Microstructural, Mechanical, and Tribological Characteristics of Ceramic Reinforced Al/Cu Hybrid Matrix Composites

Al and its alloys have a wide range of applications thanks to their low density, cost, and superior specific strength. Especially Al–Cu matrix composites are promising alloys with superior microstructural and mechanical performance characteristics. Thanks to the formation of the intermetallic due to the contained Cu, they significantly improve the properties of their Al-based alloys. In this study, pure aluminum–Cu matrix composites reinforced mainly with ceramic microparticles based on SiC carbide and ZrO₂ oxide were fabricated by powder metallurgy. Three different values were determined for the Al–Cu content of the compositions, and these were produced in tube furnaces at 380 and 580°C for 4 h under an inert atmosphere using liquid phase sintering. According to the data of SEM and EDS analyses, microstructures formed in all samples were homogeneous. It was found that increasing sintering temperature increased microstructural densification. Adding mainly Cu and ceramic reinforcements to the microstructure significantly improved the hardness up to 2.05 times. Due to their intermetallic formation, the highest hardness values were determined in the samples containing high amounts of Cu, such as 173.73 HV. In the wear tests, it was observed that the samples sintered at high temperatures showed superior tribological performance characteristics. Also, the high Cu content improved the samples’ friction behavior (COF). Since the increasing Cu content enhances intermetallic formation, superior wear resistance was observed in the samples containing a high amount of Cu sintered at higher temperatures up to 1.59 and 5.94 times. Optimum production parameters and chemical compositions were determined per the tests performed.