Improving the wear and microstructural properties of piston alloys using ZrO2 reinforcing particles

Al-Si alloys are commonly used in the manufacture of auto parts, including pistons. Although this alloy offers desirable properties for use in pistons, several microstructural properties, such as the presence of needle-like silicones or dendrites, interfere with the performance of the components produced. In this study, ZrO2 reinforcing particles were used to produce metal-based composites by friction stir process. First, the microstructural characteristics of the stir zone (SZ) of the samples produced were studied using a optical microscope. The results showed that the friction stir process improves the microstructural properties of the base metal, including the size of the silicon particles, and the distribution of these particles in the base metal. Then the particle distribution and bond quality between ZrO2 and aluminum reinforcing particles were investigated using SEM. Then, hardness and wear tests were performed to determine the wear and hardness of the composites. Pin-on-disk wear tests were performed at speeds of 1 m / s and 2 m / s and normal applied loads of 5 N, 10 N and 20 N. The wear test results showed that the wear resistance of the produced composite was improved by about 172% compared to the base alloy.