Wear of Diamond Cutting Tool in Ultra-precision Single Point Turning

The wear mechanisms of monocrystalline diamond cutting tool in ultra-precision single point diamond turning of aluminum alloy, OFHC copper and single crystal silicon were investigated by carrying out single point diamond turning test. The effect of tool wear on the diamond turned surface roughness was examined, and the macro and micro tool wear morphologies were observed using an optical microscope and atomic force microscope. By combining the test with the theoretical analysis in terms of thermodynamics, chemical reaction and mechanical abrasion, the wear mechanisms of the diamond cutting tool in ultra-precision turning aluminum, copper and silicon were comparatively analyzed in detail. As the results, the diamond cutting tool was characterized by different features in turning different materials. It was suggested to abate the cutting tool wear under reduced oxygen environment or using oxygen free coolant in turning of copper. In turning aluminum alloy, some kinds of “inhibitor” such as lubricant or isolated surface layer should be applied, while in turning of single crystal silicon, the processing should be performed in the reduced cryogenic or oxygen environment. In addition, the reasonable small depth of cutting and feed rate should be applied to eliminate the vibration impact and suppress the mechanical wear of the diamond tool.