Estudo do gradiente térmico durante o processo de retificação de um inserto de metal duro

Abstract

Grinding is a high-value-added machining process responsible for providing surface finish and ensuring adequate surface integrity. To achieve low surface roughness, high cutting speeds are commonly used, which are linked to the generation of high thermal loads. These thermal loads, originating from the heating during the grinding process, are quite problematic as they generate tensile residual stresses, in addition to facilitating the creation of cracks and, in more extreme cases, material burning. In this work, a thermal model was developed using the finite element method to evaluate the temperature fields throughout the grinding process of a cemented carbide insert for two critical scenarios involving the chip thickness per grain. The study demonstrated that, at all points of the insert, there was heating, with the lowest temperatures concentrated in the areas farthest from the ground face and the highest temperatures close to the ground face and the bottom face. In addition, the maximum temperature was not uniformly distributed on the ground face, presenting significant variations. Temperatures were recorded that exceeded the critical limit for energy partition greater than 20% in grinding with minimum chip thickness per grain and greater than 30% in grinding with maximum chip thickness per grain. Finally, it was observed that the temperature evolution follows a logarithmic behavior due to the variation of the thermal properties of the cemented carbide.