An investigation of the film formed in the borate oil immersion test

Oil immersion tests of steel blocks with tridodecyl borate oil were carried out at various temperatures for various test durations. The chemical composition and chemical state of the film formed were investigated using both X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The friction and wear properties of the film were evaluated using a one-way reciprocating friction tester under lubrication with white oil. The results of the XPS and AES analyses indicate that the film formed in the oil immersion test may contain iron or iron oxide and degraded borate. The results of the friction tests indicate that the film exhibits good antiwear and friction-reducing performances.