Study on the effects of manganese on the grain structure and mechanical properties of Mg-0.5Ce alloy

Abstract

A novel sandwich grain structure of an Mg–Mn–Ce alloy was achieved by controlling the content of Mn in the traditional extrusion process. The solid-state Mn was dynamically precipitated during the extrusion. These finely precipitated particles hindered the grain boundary migration and refined the dynamically recrystallized grains. A sandwich-like grain structure was formed in as-extruded Mg–Mn–Ce alloys with Mn content increasing from 0.3 wt% to 0.9 wt%. This sandwich-like grain structure induced a tensile yield stress (TYS) that was improved from 86.5 MPa to 166.7 MPa; the Mg-0.9Mn-0.5Ce alloy exhibited improved yield isotropy. Here we discuss the formation mechanism for the sandwich-like grain structure and the strengthening mechanism in detail.