Electroformed Diamond Tool Adaptable to Nanometer Grinding of Cemented Carbide

Abstract

An electroformed diamond tool with a tool tip radius of 0.2 mm was developed to achieve a surface roughness of less than 10 nm Rz on a mould made of cemented carbide. A polycrystalline diamond disc with a primary grain size of 0.5 µm and a diameter of 15 mm was used as a truer. A concentric guide groove with a reverse profile relative to the hemispherical tool and a surface roughness of 0.5 µm Rz was preformed on the truer by laser machining and wet lapping. It was verified through a truing test that 93 % of the diamond grains on the tool working surface could be flattened when the tool was placed in elastic contact with a guide groove with a depth of 50 µm. A grinding test revealed that the tool had the potential to efficiently fabricate a ground surface with a roughness of less than 10 nm Rz on cemented carbide with a hardness of 2600 Hv.