Evaluation of Tribological Behaviour of Stir Casted Aluminium Alloy Hybrid Composites 2023-01-5171

Employing the stir casting process, a unique hybrid composites were fabricated, using A356 as the matrix and reinforced with ZrSiO₄ and TiB₂ particulates. The produced specimens were initially in their as-cast state. Following that, the reinforcement particle concentrations were changed 2 and 4 weight percentages (wt%) of ZrSiO₄ and keeping a constant 6 wt% of TiB₂. Three samples were exposed to dry sliding conditions at room temperature using a tribometer. Two applied loads of magnitude 10N and 50N and a sliding velocity of 1m/s and 2m/s were selected as testing parameters. After measuring the wear rate (WR) and the coefficient of friction (COF), the worn-out pin surfaces were examined using scanning electron microscopy (SEM). The results of the study indicated that, under different sliding parametric conditions, the hybrid composite sample with a weight percentage of A356, specifically with 4% ZrSiO₄ and 6% TiB₂, displayed a minimal WR and a higher COF compared with the remaining samples. This superior performance can be attributed to the harder particles within the composite, which enhance its sliding performance when incorporated into the A356 softer alloy. SEM analysis revealed that soft-natured test samples showed deep and shallow grooves with no discernible cracks under a 50N applied load and a 2 m/s sliding velocity. However, the test sample with the maximum weight % addition exhibited minimal surface damage, a lack of particle pullout, and no significant cracks. These findings imply that the innovative hybrid composite formulation exhibits enhanced tribological characteristics, making it a good candidate for replacing components in the aerospace and automotive sectors.