Unraveling The Statistical Significance: Impact Of Calcium Silicate On Mechanical And Frictional Wear Properties Of Aa7075 Hybrid Composites

Recently, Aluminum Alloy (AA) 7075-based Metal Matrix Composites (MMCs) have gained widespread utilization in aerospace applications owing to their favorable strength-to-density ratio. However, it often exhibits shortcomings in tribological applications like brake rotors, piston cylinder assemblies, couplings, and load bearings. In the existing literature, the addition of ceramic material like Al2O3 to the AA7075 Hybrid Composites (AHCs) has improved their wear and thermal properties, but the density of the AHCs has also increased. In this regard, it is essential to identify a low-density ceramic to improve the wear resistance of the AHCs without affecting their density/mechanical strength. In the current study, the calcium silicate (Ca2SiO4) reinforced AA7075/Al2O3/Ca2SiO4 hybrid composites were fabricated without significantly altering their relative density (3.54 ± 0.05%) and tested in terms of mechanical and frictional wear properties. The highest tensile strength was achieved for AA7075/Al2O3(10wt.%)/Ca2SiO4(12wt.%), which is around 263 MPa, i.e., 14.8% higher than the AA7075/Al2O3(10wt.%). The lowest specific wear rate is obtained for the AA 7075/Al2O3(10wt.%)/Ca2SiO4(8wt.%) at the high applied load and the low sliding velocity, which is around 1.44×10−6 g/Nm, and its corresponding CoF is 0.158. Finally, wear maps were constructed from contour plots of responses to elucidate the underlying mechanisms and consequences of wear during the dry sliding of AHCs.