Mineral Base Oil Research Articles

Tribological behaviors and mechanisms of surface-modified sepiolite powders as lubricating oil additives

Natural sepiolite powders were modified and refined using a mechanochemical wet modification process, and one-dimensional sepiolite powders were prepared and stably dispersed in the lubricating oil. An orthogonal experimental method of 4-factors and 3-levels is applied to investigate the effect of load, reciprocating frequency, sliding duration and content on tribological behaviors of sepiolite as additives in 500SN mineral base oil using a reciprocating sliding wear tester. The morphology, microstructure, chemical composition and state, and micromechanical properties of the worn surfaces were analyzed using scanning electron microscopy (SEM), focused ion beam (FIB) and transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and nanoindentation tester. The lubrication and friction-reduction mechanisms of the sepiolite additives are discussed in detail. The results indicate that the order of factors affecting the friction-reducing performance of sepiolite additives can be given as: sepiolite content, sliding duration, applied load and reciprocating frequency. On the other hand, the influence of the factors on the anti-wear property is: reciprocating frequency > sepiolite content > sliding duration > applied load. A tribolayer consisting of metal oxides, ceramic particles, graphite and organics is formed on the worn surface, which is conducive to the excellent tribological behavior of sepiolite due to its excellent lubricity, high hardness and low elastic modulus. The formation of the tribolayer is closely related to the unique physicochemical properties of the one-dimensional mineral clay and tribological conditions.

Wear behavior of environment friendly trimethylolpropane trioleate-based lubricant

PurposeFormulation of mineral-based specialty lubricants without anti-wear (AW) and extreme-pressure (EP) additives is a challenging task. This study aims to propose an environment friendly alternative to mineral-based lubricants with superior wear preventive characteristics.Design/methodology/approachIn this study, analysis of wear under trimethylolpropane trioleate (TMPTO)-based lube using operating parameters of four-ball tester was done. The effects of type of lube oil, temperature, load and speed on specific wear rate were investigated using Taguchi L27 orthogonal array. Based on the Taguchi experimental results and single-to-noise ratios, ranking of the four ball parameters was done. The surface analysis of worn steel balls was carried out using optical microscopic images of wear scar and energy dispersive spectrometry (EDS).FindingsResults depict that the blend of sulfurized additives with TMPTO base oil showed a synergistic effect in terms of reduction in specific wear rate by the formation of protective film layer on the surface. The possible physical or chemical interactions between base oil and additives were studied based on the surface morphology of test balls.Practical implicationsThe formulated lubricant has the potential to be used as a tapping/broaching oil.Originality/valueTo the best of the authors’ knowledge, the paper is a novel study investigating the effect of different additive in TMPTO. The results could prove beneficial in making TMPTO-based lube oil a viable replacement of mineral-based oils.

Compatibility of Engine Oil Viscosity Improver and Biodiesel Fatty Acid Methyl Ester

The present work focused on the compatibility of a popular engine oil viscosity improver polymethacrylate (PMA) and a biodiesel fatty acid methyl ester methyl oleate (MO). Thermal oxidation operations of blends of PMA, MO and a mineral base oil were performed for evaluating the interactions between PMA and MO. The viscosity and viscosity index of fresh and oxidized blends were determined and calculated. Thereafter the chemical compositions of oxidized blends were characterized by a gas chromatography coupled to a mass spectrometer. Results showed that viscosities of the blends increased after oxidation, and the increases in viscosity after oxidation for blends containing MO were greater than those for blends without MO. Furthermore, PMA was substantially efficient in improving viscosity index of both fresh and oxidized blends with and without MO, although viscosity index of blends slightly declined with increasing concentrations of MO in a blend. Finally, chemical species of methacrylates were generated in the oxidation processes of blends, despite whether or not there was MO in the blends. The present results preliminarily demonstrated that direct chemical interactions between PMA and MO were unobvious, and confirmed that PMA was well compatible with MO in viscosity index improvement.

Natural Antioxidant Extracted Waste Cooking Oil as Sustainable Biolubricant Formulation in Tribological and Rheological Applications.

Developing eco-friendly formulations using waste cooking oil as renewable biomass is of great interest and commercial importance in the fuels and lubricant industry. This manuscript reports novel study on preparing a biolubricant formulations as WCO-1, WCO-2 and WCO-3 by blending the curcumin extracted soybean waste cooking oil in three different compositions viz 10%, 20%, 30% v/v with the mineral base oil N-150. Curcumin was extracted as a natural antioxidant in 0.5 wt% waste cooking oil to inhibit thermal oxidation. This study comprises a detailed analysis in terms of tribological, rheological and thermophysical characteristics such as viscosity, viscosity index, pour point and flash point parameters of the biolubricant by standard ASTM methods. Further, tribological and rheological analysis was done by the four-ball wear tester and Anton Paar, MCR-72, respectively. The thermophysical evaluation of WCO formulated biolubricant has shown excellent properties. The viscosity index of the formulated biolubricant increases with an increase in the concentration of waste cooking oil. In contrast, the pour point has also been depressing at lower temperature conditions. Thus, WCO based biolubricant was found to be more effective at extreme temperature conditions than the mineral base oil (N-150). Rheological studies have indicated the non-Newtonian behaviour of the biolubricant with an increase in shear rate. Whereas, tribological analysis demonstrates that wear scar diameter has significantly reduced from 0.685 to 0.573 mm, and the coefficient of friction decreased from 0.117 to 0.080 with respect to the mineral base oil. Thus, a straightforward green approach has been discovered by directly utilizing waste cooking oil for biolubricant formulation.Graphical abstract

Moringa oil with graphite and hexagonal boron nitride particles as additives for lubrication

Tribological behaviour of bio-lubricants is constantly evolving to be improved. Vegetable and synthetic oils owing the increasing interest of the environmental impact constitute a suitable alternative for lubrication. The addition of particles as additive show a great potential to improve the tribological properties of bio-lubricants. This paper overviewed the effect of graphite and hexagonal boron nitride (hBN) particles as additives on the tribological properties of different lubricating base oils such as mineral oil (dodecane), vegetable oil (moringa oil) and vegetable/dodecane blends. The addition of particles (0.5 and 1 w%) has indicated an improvement of the mineral base oil. At the addition of small amounts of moringa oil (MO), a reduction of about 55% of friction and wear performances of dodecane. We showed that the more promising results were obtained for the blend containing 3 w% of MO with hBN particles. These new formulations lubricant represent an excellent alternation for lubrication environmentally friendly.

Synthesis of biological base oils by a green process

Abstract In this study, the chemical conversion of catfish fat (CFF) into bio-based oils using the cavitation technique has been carried out. The influence of parameters on the reaction yield, including inlet pressure, amount of reactant, temperature, and time were investigated. The results obtained have demonstrated the outstanding efficiency of applying the cavitation technique to the chemical synthesis process. The optimum conditions of ring-opening reaction of epoxy catfish oil (ECFO) were as follows: 60 psi, the molar ratio of iso-propanol/epoxy ring of 1.75/1, 75°C, time of 7 min, and the yield reached 91.3%. The results of FT-IR, 1H-NMR, and 13C-NMR analysis showed that the chemical conversion of double bonds (C═C) of CFF were converted to functional groups of hydroxyl and ether in polyol catfish oil (CFO) products through the intermediate stage of the formation of the epoxy ring. The results showed that the polyol CFO has better operating conditions at low temperature, higher viscosity, viscosity index, and oxidation stability than other oils, and the biodegradability of bio-polyol CFO was much higher than that of SN500 mineral base oil. Polyol CFO has not only been used as a substitute for mineral base oils but also as an eco-friendly green product.

Friction condition of aluminum alloy AA6061 lubricated with bio-lubricant in cold forging test

PurposeCold forging operation is one of the widely used techniques in industry production. This paper aims to present a case study in highlighting and modelling the use of different type of palm oil-based [palm stearin (PS), palm kernel oil (PKO) and palm mid olein (PMO)] as a bio-lubricant in cold forging process using experimental and finite element method.Design/methodology/approachRing compression test plays a fundamental role in the understanding of materials science and engineering because of the deformation, friction and wear behaviour. Aluminium (A6061) was used in this test to observe the deformation of the ring with different palm oil and its derivatives by comparing with commercial metal forming oil.FindingsThe presence of certain type of palm oil-based lubricant has a good performance compared to mineral-based oil in terms of surface roughness but when observed in terms of friction the result shows that palm oil-based lubricant has poor friction performance compared to mineral oil-based lubricant (m = 0.25), where PS has the lowest friction at m = 0.3 compared to PKO (m = 0.35) and PMO (m = 0.38).Research limitations/implicationsThis research is using palm oil in cold forging test to study the friction, formation and stress at certain levels of stroke. The detail of the test is explained in the manuscript as attached.Social implicationsThis research is trying to promote the use of biodegradable material to reduce pollution to the surrounding.Originality/valueThe originality of this paper has been checked using Turnitin and the result is 13%.

Investigation of bio-based cooling lubricants for the machining of aircraft stainless steels

Water-miscible cooling lubricants are used in approx. 90% of metalworking processes mainly for lubrication and cooling of the contact zone between tool and workpiece. The base oils of the widely used water-miscible emulsions are often of mineral origin and represent a significant share of the CO2-fingerprint in production systems in terms of their extraction, processing and the possibility of recycling. Cooling lubricants are furthermore negatively discussed regarding to their health compatibility. Those disadvantages of conventional cooling lubricants drive the research for replacing mineral base oils with vegetable base oils, which contribute to a safer work environment and greener production. In this work, both conventional cooling lubricants and several water-miscible emulsions with various edible and non-edible vegetable-based oils were prepared and characterized regarding their suitability as cooling lubricants for the milling of aircraft stainless steels. Comprehensive experimental investigations were carried out to determine the process forces and the resulting tool wear as technical performance indicators for the test evaluation.

Performance assessment of varying nanoparticles in a base mineral oil for domestic refrigeration system

Nanoparticles have been known to enhance the performance of refrigerating systems. In this work, the walnut shell was used as a reducing agent to synthesise copper oxide nanoparticles. The nanoparticle was mixed with mineral oil to investigate its effects on the refrigeration system and see if it ensured better performance than when using conventional mineral oil. The mixing ratio used for this project started with 250 ml of mineral oil to 0.50 g of the NP, while the concentration of the NP’s increased by 0.25 g as the samples progressed. The control sample of pure mineral oil was used to get a baseline for which the performance of each sample was based. Pull-down time and Net Refrigeration Effect (NRE) were used in determining the performance of all the samples and control. From the result, two samples, 0.75 g of NP and 1.25 g of NP, showed consistency in reducing the pull-down time and increasing the NRE compared to the control. A reduction in pull-down time by 8.98% and an increase in NRE by 9.3% was recorded for sample 0.75 g, while a reduction in the pull-down time by 9.51% and an increase in NRE by 19.05% was recorded for 1.25 g of NP.

Effect of Temperature Variation on Oil in Oscillation of Mass/Load

Abstract: In this investigation a model was made to replicate the working of a shock absorber and the liquid that is used in place of the hydraulic fluid was vegetable oil. Hydraulic fluid is composed of a mineral oil base stock [1]. The working of the model of a shock absorber was tested at different temperatures. It is studied that the relation between the temperature and the time taken by the load attached to the spring to stop oscillating and presented in graph. An optimum temperature, at which the time taken by the mass of 1.50 kilograms suspended in the vegetable oil to stop oscillating and it is the least mass used in the study. In addition to this, the freezing point of the vegetable oil will also be found. It is found in this study that the two variables that is temperature of the vegetable oil and the mass of 1.5 kilograms at rest is linear. Keywords: Temperature Variation, Oil, Oscillation, Mass, Load.

Machinability Evaluation of Nanoparticle Enriched in Vegetable-Based-Nanofluids for Machining Process

Vegetable oil had been studying to replace mineral-based oil as metalworking fluids (MWFs) as it is non-toxic, bio-degradable and environmentally friendly. Due to vegetable oil's high viscosity and poor thermal conductivity, some improvements had been applied to a vegetable oil such as chemically modified and the addition of additives. This study aims to evaluate the machining capability of modified jatropha oil (MJO) with nanoparticle additives of 0.025wt% copper oxide (CuO) (MJOc) and 0.025wt% hexagonal boron nitride (hBN) (MJOh) as metalworking fluids. Through the turning process, the machining performance of MJOc and MJOh was compared withcommercial synthetic ester (SE) in terms of cutting temperature, surface roughness, tool life, and tool wear. The results indicate that MJOc and MJOh outperformed SE in terms of machining performance. Compared to MJOc, MJOh has better machining performance in terms of cutting temperature and surface roughness. In addition, MJOh had the same tool life performance with SE which is at a cutting length of 6000mm and machining time of 42 minutes. In conclusion, the overall best machining performance is MJOh (MJO+0.025wt% hBN) and has the potential as sustainable MWFs in the lubricant market.

AN ANALYSIS OF THE INFLUENCE OF CARBON NANOPARTICLES ADDITIVE ON SELECTED PROPERTIES OF LUBRICATING OILS

This paper presents the results of an analysis of the influence of the addition of various types of carbon nanoparticles on selected essential physical and operational properties of lubricating oils. Two selected oils, i.e. the mineral base oil without additives and the typical marine lubricating circulating oil Marinol RG 1240, were modified with the addition of shungite nanoparticles, graphite nanotubes, and C60 fullerenes. The mass fraction of modifiers was 0.2% wt for each of the additives. As part of the experimental tests, measurements were made of the impact of the above-mentioned modifiers on the change in the value of the ignition temperature of oils, the effect on the changes in the value of the dynamic viscosity coefficient in the aspect of changes of temperature and shear rate, as well as the impact on the changes in the friction coefficient and the size of the wear size scar. These tests were carried out on an EraFlash automatic apparatus for determining ignition temperature using the closed cup method, with a Haake Mars III research rheometer, and a T-02U tribometer with a four-ball head.

Synthesis and Physicochemical Properties of Low Viscosity 2‐Ethylhexyl Alkyl Ethers Made from Palm‐Based Esters as Potential Biolubricant

AbstractA series of 2‐ethylhexyl alkyl ethers (EHAE) are synthesized from palm‐based esters via a one‐step reaction under mild reaction conditions for potential usage as biolubricant. In this work, 2‐ethylhexyl esters with varying fatty acid chain lengths are reacted with 1,1,3,3‐tetramethyldisiloxane (TMDS), catalyzed by indium bromide (InBr3) at 40 °C to afford EHAE with lauryl, palmityl, stearyl, and oleyl alkyl chain with 55–68% isolated yield. These compounds are characterized using Fourier‐transform infrared (FTIR) and NMR spectroscopic methods and are evaluated for their viscosity, thermal, cold‐flow, oxidative, and anti‐wear properties. The synthesized EHAEs demonstrate low viscosity (1.65–2.55 cSt at 100 °C) with excellent viscosity indices (130–182). These EHAEs show comparable wear scar diameter (0.6–1.0 mm) in comparison with commercial mineral oil base stock (group I SN150) in the four‐ball wear test. Thermal‐oxidative investigation of the EHAE reveals that the thermal degradation temperatures are in the range of 200–250 °C and oxidation onset temperatures are between 165 and 184 °C. Among the EHAEs, 2‐ethylhexyl lauryl ether with the shortest alkyl chain has the lowest pour point of −27 °C. The physicochemical properties of synthesized EHAEs indicate that they are potential as biolubricant base stocks.Practical Applications: The EHAEs produced from this work exhibit promising physicochemical and lubricity properties, which offer great potential to be used as lubricant base stock especially for internal engine oil application.

Study of Mineral-Based oils with Jatropha curcas L. as Bio-Additive Through Thermal and Kinematic Viscosity Properties

Study of Mineral-Based oils with Jatropha curcas L. as Bio-Additive Through Thermal and Kinematic Viscosity Properties

Comparative evaluation of crude Tamanu oil performance as metalworking fluids

In manufacturing industry, metalworking fluids which are mineral based oils are widely applied as feedstock for many sorts of lubrication and cooling applications, posing environmental and health risks. As an alternative replacement, plant-based oils are found to be a viable contender to the mineral-based oil performance. However, crude vegetable oils possess high viscosity values, and low thermal oxidative stability, which prompted the oil modification method to improve the oil's physicochemical properties. The purpose of this study is to investigate the machining performance of a novel Crude Tamanu oil (CTO), a product from Pahang, Malaysia, market ready Crude jatropha oil (CJO), commercially available Refined, bleached & deodorized palm olein (RBDPO) and Synthetic ester (SE) during the turning process of AISI 316L stainless steel disc using minimum quality lubrication (MQL) technique. The process outcomes are cutting forces, deformed chip thickness, chip curling effect, and elemental compositions on the surface morphology of the cutting inserts. Based on the experimental results, the best plant-based lubricant in its crude form is revealed by the machining lubricated with CJO, which outperforms all the other tested lubricant samples. The CTO possesses a high kinematic viscosity and viscosity index values, which leads to a huge opportunity for further improvement on its lubrication properties that could improvise its antiwear and antifriction behaviors. This work could further support the sustainable manufacturing efforts in enhancing ‘greener’ metalworking applications as well as the agricultural and the socio economy of the nation.

Carbon Nanoparticles of Varying Shapes as Additives in Mineral Oil Assessment of Comparative Performance Potential.

In this work, carbonaceous nanoparticles (NPs) of varying morphology, viz., multilayer graphene (lamellar, thickness ∼ 3-7 nm), graphite (spherical ∼70 nm), and multi-walled carbon nanotubes (tubular), were selected to explore their tribo-potential in oil under identical operating conditions. A series of nano-oils were prepared using API group III mineral base oil with a dispersant (1%) and selected NPs in incremental concentration (0.5-4%). The tribo-performance of oils was evaluated on a four-ball tester and SRV-IV for extreme-pressure, antiwear (AW), and antifriction performance. Formulations were characterized for density, viscosity, and viscosity index. The stability of oils was monitored through visual observation weekly. Results revealed that the graphene particles showed excellent wear-preventive ability as an AW additive with (41-50) % increase followed by nanographite. Worn surfaces were studied to understand the plausible wear mechanism using a different spectroscopic technique. Tribo-behavior performance was supported with lateral force microscopy on the surfaces of tribo-films.

Influence of temperature on wear performance of greases in rolling bearings

Purpose Rolling bearing operation under mixed and boundary lubrication conditions may lead to heavy adhesive or abrasive wear, which may lead to wear-induced rolling bearing failure. The purpose of this paper is to investigate the wear protection capabilities of different grease compositions at varying temperatures. It is considered that the temperature influences the lubrication conditions, the behaviour of grease components, namely, bleed oil and thickener, as well as the tribofilm formation due to tribo-chemical interactions between additives and surfaces. Design/methodology/approach In this study, four different greases were produced on the basis of a mineral base oil by varying the thickener and the addition of ZDDP. Various grease-lubricated rolling bearing experiments were conducted in a wide temperature range from 0°C to 120°C. Subsequently, the wear pattern, tribofilm formation and grease structures were analysed. Thereby, the influence of the different grease thickeners and the performance of ZDDP as a common antiwear and extreme pressure additive was evaluated. Findings The results show a strong temperature-dependency and allow a classification of temperature ranges concerning wear protection. At low temperatures, all greases provide a very good wear protection without the evidence of additive-based tribofilm formation. In the experiments at elevated temperatures, ZDDP tribofilms were formed. The formation depends on the thickener type: in comparison to lithium thickener, polyurea thickener favours more protective tribofilms at the same temperature. The experimental results show that medium temperatures in the range of 40°C–60°C are critical concerning wear due to the insufficient tribolayer formation and limited load carrying capacity of the grease. Originality/value Temperature is a key operating parameter for grease lubrication in roller bearings. The experimental work enables consideration of different impact pathways of temperature by combining roller bearing tests and microanalysis.

Effect of Temperature and Surface Roughness on the Tribological Behavior of Electric Motor Greases for Hybrid Bearing Materials

Greased bearings in electric motors (EMs) are subject to a wide range of operational requirements and corresponding micro-environments. Consequently, greases must function effectively in these conditions. Here, the tribological performance of four market-available EM greases was characterized by measuring friction and wear of silicon nitride sliding on hardened 52100 steel. The EM greases evaluated had similar viscosity grades but different combinations of polyurea or lithium thickener with mineral or synthetic base oil. Measurements were performed at a range of temperature and surface roughness conditions to capture behavior in multiple lubrication regimes. Results enabled direct comparison of market-available products across different application-relevant metrics, and the analysis methods developed can be used as a baseline for future studies of EM grease performance.

An Experimental Investigation on Vegetable Oils as a Cutting Fluid under Minimum Quantity Lubrication: A Sustainable Machining Approach

Cutting fluid is a vital part of the machining process. Cutting fluid is significantly applied tolower the friction and heat generated in the machining zone. It also helps in easy chip removal, protection against oxidation, tool life improvement, and an overall improvement in the quality of the product. The current industrial practices are majorly emphasized on mineral-based oil application under flood lubrication to achieve superior quality. However, these oils and techniques are toxic and environmentally unfriendly. Machining under dry or with minimum quantity lubrication (MQL) has been mostly preferred to eliminate the use of abundant oil. The current research work has established the promising potential for vegetable oils as a cutting fluid under MQL during turning of AISI 4130 steel. The results inferred that vegetable-based cutting fluids performed better over mineral-based cutting fluids in terms of lower values of machined surface roughness, tool wear, cutting forces, and chip-tool interface temperature. The MQL machining performance in terms of cutting forces, surface roughness and tool life has been observed better in comparison to machining under flood and dry cutting conditions.

Influence of the formwork removal by polarization on the facing aesthetics in reinforced concrete

Formwork removal by means of polarization offers an alternative solution to compensate for some of the disadvantages and risks of using mineral-based oil due to its petrochemical origin. This technique consists of applying an electrical current between the steel reinforcing bars and the metal formwork wall in order to obtain a thin water film at the concrete/formwork interface and allow for formwork removal. This paper focuses on the facing quality of the reinforced concrete and formwork surface at various temperatures for both conventional and self-compacting concretes. A series of experimental tests have been conducted in the laboratory to determine the optimal polarization parameters (voltage value, time and duration of its application). On-site tests were then performed to observe the scaling effect. Results indicate that the proposed polarization technique can indeed provide an effective means to separate the concrete from its formwork without requiring demoulding oil. Concrete mixtures implemented both in the laboratory and on-site display high-quality facing without the presence of any attachment points. A chromatographic analysis of the concrete pore solution and water transported by electro-osmosis shows that ion concentrations remain unaffected. This polarization approach can thus be used as an alternative to avoid the use of oils of a chemical or petrochemical origin.