A new rare-earth-free Mg-Sn-Ca-Mn wrought alloy with ultra-high strength and good ductility

摘要

A novel rare-earth-free Mg-Sn-Ca-Mn wrought alloy with the new yield strength record of 450 MPa is developed, and a balanced ductility of similar to 5% is achieved. The role of Mn addition is associated with promoting the nucleation rate for dynamic recrystallized grains and restricting their growths by enhancing the thermal stability. Specially, the dynamic recrystallization within the twinned region readily occurs due to the extensive dislocation accumulations and high thermal stability of the pre-existed twins. Twining induced dynamic recrystallization can effectively rotate the original grains to the non-basal orientation, leading to the texture weakening and elongation improvement.