Sustainable lubrication: low molecular weight PTFE micro-particles as extreme pressure additives for heavy duty grease applications

Purpose The purpose of this paper is to formulate heavy-duty lithium complex grease using low molecular weight poly tetra fluoro ethylene (PTFE) micro-particles as extreme pressure (EP) additive manufactured by E-beam scissoring and ultra-high speed grinding process of pre-sintered PTFE scrap. Design/methodology/approach Lithium complex grease is formulated with PTFE micro-particles, and optimum treat rate was studied by standard bench tests by ASTM D 2266 and IP-239 for tribological properties and compared with commercially available Molybdenum Di sulphide (Moly)-based lithium complex grease. The performance of the grease was further evaluated by a cyclic load test at varying speeds and loads to simulate the operational field conditions. Findings The lithium complex PTFE grease was manufactured using PTFE micro-particles as EP additive. The PTFE micro-particles dispersed in the lithium complex grease significantly improve the anti-wear performance and load bearing properties. Further, when the product was tested under a cyclic load conditions on standard tribological bench test against commercially available Moly lithium complex grease, shows stable anti-wear properties and reduced coefficient of friction. Originality/value The low molecular weight PTFE micro-particles, manufactured in the in-house electron beam (E-beam) and ultra-high speed micronizer facility from a pre-sintered PTFE scrap has been used as EP additive for grease applications for the first time. The results on the cyclic load tests indicate significant performance improvement in retaining the anti-wear and friction properties. Thus, value addition is done in formulating superior performance grease and evaluating under cyclic load conditions similar to field operating conditions and also in creating value added additives by converting the pre-sintered PTFE scarp which is environmental hazard due to poor biodegradability, creating a cyclic economy and a sustainable concept.

Reasearch of The Effect of Graphene Nanoparticles and Sulfurized Additives to MQL for Machining of Ti-6Al-4V

given its favourable comprehensive properties, titanium alloy has been extensively developed and used in numerous fields. However, its low thermal conductivity and strong chemical activity have led to its reputation as a difficult-to-machine material. Thus, graphene nanoparticles and sulfur-based extreme pressure (EP) additive were added to rapeseed oil to increase the lubrication and cooling properties of the machining region. In this study, three lubricants were used to machine titanium alloy: rapeseed oil+graphene+sulfur-based EP additive, rapeseed oil+sulfur-based EP additive, and rapeseed oil; and the subsequent wear of cutting tools, cutting temperature, surface roughness, and cutting force were compared. The most favourable results were found for the combination of rapeseed oil+graphene+sulfur-based EP additive, effectively decreasing the temperature of the cutting area and wear of cutting tools. In comparison with rapeseed oil, the flank wear value decreased by 56.4%. Similarly, the surface roughness and cutting force with the rapeseed oil+graphene+sulfur-based EP additive were lowest, showing a decrease of 36.1% and 27.0% respectively when compared with rapeseed oil.

Tribo-Investigations on Oils With Dispersants and Hexagonal Boron Nitride Particles

A dispersant is almost an unavoidable additive in engine oils since it helps to keep the carbonaceous particles in a suspended form. Dispersants can be multifunctional and can therefore interfere with the functions of other additives either synergistically or antagonistically. The present work investigated the influence of four dispersants (with and without particles of hexagonal boron nitride (hBN) on selected lubrication-related properties of the oils using four ball tester. Particles of hBN, though known as effective anti-wear (AW) and anti-friction (AF) additives, did not prove effective in oil in the presence of dispersants. On the other hand, it proved to be a good extreme pressure (EP) additive by showing 27% improvement in weld load (WL). Worn surfaces were examined using scanning electron microscopy (SEM), energy dispersion X-ray analysis (EDAX), and Raman spectroscopy.

MODIFICATION OF RBD PALM KERNEL AND RBD PALM STEARIN OIL WITH ZDDP ADDITIVE ADDITION

Vegetable oils have gained worldwide concern due to environmental issues since it is biodegradable, renewable and environmental-friendly. However, the limitations of vegetable oils such as having low oxidation stability and poor low temperature properties need to be solved. The purpose of this paper is to evaluate the tribological behavior of refined, bleached and deodorized (RBD) palm kernel and RBD palm stearin by using a modified pin-on-disc tester. The influence of an anti-wear/extreme pressure (AW/EP) additive on the anti-friction and anti-wear characteristics was also evaluated. The experiment was carried out by varying zinc-dialkyl-dithiophosphate (ZDDP) additive concentration of 1wt%, 3wt% and 5wt%; load of 1kg, sliding speed of 2.5 m/s, test duration of 60 minutes and at room temperature. The findings have revealed that without an additive, RBD palm kernel and RBD palm stearin have high friction coefficient and wear as compared with synthetic oils. The addition of additives helps in the improvement of tribological performance of tested vegetable oils. It can be concluded that vegetable oils have a great potential to be used as a petroleum-based substitute.

Extreme Pressure Property of Rare Metal Zirconium

This article studies through experiments the anti-wearing property of the organic compound of rare metal zirconium as extreme pressure (EP) additive for lube oil. It proves the extreme pressure (EP) anti-wearing property of the rare metal zirconium is far better than that of traditional lead. We have developed a new type innocuous and highly efficient EP anti-wearing additive the organic compound of metal zirconium.