical properties. In this way the studied alloy was solidified under slow cooling condition in order to make a thermal analysis and to obtain a completely equiaxial macrostructure, in the other hand, under a unidirectional solidification condition to obtain columnar and equiaxial structures. The ingots were submitted to metallographic analysis (macro and microstructure), mechanical characterization by tensile testing and hardness measurements in specimens extracted at different positions along the height of the ingot. Expressions correlating the mechanical behavior with microstructure parameters were determined permitting the establishment of general correlations among grain size and secondary dendritic arm spacing with solidification processing variables. The results confirm a direct correlation between the structural refinement (macro and micro) and the increase in ultimate tensile strength (σu) and also the yield strength (σe) of the magnesium alloy ZAXLa05413.