The effects of Ca and Mn on the microstructure, texture and mechanical properties of Mg-4 Zn alloy

The microstructural evolution, texture and mechanical properties of nine Mg-4Zn-xCa-yMn alloys (x = 0.3, 0.6, 1.0; y = 0.2, 0.3, 0.7 wt.%) were investigated systematically. Alloying with Ca and Mn refined the grains of the extruded sheets and increased the unDRX fraction. Mn could be the heterogeneous nucleation site of Ca2Mg6Zn3 phase because of a good atom matching at the orientation relationship of (211)(Mn)//(1211)(Ca2Mg6Zn3),< 251 >(Mn)//< 1103 >(Ca2Mg6Zn3). The traditional texture weakening effect of Ca was strongly decreased for the simultaneously addition of Mn. With increasing Ca and Mn concentration, the strength increased and ductility decreased. Mg-4Zn-0.6Ca-0.7Mn exhibited a good combination of ultimate tensile strength (320 MPa), yield strength (286 MPa) and elongation (16%). A model of strengthening indicated that grain boundary strengthening and precipitate strengthening made a large contribution to the strength of Mg-4Zn-0.6Ca-0.7Mn. In addition, the dynamic recrystallization, texture modification and the strengthening effect from different parts also have been analyzed in detail. (C) 2020 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.

Automated summary

The systematic investigation on microstructural evolution, texture, and mechanical properties of Mg-4Zn-xCa-yMn alloys revealed that alloying with Ca and Mn can enhance strength while reducing ductility. The addition of Mn can mitigate the traditional texture weakening effect of Ca.