Tribological behaviours of surface-modified serpentine powder as lubricant additive

Abstract

Purpose – The aim of this paper is to study the tribological performance and self-repairing performance of surface-modified nanoscale serpentine powders as lubricant additives in the mineral base oil (5-CST). Design/methodology/approach – Fourier transform infrared spectroscopy spectra and thermo-gravimetric analysis of both modified and unmodified serpentine were performed to analyse their grafting ratio and suspension after modified using a long-chain naphthene aliphatic acid. The tribological properties of surface-modified serpentine as lubricant additives in 5-CST were evaluated and the worn surfaces were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES). Findings – The results show that the serpentine particles have high grafting ratio, improving the dispersity in 5-CST. When the serpentine concentration of 1.00 weight per cent is used as additives in 5-CST, friction coefficient reduces by 14.80 per cent under 294 N and wear scar diameter (WSD) decreases by 11.82 per cent. The results of X-ray absorption near edge structure and XANES show that the adsorption and tribochemical reactions occur to form self-repairing lubrication films. Originality/value – The paper illustrates a tribofilm form on the rubbed surface, which is responsible for the decrease in friction and wear, mainly containing iron oxides, silicon oxides, magnesium oxides and organic compounds. The results are useful for further applications in advanced environmental friendly lubricating oils and additives.

The purification and tribological property of the synthetic magnesium silicate hydroxide modified by oleic acid

“…Magnesium silicate hydroxide (MSH), as the main component of serpentine, has been studied widely for its environmentally friendly capacity, low price, and excellent tribological performance . Yu et al and Zhang et al demonstrated that ultrafine serpentine could conduce to the formation of a super‐hard oxide layer which possesses good wear resistance.…”

Characterisation of self‐repairing layer formed by oleic acid modified magnesium silicate hydroxide

“…When the concentration of OA‐MSH is 1.0 wt%, the friction surface is the smoothest and contains more micropores, which is a typical self‐repairing layer morphology. Figure 7D, when the content of OA‐MSH is 1.5 wt%, many burrs will appear, indicating that excessive OA‐MSH will cause abrasive wear and increase the WR 32 …”

Tribological Performance and Application of Antigorite as Lubrication Materials

“…The chemical composition of friction pair surface layer is commonly studied using energy dispersive X-ray spectroscopy (EDS) coupled with scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES), while the phase composition and structure characteristics are usually observed through transmission electron microscopy (TEM) and atomic-force microscopy (AFM). Numerous studies have reported that the Si and Mg contents of most friction pairs treated with AMNP (Figure 10, middle image) were significantly higher than that of without AMNP [14,[21][22][23]26,27,[49][50][51][52][53]55,56,61,69,72,77,85,91,[94][95][96][97][98][99]. Some friction pair surfaces treated with AMNP only detected Si but no Mg [17,25,54,55,64,66,74,78,79,84,86,91,95], or only detected Mg but no Si [18,60,100], or neither Si nor Mg were detected [5...…”