Electrolytic Abrasive Edge Honing of Cemented Carbide Cutting Tools

Abstract

The traditional mechanical cutting edge honing has some disadvantages, such as low efficiency and edge profile irregularities. Based on the phenomenon of rapid erosion on sharp corners by electrolysis and flowing abrasive to remove the oxide films, an innovative electro-abrasive honing process on the cemented carbide cutting edge is proposed. An accurate rounded contour is formed to enhance the edge strength. There are little micro-chipping or grinding traces observed near the cutting edge after honing. The surface roughness decreases from Ra0.31 to Ra0.14 inspected by white light interferometer (WLI). However, some micron-grade craters appreciably extend further into the rake/flank faces. The Co content decreases from 5.8% to 0.6% detected inside the corrosion craters by energy dispersive spectrometer (EDS). It demonstrates that the microstructure of corrosion crater is formed in the high-grade Co areas because Co has a lower electrode potential than W. Some impurity elements K, Cl, Na and N, detected in the micro craters, are estimated as the residual of electrolytes. The results of the honed surface element data show that only W, C and no oxides appear. It is verified that to remove oxide films by the electro-abrasive process is feasible.