Influence of Ti-6al-4v Particles on Mechanical Behaviors and Microstructure of Az91 Alloy

While Magnesium (Mg) matrix composites have been intensively investigated as the promising light structural materials, the relatively low ductile nature limited their wide-scale applications. Herein, we report that AZ91 Mg matrix composites reinforced by Ti-6-Al-4V (TC4) particles were prepared via powder metallurgy. Microstructure observation showed that the interfacial zone was composed of Mg 17 Al 12 and Al-rich phase. The tensile tests suggested that the yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) display peak values (211 MPa, 303 MPa, 18.7%, respectively) when the content of TC4 particles is 5 wt.%. The improvement of mechanical properties can be attributed to strong interfacial bonding between the Mg matrix and TC4 particles through the metallic mesophase. The strain distribution during the tensile process of the composite was investigated using digital image correlation (DIC) technology. It was revealed that the introduction of TC4 reinforcement can relieve the stress concentration and the composites achieve comprehensive mechanical properties with high strength and high plasticity. Furthermore, TC4 particles can improve matrix strengthening effect through increasing in work hardening capacity. The elongation of the composite also increased during tensile loading. These findings caused that the current issue of the relatively low ductile nature of Mg matrix composites to be solved effectively