The evaluation of palm oil as lubricant at low temperature

Abstract

Today, vegetable oil is much concerned for its application to a metal forming process as a lubricant because vegetable oil is renewable source and has high biodegradability compared to mineral oil. According to the OECD301C testing method, the biodegradability levels of the vegetable oils are more than 60% in 28 days while, the biodegradability level of the mineral oil is less than 30% in the same period of time (Komiya, 2005). Palm produces 3.66 ton oil for every hectare, which is 7 and 2.5 times more than soybean and rapeseed respectively (Ming et al., 2002). Then, palm oil has potential to fulfill the supply volume in demand of the vegetable-based lubricants. However, palm oil has high melting point, which cause the crystallization in high temperature. In tribological point of view, the change of viscosity affects the lubrication performance (Kamitani et al., 2002). We are investigated the performance of RBD palm olein as a lubricant in a cold metal forming process by carrying out the plane strain extrusion experiments and visioplasticity analyses (Nakanishi et al., 1977). The plastic flow velocities, strain rate and strain conditions in a deformation zone in steady state extrusion were revealed quantitatively by the visioplasticity analyses referring to the flow lines observed by the experiments.