Determining alternatives for metal forming lubricants: A study using plane strain cold extrusion process of JIS-A1100 pure aluminum billet

Abstract

Lubrication is very important in metal forming processes to control wear and friction at the interface between interacting surfaces. Non-renewable resources, such as plain mineral oils are widely used due to its ability to act as a supplier to wearing contacts; it may function as a film material or even sustain chemical transformations to become a film material. Since non-renewable resources can only last for more than a decade, renewable resources have been studied in order to find alternative lubricants that can present similar results in terms of extrusion load and product quality. Two renewable lubricants were analyzed (RBD palm olein and jatropha) together with an additive free paraffinic mineral oil, VG32, which acted as a reference lubricant. The experiment used a cold work plane strain extrusion apparatus that consists of a pair of taper die and a symmetrical work piece (billet). The billet material was made of annealed pure aluminum JIS-A1100 with radius of 5 mm in the deformation area. It was found that higher viscosity lubricants produced low extrusion load and friction during metal forming process with no major severe wear on product quality. Based on the results, it was proven that renewable resource based lubricants can be considered as a substitute for common lubricants used in the industry, since they present similar results with those currently applied in the industry.