Caracterización experimental del desgaste radial de muelas de rectificado con aglomerante vítreo

Abstract

Grinding is one of the most value-added operations in the manufacture of mechanical components. It is a finishing operation that achieves dimensional tolerances and surface finishes that cannot be achieved by other manufacturing processes. This operation allows an excellent fatigue life of the component to be obtained, which is why its presence is very important in high-tech components for aeronautics, automotive, optics, etc. The tool, the grinding wheel, is a composite that suffers wear during its interaction with the part. The wear causes loss of tolerances and surface finish, thus affecting the viability of the operation. It can even lead to damage that adversely affects the fatigue behavior of the component. Since the manufacturing of grinding wheels is very handmade, and the manufacturer does not have data on the mechanical characteristics of the abrasive and the bond, the study of wear phenomena is traditionally based on trial-and-error schemes. This work is the first step for the subsequent development of numerical models and new experimental tests to characterize the fracture behavior of the grinding wheel as a composite. Previously, it is necessary to obtain relationships between the loss of geometry of the grinding wheel and the forces, specific cutting energy and final surface finish of the part. In this work, an experimental methodology for wear quantification is presented. After describing the tests, they are carried out on a sensorized industrial grinding machine using an alumina grinding wheel. The evolution of forces, specific cutting energy and surface finish with wear under different grinding conditions is then discussed. The results reveal that it is not possible to study the fracture behavior of the grinding wheel if the phenomenon of abrasive grain loss is not isolated. The wear of the grinding wheel has increased as the volume of the ground piece has increased; however, with the tests carried out, the abrasive grains have not become detached from the bond, so actions are established to be able to isolate this phenomenon in future tests. In the preliminary tests, as the feed rate increases, the specific cutting energy decreases and Ra increases, while there is no clear trend in volumetric wear. In the characterization tests, two abrasive wear trends can be observed. The change in the trend causes an increase in specific energy and Ra. These results, presented in this article, will allow further validation of the numerical models on which work has already begun.