ABSTRACT
Four vegetable based oils were used as trial lubricants in the extrusion of aluminium billet through four different die geometries. These oils were extracted from Castor seeds, Neem seeds, Jatropha seeds and Cotton seeds respectively. Results obtained from this work as compared with other works done in the area shows that these oils were found to be suitable as lubricants in the extrusion of aluminium because of their heat reduction abilities and good surface finish. Extrusion dies with semi die angles of 300, 450 and 600were used; good quality surface finish and hardness of extruded billets were obtained. The coefficient of friction between the billet and the container wall was calculated for each process; Castor oil with good heat reduction ability and gave the least co-efficient of friction of 0.100 and 0.107 respectively. Also for all the geometries of billet extruded, round and triangular billets gave good surface finish for all the oils except for castror oil which gave the best surface finish. Based on previous experiments carried out on the extrusion of aluminium, surface cracking were major defects caused by the rise in temperature as the process proceeds. This research experiments indicated that the surface quality is good even though the temperature may be high during extrusion process.