Jianhua Fang

Friction and wear performances of borates and lanthanum chloride in water

The antiwear and friction-reducing performances of sodium borate, potassium borate and lanthanum chloride in water were evaluated on a four-ball friction tester. The topographies, element distribution and chemical characteristics of the worn surfaces were investigated by scanning electron microscope (SEM), energy dispersion of X-ray (EDX) and X-ray photoelectron spectroscope (XPS). The results indicated that sodium borate, potassium borate and lanthanum chloride increased extreme pressure, antiwear and friction-reducing capacities of water to a certain extent, of which potassium borate was the best candidate. Combination of lanthanum chloride with sodium borate and potassium borate respectively further improved antiwear and friction-reducing capacities. Scratches of worn surfaces lubricated with water containing borates and lanthanum chloride were less severe than those lubricated with water containing borates alone. A tribochemical film mainly composed of oxides of lanthanum, boron and iron reduced friction and wear for water lubricant formulated with both borates and lanthanum chloride.

Friction and wear performances of magnesium alloy against steel under lubrication of rapeseed oil with S-containing additive

Abstract A S-containing additive, sulfuration modified rapeseed oil (named as SRO), was prepared by chemical modification of rapeseed oil with sulfur compounds. The results indicate that the friction and wear of the magnesium alloy–steel tribomates could be effectively reduced by formulating SRO into rapeseed oil lubricant. The friction coefficients and the wear volumes of magnesium alloy decrease with increasing contents of SRO. The surface lubricated with SRO-doped rapeseed oil was characterized by less wear as compared with that lubricated with neat rapeseed oil. The enhanced anti-wear and friction-reducing abilities of rapeseed oil by SRO in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of SRO and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.

Preparation, friction and wear properties of hydrophobic lanthanum borate nanorods in rapeseed oil

Oleic acid (denoted as OA) surface-caped lanthanum borate nanorods, abbreviated as OA/LaBO3·H2O, were prepared via hydrothermal method. The microstructures of the as-prepared OA/LaBO3·H2O nanorods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The friction and wear properties of OA/LaBO3·H2O nanorods in rapeseed oil were evaluated with a four-ball tribo-tester. The results show that the as-prepared OA/LaBO3·H2O nanorods are hydrophobic and display nanorods morphology with uniform diameter of about 50 nm and length of up to 500 nm. In the meantime, OA/LaBO3·H2O nanorods can obviously improve the anti-wear and friction-reducing capacities of rapeseed oil, and the optimal anti-wear and friction-reducing properties of rapeseed oil were obtained at an OA/LaBO3·H2O content of 1% (mass fraction).

Impact of oleoyl glycine on biodegradability and lubricity of lubricating oil

Purpose – The purpose of this paper is to understand the impacts of oleoyl glycine on biodegradation, friction and wear performances of a mineral lubricating oil.Design/methodology/approach – The biodegradabilities of a neat oil and its formulations with oleoyl glycine were evaluated on a biodegradation tester and the microbial characters in the biodegradation sewage observed through a microscope. Also, the friction and wear performances of neat oil and the formulated oil were determined on a four‐ball tribometer. The morphologies and tribochemical features of the worn surfaces were analyzed by scanning electron microscopy and X‐ray photoelectron spectroscopy.Findings – Oleoyl glycine markedly enhanced biodegradation of unreadily biodegradable mineral oil and effectively improved its anti‐wear and friction‐reducing abilities. The enhancement of biodegradability of the mineral oil was preliminarily ascribed to the increment of microbial populations in the biodegradation processes, while the improvement of ...

Effect of lauric diethanolamide on biodegradability and performance characteristics of mineral hydraulic oil

The impacts of lauric diethanolamide as an additive on biodegradability and the performance characteristics such as friction-reducing and anti-wear abilities, corrosiveness, demulsibility and foaming property of a fully formulated petroleum-based hydraulic oil were investigated. The biodegradabilities of the neat oil and the oils doped with different contents of lauric diethanolamide were evaluated on a biodegradation tester, while the friction and wear performances of neat oil and the doped oils were determined on a four-ball tribometer. The corrosiveness, demulsibility and foaming characteristics were evaluated based on the corresponding Chinese standard methods. The results indicated that lauric diethanolamide not only efficiently enhanced biodegradation of unreadily biodegradable mineral hydraulic oil, but also to a great extent improved the friction-reducing and demulsifying abilities of said hydraulic oil, while the anti-wear capacity, corrosiveness and anti-foam property of the hydraulic oil were almost unaffected by lauric diethanolamide.