Enhancement of Strength and Ductility of Mg96Zn(2)Y(2) Rolled Sheet by Controlling Structure and Plastic Deformation

Mg-Zn-Y alloys are well known that dramatically enhanced strength during plastic deformation because the kink bands formed in the LPSO phase. On the other hands, high strength Mg-Zn-RE alloy is achieved by an extrusion process it was difficult to know a development of LPSO and Alpha Mg Phases during processing. In this present study, the effect of fine dispersed LPSO and alpha Mg phase on development of high strength Mg-Zn-Y rolled sheet a few pass schedules and its mechanical properties and the thermal stability were investigated. The tensile yield strength and elongation of Mg-Zn-Y rolled sheets achieved to 360 MPa and 5% at 673 K and 4 pass used by thermo-mechanical controlled processing, respectively. On the other hands, tensile yield strength decreases while elongation improves in 623K or more so that alpha Mg phase grain growth and kink bands induced LPSO phase recovere.