Abstract

Malleable cast irons have many applications in the industries includes pipe fittings and automotive industry. The importance and consequence of selecting efficient materials in pipe fittings and its effect on the final quality of products are apparent. In the case of the multiple criteria for selection, implementing a mathematical model is inevitable. In this study, the calculations performed in AHP and TOPSIS models with the aim of achieving the efficient materials of pipe fittings in order to ease the issues raised from trial-and-error decision making. In this regard, five alternatives for cast iron have been identified by experts and analysis carried out according to molten fluidity, shrinkage during solidification, machining capabilities, yield strength, ultimate strength and ductility. By the comparing of the outcome of these models with practical implementation for the five samples malleable cast iron, the alternative GTS-55 alloy was recognized as the best choice. It is also concluded that the difference in results is justifiable because of the similarity of the properties.

Keywords: Multi-criteria decision making; Malleable cast irons; Pipe fittings; AHP; TOPSIS