International Journal of Integrated Engineering, Vol. 3 No. 1 (2011) p. 28-31 *Corresponding author: hafissulaiman@unimap.edu.my 2011 UTHM Publisher. All right reserved. penerbit.uthm.edu.my/ojs/index.php/ijie 28 The Effect of Paraffinic Mineral Oil Lubricant in Cold Forward Extrusion S.M. Hafis 1,* , M.J.M. Ridzuan 1 , S. Syahrullail 2 , A. Amran 2 1 Mechanical Engineering Programme, School of Mechatronic Engineering, Universiti Malaysia Perlis (UniMAP), 02600 Pauh, Perlis, Malaysia. 2 Faculty of Mechanical Engineering, Universiti Teknologi Malaysia (UTM), 81310 UTM, Skudai, Johor, Malaysia. Received 21 June 2011; accepted 2 August 2011, available online 21 September 2011 1. Introduction Paraffinic palm oils have been utilised in Malaysia for many purposes, for example, in metal forming process. A research was conducted [1] on the application of palm oil lubrication on tools to perform better surface finish on a product. The influence of palm oil lubricant viscosity on material deformation may differentiate the plasticity flow patterns within the extruded part and affects the necessary extrusion loads [2]. In addition, in order to determine whether a particular billet can be extruded to a given geometry without failure during the process, many studies [3, 4] have been conducted using numerical method to predict the stress and strain distributions. Fig. 1 Schematic diagrams of cold forward extrusion. In cold forward extrusion operation, lubrication plays an important role in the two contact surface regions. Fig. 1 shows region 1 and region 2 that are located in billet- die container and billet-taper die surfaces, respectively. In this analysis, finite element analysis was performed to predict the effect of the palm oil lubricant. 2. Material Property and Friction Model The material behaviour in the billet was used as an input for the finite element model. It was determined by the uniaxial tensile test on pure aluminium alloy AA1100. The test method followed ASTM E8M-91 standard. The relationship between true stress and true strain is presented in Fig. 2. The properties of the material were; density, ρ of 2700 kg/m 3 , elastic modulus, E of 69 GPa, initial yield strength, σ Y of 56 MPa, and Poisson’s ratio, ν of 0.33. 0 20 40 60 80 100 120 0 2 4 6 8 10 12 14 16 18 20 True Stress (MPa) True Strain (%) Fig. 2 The true stress-strain curve of aluminium alloy AA1100 by uniaxial tensile test. It is reported that the lubricant quantity acts as friction coefficient between sliding surfaces [5]. In this case, Abstract: This paper presents the finite element analysis of cold forward extrusion and the analysis of the contact sliding behaviour on the die-billet surface by paraffinic mineral oil lubrication with kinematic viscosity of 92 mm2/s at 40 °C. The analysis dealt with the plasticity flow that was investigated by finite element method in order to identify the loads acting on the billet. The finite element analysis of stresses was performed based on load distributions calculated from experimental test. The time behaviour of displacements on the billet was then used as inputs for the extrusion model. The presented method provides good results with reduced computation time. The results of the extrusion model revealed that the zones of high stress located at the sharp edges of the die, which explains the observed extrusion force to reach a peak value. Keywords: Extrusion, paraffinic mineral oil, finite element analysis, extrusion load. Billet Die