Synergistic effects of Ti₃SiC₂ and NiTi on the mechanical and tribological performance of stir-cast ZE41 hybrid composites

Magnesium alloys are considered promising lightweight materials for automotive, aerospace, and other structural applications due to their low density and high strength-to-weight ratio, their limited strength, hardness, and wear resistance limit their wider industrial utilization. The present investigation is to evaluate the synergistic effects of Ti 3 SiC 2 MAX-phase particles, NiTi shape-memory alloy, and graphene oxide (GO) particles on the microstructure, mechanical and tribological performance of stir-cast ZE41 hybrid composites. Eight samples with various weight percentages (wt.%) of Ti 3 SiC 2 and NiTi and a constant GO were fabricated using the stir casting process under an argon gas atmosphere. Investigated experimental densities ranged from 1.803 to 2.232 g/cm³, while porosity increased from 2.01% to 4.19% with increasing reinforcement wt.%, as revealed by density and porosity measurements. The microstructure and interfacial bonding were significantly refined and improved by the hybrid reinforcements, as confirmed by comprehensive characterization. The best composition, Cast-5 (88 wt.% ZE41 + 5 wt.% Ti 3 SiC 2 + 5 wt.% NiTi + 2 wt.% GO), exhibited the maximum microhardness value of 86.2 HV and compressive strength (CS) of 227.9 MPa, which are 37.5% and 46.75% higher than the unreinforced ZE41. The specific wear rate was reduced from 0.000516 to 0.000223 mm³/N·m, which showed an improvement in wear resistance of 56.8%. Wear surfaces were examined by SEM, and it was found that the base alloy suffers from severe abrasive-delamination wear, and the optimized composite undergoes mild abrasive wear. The results reveal the promising performance of the ZE41 hybrid composites for lightweight potential utilization in automotive systems and aerospace industries.