Oil-based Lubricants Research Articles

Development of Lubricants Using Re-Refined Base Stocks—An Effort toward Circular Economy

<div>Re-refining of used lubricating oil is an economically attractive and effective recycling method that contributes significantly to resource conservation and environmental protection. The effective re-refining process of used lubricating oil undergoes thorough purification to remove contaminants and to produce high yield and good quality base oil suitable for reuse in lubricant formulation. Used lubricating oils have various hazardous materials, these can be processed with safe and efficient methods required to recover high-quality base oil products. Typically, used lubricating oil is a mixture of various types of additives, base oils, and viscometric grades as per the different types automotive and industrial applications. Re-refined base oils can be re-used to produce lubricants such as industrial and automotive lubricants like passenger car motor oils, transmission fluids, hydraulic oils, and gear oils. API classified base oils into two categories namely mineral base oils API Group I–III and synthetic base oils Group IV–V. Re-refined base oils meeting API Group I and II quality standards are mostly produced by re-refiners.</div> <div>In this article, the author has evaluated lubricating oils: gear oil meeting API GL4 specifications based on 25% re-refined base oil to assess the performance of these lubricants in comparison to conventional base oil-based lubricants. This study includes physicochemical tests, lab performance tests (rust, corrosion, shear stability, and oxidation), and tribological performance tests, i.e., weld load, wear scar diameter, and friction performance by MTM was also evaluated. Test results show similar performance in terms of low temperature, oxidation, and friction performance in 25% re-refined base oil-based lubricant with respect to conventional base oil-based products.<figure> <div><img/></div> </figure> </div>

Experimental and molecular dynamics simulation study of the thermal conductivity mechanism of biolubricant-based functionalized silver/carbon black additives

Lubricant degradation under elevated temperatures is a critical challenge in the automobile and manufacturing sectors, which reduces the durability of machinery components. In this study, a new environmentally friendly castor oil-based lubricant was developed utilizing tert‑butylhydroquinone (TBHQ)-functionalized silver/carbon black (Ag/CB@TBHQ) nano-additives. Herein, the mechanism of thermal conductivity improvement in Ag/CB@TBHQ nanolubricant was investigated by experimental tests and molecular dynamics simulations. Furthermore, the hybrid Ag/CB@TBHQ nano-additive presented superior thermal conductivity compared to individual nano-additives (Ag or CB) under various concentrations and temperatures. Additionally, the study presented the improved tribological performance of a novel nanolubricant under various temperatures. In summary, our results will offer promising insights to enhance the heat transfer capability and tribological performance of mechanical systems.

Oleylamine-grafted carbon nanoparticles as the friction-reducing and anti-wear additives of aviation lubricating oils

Purpose This paper aims to try to develop new, environmentally friendly and efficient lubricating additives; study the compatibility of carbon-based additives with different base oils [Polyalphaolefin (PAO)-3, PAO-20 and NPE-2]; and explore the lubrication mechanism. Design/methodology/approach Oleylamine modified carbon nanoparticles (CNPs-OA) were prepared and the dispersion stability of CNPs-OA in PAO-3, PAO-20 and NPE-2 base oils was investigated by transmission electron microscopy, Fourier transform infrared, thermogravimetric analysis, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. Universal Mechanical Tester (UMT) platform was used to carry out experiments on the effects of different additive concentrations on the lubricating properties of base oil. Findings The mean friction coefficient of PAO-3, PAO-20 and NPE-2 reduced by 32.8%, 10.1% and 11.4% when the adding concentration of CNPs-OA was 1.5, 2.0 and 0.5 Wt.%, respectively. Generally, The CNPs-OA exhibited the best friction-reducing and anti-wear performance in PAO-3. Originality/value The agglomeration phenomenon of carbon nanoparticles as lubricating additive was improved by surface modification, and the lubricating effect of carbon nanoparticles in three synthetic aviation lubricating base oils was compared.

Application of Response Surface Methodology (RSM) for Optimizing the Food Grade Bio Lubricant

With growing global concerns about the production of environmentally friendly lubricants, efforts to develop vegetable oil-based alternatives to mineral oil-based lubricants are gaining growth. However, the properties of vegetable oil-based lubricants such as poor low-temperature behaviour, low oxidative stability and poor thermal stability are concerning for industrial gear lubricant applications. Although the number of researches of using vegetable oil-based as an alternative lubricant, the scientific research for industrial gear oil application have not been studied adequately. As a result, the purpose of this study is to investigate the friction coefficient and wear rate of the blended oil using a pin-on-disc test experiment and then compare it to food grade oil, with the hope that the findings will assist the food industry in improving their machinery. Response Surface Methodology (RSM), a Box- Behnken Design approach, has been employed to optimize the lubricant characterization based on the results. The effects of three independent variables—load, speed, and additive concentration—on the coefficient of friction and wear rate have been investigated in this study. The number of tests has been reduced to 15 using this RSM methodology. At the speed of 600 RPM, 30 N load and 30% concentration concluded the lowest predicted wear rate was -38.1986 m3 /m. These results showed that blending palm oil with gear oil can increase the development of biodegradable and environment-friendly lubricants without concerns about downgrading the tribological performance.

Fabrication of surface-carbonated boron nitride nanosheets and their application as water-based lubrication additives

As a typical two-dimensional layered material, hexagonal boron nitride nanosheets (BNNSs) have high mechanical strength, good conductivity, and excellent lubrication performance, which have great potential as solid nano lubricant additives in tribology. When BNNS is used as a water-based or oil-based lubricant additive, its inherent chemical inertness and poor dispersion stability make it difficult to achieve optimal anti-friction and anti-wear performance. In this paper, a simple and efficient preparation method for obtaining hexagonal boron nitride nanosheets (C-HPC-BNNSs) with surface carbonization modification and excellent dispersion stability in water-based lubricants was proposed. Using hydroxypropyl cellulose (HPC) as a modifier, a wet ball milling process combined with high-temperature carbonization treatment effectively reduced the thickness of BNNSs while uniformly modifying N-doped carbon layers on the surface of the nanosheets. Benefit from the smaller layer thickness of C-HPC-BNNSs, they exhibit excellent dispersion stability in the water-glycol solution and can maintain no significant agglomeration behavior for up to 30 days, which is the basis for the excellent lubrication performance of lubricant systems. In addition, the N-doped carbon layer modified on the surface is beneficial for enhancing the hydrophilicity of BNNSs and synergistically enhances the tribological properties of the material with BNNSs. The test results of the four-ball friction tester show that compared with the pure water-glycol solution and the water-glycol system with added C-HPC-BNNSs, the friction coefficient (COF) and wear volume of the system with added C-HPC-BNNSs could be as low as 0.095 and 1.99 × 10−4 mm3, respectively. This work has positive significance for the preparation, surface modification, and tribological application expansion of two-dimensional layered material BNNSs, which is conducive to further understanding the relationship between.

Synthesis and Performance Evaluation of Metallocene Polyalphaolefins (mPAO) Base Oil with Anti-Friction and Anti-Wear Properties

Anti-wear and anti-oxidation abilities are two key properties of lubricants that play a crucial role in ensuring long-term stable equipment operation. In this study, we aimed to develop a base oil with good anti-oxidation and anti-wear properties for use under extreme pressure. The as-prepared metallocene polyalphaolefin (mPAO) was chemically modified using the trifluoromethanesulfonic acid (TfOH) catalysis through an alkylating reaction with triphenyl phosphorothioate (TPPT). During the experiments, when the reaction temperature exceeded 70 °C or the concentration of TfOH exceeded 2.67%, the β-scission reaction in the alkylation process became significantly more pronounced. The physical and chemical properties of TPPT-modified mPAO (T-mPAO) were evaluated by nuclear magnetic resonance spectroscopy, Fourier trans-form infrared spectroscopy, gel–permeation chromatography, and ASTM standards. T-mPAO showed significantly improved antioxidant capacity, with the initial oxidation temperature increasing by 32 °C compared to the base oil, and it exhibited the slowest increase in acid number in the 96-h oven oxidation test. The tribological tests showed that T-mPAO had the lowest friction coefficient, wear track, and wear rate (72.7% lower than that of mPAO) as well as the highest PB (238 kg) and PD (250 kg) among all tested samples. Compared to mPAO, the average friction coefficient of TPPT-modified mPAO in the four-ball friction test was reduced by 30.5%, and by 16.4% in the TE77 reciprocating friction test. Based on the experimental results, T-mPAO had strong anti-oxidation ability and excellent lubricating performance.The successful synthesis of multifunctional mPAO has enabled lubricant base oil additization, making it possible to use it in more demanding work scenarios, greatly broadening its application scope and making lubricant formulation blending more flexible.

Exploring the potential of coal derived graphite as next generation lubricant additive for multifunctional applications

In the present study, the friction and wear characteristics of steel/steel contact under reciprocating sliding conditions were investigated using composite mixtures made from Polyalphaolefin 4 (PAO4) as base oil lubricant and North Dakota lignite-derived graphite (LG) as high-value carbon additive. The results show that addition of 1 wt% LG to PAO4 led to a reduction in the friction coefficient and wear volume by ∼15 % and ∼13 %, respectively. In addition, the oxidation induction time (OIT) at 160 °C was increased by ∼29 %, which further indicates good stability of the formulated composite lubricant against oxidative degradation. The primary wear mechanism on AISI 52100 steel flat and counter-body was found to be abrasive wear under high-contact stress reciprocating sliding conditions, where tribo-oxide films of 100–200 nm were observed on the wear tracks of 52100 steel surfaces using focused ion beam scanning transmission electron microscopy (FIB-STEM). Furthermore, cross-sectional analysis of the wear track of AISI 52100 steel revealed that 1 wt% of LG additive reduced the thickness of the sub-surface deformation zone by 44 %, which indicates higher load-bearing capacity and improved wear resistance.

Characterization of Recycled Base Oils for Lubricants Using Statistical Approaches on Orbitrap Mass Spectrometry Data

Characterization of Recycled Base Oils for Lubricants Using Statistical Approaches on Orbitrap Mass Spectrometry Data

Exploration on the synergistic effect of antioxidants for coal-to-liquid base oil: From the perspective of oxidation resistance and thermal stability

Coal-to-liquid (CTL) base oil is a high-quality lubricant base oil made from coal. However, its poor oxidation stability and short service life limit its application. Pressurized differential scanning calorimetry and Rotary bomb oxidation test are utilized for the evaluation of oxidation stability. Thermogravimetric analysis is performed for the thermal stability assessment. The results showed the reasonable combination of commercial antioxidants can significantly improve the oxidative and thermal stability of two typical CTL base oils, CTL3 and CTL6. The synergistic mechanism of antioxidants in CTL base oil was studied from the perspective of pyrolysis kinetics and pyrolysis mechanism. For CTL3, adding the compound antioxidant 2,6-di-tert-butyl-4-methylphenol (T501) and n-phenyl-1-naphthylamine (T531) results in an almost eightfold increase in oxidation induction time (OIT) and a 33.4 % increase in activation energy compared to pure CTL3. For CTL6, adding the compound antioxidant dialkyl dithiophosphate (T203) and diphenylamine (L57) results in an almost tenfold increase in OIT and a 10.9 % increase in activation energy compared to pure CTL6. The designed commercial antioxidant compound systems had excellent synergistic effects and the synergistic mechanisms were illustrated.

Tribological performance and mechanism of graphite, hBN and MoS2 as nano-additives in palm kernel oil-based lubricants: A comparative study

Layered nanoparticles have received considerable interest in tribological applications owing to their outstanding tribological performances, including in vegetable oil-based lubricants. Despite the advantages of vegetable oil-based lubricants over petroleum-based lubricants, the limited manufacturing scale of vegetable oil-based lubricants restricts their more comprehensive implementation in various industries. In order to gain further insights into the exquisite nano-additive properties of layered nanoparticles, this research was conducted to explore the tribological performance of palm kernel oil-based lubricants combined with three different layered nanoparticles, namely graphite, hexagonal boron nitride (hBN), and molybdenum disulfide (MoS2), using a four-ball tribotester. The four-ball tribotester analysis indicated that the wear scars lubricated with graphite, hBN, and MoS2 nanolubricants exhibited a lower coefficient of friction (COF) and wear scar diameter (WSD) than the base lubricant. The findings also showed that the MoS2 nanolubricant had the best friction reduction and anti-wear performance, with a 24.9% drop in COF and a 12.3% drop in WSD. It was followed by the hBN and graphite nanolubricants. To fully understand the lubricating mechanisms involved, the worn surfaces of the tested balls were characterised using various microscopic and spectroscopic methods. Accordingly, the structural changes that occurred during sliding were shown to affect the formation of protective tribofilm. In summary, the findings in this study suggest that the formulated layered nanolubricants possessed exceptional tribological performance, which was contributed by the inherent properties of the individual nanoparticles and the formation of effective tribofilms.

Synthesis and tribological assessment of oil-based nanolubricants blended with nano-zeolite for steel–steel contact

This study aims to synthesize zeolite with nano-sized morphology and investigate the tribological performance of nano-zeolite as a lubricating additive dispersed in an oil-based lubricant. Tribological tests were performed and morphologies of wear tracks were characterized to investigate the friction reduction and anti-wear properties of zeolite, respectively. The lubrication mechanism was discussed by illustrating the effects of concentration and particle size on the tribological behavior of zeolite. The optimal concentration of nano-zeolite to improve the tribological performance of the base oil was 2 wt.%, which exhibited a friction reduction of 34.3%. Zeolite particles with larger diameters showed better dispersion stability but worse lubrication performance, which could be concluded from the decrease in the friction reduction ratio. Moreover, the friction coefficient under the lubrication of zeolite at 200°C was 15.8% lower than that of the pure base oil, demonstrating the thermal stability of zeolite. Notably, the application of zeolite resulted in an increase in wear depth due to the occurrence of the three-body abrasion, while the surface asperities of the counterpart were also smoothed in the meantime. This work demonstrates the potential of nano-zeolite to enhance the tribological performance of oil-based lubricants in industrial applications, which could be attributed to their porous structure, lipophilicity, and chemical–thermal stability.

Biophysical impact of lubricating base oil aerosols on natural pulmonary surfactant film

Lubricating base oils have been extensively employed for producing various industrial and consumer products. Therefore, their environmental and health impacts should be carefully evaluated. Although there have been many reports on pulmonary cytotoxicity and inflammatory responses of inhaled lubricating base oils, their potential influences on pulmonary surfactant (PS) films that play an essential role in maintaining respiratory mechanics and pulmonary immunity remains largely unknown. Here a systematic study on the interactions between an animal-derived natural PS and aerosols of water and representative mineral and vegetable base oils is performed using a novel biophysical assessing technique called constrained drop surfactometry capable of providing in vitro simulations of normal tidal breathing and physiologically relevant temperature and humidity in the lung. It was found that the mineral oil aerosols can impose strong inhibitions to the biophysical property of PS film, while the airborne vegetable oils and water show negligible adverse effects within the studied concentration range. The inhibitory effect is originated from the strong hydrophobicity of mineral oil, which makes it able to disrupt the interfacial molecular ordering of both phospholipid and protein compositions and consequently suppress the formation of condensed phase and multilayer scaffolds in a PS film. Environmental ImplicationUnderstanding the biophysical influence of airborne lubricating base oils on pulmonary surfactant (PS) films can provide new insights into the environmental impacts and health concerns of various industrial lubricant products. Here a comparative study on interactions between an animal-derived natural PS film and the aerosols of water and representative mineral and vegetable base oils under the true physiological conditions was conducted in situ using constrained drop surfactometry. We show that the most frequently used mineral base oil can cause strong inhibitions to the PS film by disrupting the molecular ordering of saturated phospholipids and surfactant-associated proteins at the interface.

Selective and Controllable Cracking of Polyethylene Waste by Beta Zeolites with Different Mesoporosity and Crystallinity.

Waste plastics bring about increasingly serious environmental challenges, which can be partly addressed by their interconversion into valuable compounds. It is hypothesized that the porosity and acidity of a zeolite-based catalyst will affect the selectivity and effectiveness, enabling a controllable and selective conversion of polyethylene (PE) into gas-diesel or lubricating base oil. A series of embryonic, partial- and well-crystalline zeolites beta with adjustable porosity and acidity are prepared from mesoporous SBA-15. The catalysts and catalytic systems are studied with nuclear magnetic resonance (NMR), X-ray diffraction (XRD), and adsorption kinetics and catalytic reactions. The adjustable porosity and acidity of zeolite-beta-based catalysts achieve a controllable selectivity toward gas-diesel or lubricating base oil for PE cracking. With a catalyst with mesopores and appropriate acid sites, a fast escape and reduced production of cracking of intermediates are observed, leading to a significant fraction (88.7%) of lubricating base oil. With more micropores, a high acid density, and strong acid strength, PE is multiply cracked into low carbon number hydrocarbons. The strong acid center of the zeolite is confirmed to facilitate significantly the activation of hydrogen (H2),and, an in situ ammonia poisoning strategy can significantly inhibit hydrogen transfer and effectively regulate the product distribution.

Lubricating properties of thymol-based deep eutectic solvents

PurposeThis study aims to prepare thymol-based deep eutectic solvents (DESs) and use them as lubricates for friction and wear tests to simulate the wear conditions of hybrid bearings.Design/methodology/approachThrough the characterization and analysis of the morphology of wear scars and the elemental composition of friction films, the tribological behavior and wear mechanism of sample materials as lubricants were investigated and the anti-wear mechanism of thymol-based DESs was discussed.FindingsThe findings demonstrate that because of the formation of a fluid lubrication film and excellent kinematic viscosity, the lubrication effect of the prepared DES is improved by about 50% compared to the base lubricating oil. The prepared [Ch]Cl-thymol DES has a better anti-friction and lubrication effect than citric-thymol, EG-thymol and urea-thymol DESs, with an average friction coefficient of about 0.04.Originality/valueIn this work, the friction reduction properties of thymol-based DESs were studied as lubricants for the first time, and the lubrication mechanism of sample materials was investigated.

Effect of palm oil methyl ester on coconut oil as a viable bio‐lubricant alternative to traditional mineral‐based oils

AbstractVegetable oils are promoted as a base oil for automobile lubricants due to increased concerns about the environmental damage caused by synthetic and mineral oils‐derived lubricants. Coconut oil exhibits excellent tribological properties but poor cold flow properties. This work investigates the effect of the addition of palm oil methyl ester (POME), obtained from the transesterification of palm oil, on coconut oil by blending it in three proportions with varying volumes and evaluating for lubricant properties namely tribological properties, rheological properties, thermal properties, chemical properties and corrosion and oxidative stabilities. Fatty acid composition are evaluated for the base oil and the blends. The findings show that the addition of POME improves the base oil's pour point and reduces friction and wear. The corrosion test shows only slight tarnishing of copper strips, while the HOOT and chemical tests indicate appreciable resistance to oxidation. Therefore, this blended mixture has the potential to be a viable bio‐lubricant alternative to traditional mineral‐based oils.

(045) A PHYSICIAN'S GUIDE TO LUBRICANT FOR SEX

Abstract Introduction Lubricant use during sexual activity has numerous benefits, minimal harms, and can play a role in managing common concerns in primary care. However, navigating evidence-based conversations about lubricant use can be challenging since there is a lack of easily accessible and reliable information. As a result, physicians are often hesitant to discuss the topic and can only offer anecdotal advice. Objective To review literature on lubricants used during sexual activity to (1) inform the development of an inclusive and practical evidence-based tool for physicians to help incorporate patient-specific recommendations for lubricants into clinical practice, and (2) create accessible materials for patients. Methods We conducted a scoping review of peer-reviewed literature using the Arksey and O’Malley framework. Using relevant keywords, we searched two electronic databases, one search engine, and reference lists for articles published in 2003 and onward. Articles generated were manually reviewed for relevance with further inclusion criteria: (1) identifies patient populations most likely to benefit from using lubricant during sexual activity, (2) addresses benefits and drawbacks of different lubricant classes, or (3) describes ingredients in or properties of lubricants that may cause harm. All sexually active individuals were deemed eligible for inclusion in the study, with no restrictions placed on location, age, gender, or sexual orientation. Following the completion of our scoping review, we used an evidence-based approach to develop a clinical practice tool and patient handout. During their development and to validate our findings, family physicians, nurses, psychologists specializing in sexual concerns, and sexual health educators provided iterative review. Results 27 articles were deemed eligible for inclusion in our scoping review. Results showed lubricant use to be especially beneficial for patients who (1) experience dryness, pain, or sexual dysfunction during any type of sex, (2) are at a higher risk of STI transmission (by reducing condom breakage), or (3) want to reduce the risk of having an unplanned pregnancy (by reducing condom breakage). There are three main types of lubricant available: oil, water, and silicone-based. Oil-based lubricant is not recommended since it is incompatible with latex condoms and is more likely to irritate genital epithelium and negatively impact genital microbiota. When comparing silicone and water-based lubricant, silicone-based lubricant lasts longer but is more difficult to wash off. Silicone-based lubricant is not compatible with silicone-based sex toys, whereas water-based lubricant is compatible with all types of sex toys. Water-based lubricant is also more likely than silicone-based lubricant to contain potentially irritating ingredients and properties, such as glycerol, propylene glycol, parabens, or a high osmolality. For patients who are struggling with infertility, most lubricants should be avoided as they can negatively affect sperm motility and viability. Conclusions Numerous patients can benefit from lubricant use during sexual activity. In particular, silicone and water-based lubricant without harmful additives or properties are recommended. Our guide on lubricants will assist physicians in identifying patients who may benefit from using lubricant and incorporating patient-specific recommendations into clinical practice. This, in addition to our patient handout, will help to improve discussions between patients and healthcare providers regarding sexual well-being and lubricant use. Disclosure No.

Functionalized N-doped carbon nanosheets derived from metal−organic framework as oil-based lubricant additives for improved tribological performance

Herein, the functionalized N-doped carbon nanosheet (N@PCNs) was successfully achieved through pyrolysis of metal−organic framework (MOF) and then surface modification with anti-wear agent. Firstly, the N@PCNs was obtained via carbonization of copper pyridine coordination polymer-based MOFs. Then tannic acid (TA) cross-linked by polyethylenimine (PEI) via Michael addition was grafted on the N@PCNs surfaces. Finally, the anti-wear agent 2,5-dimercaptothiadiazole dimer (DTD) was grafted onto N@PCNs via Michael addition reaction with TA to obtain DTD-N@PCNs. The average COF of 500SN decreases to 0.110 from 0.195, accompanied by 69.3% reduction in wear volume with 1.00 wt% DTD-N@PCNs addition. The lubrication performance is ascribed to the formation of a stable protective film through DTD-N@PCNs facilitating tribochemical reactions, preventing direct contact of the ball-disc pairs.

Shape selection of alkane hydroisomerization over one-dimensional zeolite supported Pt catalyst: Pt/ZSM-48 versus Pt/ZSM-22

Hydroisomerization of long-chain n-alkanes plays a vital role in petrochemical and coal chemical industries, because it can produce high-quality hydrocarbon fuels and lubricant base oils. ZSM-48 (0.56 × 0.53 nm) and ZSM-22 (0.57 nm × 0.46 nm) are characteristic of one-dimensional 10-member ring zeolites suitable for n-alkanes hydroisomerization reaction. Here, the effect of the structure difference between ZSM-48 and ZSM-22 zeolites on hydroisomerization is titrated by the isobutane and n-dodecane. The product distribution of hydroisomerization of isobutane to n-butane shows the reaction pathway on Pt/ZSM-48 and Pt/ZSM-22, in which the monomolecular hydroisomerization of isobutane is involved within the active sites in zeolite channels, while the polymerization-cracking bimolecular reaction occurs on the pore-mouth of zeolite. Pt/ZSM-48 zeolite, possessing larger channel and aperture size than those of Pt/ZSM-22, is more conducive to the diffusion of butane molecules and bimolecular polymerization. Therefore, the isobutane conversion (14 %) on Pt/ZSM-48 produces less C1+C2 (1.7 wt% vs. 3.4 wt%) and more C3+C5+C8 (19.2 wt% vs. 16.9 wt%). For the hydroisomerization of n-dodecane, the iso-dodecane selectivity of Pt/ZSM-48 (43.3 wt%) is significantly higher than that of Pt/ZSM-22 (12.4 wt%) at the similar n-C12 conversion (40 %). Compare with the isomers of Pt/ZSM-22, the mono-branched isomers with methyl near the middle of the chains and multi-branched isomers are more easily formed on Pt/ZSM-48, which is conducive to the “key-lock” catalysis mechanism. The larger pore size of ZSM-48 is conducive to n-C12 insertion into zeolite pores, methyl migration and isomer diffusion, and its adjacent pores are more compatible with double-branched isomers. In addition, a high selectivity of C4∼C5 alkanes (53.2 wt%) on Pt/ZSM-22 and a high selectivity of C6∼C9 alkanes (44.7 wt%) on Pt/ZSM-48 show obvious difference in cracking product distribution, implying different position of methyl groups in i-C12 isomers on Pt/ZSM-22 and Pt/ZSM-48 samples, respectively. The present comparison between Pt/ZSM-48 and Pt/ZSM-22 benefits the selection and development of one-dimensional zeolitesupported metal catalyst in a wide range of hydro-processing reactions.

Investigating the Wear Mechanism of TiAlN/TiN PVD-Coated WC Inserts in End Milling of Incoloy 925 Under Synergy of Bio-Degradable Fatty Acids and Nano-Metallic Solid Lubricant

Abstract Rapid tool wear in machining difficult-to-cut material is a significant challenge since it is related to tool cost, surface integrity of machined components, and power consumption. The reduction in tool wear may be accomplished by cutting fluids, especially in modern biodegradable fatty acids. Because of its high lubricity, coconut oil is the best choice for lubricating fatty acids. However, this oil has poor heat transfer properties. Hence, to further improve its properties, copper (Cu) nanoparticles (NPs), which have a high thermal conductivity to cost ratio compared to other nanoparticles in addition to anti-frictional and anti-wear properties (due to self-repairing properties caused by their low shear strength and easy deposition on contacting surfaces), have been dispersed in coconut oil, thus creating a nano-lubricant (nanofluid). It is found that synthesized nano-lubricants perform better in thermo-physics and tribology than pure coconut oil. Further, research has been carried out on the combined effects of coconut oil and 0.3 vol% Cu-NPs on Incoloy 925's end milling performance and tool wear mechanism (viz., coating delamination, adhesion, abrasion, and oxidation). It is found that tool wear-rate is reduced, which in turn increases tool life, due to effective cooling and lubrication when nanofluid-based minimum quantity lubrication (NMQL)-assisted machining is performed rather than dry and pure oil-based minimum quantity lubrication (MQL) conditions. Consequently, energy consumption in machining and surface quality of machined components are improved.

Tribological investigations of water-based lubricants for application in the deep drawing process

This paper describes the tribological investigation of water-based lubricants in the context of a deep drawing process. Therefore, different methods were conducted in order to determinate the suitability of these lubricants for a deep drawing process. Three lubricant manufacturers each provided their lubricants as part of this work. The sheet materials investigated are an aluminum material (AA6014) and two steel materials (DC04, DP800), each with a thickness of 1.5 mm. All sheet materials were examined in the as-delivered condition as part of this work. The hypothesis for this research proposal is that it is possible to achieve comparable tribological properties in sheet metal forming using water-based lubricants as when using mineral oil-based lubricants. The aim is to optimize a tribological system for water-based lubricants when used as additional lubrication in order to replace mineral oil-based lubricants and, as a result, to shorten the representative process chain by one process step (cleaning). In the course of this work, topographical measurements of the sheet materials were carried out in order to investigate the lubricant holding capacity of the sheet materials. Furthermore, strip drawing tests were performed to determine the friction coefficients of the different lubricant-sheet combinations. The final step was to conduct deep-drawing tests to determine the limits of use of the water-based lubricants by continuously increasing the holding-down force.