Punch Wear in the Forming of Deep Holes with Pulse Ram Motion on a Servo Press

Abstract

For the fabrication of lightweight components such as hollow components, we proposed a cold extrusion method for forming of deep holes that utilizes a punch with an internal channel for the supply of liquid lubricant using a servo press. The relationship between the punch ram motion and the punch wear in the proposed forming method is investigated by the finite element analysis in this study. The punch wear is determined by using the Archard’s equation. Although low friction at specimen–punch interface realizes in the forming with pulse punch ram motion (proposed forming method), the punch wear in the backward extrusion with pulse punch ram motion is 1.1–2.4 times larger than that with no pulse punch ram motion (conventional forming method). The influence of punch ram motion and friction on the punch wear is discussed.