Tribological behavior of surface mechanical attrition treated (SMAT) magnesium alloy

Abstract

In this study, the tribological behavior of surface mechanical attrition treated (SMAT) magnesium alloy (AZ91D) is investigated. SMAT is an effective tool to generates a nanostructured surface layer on AZ91D alloy. X-ray diffraction (XRD), micro-vicker’s hardness test, and scanning electron microscopy (SEM) analysis techniques are used to characterize the SMATed AZ91D alloy. SMAT causes the decrement in βphase of the AZ91D alloy. XRD result confirms the dissolution of the secondary phase (β-Al17Mg12) within the deformed surface layer. Further, the SMAT causes 2 times improvement in surface hardness and 2.5 times improvement in the surface roughness value of Mg alloy. The tribological behavior of AZ91D is studied by performing dry sliding wear tests at room temperature on as-received and SMATed specimens at 5, 10, and 20 N load with 0.1, 0.2, and 0.3 m/s sliding velocity using ball-on-disk wear testing machine. SMAT enhances the tribological properties of AZ91D Mg alloy. At high load and velocity, the SMATed specimens show superior tribological performance than that of mild test conditions.