Conductive capacity and tribological properties of several carbon materials in conductive greases

Abstract

Purpose The purpose of this paper is to synthesize a new kind of conductive grease which possesses a prominent conductive capacity and good tribological properties. Design/methodology/approach A two-step method was used to prepare complex lithium-based grease. Ketjen black (KB), acetylene black (AB) and carbon black (CB) were characterized by transmission electron microscope and used as lubricant additives to prepare conductive greases. Conductive capacity was evaluated by a conductivity meter, a surface volume resistivity meter and a circuit resistance meter. Tribological properties were investigated by a reciprocating friction and wear tester (MFT-R4000). The worn surfaces were analyzed by a scanning electron microscope, Raman spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscope. Findings The conductive grease prepared with KB has a prominent conductive capacity at room temperature, 100°C and 150°C. Further, this conductive grease also possesses better tribological properties than AB and KB greases. When the concentration of KB is 1.8 Wt.%, the coefficient of friction and wear width reduced by 11 and 14 per cent, respectively. Originality/value This work is a new application of nanometer KB as a lubricant additive in grease, which provides a direction for preparing conductive grease. The conductivity and tribology experiments have been carried out though the variation of experiment conductions.

A synergetic strategy based on laser surface texturing and lubricating grease for improving the tribological and electrical properties of Ag coating under current-carrying friction

“…Figure 4(a) depicts the SEM image of MG. MG exhibits a large two-dimensional planar structure, which is beneficial for promoting contact between the graphene sheets in grease to form a network, which improves the electrical and thermal conductivities of the grease. Moreover, this network functions as a protective film to minimize the friction and wear [20,25]. Figure 4(b) depicts the thermal stability of MG and MGLG.…”

“…When the surface texture associates with the lubricant, the combination can exhibit some synergistic lubrication mechanisms including acting as micro-reservoirs of lubricants to increase the local lubricant supply and functioning as microhydrodynamic bearings to increase the load-carrying capacity, which can greatly enhance the tribological properties [8,[17][18][19]. However, the lubricant applied for sliding electrical contacts should possess outstanding lubricating ability and preferable conductivity [20][21][22]. When performing the functions of friction reduction, anti-wear, cooling, and corrosion prevention, the lubricants could also form conductive paths to transmit current between the contact interfaces, thereby reducing the ECR.…”

Conductive and tribological properties of TiN-Ag composite coatings under grease lubrication

“…Various conductive additives can affect electrical properties. Ge et al [17] prepared conductive greases with carbon nanotubes, carbon black [18], ionic liquids [19][20][21][22][23], and Sb-doped SnO 2 [24]. They discovered that all these conductive additives improved the conductivity and tribological performances of conductive greases.…”

An investigation of thermal and tribological behaviors of PTFE‐based silicon composites filled with AlN and flake graphite particles

“…PTSCs showed excellent conductivity properties when the proportion of AlN/FG was 4/7 and 2/9. According to tunnel effect theory, with increasing of FG, the composite's conductive capacity improved because the distance between graphite sheets decreased, making it easier for electrons to cross the graphite layers . An interesting phenomenon was that the volume resistance of AlN/GF‐PTSC (2/9, containing ∼5% AlN and ∼25% FG) was higher than that of FG–PTSC (25% FG).…”

“…However, according to the application requirement of thermal silicon composites used in power lines, electrical tribological properties are another important factor to be considered. Xia et al . have revealed that several additive materials, such as graphene, multiwalled carbon nanotubes, carbon black, and ionic liquids, enhance grease electrical and tribological properties, mainly because they form an effective conductive pathway for electrical transfer.…”