Influence of micro-pits indentation and palm based-oil on taper die sliding contact surface in cold extrusion process

Abstract

Surface texturing is among the cheapest solutions for die modification if compared to tool change and hot works. In extrusion die design, the addition of micro-pits has increasingly been used to balance the metal flow. Such balance is particularly important for multiple cavity dies or sections with varying thicknesses in order to maintain a uniform velocity profile across the face of the die. In this research, surface texturing (called as micro-pits) was embedded on taper die sliding contact surface to explore its effectiveness on finish product of cold extrusion process. Palm oil based lubricants were tested for cold extrusion processes and mineral oils were used for comparison purpose. It was found that taper die with micro-pits (PA) performed a lessened extrusion load than taper die without micro-pits (NA), so as enhanced the performance of other tests parameter. In addition, viscosity of lubricant seems to be very important in ensuring that no material and tribological failures occur during the metal forming process.