A study of minimum quantity lubricant of refined bleached deodorized palm stearin in plane strain extrusion

Abstract

Large quantities of lubricant are being widely used in the metal forming industry and this high consumption is negatively affecting the environment. Finding an alternative to this current situation is getting more serious and urgent in response to environmental and operational cost pressures. This paper deals with an experimental investigation to obtain the minimum quantity of lubricant (MQL) of RBD palm stearin, which is used as lubricant between the contact sliding surfaces of the taper die and billet via plane-strain-extrusion apparatus. The symmetrical workpieces are designed as combined billets made from pure aluminium A1100. The dies of the apparatus are made of SKD 11 steel. The extrusion ratio of the processes is 3 and the workpieces are extruded by hydraulic press machine. Four conditions of the quantity selected are 0.1 mg, 1 mg, 5 mg, and 20 mg. The analysis of the result shows that the conditions of the quantity are in the load reducing order from 0.1 mg, 1mg and 5 mg. The highest distribution of surface roughness is at 0.1 mg, whereby for others, the conditions are quite similar. However, the distribution of velocity and effective strain are lowest at 5 mg. The minimum quantity of lubricant (MQL) of the RBD palm stearin as lubricant on the contact sliding surfaces in planestrain-extrusion is determined based on the results of load, surface roughness, velocity and effective strain.