Nanoindentation and Scratch Resistance Characteristics of AZ31–WC Nanocomposites

Abstract

This work examines the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-induced wear behavior of Mg-based metal matrix nanocomposites. Ultrasonic vibrator-equipped stir casting furnace is used to fabricate Mg–WC nanocomposites. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD) are employed to conduct the characterizations of base alloy and Mg–WC nanocomposites. Vickers microhardness tester is used to obtain the microhardness values of the fabricated materials. Nanoindentation tests are performed to find the effect of wt.% of WC on the mechanical properties, i.e., nanohardness and elastic modulus. Nanohardness and elastic modulus present nearly 122% and 169.37% increments, respectively, compared to the base alloy when only 2[Formula: see text]wt.% of WC is present as reinforcement. Scratch tests are performed to find the effects of wt.% of WC and applied load on the scratch-induced wear and coefficient of friction (CoF) of the base alloy and Mg–WC nanocomposites. Wear volume also decreases continuously with increase in the weight percentage of WC in magnesium alloy. The COFs of nanocomposites are almost constant but they are inclined to increase with the increase in wt.% of WC. Finally, SEM micrographs of scratch grooves are analyzed to find the wear mechanisms. Abrasive wear mechanism is found to be the dominant one regarding the scratch of Mg–WC nanocomposites.