Mechanical and Dry Sliding Wear Behaviour of AZ31-TiO2 and AZ31-TiO2-Sn Metal Matrix Composites

The primary objectives of this study were to prepare, mechanically characterize, and evaluate the dry sliding wear behaviour of AZ31/(0.5, 1.5, and 2.5) wt% TiO2 metal matrix composites and hybrid AZ31/1.5 wt% TiO2/(3, 6, 9, and 12) wt% Sn metal matrix composites. The microstructural characteristics of the synthesized composites reveal the uniform distribution of the reinforcement particles. When the amount of reinforcement was increased, the tensile characteristics improved up to 1.5 wt% of TiO2 in single-reinforcement composites and 6 wt% of Sn in hybrid composites and then started to decline. A similar pattern was also shown by the microhardness and compressive properties. From the study of the mechanical behaviour of AZ31 composites reinforced with TiO2, the composite with 1.5 wt% of TiO2 had better mechanical characteristics, and the reinforcement amount was chosen to fabricate hybrid composites additionally reinforced with Sn microparticles. For the AZ31 alloy, AZ31/1.5TiO(2), and the hybrid composites, dry wear experiments were carried out using a pin-on-disc tribometer at the normal loads of 10 N, 20 N, 30 N, and 40 N, a sliding speed of 0.5 m/s, and for a total distance of 1000 m. In comparison to other composite samples, the hybrid composite with specimens containing 6 wt% of Sn showed a notable improvement in mechanical and wear characteristics. Through FESEM and EDS, the morphological examination of the worn surfaces identified various wear mechanisms, including abrasion, adhesion, and delamination.