Study of the tribological properties the mixture of soybean oil and used (waste) frying oil fatty acid methyl ester under boundary lubrication conditions

Abstract

This study has been conducted with the purpose of studying the tribological properties the mixture of soybean oil and used frying oil the Fatty Acid Methyl Esters(FAMEs) under boundary lubrication conditions. Tests have been conducted between steel ball and the journal bearing material sample connecting to the disc of Pin-on-Disc Test apparatus. It was selected experimental parameters such as 5, 10 and 20 N loads, 100, 300, 500 rpm sliding velocities and 500 m sliding distance. The surface roughness of the samples has been measured prior to and after each test. Wear rate has been measured through mass loss method prior to and after each test. Also, specific wear rates (ws) of the test specimens were calculated. SEM and EDS analyses were also conducted to wear contact surfaces. When all the friction coefficient (μ) values acquired from boundary lubrication conditions are compared to μ values acquired from dry (lubricant-free) test conditions, very lower friction coefficients have been achieved. Usage of the mixture of soybean oil and used frying oil FAMEs as lubricant candidates are quite good a performance under boundary and/or mixed lubrication. It has also been observed that with the increase of load, specific ws values are generally decreasing.