Development of Pulse Forming Method Utilizing Servo Press and Die with Internal Channel for Lubricant

提出了一种利用具有用于向凸模鼻部供应液体润滑剂的内部通道的凸模的成形方法。(1)将所提出的成形方法应用于纯钛试件的伺服压力机成形。在所提出的成形方法中，通过适当的脉冲冲头运动，成功地获得了成形孔深/直径为2.0的成形钛试样。(2)发现所提出的成形方法产生具有高形状精度的成形孔。结合实验和有限元模拟结果，从润滑状态和温度变化两个方面讨论了成形孔的形状精度。(3)将脉冲冲杆运动的成形方法应用于大高径比的正、反挤压成形。通过脉冲冲杆运动挤压过程中铝试样的材料流动来确定试样-冲杆界面处的剪切摩擦系数。

A forming method utilizing a punch having an internal channel for supplying liquid lubricant to the punch nose was proposed. (1) the proposed forming method was applied to forming of pure titanium specimen using a servo press. The formed titanium specimen with formed hole depth/diameter of 2.0 was successfully obtained in the proposed forming method with appropriate pulse punch ram motion. (2) the proposed forming method was found to produce the formed holes with high shape accuracy. The shape accuracy of the formed hole was discussed with experimental and finite element simulation results in terms of lubrication state and temperature change. (3) The proposed forming method with pulse punch ram motion was applied to combined forward-backward extrusion process with a high height/diameter ratio. The coefficient of shear friction at the specimen–punch interface was identified from the material flow of the aluminum specimen during the extrusion with pulse punch ram motion.