Plasticity analysis of pure aluminium extruded with an RBD palm olein lubricant

Abstract

In this study, a cold-work plane strain extrusion apparatus was used to perform plasticity analysis of a work piece that was extruded using RBD palm olein as a cold metal forming lubricant. The experimental apparatus consists of a set of two taper dies with 45-degree die half angles and a billet (work piece). The experiments were carried out at room temperature, which was within the range of 28 to 32°C. The testing lubricant was refined, bleached and deodorized palm olein (RBD palm olein). The billet material was annealed pure aluminium, Al 100. The experimental results focused on the extrusion force, surface roughness of both the deformation area and the product surface and sliding velocity. The grid lines, which were scribed on the billet, were used to observe and analyze the plastic flow in the material. The velocity distributions on the experimental surface of the billet were calculated using a visioplasticity method. Similar experimental and analytical investigations were carried out using additive-free paraffinic mineral oil and were compared to the investigation with RBD palm olein. The RBD palm olein showed a reduced extrusion force and a better quality surface roughness. The work piece that was extruded with RBD palm olein showed better plastic behavior as compared to those that were extruded with paraffinic mineral oil. It was confirmed that RBD palm olein shows satisfactory lubrication performance as compared to additive-free paraffinic mineral oil.