A new approach to cold extrusion process: Dimples indentation on sliding contact surface and palm oil as an alternative lubricant

Abstract

Surface texturing is one of the economic solutions to die modification if compared with tool change and hot works. In extrusion die design, it has become increasingly common to add dimples to maintain lubricant flow along the metal forming process. For that reason, this research was done by embedding dimples in a tapered die sliding contact surface to explore its effectiveness in a finished product of cold extrusion process. Besides, an alternative lubricant from palm oil was also tested, and mineral oil was used for comparison purposes. As a result, dimpled tapered die may help decrease the extrusion load of cold extrusion process, leading to ner surface roughness of extruded product. Palm oil-based lubricant also presents similar results to those of mineral oil, meaning that palm oil has a potential to be considered as a new metal forming lubricant in the future.