Investigations on Mechanical and Wear Properties of Molybdenum Trioxide-Reinforced Aluminum Alloy (AA7075) Matrix Composites Produced via Stir Casting Process

AA7075-based composites with 2.5, 5, 7.5 & 10 wt.% of molybdenum trioxide (MoO3) were fabricated by stir casting route, and detailed investigation was carried to assess the mechanical and tribological properties of the novel composites formed. Also, their behavior was compared with the base material. The casted components were subjected to hardness test, impact test, and tensile test. 10 wt.% MoO3-reinforced Al7075 composites exhibits highest impact strength of 126 MPa among other composites. 10 wt.% MoO3-reinforced Al7075 composites also exhibits highest porosity of 3.9% among other prepared composites. Various parameters such as wt.% of MoO3, Load (P), sliding distance (D) and Sliding speed (V) were varied and experimentation was done by using pin on disk wear tester to determine the wear rate (WR) and coefficient of friction (COF). Maximum COF was obtained for 10 wt.% at applied load of 20 N and 1 m/s. Also, at higher load of 40 N, the wear rate of 0.00674 mm(3)/min was obtained for 10 wt.% MoO3 at applied load of 40 N and sliding speed of 4 m/s. The statistical technique, ANOVA, reveals that applied load is the foremost factor in affecting wear rate followed by weight percentage of MoO3, sliding distance and sliding speed. Further, the wear resistance of the 7.5 wt.% of MoO3-reinforced composite is found to be better than 2.5, 5 and 10 wt.% of MoO3-reinforced composite. The morphological characterization of the Worn surfaces of AA7075-MoO3 composites was done with scanning electron microscope and the micrographs also revealed the nature of wear experienced.