The influence of heat treatment on the heterogenous structure and deformation behavior of a high pressure die-cast Al-10Si-0.5Mn-0.3Mg alloy

<p indent="0mm">The network of coralloid-shaped eutectic Si particles in a high-pressure die-cast Al-10Si-0.5Mn-0.3Mg alloy can lead to stress concentration and induce cracking during deformation, resulting in reduced ductility. To enhance ductility, a crucial step involves transforming these coralloid-like Si particles into globular forms through heat treatment. This study focuses on investigating the effects of T7 heat treatment on the microstructure and deformation behavior of high-pressure die-cast Al-10Si-0.5Mn-0.3Mn alloy. The findings reveal that the high-pressure die-cast Al-10Si-0.5Mn-0.3Mg alloy displays a sandwich microstructure, comprising two skins enveloping a core. After T7 treatment, the coralloid-like eutectic Si particles undergo transformation into globular and rod-shaped structures. However, T7 treatment does not lead to a significant improvement in deformation homogeneity, as both the as-cast and heat-treated samples exhibit apparent deformation heterogeneity. Notably, the core displays more pronounced inhomogeneous deformation compared to the skin. Despite the observed reduction in strength after T7 treatment, a noteworthy improvement in ductility is observed. The spheroidization of eutectic Si particles is identified as a primary factor contributing to the shift in cracking mode and the enhancement of ductility.