Tribological effect of palm sterin and engine oil (CMEO) on pure aluminium pin steel disc with varies speed and constant load

Abstract

Palm stearin has high biodegradability and produces low pollution to the environment. This oil can be improved based on its natural behaviour and can be used as an alternative to replace widely used commercial mineral oils. Thus, the negative impact towards the environment can be reduced. The purpose of this research is to study the performance of two type of lubricants which are vegetable oil (Palm Stearin) and commercial mineral engine oil (CMEO). The sample will be tested using pin on disc tribotester machine that follows ASTM G99 standard. The materials used for this experiment are pure aluminium pin (A110) with spherical head and stainless steel disc (SKD11) with four grooves. The experiment will take approximately one hour to complete one test. The conditions that were considered before the beginning of the experiment are constant loads of 1 kg, varying sliding speeds of 1.5 m/s to 3.5 m/s with incremental 1 m/s and 2.5 ml volume of oil. The wear rate and coefficient of friction can be determined in this experiment. From the result obtained, the coefficient of friction (COF) of palm stearin is 45% higher than CMEO and also the trend for both oils are inversely proportional with sliding speed. Besides that, the wear rate of palm stearin is also higher than CMEO, which shows that CMEO has better lubrication performance when compared to palm stearin. The additives are needed for palm stearin so that the lubrication performance can compete with the CMEO. Furthermore, the results also reveal that vegetable oil shows a potential to be a commercial lubricant when the deficiencies can be overcome.