Material Selection for Automotive Piston Component Using Entropy-VIKOR Method

Development and selection of appropriate material with unlike properties (density, hardness, compressive strength, tensile strength, flexural strength, friction coefficient, wear rate and many others) for piston material is one of the most exigent tasks. Inappropriate material often causes component failure at some point during functioning. Therefore, in this article, piston material containing different amount of recycled porcelain (used as reinforcement) were manufactured by induction furnace. The density, mechanical strength and specific wear behaviour were tested. The weight percentages of porcelain were in the range of 0 wt%-8 wt% in the base i.e. LM-26 alloy (Al-Si10Cu3Mg1). Micro-hardness tester and universal testing machine (INSTRON-5967) apparatus were utilized to record the mechanical properties of the manufactured materials and Pin-on-disc tribometer was conducted to evaluate the friction coefficient and specific wear rate at room temperature. Since no single material could merely satisfy all the desired characteristics, the Entropy-VIKOR (Vise Kriterijumska Optimizacija Kompromisno Resenjemeaning) multi criterion decision technique was employed to choose the preeminent composite amongst the examined materials. The entropy was applied to calculate weights of criteria, and VIKOR method was implemented for the ranking of manufactured composites. From the results obtained, it was indicated that A-3 (having 6 wt.% porcelain) piston material possesses the best combination of all the properties for a given application. Also, sensitivity analysis is performed to study the stability and robustness of the ranking with respect to the weights of the criterions.