Excellent wear performance of magnesium alloy from composite modified layer containing TiC coating and gradient microstructure

• A composite modified layer containing TiC coatings and gradient microstructures was created on magnesium alloys. • The composite modified layer achieves higher hardness and compressive residual stress. • Superior wear performance was obtained through the synergistic effect of TiC coatings and gradient microstructures. The inferior wear resistance of magnesium alloys severely restricts their broader application. In this study, a novel method (referred to as SUSP) combining ultrasonic shot peening with TiC particles was explored, which fabricated the composite modified layer containing TiC coatings and gradient microstructures on the surface of AZ80 magnesium alloys. Detailed characterization and experimental analysis demonstrated that the SUSP-treated sample achieved a peak hardness of 3.04 GPa and a maximum compressive residual stress of –125.1 MPa. The SUSP-treated exhibited excellent wear performance with a reduction in wear rate of 77.45 % and 62.72 % compared to untreated and conventional ultrasonic shot-peened samples, respectively. This improvement resulted from the synergistic effects of TiC coatings and gradient microstructures, which considerably reduced abrasive, fatigue, and adhesive wear. This study presents a novel strategy for enhancing the wear resistance of magnesium alloys and offers potential technical support to extend their lifespan in the aerospace, automotive, and biomedical fields.