Preparation and Tribological Properties of TiC Reinforced Hypereutectic AlSiCuMg Matrix Composites

Al-25Si-4Cu-Mg matrix composites with different TiC contents were prepared using the powder metallurgy method. The effects of TiC on the phase composition, microstructure, mechanical properties, and tribological properties were investigated by XRD, SEM, and XPS. The results showed that the addition of TiC particles inhibited the formation of Al₂Cu phase, and the composites were mainly composed of Al phase, Si phase, and TiC phase. The size of Si phase increased obviously in matrix alloy due to the high content of TiC. The compressive strength and hardness of the composites containing 30% TiC and above were more than 2 times those of Al-25Si-4Cu-Mg alloy. The addition of TiC not only effectively promoted the formation and stability of the mechanical mixed layer, but also prevented the formation of the deformation layer. The wear rate of Al-25Si-4Cu-Mg matrix composite containing 20% TiC was only 25% of that of Al-25Si-4Cu-Mg alloy, showed the best tribological properties. The wear mechanism of Al-25Si-4Cu-Mg alloy was mainly serious fatigue wear, while the wear mechanisms of the composites were mainly abrasive wear and fatigue wear.