Enhanced very high cycle fatigue performance of extruded Mg–12Gd–3Y–0.5Zr magnesium alloy

Abstract

Very high-cycle fatigue behaviors of extruded Mg–12Gd–3Y–0.5Zr (GW123k) magnesium alloy have been investigated and compared to that of conventional extruded AZ31 magnesium alloy. Typical post-fatigue microstructure and surface morphology features are presented for both the GW123k and the AZ31 alloy in order to stand out the uniqueness of GW123k alloy. Respective fatigue damage mechanisms for both alloys were also proposed in accordance. It is found that GW123k alloy contains a large amount of precipitated particles and possesses a relatively weak texture, which give rise to its much relieved tension–compression yield asymmetry and enhanced fatigue failure resistance. The much homogenized deformation mechanism in GW123k alloy is considered the underline reason for the improvement of material's fatigue performance.