Mineral-based Lubricants Research Articles

Sustainable Biocatalytic Synthesis of a Second-Generation Biolubricant

Background: Biolubricants represent a category of lubricating substances derived from sustainable sources such as vegetable oils, animal fats, and other bio-based materials. They are considered more environmentally friendly than mineral-based lubricants because they are biodegradable and nontoxic. Biolubricants derived from vegetable oils or animal fats were used as first-generation biolubricants. They have limited performance at extreme temperatures, both high and low, as well as low oxidative stability. Substitution of the double bonds by branching improves the performance and stability of the resulting second-generation biolubricants. Methods: In the past, the production of these compounds has relied on the chemical pathway. This method involves elevated temperatures and inorganic catalysts, leading to the necessity of additional purification steps, which decreases environmental sustainability and energy efficiency. A more environmentally friendly alternative, the enzymatic route, has been introduced, in accordance with the principles of “Green Chemistry”. Results: In this paper, the esterification of 2-methylhexanoic acid with 2-octyl-1-dodecanol and its optimization were developed for the first time. The synthesis was conducted within a jacketed batch reactor connected to a thermostatic bath in a solvent-free reaction medium and using Lipozyme® 435 as biocatalyst. Conclusions: The high viscosity index value of this new hyperbranched ester (>200, ASTM D2270) suggests that it may be an excellent biolubricant to be used under extreme temperature conditions. Regarding sustainability, the main green metrics calculated point to an environmentally friendly process.

Yield optimization of nonedible vegetable oil-based bio-lubricant using design of experiments

In recent years, there has been a focused effort to reduce the harmful effects of synthetic and mineral-based lubricants by emphasizing the use of biodegradable-based lubricants. These lubricants play a crucial role in minimizing friction, ensuring smooth operation of machines, and reducing the likelihood of frequent failures. With petroleum-based reserves depleting worldwide, prices are rising, and environmental damage is increasing. However, biolubricants derived from nonedible vegetable oils offer environmental benefits as they are nontoxic, emit minimal greenhouse gases, and are biodegradable. In this study, biolubricants are synthesized from jatropha and jojoba oil using sulphuric acid (H2SO4) and hydrochloric acid (HCl) as catalysts through the transesterification and epoxidation processes. The optimization of influencing parameters is achieved using Taguchi’s orthogonal array, a statistical methodology. By employing design of experiments (DOE), the number of experimental trials is minimized while providing comprehensive details on the impact of control factors such as molar ratio, catalyst concentrations, and temperature. The results obtained from DOE reveal that the best optimized yield for jatropha biolubricant with H2SO4 and HCl catalysts is achieved with a molar ratio of 0.5:1.5, a temperature of 70 °C, and a catalyst concentration of 1.2 ml. The experimental yield for jatropha biolubricant with H2SO4 and HCl catalysts was measured at 226 ml and 238 ml, respectively, while the model predicted yield was 221 ml and 231 ml, respectively. The experimental yield for jojoba biolubricant with H2SO4 and HCl catalysts was recorded at 232 ml and 248 ml respectively, whereas the model predicted yield was 226 ml and 245 ml, respectively. Based on the analysis of variance (ANOVA) results, it is evident that among the three control factors, the molar ratio significantly influences the yield of both jatropha and jojoba biolubricants, as indicated by a p-value of less than 5%. The percentage contribution of the molar ratio in jatropha biolubricant with H2SO4 and HCl catalysts is found to be 98.99% and 97.2%, respectively. Furthermore, the R2 value, which exceeds 90%, signifies a strong relationship between the independent and dependent variables. The deviation between the experimental and regression-predicted equations for the yield remains within 2.5% for all combinations of jatropha and jojoba biolubricants. In conclusion, the study successfully prepared biolubricants from jatropha and jojoba-based non-edible vegetable oils and determined the optimal conditions for their production.Graphical abstract

New application of ionic liquid as a green-efficient lubricant

In the present work, it has been attempted to use ionic liquid as a green and compatible additive to base cutting fluid for the grinding process. Grinding forces in tangential and normal directions and the surface quality of the Inconel 718 superalloy were determined as a criterion for comparing the results, and the cutting parameters, such as the wheel rotation speed, workpiece speed, and cutting depth, were also selected as variable parameters in three levels. The experimental results showed that, in addition to the compatibility issue of the ionic liquids, the normal force in the case of ionic-liquid and mineral-based lubricants was declined by approximately 49.3 % than that of non-used cutting fluid technique. By increasing cutting depth from 20 to 60 μm, workpiece speed from 1000 to 3000 mm/min, and wheel speed from 10 to 30 m/s led to an increase of 168 % and 139 %, 46 % and 38 %, and 167 % and 78 % in normal and tangential forces, respectively. The results showed that the grinding forces reduced and the surface integrity of the workpiece improved when using ionic liquid as an additive compared to the mineral-based one. The reason of this superiority can be attributed to the more tendency of liquid molecules to adhere to the surface of the superalloy and form a strong lubricant layer with a lower static contact angle, compared to the mineral-based fluid, which leads to the creation of stable lubrication conditions in the high-stress grinding affected zone. The static contact angle of the DI water was approximately 62 °, while by changing the droplet type to mineral-based fluid and ionic liquid, the CA value was diminished to 51 ° and 38 °, respectively, with reducing rate of 18 %, and 39 %. In addition to experimental study, mathematical models were also developed to predict the grinding forces and surface roughness by means of response surface methodology (RSM). The result of analysis of variance (ANOVA) showed that the fitted models have high accuracy compared to the experimental results.

Eco-friendly lubricants for improving performance and environmental impact in cold rolling

Cold rolling of strips is a well-known metal forming process, carried out below the material recrystallization temperature to improve the surface finish and the geometrical tolerance of the rolled strip. Friction plays a fundamental role in the rolling process and, even in case of a favorable roll bite condition, a non-optimal lubrication causes the rapid wear of the work rolls and high energy consumptions. Most of the currently used lubricants are based on synthetic or semi-synthetic formulations. However, the increase in the cost of petroleum-based products and the tightening of the environmental regulations is pushing the scientific and industrial community to search for more sustainable alternatives. Recently, the demand for green lubricants capable of matching non-toxicity, high biodegradability while keeping good lubricating performance is becoming of outmost importance. In the present work, the environmental impact and the lubricating performance of two innovative natural-based lubricants have been assessed using laboratory tests. An animal-based (AB) and a vegetable-based (VB) formulation were investigated and the results compared with a commercial mineral-based (MB) one. As concerns the environmental impact, emulsions at 2% oil concentration were chemically treated using a powder composed of bentonite and activated carbons and the Chemical Oxygen Demand (COD) and total Surfactants in the aqueous phase were evaluated. The lubricating performance of the emulsions at 2% oil concentration was assessed by conducting tribological tests using the Falex tribometer in accordance with the Standard. The experimental comparison revealed that it is not only feasible but also convenient in terms of both environmental impact and performance to replace the mineral-based lubricant.

Feasibility study on formulation of cutting fluid from waste palm oil

From an industrial, environmental, and scientific standpoint, the creation of renewable and sustainable products to replace fossil fuels is an important concern in this decade. Due to the growing use of different lubricant types, the majority of which are mineral-based, there is an unavoidable flow of mineral-based lubricants into the environment. Another issue is using cooking oil that pollutes the environment when discarded. Both of these issues can be resolved by creating bio-based lubricants from discarded cooking oil. This article discusses formulating a green cutting fluid made from used cooking oil. This enables the use of waste oil as a cutting fluid while retaining its tribological and environmental characteristics. In order to compete in the market, biodegradable cutting fluid might gain from decreased costs for used natural oils. The many components and trends that make up this topic are briefly covered in this article, along with waste cooking oils’ potential application as a bio-based lubricant.

Tribological characterisation of bio lubricant from cucurbita pepo L. seed oil

ABSTRACT In recent years Bio-lubricants much desired in numerous applications in machineries due to their renewable characteristics, which have high biodegradable nature and produce fewer pollutants compared to mineral-based lubricants. Thus, in this paper, the effect of bio-lubricant (Cucurbita Pepo L. seed oil) on wear and friction characteristics in pin on disc tester is studied and compared with commercially available lubricant SAE20W40. Tests were conducted at different loads of 10 N, 50 N, 100 N, 150 N and 200 N at a constant speed of 3 m/s for 60 min to evaluate the behaviour of friction coefficient (COF) and wear at a temperature of 28°C and 100°C. It is observed from the results that, the COF decreases whereas, the wear increases with the rise in temperature and load. Cucurbita pepo L. seed oil (CPO) resulted in a lower wear rate in comparison to commercial SAE20W40. Wear scars on the surface lubricated with SAE20W40 show a rougher surface compared to the pin lubricated with CPO at both lower temperature (28°C) and higher temperature (100°C). This shows that CPO has better lubricity than SAE20W40. The present work indicates that CPO can be a possible substitute to mineral-based lubricant SAE20W40 for higher-temperature workplaces.

A novel class of bio-lubricants are synthesized by epoxidation of 10-undecylenic acid-based esters

Mineral-based lubricants are being supplanted by bio-based lubricants because of environmental concerns and the depletion of fossil resources. The derivatives of edible and non-edible oils are considered potential alternatives to existing natural mineral oil base stocks in certain lubricant applications, where immediate intraction with the environment is predicted. A new class of epoxides were synthesized from the undecylenic esters of 2-ethyl hexanol, neopentyl glycol (NPG), and trimethylolpropane (TMP). These unsaturated esters were epoxidized by using meta chloro perbenzoic acid. The synthesized epoxides were characterized by spectral studies (1HNMR, 13CNMR, IR) physio-chemical (density, specific gravity) and lubricant properties (kinematic viscosity, viscosity index, flash point, fire point, cloud point, pour point, copper strip corrosion). TMP epoxide has a high viscosity index, high flash point, and low pour point compared to 2-ethyl hexyl epoxide and NPG epoxide.

A review of the tribological properties of nanoparticles dispersed in bio-lubricants

Mineral oil resources are dwindling and the mineral-based lubricants are not compatible with the environment, and thus there is great interest in replacing them with bio-based lubricants. Automotive engines are an important application for bio-lubricants. In this context, this review investigates recent advances and research gaps in automotive-related applications of bio-based lubricants. The main objective of the current article is to review the tribological and thermophysical properties of nanoparticles in bio-oils, which could be used as a reference in the future development of bio-lubricants. The various nanomaterials, concentrations, surfactants, and mixing techniques have been presented. The key mechanisms which can result in superior tribological and thermal behavior of bio-lubricants are explained. Studies on the tribo-chemical reactions and between nano-additives and bio-oils are included in this review. It was reported that the tribological and thermophysical performance of bio-oils could be improved especially after adding nanomaterials according to the recent studies results. Furthermore, the major challenges for developing bio-lubricants performance are illustrated. Our present review assists in providing a basis to select bio-oils, nano-additives, and chemical processing according to their tribological properties.

Current Status and Future Prospects of Biolubricants: Properties and Applications

Biolubricants generated from biomass and other wastes can reduce the carbon footprint of manufacturing processes and power generation. In this paper, the properties and uses of biolubricants have been compared thoroughly with conventional mineral-based lubricants. The biolubricants, which are currently based on vegetable oils, are discussed in terms of their physicochemical and thermophysical properties, stability, and biodegradability. This mini-review points out the main features of the existing biolubricants, and puts forward the case of using sustainable biolubricants, which can be generated from agro-residues via thermochemical processes. The properties, applications, and limitations of non-edible oils and waste-derived oils, such as bio-oil from pyrolysis and bio-crude from hydrothermal liquefaction, are discussed in the context of biolubricants. While the existing studies on biolubricants have mostly focused on the use of vegetable oils and some non-edible oils, there is a need to shift to waste-derived oils, which is highlighted in this paper. This perspective compares the key properties of conventional oils with different oils derived from renewable resources and wastes. In the authors’ opinion, the use of waste-derived oils is a potential future option to address the problem of the waste management and supply of biolubricant for various applications including machining, milling applications, biological applications, engine oils, and compressor oils. In order to achieve this, significant research needs to be conducted to evaluate salient properties such as viscosity, flash point, biodegradability, thermo-oxidative and storage stability of the oils, technoeconomics, and sustainability, which are highlighted in this review.

Transesterification of methyl oleate for sustainable production of biolubricant: Process optimization and kinetic study

Trimethylolpropane fatty acid triester (TFATE) is a promising biolubricant as an environmentally friendly substitute to conventional mineral-based lubricants. However, the issues of extensive energy consumption from vacuum maintenance and feedstock saponification caused by strong alkaline catalysts exist in current TFATE-based biolubricant synthesis. Here, sustainable production of biolubricant was achieved with methyl oleate (MO) from non-edible oil sources as the feedstock and moderate alkaline K2CO3 as the catalyst. Nitrogen gas stripping method instead of vacuum was adopted for methanol removal. The effects of agitation speed, N2 flow rate, catalyst amount, MO to trimethylolpropane (TMP) molar ratio and temperature on MO conversion and TFATE selectivity were examined. The TFATE selectivity reached 95.6% under the optimized conditions. Leaching tests indicated neglectable K2CO3 dissolution in reaction products. The kinetic parameters for the three consecutive transesterification reactions were calculated. In addition, the synthesized biolubricants exhibit low acid value and volatility, moderate iodine value, superior thermal stability, and good rheological and frictional properties.

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.

An Experimental Investigation of Static Properties of Bio-Oils and SAE40 Oil in Journal Bearing Applications.

Considerable research has been conducted in the past decade and a half regarding the bio-lubricants potential to replace mineral-based lubricants as mainstream lubricants such as engine oil, hydraulic oil, compressor oil, and metalworking oil. This study studied several bio-lubricants (rapeseed oil, palm olein, and soybean oil) and a mineral-based lubricant, SAE40. The bio-lubricants have better physiochemical, tribological characteristics and environmental friendly nature, and are promising to replace mineral-based lubricants. In this study, a journal bearing test rig (JBTR) was developed in order to investigate the effect of journal speed on the temperature of oil film with time. Additionally, the load-carrying capacity of bio-oils was tested against the mineral-based lubricant SAE40 by adding a load on the journal. For all three speeds, i.e., 1000, 1500, and 2000 rpm, the bio-lubricants recorded minimum temperature. At 1000 rpm, rapeseed oil recorded a 9.2% lower temperature than SAE40. Similarly, at 2000 rpm, rapeseed oil recorded a minimum temperature that was 2.5% lower than SAE40; in comparison, at 1500 rpm, palm olein recorded a minimum temperature that was 1.8% less than SAE40. Overall, the results of this study revealed that bio-oils recorded a lower temperature rise than mineral oil. These results are very encouraging for further research in this area.

Enzyme-catalyzed synthesis and properties of polyol ester biolubricant produced from Rhodotorula glutinis lipid

Biolubricants do not cause the environmental pollution resulting from the manufacturing and use of mineral-based lubricants, but the commonly adopted chemical method of preparing biolubricants using expensive vegetable oils as raw materials is still environmentally and economically unsatisfactory. In this study, R. glutinis lipid with a high oleic-acid content was esterified with trimethylolpropane (TMP) by using the Candida sp. 99–125 enzyme in a solvent-free system, and the effect of the microbial oil with the high oleic-acid content on the performance of resulting biolubricants was investigated. The purpose of this study was to solve the problems of pollution caused by the chemical synthesis of biolubricants and of the uneconomical use of vegetable oils as raw materials. Further, this study aimed to improve the performance of biolubricants by using the microbial lipid with a high oleic-acid content. As a result of optimization of the reaction conditions, the yield of trimethylolpropane fatty acid triester (TFAT) reached 89.5%. The synthesized biolubricants had excellent low-temperature lubrication performance (pour point=−45 °C), and the physicochemical performance reached the ISOVG-46 grade. The results of the high-frequency reciprocating friction test (HRFT) show that the products have better tribological properties than mineral-based lubricants of the same viscosity grade (friction coefficient=0.085; average wear scar diameter=187 µm).

Eco-green machining of superalloy A286: Assessment of tool wear morphology and surface topology

Unstable crude oil derivatives are among the main substances added to the mineral-based lubricants (MBL). However, the high purification and disposal costs of such lubricants and consequent environmental difficulties are the major drawbacks of cutting fluid consumption. The lower use of MBL or replacing them with less harmful ones, in principle, vegetable-based lubricants (VBL) are the prime importance of achieving less operating costs and pollution. Furthermore, the use of VBLs is much more recommended if machinability aspects, including tool life, surface, and edge quality, would also be improved. Therefore, in the present study, cutting parameters and lubricant types were used as the experimental variables in the MQL-turning of A286 superalloy. A286 is classified as a difficult-to-cut material with a wide range of applications in the energy and turbine industries. No experimental study was found on the machining of A286 under separate cooling and lubrication with two MQL systems simultaneously. The effects of cutting parameters on both average surface roughness Ra and tool wear morphology were evaluated. Experimental results denoted that the use of VBLs led to better surface topology. On the other hand, the tendency of the built-up layer (BUL) and built-up edge (BUE) phenomenon were intensified when MBL was used. On the word, better tool life is also expected when using VBL. This observation revealed that the use of VBL not only tends to improve productivity and environmental safety aspects but also machinability aspects; in principle, better surface topology and longer tool life are also expected.

Development and Optimization of a Tribometer for Radial Shaft Seals

Abstract In order to systematically investigate the tribological behavior of machine elements, several different tribometers based on simplifications of the contact situation have been developed and used successfully in the past. Many of these tribometers have become a standard testing equipment for tribologists. For the contact of radial shaft seals (RSSs), currently no such tribometer exists that can be used to characterize their behavior in a satisfying manner. In this paper, a tribologically equivalent system for RSSs is presented. The contact between the sealing lip and shaft is reproduced using a ring-shaped sample prepared from elastomer test slabs of the respective application material in contact with a conical shaft. The cone angle is chosen to properly represent the contact angles of the RSS under investigation by means of finite element (FE)-simulation of the contact pressure. The test rig allows for the on-line determination of friction, contact temperature, and wear progress. Results show good agreement of friction coefficient and wear behavior for the pairing of two typical elastomers with synthetic and mineral-based lubricants.

Risk assessment for hazardous lubricants in machining industry.

Knowing that over two-thirds of lubricant disposals return to the environment with no purification process, adequate strategies are demanded to reduce their risks. For this reason, the main focus of the present study is to describe an environment-friendly approach. In the first part, two widely used lubricants (mineral-based and vegetable-based) were introduced, and the reasons for their hazards were investigated. The composition of mineral-based lubricant was characterized by x-ray fluorescence elemental analysis. The result showed the presence of phosphorus, chlorine, and zinc dialkyl dithiophosphate in its composition that many scholars considered them to be the leading risk factor in the chemical composition of mineral-based lubricants. It has been focused on the potential risks of vegetable-based lubricants, which many researchers have identified as a safe lubricant. The Pseudomonas microbe was cultivated in the vegetable-based sample, and the result showed that although vegetable-based lubricants are compatible with humans, bacteria colony can quickly grow there without making any apparent changes that lead to harm to operators in a mysterious way. In the present work, the hypothesis of the safety of unreinforced vegetable-based lubricants has been rejected, and a new window on the environmental issues of vegetable-based lubricants has been presented. In the final, to eliminate environment-human risks and to reduce consumption of lubricant and natural resources to green manufacturing, a comprehensive study on the possibility of completely removing lubricant was performed. The results showed that the machining without lubricant could be replaced with the traditional method.

Cottonseed Trimethylolpropane TMP Ester as Lubricant and Performance Characteristics for Diesel Engine

Many researchers have been working on bio-based lubricant which is complete or partial replacement for mineralbased lubricant. Mineral-based lubricant is highly pollutant and possesses environmental threat as it is not biodegradable, in the initial days of the industrial revolution bio-based lubricants were widely used, later it was replaced by more sustainable and easily available but environmental polluting mineral oils, currently due to environmental concerns and scarcity of mineral oils, bio-based lubricant has gained importance. Bio-based lubricants are now a day’s used for various applications such as transformer oil and processes where there is complete loss of lubricants. They possess very good properties in such applications, whereas bio-based lubricants are also used internal combustion engines, pure biobased lubricant may not be suitable for long-duration, but genetically and chemically modified bio-based lubricants will be suitable for IC engine. Though bio-based lubricant possesses many good properties as a lubricant for IC engine and various other application, it is still at large to become commercial, more study is required for checking performance of such pure and modified bio-based lubricants oils, in this paper such study of cotton seed Trimethylolpropane (TMP) ester oil and its effects on performance of brake specific fuel consumption (BSFC), brake thermal efficiency (BTh) and emission of gases like hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2 ) nitrogen oxides (NOx ) are studied, bio-based have poor cold flow properties and oxidation stability to improve these additives are added. The experimental study shows that Cottonseed Trimethylolpropane Ester (CSTE) displays similar characteristics of thermal efficiency, brake specific fuel consumption and emission of gases as compared to mineralbased lubricating oil hence can be used in the IC engine instead of mineral-based lubricants.

Modification and synthesis of low pour point plant-based lubricants with ionic liquid catalysis

Due to the poor biodegradability and toxicity of mineral-based lubricants, the development and application of plant-based biolubricants are increasing. However, low stability and poor low temperature performance restrict plant oils to use as lubricants directly. Hence, the paper tried to find an efficient and green way to modify the plant oil derivate oleic acid and obtained high-performance biolubricants. This study demonstrated that modification of oleic acid through epoxidation combined with ring opening reaction, and further esterification, was an efficient strategy for modifying unsaturated fatty acids for the biolubricant production. Meanwhile, catalytic effects of ionic liquids were compared with other catalysts. The results indicated that ionic liquid [HMIm][PF6] is an efficient catalyst for the ring opening and esterification for the synthesis of biolubricants with different kinds of fatty acids. Modified biolubricants from this research exhibited excellent viscosity index (>116) and low temperature performance (pour point < −48 °C). The results of high frequency reciprocating friction experiments exhibited superior lubrication performance of the lubricant. These findings provide a new green and efficient method for improving plant oils as biolubricants.

Vegetable Oil-Based Lubrication in Machining: Issues and Challenges

The use of vegetable oil as a replacement for conventional mineral-based lubricant has gained many interests in recent years from the machining industries. This is due to the problematic issues with the use of conventional mineral-based lubricant that can cause negative effects on the manufacturing cost, operators’ health and the environmental. As vegetable oil is renewable, biodegradable, and non-toxic and has remarkable tribological characteristic from its triglycerides structure, it has been identified as the best replacement for mineral-based cutting lubricant. However, formulating vegetable oil into machining lubricant has its challenges where it must overcome its nature of poor low-temperature properties and low oxidative stability. Therefore, this paper will elaborate the present issues and challenges in formulating green machining lubricant using vegetable oil and its stand under sustainable machining. This includes the method and technique of formulating vegetable-based lubricant and the output performance obtained from vegetable-based lubricant under machining in comparison to the conventional mineral-based lubricant. The result shows that utilizing the vegetable-based lubricant at minimum quantity has comparable or better performance to conventional mineral-based lubricant in terms of surface finish. Therefore, the use of vegetable oil has its challenges and issues as machining lubricant, but it is one of the current best viable alternatives to the mineral-based lubricant in promoting sustainable machining.

Tribological evaluation of the Jatropha and Tung-based oils as bio-lubricants on Al-7050-T7451 alloy

The search for more sustainable products has motivated the metalworking sector to replace its mineral-based lubricants with renewable products. Vegetable-based oils are renewable resources, more biodegradable, less toxicity and can have a high lubricant potential. Therefore, the vegetable-based oils are a more environmentally friendly alternative to replace the mineral-based oils. The objective of this paper is to evaluate the technical viability of the Tung and Jatropha oils for use in formulation and development of environmentally friendly metalworking fluids (MWFs) for machining processes of Al7050-T7451 alloy. Physical–chemical, tribological (pin-on-disk and reichert tests) and machining analyses were performed to study the technical viability of the vegetable-based oils as a bio-lubricants. The linoleic (C18:2) and linolenic (C18:3) fatty acids of Jatropha oil provide the lubricant film with less resistance to movement between the tribological pair in comparison with Tung oil, leading to lower coefficient of friction (COF). The higher concentration of linolenic fatty acids (C18:3) of Tung oil provides greater resistance to movement, resulting in a higher COF. The unsaturations present in vegetable-based oils carbon chain make it difficult to fill gaps between molecules, reducing metal/metal contact, providing lower wear and better thermo-oxidative stability. Tung emulsion also showed better cooling property, important factor for MWFs. It can be concluded that the vegetable-based oils can be used for formulation and development of environmentally friendly MWFs for the metal-mechanical sector.