Microstructure, mechanical properties and die-filling behavior of high-performance die-cast Al-Mg-Si-Mn alloy

Abstract

This work aims to reveal the relationships between the microstructure, mechanical properties and flow behavior of die-casting AlMg5Si2Mn alloy. Results indicated that the microstructure of the die-cast AlMg5Si2Mn consists of a1-Al grains, fine-size a2-Al grains and (Al ? Mg2Si) eutectic. The surface layer observed has the thickness in a range of 120-135 lm, while an ellipse-like surface layer edge is observed in the corner of the plate-like sample. Tensile strength and elongation (d) of the specimens are slightly decreased along the die-filling direction due to the backflow of melt. Pure (Al ? Mg2Si) eutectic layer and ultra-fine-size a2-Al grains observed are around the overflow channels. Mass feeding is predominantly responsible for the superior mechanical properties of the round bars as compared to those of plate-like samples.