Micro-Ball Endmilling of Tungsten Carbide for Micro-Molding and Prototyping Applications

This paper presents micro-ball end milling of tungsten carbide using a CBN cutter to investigate its capability for machining slots for micro-moulds. Crack-free slots were machined at different axial depths of cut by inclining the work piece surface at different angles to the spindle axes to study the influence of these machining parameters on the cutting mechanism and surface finish. The experimental results show that up to 150 µm deep slots can be finished efficiently on tungsten carbide work pieces without leaving any fracture marks. It was identified that the chip disposal ability of micro-ball end milling reduced with increase in axial depth of cut. The cutting action was more efficient in up milling cuts compared to that in down milling when machining a slot. The inclination of the work piece proved propitious for machining slots with high-quality finish on tungsten carbide work pieces and a larger inclination angle also facilitated chip disposal.