Analysis of shear edge quality for different punch velocities in micro-blanking process

A die clearance is the main factor that influence a proportion of a shear edge. With a larger die clearance, the shear edge will be more irregular. A good blanking quality has a shear edge with a large portion of shear zone, i.e. a smooth and shiny area, and small portions for the rest. In this research, the investigation was held to study about the shear edge occurrence on micro-blanked-part with a specified die clearance and a varying punch velocities. The investigations of the shear edge in micro level provide more distinct difficulties comparing with the macro level due to the restricted size of micro-part. The experiment applied 0.5 mm/s and 5 mm/s of punch velocities in blanking of aluminum and copper foil with 0.1 mm thickness. The die clearance was determined at 0.033 mm. The material foils were set at longitudinal and transverse direction to observe the influence of the rolling direction to the shear edge proportion. The result showed that with a higher punch velocity, the shear zone portion became larger. It is concluded that with the specified die clearance, the shear edge quality can be improved if higher punch velocity was applied.