Microforming a Miniature Cup-Shaped Internal Gear Using a Cold Lateral Extrusion Process

Abstract

This study determines the micro forming of copper alloy to form a cup-shaped internal gear. The as received material, copper alloy C1100, is annealed to obtain the initial grains and to determine the effect of the initial grain size on the mechanical properties, the deformability and the filling rate for a tooth cavity. The experimental results show that the specimen that is annealed at a temperature of 500 °C has an initial grain size of 25.5 µm, which increases ductility and allows a cup-shaped internal gear to be formed with the highest filling rate of 99.2%. Except for the as received material, the Vickers hardness, the extrusion force and the filling rate decrease as the initial grain size increases. The hardness is approximately homogeneous along the addendum and dedendum edges but gradually becomes less homogeneous along the edge of the tooth profile from the addendum to dedendum.