Investigation on wear properties of AZ31-MWCNT nanocomposites fabricated through mechanical alloying and powder metallurgy

The wear properties of Mg alloy AZ31 (Al 3%, Zn 1%, rest Mg) nanocomposites reinforced with multi-wall carbon nanotubes (MWCNTs) were studied by conducting experiments on pin-on-disc wear test apparatus. The composites were fabricated by powder metallurgy technique by homogeneously reinforcing variable percentages of MWCNTs (0.33 wt%, 0.66 wt%, and 1.0 wt%) into Mg alloy AZ31 matrix through mechanical alloying. The effect of varying percentages of MWCNTs on the wear properties of AZ31-MWCNT nanocomposites and the mechanism behind that were investigated through scanning electron microscope and energy dispersive spectroscope analysis. The microstructure investigation revealed that an increase in reinforcement of MWCNTs in AZ31 alloy increased the hardness and reduced the wear rate of the composites with 0.33 wt% and 0.66 wt% due to homogeneous distribution and high interfacial strength between AZ31 and MWCNTs. However, with the addition of 1.0 wt% MWCNTs to AZ31 alloy led to high agglomeration of MWCNTs, resulting in poor interfacial strength and weak bonding between AZ31 and conglomerated MWCNTs, subsequently increasing the wear rate.