Material selection through of multi-criteria decisions methods applied to a helical gearbox

The aim of this study was to select the best material using the multi-criteria decision methods, obtaining the best results and the respective choice of material, optimising surface fatigue and increasing its resistance to wear applied to a gearbox. For which the multi-criteria decision methods were done to obtain an order or ranking of the set of alternatives. To obtain this ranking, the set of alternatives must be well defined, just as the criteria must be well determined. After using the multi-criteria, it was determined that the material chosen according to the ranking and is the third alternative that has relevant characteristics such as elastic limit, tensile strength and good thermal capacity. The entropy method applied to the weights helps avoid the subjectivity of the designer and make it conform to real parameters. According to the methods COPRAS, TOPSIS, PROMETHEE and VIKOR; the best material is the AISI 4140, due to the best mechanical and thermal properties. On the basis of the numerical results, it can be concluded that the proposed methods can deal with the problems of material selection with the dependence of criteria.