Effects of nano-TiCp on the microstructures and tensile properties of TiCp/Al–Cu composites

Many experimental and theoretical studies indicated that the decrease of the size of the reinforcing particles can lead to substantial improvements in the mechanical performance of the composites. However, the investigations on the addition of the nano particles into conventional metal materials are still rare, especially the nano-TiCp into the Al–Cu alloys. In this study, the Ni coated nano-TiCp reinforced Al–Cu matrix composites were successfully fabricated by a casting route. It was found that the nano-TiCp was in the α-Al grains. The α-Al dendrites became finer and more developed. Moreover, the θ′ precipitates in the Al–Cu matrix were finer and uniformly distributed. The tensile strength and elongation of the composites increased simultaneously. After T6 heat treatment, compared with the unreinforced Al–Cu alloy, the tensile strength and elongation of the 0.8 wt.% nano-sized TiCp/Al–Cu composite increased from 485 MPa and 6.6% to 573 MPa and 12.4%, respectively.