Microstructure, mechanical properties and wear resistance of Ti particles reinforced AZ31 magnesium matrix composites

The compromise between strength and plasticity has greatly limited the potential application of particles reinforced magnesium matrix composites (MMCs). In this work, the Ti particles reinforced AZ31 magnesium (Mg) matrix composites achieved simultaneous improvement in strength, elongation and wear resistance. The Ti particles reinforced AZ31 composites were fabricated by ultrasonic-assisted stir casting with hot extrusion. The results showed that a strong interfacial bonding was obtained at Ti/Mg interface because of the formation of semi-coherent orientation relationship of TiAl/Mg, TiAl/Al2Ti and Al2Ti/Mg interfaces. The as-extruded 6 wt.%Ti/AZ31 composite presented the best compressive mechanical properties and wear resistance with ultimate tensile strength, elongation and wear rate of 327 MPa, 20.4% and 9.026 × 10−3 mm3/m, obviously higher than those of AZ31 alloys. The enhanced mechanical properties were attributed to the grain refinement and strong interfacial bonding. The improved wear resistance was closely related to the increased hardness of composites and the formation of protective oxidation films.