Multi–criteria decision analysis (MCDA) on the mechanical properties of hybrid reinforced aluminium metal matrix composites

Hybrid-reinforced aluminum metal matrix composites (AMMCs) are considered highly sought-after materials for advanced engineering applications. In selecting the optimal composition for these composites, it is necessary to balance conflicting properties, including Brinell Hardness Number (BHN), Ultimate Tensile Strength (UTS), Yield Strength (YS), %Elongation, Fracture Toughness, Density, and % Porosity. In this study, multi-criteria decision analysis (MCDA) was adopted, where ten alternatives, hybrid-reinforced AMMCs, were ranked. The amounts of PKSA (Palm Kernel Shell Ash) and SiC essential for the development of hybrid reinforced composites (2, 4, 6, 8, and 10 wt%) in the matrix were evaluated via charge calculation, consisting of PKSA to SiC ratios (0:0, 0:2, 2:2, 4:2, 6:2, 8:2). The objective weights were computed using the CRITIC method, and obtained as 0.1236, 0.1121, 0.1243, 0.1992, 0.1662, 0.1456, 0.1290 for BHN, UTS, YS, % Elongation, Fracture Toughness, Density, and % Porosity, respectively. COPRAS and TOPSIS were the MCDAs used to rank the alternatives, where they consistently ranked alternatives A0, A6, and A1 as the most preferred (1st), more preferred (2nd), and preferred (3rd), respectively, while alternative A9 was ranked worst. A Spearman rank correlation of 0.9636 between COPRAS and TOPSIS confirms the consistency and robustness of the ranking results. For tailored utility in aerospace and wear-resistance tooling applications, Samples A 4 and A 5, and Samples A 9 and A 8 , were respectively ranked as the best decision. Integration of CRITIC with COPRAS and TOPSIS provides a data-driven, robust approach to selecting hybrid-reinforced aluminum metal matrix composites, using identified mechanical properties as decision-making criteria.