Exploring kink strengthening in WZ21 magnesium alloy via slow solidification and extrusion

• Large-grained materials with MF structure are highly susceptible to kinking. • Specific grain orientations are more favorable for kinking and twinning. • Kinking greatly improves strength of material. • Texture strengthening improved strength but reduced ductility. • Corrosion and ignition properties of prepared samples are acceptable for application. The Mg-Y-Zn magnesium alloy system is known for the presence of Long-Period Stacking Ordered (LPSO) phases that improves strength and ductility with minimal amounts of alloying elements. Even better improvements are associated with the specific microstructure known as the Mille-Feuille (MF) structure that can occur in this alloy as well after proper heat treatment. This study systematically compares the traditional ingot metallurgy method with the Bridgman method (slow cooling), coupled with diverse heat treatments and extrusion process. Microscopic analyses reveal variations in the presence of LPSO phases, MF structure, and especially grain size, leading to divergent mechanical and corrosion properties. The Bridgman approach surprisingly stands out, ensuring superior mechanical properties due to kink and texture strengthening.