A Discussion on Material Removal Mechanisms in Grinding of Cemented Carbides

Abstract

In the literature, cemented carbides are described as hard and brittle materials. The material removal mechanisms in grinding of brittle materials, such as cemented carbides, significantly differ from the material removal mechanisms of ductile materials [1–3]. The material removal mechanisms in grinding of ductile materials are comparatively well investigated in comparison to the material removal mechanisms in grinding of brittle materials. In the existing literature, it has been shown that the material removal mechanisms in grinding of cemented carbides can be ductile or brittle. The present material removal mechanisms are dependent on the thermomechanical stress collective, which acts on the surface zone of the cemented carbides. In this paper, the material removal mechanisms in grinding of cemented carbides are discussed fundamentally. In order to analyze the occurring material removal mechanisms in grinding of cemented carbides, single grain cutting tests were carried out. Subsequent to the tests, the surface zone of the cemented carbide has been analyzed in detail. Therefore, scanning electron micrographs have been made to analyze the workpiece surface to identify the transition from predominantly ductile to predominantly brittle material behavior. Furthermore, focused ion beam (FIB) preparation, which has minimum invasive influence on the subsurface, was applied in order to get an insight into the surface zone. The FIB lamellae have been analyzed with transmission electron microscopy (TEM) to get a better understanding of the impact of material removal mechanisms on the surface zone. The drawn conclusions contribute to an improved process understanding in grinding of cemented carbides.