Research progress on hot tearing of magnesium alloys: Based on nucleation, propagation and feeding

Magnesium alloys are prone to hot tearing during solidification, which severely limits their widespread application. Current research on hot tearing tends to establish direct correlations between apparent factors (such as alloy composition and process conditions) and hot tearing susceptibility, which easily falls into the cognitive misunderstanding of monotonous change. In fact, alloy compositions and process conditions mainly affect the nucleation-propagation-feeding of hot tearing by regulating thermophysical parameters and microstructure, thereby improving the hot tearing resistance. Therefore, with a focus on nucleation-propagation-feeding, this paper summarizes the hot tearing theories, criteria, simulation technologies, research methods and influencing factors. It systematically reveals the direct influence mechanisms of key factors (such as thermophysical parameters and microstructure) on the nucleation-propagation-feeding of hot tearing, providing theoretical support for optimizing apparent factors like alloy composition and process conditions to precisely control the hot tearing behavior of magnesium alloys.