Estudio de las propiedades de las arenas y su influencia en las piezas fundidas en ciertos talleres de fundición de la ciudad de Quito.

Abstract

In Quito there are several foundry workshops that carry out their work manually, without control over the variables that influence their products. Hence, in this study the properties of the molding mixtures used in each workshop are determined and according to these results a new composition of molding mixture that improves the properties of the original mixture is proposed and the influence of these properties on the castings in the two types of mixture is determined as well. To determine the properties of the sands, tests were performed on granulometry, size and shape of grain, moisture and clay content, permeability, hardness, shear and compression strength; in addition, mechanical tensile and surface hardness tests were performed on melted specimens with the two mixtures for each workshop. Once the tests were concluded, the results obtained were compared, in the molding mixtures and mechanical tests, between original and new mixtures to determine the differences produced with the changes made and the influence of the properties of the molding mixtures on the mechanical properties. Due to this results, an evident improvement in the properties of the molding mixtures was obtained by reducing the moisture and clay content, however no relevant change in the mechanical properties of the castings was noticed.