The Effect of the Addition of Ti Metal Fiber and Al-Mg Alloy Binder on the Mechanical Properties of Al-Si/SiCp Metal Matrix Composites Fabricated by Powder Metallurgy

The aim of this study was to reinforce Al-Si/SiCp metal matrix composites (MMCs), which have homogeneous microstructures, by adding the Ti fibers and the Al-Mg powder. The Al-Si/SiCp MMC powder was fabricated by gas atomization for homogeneous distribution of the SiC particles. The Ti fibers were mixed with the Al-Si/SiCp MMC powder to structurally reinforce and enhance the interfacial bonding force between the Al-Si matrix and the Ti fibers. The Al-Mg powder was added as a binder to promote liquid phase sintering and to remove the oxide layer on the Al-Si/SiCp MMC powder. The Al-Si/SiCp system had homogeneous microstructures without any clustering of the SiC particles. The Ti fibers formed a diffusion layer at the interface of the Al-Si matrix and the Ti fibers. By adding the Ti fibers, the ultimate tensile strength and elongation increased from 194 to 234 MPa and from 6.2% to 7.6%, respectively. The Al-Mg powder liquefied during sintering and filled the pores between each particle, but the toughness of the Al-MMC decreased.