Fabrication of TiB2 particulate reinforced magnesium matrix composites by two-step processing method

The magnesium matrix composites reinforced with 2, 5 and 7.5 wt.% fine TiB2 (∼7 μm) particulates were fabricated by a novel two-step processing method, i.e. adding a TiB2-Al compact mixed with fine TiB2 and Al powders to magnesium melt and using a semi-solid slurry stirring technique. The microstructure and properties such as porosity, hardness and wear resistance of the composites were investigated. The distribution of fine TiB2 particulates is relatively homogeneous throughout the Mg matrix. As compared with as-cast AZ91, the hardness and wear resistance of the Mg composite was higher and increased with increasing of TiB2 content, but the porosity of the composites was relatively higher and increased with increasing of TiB2 content.