Effects of the sole and the combined addition of Ca and Sr on microstructure and mechanical properties of as-cast and as-rolled Mg-5 Zn alloys were carefully investigated by OM,SEM,hot-compression testing and tensile ...Effects of the sole and the combined addition of Ca and Sr on microstructure and mechanical properties of as-cast and as-rolled Mg-5 Zn alloys were carefully investigated by OM,SEM,hot-compression testing and tensile testing.Ca is more effective than Sr in the microstructural refinement of as-cast alloys.High-strain-rate rolling(HSRR)produces more deformed twins and thus provides more nucleation sites for dynamic recrystallization(DRX).The addition of Ca and Sr can promote dynamic precipitation during HSRR,the precipitation process would consume the storage energy and thus increases the critical strain value of DRX,resulting in the retarded DRX effect by the addition of Ca and/or Sr.The as-rolled Mg-5 Zn-0.4 Ca-0.2 Sr alloy exhibits a good combination of strength and ductility,with the ultimate tensile strength of 317 MPa,the yield strength of 235 MPa and the elongation to rupture of 24%.展开更多
基金Projects(51471066,51571089) supported by the National Natural Science Foundation of ChinaProject(2019JJ40044) supported by the Natural Science Foundation of Hunan Province,China
文摘Effects of the sole and the combined addition of Ca and Sr on microstructure and mechanical properties of as-cast and as-rolled Mg-5 Zn alloys were carefully investigated by OM,SEM,hot-compression testing and tensile testing.Ca is more effective than Sr in the microstructural refinement of as-cast alloys.High-strain-rate rolling(HSRR)produces more deformed twins and thus provides more nucleation sites for dynamic recrystallization(DRX).The addition of Ca and Sr can promote dynamic precipitation during HSRR,the precipitation process would consume the storage energy and thus increases the critical strain value of DRX,resulting in the retarded DRX effect by the addition of Ca and/or Sr.The as-rolled Mg-5 Zn-0.4 Ca-0.2 Sr alloy exhibits a good combination of strength and ductility,with the ultimate tensile strength of 317 MPa,the yield strength of 235 MPa and the elongation to rupture of 24%.
