Optimal selection of SiC and TiO2 reinforced ZA27 hybrid nanocomposite exercising PSI approach under fuzzy environment for bearing application

The correct selection of material with adequate characteristics for bearing races has been troublesome owing to the wide availability of materials with different sets of characteristics. In the same context, the present work deals with selection of the best composite formulation using multi-criteria decision making (MCDM) method among the set of prepared composite alternatives. The preference selection index (PSI) method was utilized in ranking alternatives under uncertain (fuzzy) environment. Four hybrid Zinc alloy (ZA-27) nanocomposite reinforced with varying wt% of micro SiC and nano TiO2 were fabricated using stir casting technique, and different performance characteristics are examined to select the best composite formulation for bearing races. The rationale for selecting this combination of materials stems from the enhanced hardness and thermal resistance provided by micro SiC particles, while TiO₂ contributes to improved wear resistance and reduced friction, critical for enhancing the performance and longevity required in bearing application. The results demonstrate significant improvements in the mechanical and tribological properties of the composites, with A-1 composite sees 107% increase in tensile strength, a 78% increase in hardness, and 24% enhancement in wear resistance compared to the unreinforced ZA-27 alloy. Finally, it was concluded that A-1 (having 2.5 wt% SiC and 2.5 wt% TiO2 as reinforcement) composite formulation comes out as the best alternative among available options, which was validated by fuzzy TOPSIS and fuzzy VIKOR approaches, for the bearing races application.