Mechanical and wear behavior of room-temperature ECAPed Mg-4Li alloy

Abstract

The excellent specific strength of magnesium and its alloys makes them appealing for use in many engineering applications especially in the transportation industry. However, its use is restricted due to poor formability and wear resistance. Li addition enhances the formability of magnesium alloys while diminishing their strength. Equal channel angular pressing (ECAP) is one of the effective severe plastic deformation (SPD) methods that improves the strength by grain refinement thereby wear resistance. In this study, the effect of ECAP on the mechanical and wear behavior of Mg-4Li alloy is studied and correlated with grain refinement and microstructural features. The substantial grain refinement was obtained after three passes of ECAP and the sample was processed in the route BC displayed a minimum grain size of ∼9 µm. The ECAPed samples showed improved hardness and tensile properties and the sample ECAPed in the route BC displayed superior mechanical properties owing to its more refined microstructure. The microstructural features are analyzed using X-ray diffraction line profile analysis (XRDLPA) and correlated with the mechanical properties. The wear behavior viz. wear rate, coefficient of friction (COF) and roughness were investigated. It was demonstrated that the wear properties are improved after ECAP due to the refined microstructure and enhanced hardness and the obtained wear results are in good agreement with Archard’s wear law.