Effect of Hot Extrusion on the Microstructure, Mechanical Properties, and Corrosion Behavior of Mg–11Li–3Al–2Zn–1.5Nd–0.2Zr Alloy

Abstract

The microstructure, mechanical properties, and corrosion behavior of Mg–11Li–3Al–2Zn–1.5Nd–0.2Zr alloy before and after hot extrusion were studied. The results show that both as-homogenized and as-extruded alloys consist of β-Li, AlLi, MgLi2Al, and NdAl3 phases. The ultimate tensile strength and elongation of as-extruded alloy are 149.86 MPa and 42.33%, respectively, which are higher than those of as-homogenized alloy (132.99 MPa and 19%). The as-extruded alloy shows a better corrosion resistance with a lower hydrogen evolution rate and a higher charge transfer resistance. The improvement of mechanical properties and corrosion resistance of Mg–11Li–3Al–2Zn–1.5Nd–0.2Zr alloy after hot extrusion are as a result of the grain refinement and the uniform distribution of crumbled intermetallic phases.