Tribological behavior of AA7075 hybrid composites reinforced with Al2O3 and TiO2 particles

The study investigates the wear behavior of AA7075 hybrid composites reinforced with varying percentages of Al2O3 and TiO2. The microstructure reveals a homogenous distribution of reinforcing particles in the aluminum alloy matrix, enhanced by the addition of K2TiF6 flux. The wear process parameters, including % reinforcement, applied load, temperature, sliding velocity, and sliding distance, are systematically studied to understand their effects on wear resistance. The results reveal a non-linear trend in wear rate with increasing % reinforcement, showing an optimal percentage for the lowest wear rate. Applied load initially improves wear resistance but can lead to increased wear rates beyond threshold limit. The wear rate decreases initially with increasing temperature, indicating improved wear resistance, but increased at higher temperatures due to thermal softening effects. Sliding velocity and distance also significantly influence wear behavior, with lower wear rates observed at moderate velocities and distances due to the formation of protective layers. The addition of reinforcement reduces the COF, the relationship between COF and wear rate is inversely proportional, with lower COF leading to lower wear rates. The presence of reinforcement stabilizes the COF at different sliding distances, indicating improved wear resistance. The worn surface morphology indicates severe abrasion, micro-cutting, and plastic deformation, influenced by particle characteristics and load.