Preparation and characterization of the Al-Cu-Mg-Si-Mn composites reinforced by different surface modified SiCp

Abstract

In this paper, the 4 vol% SiCp/Al-Cu-Mg-Si-Mn composites were prepared by method of stirring casting. The effects of SiCp surface modifications (oxidization and Ti-coating) and particle sizes (5 μm, 10 μm and 15 μm) on the microstructure and tensile properties of the composites were analyzed. The effects of SiCp sizes on the distribution of SiCp in the pre-oxidized SiCp/Al-Cu-Mg-Si-Mn composites were larger than those in Ti-coated SiCp/Al-Cu-Mg-Si-Mn composites. The Al-Cu-Mg-Si-Mn composites reinforced with Ti-coated SiCp exhibited more uniform SiCp distributions and higher tensile mechanical properties than those reinforced with the pre-oxidized SiCp. When the SiCp size was 15 μm, the Ti-coated SiCp/Al-Cu-Mg-Si-Mn composite showed the best yield strength (σ0.2), ultimate tensile strength (σUTS) and fracture strain (εf) of 410 MPa, 548 MPa and 7.6% with the increase of 10.2%, 2.6% and 5.6% than that of reinforced by pre-oxidized SiCp. The more uniformly dispersed particles and better tensile properties of the Ti-coated SiCp/Al-Cu-Mg-Si-Mn composites could be attributed to the better wetting between Ti-coated SiCp and molten Al.