Understanding the microstructural evolution, mechanical properties, and tribological behavior of AA8011-reinforced nano-Si₃N₄ for automobile application

Nanoceramic-reinforced aluminum composites have been utilized in most engineering applications such as the automotive and aerospace components due to their mechanical strength efficiency, and tribological performances. In this research, efforts were made to develop AA8011 composite with varying weight fraction of nano-Si₃N₄ up to 20% in a step of 5 through a two-step stir casting process. Scanning electron and the optical microscope were employed to investigate the microstructural evolution and modification of the developed composite, which reveals even dispersion of Si₃N₄ particulates. The X-ray diffraction analysis was conducted to check the phases present, and the broad peak shows mainly the presence of Si₃N₄. Likewise, the mechanical properties, viz, ultimate tensile strength, yield strength propagation, and hardness, were examined to determine the strengthening mechanism of the developed composite. The results show that the reinforced composite possesses better mechanical properties compared with the unreinforced AA8011 and the composite with 20% Si₃N₄ inclusion had the best properties. Moreover, the wear behavior and the friction coefficient of the developed composite results depicted an enhanced wear resistance and decrease in the coefficient of friction by increasing the Si₃N₄ particulate, though the wear rate increases with an increase in the applied load from 20 to 40 N.