The effect of Ti on the microstructure and mechanical properties of (Ti + Mg3Sb2)/Mg composites

In the present research work, (titanium (Ti) + magnesium antimonide (Mg3Sb2)/magnesium (Mg) composites with Ti contents of 0, 5%, 10%, and 15% (mass fraction, %) were fabricated by powder metallurgy. The effect of different Ti contents on the microstructure and mechanical properties of (Ti + Mg3Sb2)/Mg composites was investigated. The results show that the volume of Mg3Sb2 compounds can be significantly refined and the distribution uniformity of Mg3Sb2 compounds can be improved by adding an appropriate amount of Ti. Part of Sb reacts with Ti in situ to form TiSb2 compounds at the periphery of Ti particles. However, the reaction is not sufficient, and there is still the remaining Ti distribution in composites. Both Ti particles and TiSb2 compounds form (Ti + TiSb2) microstructures, which have different degrees of agglomeration with the increase of Ti contents in composites. The appropriate amount of Ti can improve the mechanical properties of the composite, but excessive Ti can reduce the tensile strength of the composite.