Grinding Force, Specific Energy and Material Removal Mechanism in Grinding of HVOF-Sprayed WC-Co-Cr Coating

摘要

The present study applies the machining approach and other analysis techniques to investigate the material removal behavior during surface grinding of high-velocity oxy-fuel (HVOF) thermally sprayed WC-10Co-4Cr coating using a resin-bonded diamond wheel. The basic grinding factors such as force ratio, specific material removal rate, maximum undeformed chip thickness, and specific grinding energy have been investigated and discussed. The mathematical models containing linear terms and interactions of the first-order have been used to investigate the effect of the grinding parameters on the grinding force. The results have shown that both tangential and normal grinding forces depend not only on the depth of cut, feed rate, and cutting speed, but also on the depth of cut and feed rate interaction. Scanning electron microscopy (SEM) examination of the ground surface has revealed that the mechanism of material removal presents both brittle fracture and ductile flow modes. Considering the effect of the process parameters on the grinding mechanism, it has been inferred that the portion of the material removal mechanism associated with brittle fracture or ductile flow can be different according to the grinding parameters variations. Also, the SEM photographs have shown that large amounts of energy have been expended by plastic deformation due to plowing.