Achieving outstanding heat-resistant Mg-Gd-Y-Zn-Mn alloy via introducing RE/Zn segregation on α-Mn nanoparticles

A novel Mg-8Gd-2Y-1.5Zn-1Mn (GYZ-1Mn, wt.%) alloy with extraordinary high-temperature mechanical properties was developed by introducing RE/Zn segregation on α-Mn nanoparticles. Its ultimate tensile stress (UTS) and yield stress (YS) are 312 MPa and 248 MPa at 300 ℃, which are 87 MPa and 52 MPa higher than the highest strengths of other Mg-Gd-Y-Zn alloys reported in the previous literature. The outstanding performance of GYZ-1Mn alloy was associated with the segregation of RE/Zn atoms on the α-Mn nanoparticles, which facilitated the formation of fine lamellar long period stacking ordered (LPSO) phase and impeded the coarsening of α-Mn. Consequently, retarded dynamic recrystallization behavior occurred in the GYZ-1Mn, resulting in fine grain size, high density of geometrically necessary dislocations and strong fiber texture intensity to strengthen the high-temperature mechanical properties. Hence, this work paved a novel path for the development of heat-resistant Mg alloys by introducing elemental segregation on nanoparticles.