Tribological behavior of octadecylamine functionalized graphene oxide modified oil for wire rope in mine hoist

Abstract

The operating conditions of hoisting wire ropes are extremely harsh in coal mines, which often accelerates wear due to lubrication failure. This paper starts with the modification of lubricating oil to improve the service life of wire ropes in mine hoists under severe working conditions. First, the modification methods of octadecylamine functionalized graphene oxide (ODA-GO) and its reduced product by hydrazine hydrate (ODA-rGO) were introduced, followed by characterization with Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), Raman spectroscopy, thermogravimetric (TG) spectroscopy and transmission electron microscope (TEM). Then, the dispersion stabilities of these additives in IRIS-550A lube oil (IRIS) were recorded and quantitatively analysed by a UV–Vis spectrophotometer. Finally, the tribological properties of ODA-GO- and ODA-rGO-modified oils were evaluated through a four-ball tribotester, and ODA-GO-modified oil was further tested using a wire rope sliding wear rig under different contact loads and sliding speeds. The results show that octadecylamine is attached to graphene oxide (GO) through covalent bonds. ODA-GO shows a better dispersion stability in IRIS than ODA-rGO due to its high concentration of octadecyl chains. The coefficient of friction (CoF) between wire ropes varies under different test conditions, but the wear is reduced in all cases.