Four-ball Tribotester Research Articles

The Tribological Characteristic of the Blends of Rbd Palm Olein with Mineral Oil Using Four-ball Tribotester

Vegetable oils are sustainable fluids which have been promoted to replace petroleum-based oils due to its environment friendly characteristics; it is being a very important supply of biolubricant. The excellent advantage of vegetable oil is the fact it is really which can be used environment friendly supplier. In addition, vegetable oil based lubricant clearly show the possibility to minimize carbon monoxide also hydrocarbon emissions when used in IC engines. There are basically two different ways to using vegetable oil to be a bio-lubricant, either one by directly use the pure vegetable oil with additives or use certain blending ratio of vegetable oil with mineral lubricant. In this paper, the influences of the blending ratio of mineral oil with RBD palm olein on the tribological characteristics were investigated and compared with commercial lubricant oil by using the four ball tribotester. The blending ratio was varied from neat with interval of 20% by volume. All experimental works were conforming to ASTM D4172. The results exhibited that the blend of RBD palm olein with commercial lubricant oil has lower the wear scar of ball bearings and coefficient of friction compared to commercial lubricant oil. As a conclusion, the blending of RBD palm olein with commercial lubricant oil has better performance compared to commercial lubricant oil or pure RBD palm olein.

The Influence of Normal Load in Wear Resistance Characteristic of Palm Fatty Acid Distillate

The aims of this study were to determine the friction coefficient and the wear behaviour of palm fatty acid distillate (PFAD) using a four-ball tribotester, following the ASTM D-4172. In this paper, the normal load applied on the ball bearings varied from 40 kg to 120 kg. Experimental temperature was held constant at 75oC, while rotational speed was fixed at 1200 rpm. The test duration was one hour. Tests that were carried out using palm fatty acid distillate were conducted in exactly the same way using commercial hydraulic oil (HO) as a reference lubricant. The analyses focused on the friction coefficient and worn scar characteristic. Wear scar diameter was measured and the worn surface condition was observed using a high resolution microscope. Results showed that PFAD has a lower coefficient of friction than commercial hydraulic oil.

Preparation, Friction, and Wear Behaviors of Cerium-Doped Anatase Nanophases in Rapeseed Oil

Composite cerium-doped anatase nanophases with an average diameter of 20 nm were prepared via sol–gel method followed by surface modification with stearic acid, abbreviated SA/Ce-TiO2. The microstructure of materials was characterized by XRD, FTIR, and SEM. Furthermore, the antiwear and friction-reducing capacities of SA/Ce-TiO2 as lubrication additives in rapeseed oil were evaluated on a four-ball tribotester. The chemical characteristics, elemental composition, and morphology of worn surfaces of steel balls were investigated by XPS and SEM. The results show that SA/Ce-TiO2 could obviously improve the antiwear and friction-reducing capacities of rapeseed oil, especially for the nanophases doped with 2.0 and 3.0% cerium in molar ratio, respectively. The excellent tribological performance of SA/Ce-TiO2 in rapeseed oil can be attributed to the formation of a complex boundary lubrication film mainly consisting of Fe2O3, TiO2, and CeO2 as well as the formation of an adsorption film of SA and base oil on the f...

Experimental Investigation of the Relationship Between Lubricants' Tribological Properties and Their Lubricating Performances in Cold Rolling

In this paper, three lubricants are tested by a four-ball tribo-tester and in a cold rolling process. Our experimental results show that the data from the four-ball tests and the cold rolling tests are generally consistent with each other, implying the tribological properties measured by a four-ball tribo-tester are able to indicate the lubricants' lubricating performance in cold rolling reasonably well. Nevertheless, our experimental results also reveal certain discrepancies between the data from the four-ball tests and cold rolling tests. Especially, the friction coefficients from the four-ball tests are always considerably smaller than their counterparts from the cold rolling tests. Based on our analysis, the friction coefficients measured by cold rolling tests appear to be a more reliable indicator for the lubricants' performance in cold rolling than the friction coefficients measured by the four-ball tests.

Evaluation of Lubrication Properties of Refortified Hydraulic Oils

Used lubricating oil contains more than 90% of good base oil and available additives, providing the potential of energy conservation, environmental protection, and economy, though it loses its useful performance because of contamination by impurities, oxidation, and degradation of additives. Many countries around the world have focused on reclamation and re-refining methods to treat and reuse waste lubricating oils for many years. But the regeneration rate of waste oils is very low in China, less than 20% of the lubricant consumption. Few studies on the performance, especially lubrication properties of recycled lubricating oils, have been considered. In this article, based on differences between used and fresh oils, used oils were reclaimed and replenished with additives (henceforth refortified oils). The physical and chemical properties, including viscosity, total acid number, moisture content, copper corrosion, and water separability from petroleum oil and synthetic fluid as well as the lubrication characteristics of three kinds of refortified hydraulic oils were investigated. The lubrication performance was evaluated using a four-ball tribotester and a Universal Micro-Tribotester (UMT) reciprocating tester. Moreover, the worn surfaces were analyzed using confocal scanning optical microscopy (CSOM), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. The results showed that refortified oils provided good physical and chemical properties, close to those of fresh oils, and produced better tribological characteristics than used and even fresh oils. There were compositional differences between the films of fresh, used, and refortified oils.

Effect of hBN/Al2O3 Nanoparticle Additives on the Tribological Performance of Engine Oil

Nanotechnology currently has an important role in reducing engine wear and improving fuel efficiency within engines using nanoparticle additives in engine oil. In this work, the effect of hexagonal boron nitride (hBN) and alumina (Al2O3) nanoparticle additives, on the tribological performance of SAE 15W40 diesel engine oil, was studied. A tribological test was conducted using a four-ball tribotester. The results show that the coefficient of friction (COF) and wear rate of the ball reduced significantly by dispersing hBN nanoparticle additives in SAE 15W40 diesel engine oil; compared to without or with Al2O3 nanoparticle additives. This is in accordance with the significant reduction of wear scar diameter and smoother worn surfaces observed on the balls.

Preparation and tribological properties of surface-modified calcium borate nanoparticles as additive in lubricating oil

Purpose – To develop a potential substitute for conventional lubricant additive and improve the oil-solubility of nanoparticles, calcium borate nanoparticles modified by an eco-friendly or “green” modifier lauric acid (CBLA) were prepared. The paper aims to discuss these issues. Design/methodology/approach – The microstructures of the as-obtained samples were characterized by X-ray power diffraction (XRD) transmission electron microscope (TEM) and infrared spectra (IR). The contact angle was also measured. Tribological properties of CBLA used as additive in base oil were evaluated with a four-ball tribotester and compared with a commercial additive. The worn surface was investigated by polarized microscope (PM) and X-ray photoelectron spectroscopy (XPS). Findings – The results indicate that the average size is in the range of 50-100 nm and the surface of calcium borate was altered from hydrophilicity to hydrophobicity. At the same time, the nanoparticles can be dispersed well in the base oil. Tribological results show that CBLA have good antiwear property and friction-reducing property in base oil, and it can be found that during the sliding process, a continuous wear resistance film was formed which containing depositions and the tribochemical reaction products such as B2O3, FeB, Fe2O3 and CaO. Originality/value – An eco-friendly or “green” modifier lauric acid could change the surface of calcium borate from hydrophilicity to hydrophobicity, and calcium borate modified by lauric acid has good tribological properties in lubricating oil.

Investigate Jatropha Oil as New Source of Lubricant Oil

This research investigated the physical properties of Jatropha oil to determine its viability as a clean and renewable source of lubricant oil. The study was performed using a four-ball tribotester, CCD camera, digital microscope and viscosity meter. The experiment was conducted using different temperatures (55, 75 and 105°C). The experiment was conducted of constant parameters as speed; load and time under the American Society for Testing and Materials (ASTM), number D 4172.The data included the evaluation of anti-wear, anti-friction and viscosity of Jatropha oil. To evaluate lubricant ability all results of this research were compared to findings regarding hydraulic oil as a mineral oil-based lubricant. The results showed that, under various temperatures Jatropha oil had better lubricant ability compared to hydraulic mineral oil.

Tribological and tribochemical properties of magnetite nanoflakes as additives in oil lubricants

This detailed the tribological and tribochemical properties of magnetite (Fe3O4) nanoflakes used as additives in #40 base oil in a four-ball tribo-tester. The average friction coefficient of the friction pair for lubricant containing the Fe3O4 nanoflakes of 1.5wt% as a lubricant additive in the base oil is decreased by 18.06% compared to that of solely base oil. The chemical composition of base oil with the Fe3O4 nanoflake additives did not change during the 48-h friction assessment. The decreased saturation magnetization and increased coercivity of magnetite nanoflakes occurred due to the distortion of the basal planes and the presence of hematite (α-Fe2O3) generated by the tribochemical reactions during the friction process. The multi-layer low-shear-stress tribochemical lubrication films on the surface of the friction pair could form because the nanoflake particles arrange and adhere onto the surface of the friction pair in an orderly manner, and the tribochemical reactions of the friction pair in the presence of the nanoflakes occur as Fe→FeO→Fe3O4→γ-FeOOH→γ-Fe2O3→α-Fe2O3. The formation of the films can improve the tribological properties.

Tribological Performance Evaluation of Task-Specific Ionic Liquids Derived from Amino Acids

Aspartic acid and glutamic acid derived ionic liquids were found to be efficient antiwear and friction-reducing additives for base oils. The tribological performance evaluation of lubricant blends, prepared as 0.15%, 0.3%, 1%, 1.5%, 2%, and 3% concentration by weight into the mineral base oil, was carried out on a four-ball tribotester. The concentration of ionic liquids along with the chain lengths of alkyl groups influenced the tribological performance of the formulated blends. The synthesized ionic liquids exhibited excellent antifriction and antiwear characteristics.

Wear Resistance Characteristic of Vegetable Oil

The main source for lubricant oils is mineral oils, but the source of mineral oils are depleting from day to day and it is also a major cause for environmental pollution in the world. This aim of research is to introduce vegetable oil as an alternative source of lubricant oil in industrial applications. In this study, we measured the physical properties of Jatropha, palm fatty acid distillate (PFAD) and empty fruit bunches. All experiment were done according to the American Society for Testing and Materials (ASTM) condition, method B and with the use of four-ball tribotester, CCD camera, microscope and viscometer to obtain results. The test oils were measured of their coefficient of friction, wear, viscosity and flash temperature parameter. To evaluate the results, the same conditions were applied for all experiments with the use of engine and hydraulic mineral oil. The results showed that the anti-friction ability of Jatropha oil and PFAD was higher than the engine and hydraulic mineral oils.

The Influence of Temperature in Wear Resistance Characteristic of Palm Fatty Acid Distillate

Palm fatty acid distillate (PFAD) has potential to be used as a lubricant. PFAD is a by-product from palm oil refinery, and it is classified as non-edible oil. However, vegetable oil has poor thermal performance and high oxidation rate. In this paper, the tribological performance of PFAD in different working temperature was investigated by using four-ball tribotester. Tests were conducted at temperatures 50oC, 75oC, 100oC and 125oC, under a normal load of 40 kg for one (1) hour. The rotational speed was set at 1200rpm. Similar tests were conducted using industrial hydraulic oil as a comparison lubricant. Analyses were focused on the coefficient of friction (CoF), wear scar diameter (WSD) and worn surface observation. Results show that coefficient of friction and wear were increased with the increment of temperature. However, palm fatty acid distillate show a better performance in term of friction reduction compared to industrial hydraulic oil.

Friction Characteristics of RBD Palm Olein Using Four-Ball Tribotester

In this study, the effect of load on the tribological performance of RBD palm olein is investigated using a four-ball wear tester according to the standard test of ASTM D4172. Tests were conducted with 40, 60, 80, 100 and 120 kg normal loads. The experimental temperature and rotational speed were held constant at 75 °C and 1200 rpm, respectively. The test duration was 60 minutes in all cases. For each load, the tribological properties of RBD palm olein were compared with the properties of additive-free paraffinic mineral oil. The results focused on the frictional torque, wear scar diameter, friction coefficient and the flash temperature. Following the completion of the wear test experiments, the ball wear condition and lubricant properties were observed. These results show that RBD palm olein has a lower coefficient of friction than paraffinic mineral oil; however showed a high oxidation effect under high temperature work conditions.

Palm Fatty Acid Distillate as an Alternative Source for Hydraulic Oil

This study investigates the physical properties of pure palm fatty acid distillate (PFAD) as a new, clean and renewable source of lubricant and hydraulic oil. This study is done using a four-ball tribotester. The experiments are conducted at five different temperatures of 55, 75, 95, 105 and 125 °C. The rotational speed was fixed at 1200 rpm, normal load was 40 kg and duration was 1 hour. For evaluating the results, all experiments again were conducted using commercial engine mineral and hydraulic mineral oil and at the end all results were compared together. The results show that PFAD has higher anti friction and anti-wear ability.

The Effect of Sliding Speed on Friction and Wear of RBD Palm Olein

In this paper, the effect of sliding speed on the anti-friction of RBD palm olein was investigated using four-ball tribotester. The speeds were varied from 800 to 1400 rpm. The normal load was set to 40 kg and the test oil was heated up to 75 °C before the experiments. The result showed that palm olein has low friction coefficient compared to additive-free paraffinic mineral oil.

Improvement of the resistance to oxidation of the ecological greases by the additives

This article presents the results of research aimed at improving the oxidation stability of the ecological greases addressed toward application in machines working in the food industry. In order to improve the functional properties of grease, additives that modify the thermal stability have been added. Then, the influence of the additive on the grease resistance to the oxidation was examined. The results of tests of lubricants containing different types of additives are presented. The thermal examinations of the greases were carried out with the use of scanning differential calorimetry techniques. The lubricated properties of greases were investigated with the use of a four-ball tribotester. Based on the results, the relationships between the kind of additive, the resistance to oxidation and the lubricated properties of the grease were analysed, and the relationships between thermal and antiwear properties of grease were identified. Based on the results of this research, a new formulation of grease was proposed, which meets both the ecological needs and the working conditions in the food industry.

Tribological properties of magnetite nanoparticles with various morphologies as lubricating additives

The aim of this paper was to investigate the tribological properties of magnetite (Fe3O4) nanoparticles (NPs) with various morphologies (i.e., hexagonal, octahedral, and irregular morphologies) utilized as lubricating additives on a four-ball tribo-tester. The diameters of wear scar and the friction coefficients were measured using a scanning electron microscope (SEM) and a statistical software, respectively. The properties of the friction pair surfaces were examined by a SEM, atomic force microscope, energy dispersive X-ray spectroscope, and X-ray photoelectron spectroscope. The results show that the Fe3O4 NPs, especially the NPs with hexagonal morphology, have superior antifriction properties as lubricating additives. In addition, the antifriction mechanism of the Fe3O4 NPs as lubricating additives was also discussed.

Enhanced biodegradability and lubricity of mineral lubricating oil by fatty acidic diethanolamide borates

The impacts of two fatty acidic diethanolamide borates, viz. oleic diethanolamide borate and lauric diethanolamide borate, as additives on biodegradability and lubricity of an unreadily biodegradable mineral lubricating oil were studied. The biodegradabilities of neat lubricating oil and its formulations with the borate esters were evaluated on a biodegradation tester. Furthermore, the anti-wear and friction-reducing abilities of neat oil and the formulated oils were determined on a four-ball tribotester, respectively. The tribochemical species of the worn surfaces were analyzed by an X-ray photoelectron spectroscope (XPS). The results indicated that oleic diethanolamide borate and lauric diethanolamide borate markedly enhanced biodegradability and lubricity of the lubricating oil. The improvement of anti-wear and friction-reducing abilities of the mineral oil by the borates was mainly ascribed to the formation of a composite boundary lubrication film thanks to the adsorption and tribochemical reactions of the borates on the friction surfaces.

Friction Characteristic of Mineral Oil Containing Palm Fatty Acid Distillate Using Four Ball Tribo-tester

Vegetable oil was one of the main sources of lubricating oil before the discovery of petroleum. Nowadays, due to vegetable oil's poor performance at high temperatures and oxidation, it has not been widely used in the industrial sector. However, the fatty acids contained in vegetable oils may significantly reduce the frictional coefficient. To optimize lubrication, vegetable oil can be mixed with mineral oil. In this paper, palm fatty acid distillate (PFAD) was mixed in mineral oil and it lubricating properties were tested. Palm oil is one of the major vegetable oils produced in the world, and PFAD is one of the by-products of the palm oil refinery process. It is classified as a non-edible oil, and therefore, the increased use of this product for mechanical lubrication would not affect the production of cooking oil, the food chain or increase food prices. The mixing percentage (PFAD to mineral oil) varies from 5% to 25% of the total mass. Testing was conducted using a four-ball tribotester accordance with the American Society for Testing and Materials (ASTM) standard 4172. The results show that by mixing a 20% total mass of palm oil in the mineral oil, the coefficient of friction reached its lowest value. The wear scars on the ball bearings lubricated with this mix of oil also showed acceptable diameter values when compared to other conditions. From these results, it can be concluded that the performance of the mineral oil could be enhanced by mixing it with vegetable oil (instead of mineral oil). However, the percentages should be determined properly.

Tribological behaviour of refined bleached and deodorized palm olein in different loads using a four-ball tribotester

Vegetable oil is one of the bio-oils that have been promoted to replace petroleum-based products due to its eco- friendly characteristics. Palm oil has high productivity rate, and so it could fulfil the demand for a bio-lubricant. In this paper, the influence of the normal load on friction and wear performance were investigated for a RBD palm olein and compared with paraffinic mineral oil using four-ball tribotester. The normal load was varied from 30 kg to 60 kg. All experimental works were conforming to ASTM D 4172. The results exhibited that the RBD palm olein has lower coefficient of friction compared to paraffinic mineral oil. However, the wear scar of ball bearings lubricated with RBD palm olein showed larger diameter compared to paraffinic mineral oil. As a conclusion, RBD palm olein has better performance compared to paraffinic mineral oil in terms of capability to reduce friction.