Fabrication of TiB_2 particulate reinforced magnesium matrix composites by two-step processing method

摘要

The magnesium matrix composites reinforced with 2, 5 and 7.5 wt. percent fine TiB_2 (~7 mu m) particulates were fabricated by a novel two-step processing method, i.e. adding a TiB_2-Al compact mixed with fine TiB_2 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 TiB_2 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 TiB_2 content, but the porosity of the composites was relatively higher and increased with increasing of TiB_2 content.