Performance characteristics of lubricant based on rapeseed oil containing different amounts of metal-containing additive

Abstract

Purpose The purpose of this study was to investigate the biobased (rapeseed) oil with the addition of different amounts of metal-containing additive in a steel–bronze tribological system. The additional purpose was to find the optimal value of the additive. Design/methodology/approach This paper exposes experimental results of the performance characteristics (coefficient of friction (COF), working temperature and wear) of the biolubricant based on rapeseed oil. The amount of commercial metal-containing additive in formulated lubricant was 1, 1.5, 3 and 5 wt.%. All results were compared with the results obtained for the base rapeseed oil. Two different tribometers were used, with the same tribosystem elements materials (bronze and steel). COF experiments were performed under four different normal loads and fixed sliding speed and time. Temperature and wear were continuously monitored. Findings Results showed that the metal-containing additive in rapeseed oil reduced all monitored characteristics. It was also found that the dependence of all characteristics on the amount of additive is nonlinear and that there is an optimal value of it. Originality/value Owing to growing environmental concerns, vegetable oil-based lubricants and other biodegradable lubricants are expanding their area of application. Currently, one of the most widely used vegetable oil is rapeseed oil. The metal-containing additive used in this study is previously investigated as an addition to mineral- and synthetic-based oils. There are very few studies that investigate its influence on the vegetable oil-based lubricants. In addition, there is no comparative investigation of its influence on several performance characteristics (COF, temperature and wear).