Performance evaluation of Al7075 composites reinforced with dual-scale ZrO ₂ particles for engineering applications

To reinforce Al7075 alloy, this investigation utilized Micro-ZrO 2 and Nano-ZrO 2 to create in situ titanium diboride particles. Stir casting was used to make this composite. The melt’s interior is where the reinforcement particles were produced in situ . 650 °C was chosen as the operating temperature for both melting and casting. The study examined the impact of additives containing zirconia oxide on the composite. According to the findings, zirconia oxide reduced the agglomeration of reinforcing particles in the melt. In addition to improving the distribution of reinforcing particles in the composite, cryolite also boosted melt flow and inhibited melt oxidation. Tribological evaluation using pin-on-disc testing showed that ZrO 2 reinforcement significantly enhanced wear resistance and reduced the coefficient of friction. Nano-ZrO 2 samples exhibited lower wear rates than Micro-ZrO 2 due to better dispersion and higher surface area. Because of zirconium, the composite’s tensile strength was enhanced, its structure was refined, and the agglomeration of ZrO 2 particles was reduced. Furthermore, in samples of wear modified by Zr, the predominant fracture mode. When Nano ZrO 2 and Micro were added to the samples, brittle fracture predominated over ductile fracture in ZrO 2 . The variation range of weight loss among all samples is approximately 0.44 g (from 0.78 g to 0.34 g), indicating significant performance differences.