Mechanical and thermal expansion behavior of hybrid aluminum matrix composites reinforced with SiC particles and short carbon fibers

Abstract

In recent years, the research of hybrid composites reinforced by multiple reinforcements has received increasing attention because these composites have great potential to be tailored for various applications. In the present work, hybrid aluminum (Al) matrix composites reinforced with SiC particles and carbon fibers (SiCp-Cfs/Al composites) were fabricated by the colloidal dispersion and suction filtration method. It was found that SiCp-Cfs/Al composites had a dense structure and the carbon fibers and SiC particles were uniformly distributed in the Al matrix. The mechanical properties of SiCp-Cfs/Al composites with different reinforcement volume fractions were investigated. The results showed that the SiCp-Cfs/Al composites exhibited high tensile strength and elastic modulus (tensile strength 207 MPa and elastic modulus 92 GPa) when the volume fraction of SiC particles was 5% and the volume fraction of carbon fiber was 7%, which were significantly higher than that of SiCp/Al composites with 5% volume fraction of SiC particles (tensile strength 112 MPa and elastic modulus 80 GPa). The homogeneous distribution of carbon fibers and SiC particles in the Al matrix, which serves as co-reinforcing, is responsible for the high tensile strength and elastic modulus of SiCp-Cfs/Al composites. The coefficient of thermal expansion (CTE) of SiCp/Al composites and SiCp-Cfs/Al composites were measured at temperatures ranging from 25 °C and 400 °C. The results showed that the addition of carbon fibers caused the CTE of SiCp-Cfs/Al composites to be much lower than that of SiCp/Al composites.