Synthesis, Characterization, and Tribological Behavior of Neopentyl Polyol Ester-Based and Mixed Oil-Based Titanium Complex Grease

Four types of titanium complex grease were synthesized using a 3-l reaction vessel, and their friction and wear behavior were evaluated using a four-ball tester in the presence of two base oils: neopentyl polyol ester and a mixture oil of neopentyl polyol ester, 650SN, and epoxidized soy bean oil (4.5:2.5:1), with two compositions: benzoic acid/stearic acid and sebacic acid/stearic acid. The results indicate that mixed oil-based titanium complex grease has excellent tribological properties. Moreover, compositions affect the physical characteristics of titanium complex grease but have little effect on the friction-reduction, antiwear, and load-carrying capability of the same types of oil-based titanium complex grease. In addition, base oils also affect the tribological property of titanium complex grease. Based on scanning electron microscopy and x-ray photoelectron spectrometer of the worn surfaces of steel balls lubricated with the different types of grease, synergistic boundary lubrication was proposed to illustrate the friction-reduction and antiwear properties of titanium complex grease.