Effect of hybrid ratio on friction and wear behavior of AZ91D matrix nanocomposites under oil lubricated conditions

Friction and wear behavior of AZ91D and its nanocomposites reinforced by different contents of hybrid multi-walled CNTs and nano-SiC particulates under oil lubrication was investigated using a MRS-10P four-ball tribometer. Friction coefficients and wear rates were measured within a load range of 200-1000 N at a spindle rotary speed of 380 r/min. Worn surface morphologies, phase and element compositions were studied by scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS), respectively. The mechanism of synergistic effect of CNTs and SiC nanoparticles was discussed. The results indicate that the AZ91D nanocomposites show better wear resistance properties and different wear mechanisms compared with AZ91D. The AZ91D nanocomposites reinforced with 0.5% CNTs and 0.5% nano-SiC have the best tribological capacity. The wear mechanisms for the Mg-based hybrid nanocomposites appear to be a mix-up of micro-ploughing, micro-cutting, slight adhesive wear and delamination.