Enhancing AW/EP tribological characteristics of biolubricant synthesized from chemically modified cotton methyl-esters by using nanoparticle as additives

Purpose The purpose of this study is to improve the tribological characteristics of cotton-biolubricant by adding nanoparticles at extreme pressure (EP) conditions in comparison with commercial lubricant SAE-40. Design/methodology/approach This research involved the synthesis of cotton-biolubricant by transesterification process and then the addition of nanoparticles in it to improve anti wear (AW)/EP tribological behavior. SAE-40 was studied as a reference commercial lubricant. AW/EP characteristics of all samples were estimated by the four-ball tribo-tester according to the American Society for Testing and Materials D2783 standard. Findings The addition of 1-Wt.% TiO2 and Al2O3 with oleic acid surfactant in cotton-biolubricant decreased wear scar diameter effectively and enhanced the lubricity, load-wear-index, weld-load and flash-temperature-parameters. This investigation revealed that cotton-biolubricant with TiO2 nano-particle additive is more effective and will help in developing new efficient biolubricant to replace petroleum-based lubricants. Research limitations/implications Cotton biolubricant with TiO2 nano-particles appeared as an optimistic solution for the global bio-lubricant market. Originality/value No one has not studied the cotton biolubricant with nanoparticles for internal combustion engine applications at high temperature and EP conditions.

Eliminating Delayed Cracks in Deep-Drawn SUS304 Cups Under Wider Range and Lower Magnitude of Blank Holding Forces Using Tin Coated Die

The effect of TiN coated die on eliminating delayed cracks in deep drawing processes of stainless steel SUS304 cylindrical cups under elevated blank holding forces (BHF) using a commercial lubricant at room temperature is investigated in the experiment. For comparison, the experiment is repeated using an uncoated and finely polished die under the same conditions. The results shows that the crack-free BHF range for the coated and the uncoated dies are 5~10 kN and 12 kN, respectively. Both the magnitude and range of the crack-free BHF are successfully lowered and enlarged by applying TiN coating to the die surface. Lower magnitude and wider range for BHF are preferred in the industries as it is difficult to maintain a high, constant and precise BHF during the deep drawing process using coil springs or die cushions. The elimination of the cracks is mainly due to the decrease in amount of strain-induced martensite resulting from the lower amount of wall thickening, particularly in the valley points along the cup earring profiles. The improved tribological performance by the coating enhances the radial flow of the materials into the die cavity resulting in lower amount of wall thickening. The chance for delayed cracks is reduced with decreasing amount of wall thcikening. Overall, the amount of tensile residual stresses along the outer surface of the cup, particularly in the upper portion is reduced with the coated die due to its low BHF. Therefore, the risk for the cracks is reduced.

Synthesis of Dioxo-Dioxane and Dioxo-Dioxepane Ethyl Oleate Derivatives as Bio-Lubricant Base Stocks

In this study, two novel compounds, i.e., ethyl 8-(3-octyl-5,6-dioxo-1,4-dioxan-2-yl)octanoate and ethyl 8-(3-octyl-5,7-dioxo-1,4-dioxepan-2-yl)octanoate were prepared from oleic acid as the starting material. Both compounds were obtained from the esterification of the ethyl 9,10-dihydroxyoctadecanoate with dicarboxylic acids in the presence of p-toluenesulfonic acid as a catalyst. The chemical structures of the synthesized products were confirmed by FTIR, 1H-NMR, and MS spectrometers. The bio-lubricant properties of the products, such as density, total acid number, total base number, and iodine value, were determined and the effect of the dioxane and dioxepane heterocyclic rings to their bio-lubricant properties was discussed. The esterification of ethyl 9,10-dihydroxyoctadecanoate with oxalic acid gave ethyl 8-(3-octyl-5,6-dioxo-1,4-dioxan-2-yl)octanoate compound in 93.9% yield, while the esterification of ethyl 9,10-dihydroxyoctadecanoate with malonic acid gave ethyl 8-(3-octyl-5,7-dioxo-1,4-dioxepan-2-yl)octanoate compound in 89.6% yield. The density and total base number of the products were close to the standard commercial lubricant values. Meanwhile, the total acid number and the iodine value of the ethyl 8-(3-octyl-5,6-dioxo-1,4-dioxan-2-yl)octanoate were smaller than the standard commercial lubricant, showing that this compound is a promising bio-lubricant in a real application.

A Comparative Study of the Influence of Different Types of Polymers on Viscosity Index and Pour Point of Iraqi Base Oils

In this study, the effects of blending the un-branched acrylate polymer known as Poly (n-decyl acrylate), and the branched acrylate polymer known as Poly (iso-octyl acrylate), on the viscosity index (VI), and the pour point of the Iraqi base stocks 40, and 60 respectively, were investigated. Toluene was used as a carrier solvent for both polymer types. The improvement level of oils (VI, & pour point) gained by blending the oil with the acrylate derived polymers was compared with the values of (VI, and pour point) gained by blending the oil with a commercial viscosity index, and pour point improver. The commercial lubricant additive was purchased and used by Al-Daura Refineries. It consisted of an un-known olefin copolymer dissolved in an un-known carrier solvent. All polyacrylate derivatives and the commercial lubricant additive named HITEC5748 were blended with each type of oil in weight percentage of (2, 4, 6, 8, & 10) wt. %. The result of the study was that the improvement in the viscosity index and the pour point of both base stock types was higher when using the polyacrylate derivatives than when using the commercial olefin copolymer additive.

A Comparative Study of the Influence of Different Types of Polymers on Viscosity Index and Pour Point of Iraqi Base Oils

In this study, the effects of blending the un-branched acrylate polymer known as Poly (n-decyl acrylate), and the branched acrylate polymer known as Poly (iso-octyl acrylate), on the viscosity index (VI), and the pour point of the Iraqi base stocks 40, and 60 respectively, were investigated. Toluene was used as a carrier solvent for both polymer types. The improvement level of oils (VI, & pour point) gained by blending the oil with the acrylate derived polymers was compared with the values of (VI, and pour point) gained by blending the oil with a commercial viscosity index, and pour point improver. The commercial lubricant additive was purchased and used by Al-Daura Refineries. It consisted of an un-known olefin copolymer dissolved in an un-known carrier solvent. All polyacrylate derivatives and the commercial lubricant additive named HITEC5748 were blended with each type of oil in weight percentage of (2, 4, 6, 8, & 10) wt. %. The result of the study was that the improvement in the viscosity index and the pour point of both base stock types was higher when using the polyacrylate derivatives than when using the commercial olefin copolymer additive.

T RIBOLOGICAL PERFORMANCE OF MUSTARD SEEDS OIL UNDER DIFFERENT LOADS USING PIN-ON-DISK TRIBOTESTER

Vegetable oil has been investigated to displace products which are derived frompetroleum because of its environmentally-safe properties and has become a vital source forbio-lubricants. Vegetable oil availability as one of the renewable sources is one of theusefulness of it. Additionally, the vegetable oils based lubricant has indicated the potentialsfor reducing carbon dioxide and hydrocarbon emission while operating in internalcombustion engines and in industrial processes. In this study, the mustard seeds oil wasinvestigated to study its lubricant characteristics under different loads while comparing itwith commercial lubricant using a pin-on-disk tribometer. The whole experiential workswere corresponding to American Society for Testing and Materials (ASTM G99).Under lowload, the results exhibit that the mustard seeds oil shows adequate tribological characteristicscompared to other petroleum oil samples. In conclusion, the mustard seeds oil has a betterwear and friction resistance. Therefore, mustard seeds oil can be used for lubrication ofmating components.

Thermal characterization of castor oil as additive in lubricant oil using photothermal techniques

Over the last years extensively research has been carried out on full or partial substitution of supplies resources coming from renewable resources on traditionally non-renewable, in the case of the automobile sector there are progresses in bio-combustibles (biofuel) and synthetic oils coming from vegetable sources. There are strong efforts to find oil additives which can improve oils features in automobile industry, by adding vegetables oils to commercial lubricant oils, is expected to improve oil thermal stability. In the present research, different ratios of castor oil (ricinus comunis)-motor oil blends were obtained and their thermal properties were characterized by using the so-called Back and Front Photopyroelectric (BPPE/FPPE) techniques. Several oil-additives concentrations were measured and thermal diffusivities and effusivities as well as densities are reported, getting full thermal characterization for every concentration.

THE TRIBOLOGICAL CHARACTERISTICS OF THE CACTUS AND MINERAL OIL BLENDS USING FOUR-BALL TRIBOTESTER

The oil derived from vegetables has been seen as an alternative to mineral oils for lubricants because of certain inherent technical properties, renewable source and their abilities to biodegrade. Vegetable oil is known to have a high viscosity index with a higher lubricity value compared to mineral oil. Despite its potentiality as a candidate alternative, vegetable oil has several limitations. It has a low wear resistance, and it is highly sensitive to temperatures with tribological characteristics. The majority of technical solutions, including additivation, chemical alterations, and blending, are being proposed as means of overcoming the listed limitations. This study seeks to investigate the characteristics of cactus oil with respect to its use as a bio-lubricant as well as the characteristics of environmentally friendly vegetable oil when they are mixed with mineral oils as alternative oil for petroleum, using the four-ball tribotester. The volumetric blending ratio was varied (20% to 80%) and these blends were performed at 1200 rpm, for one hour, with 40 kg of load at a temperature of 75ºC (ASTM D4172-B) standard. According to the results, it was found that the lowest wear scar diameter was 431.23µm, which was identified in the blend of 20% cactus oil with 80% mineral oil which symbolized by (CC20%), compared to that of neat cactus oil at 669.16 µm and mineral oil at 546.46 µm.In addition, the result also indicates that a 80% addition of cactus oil, the coefficient of friction tends to decrease compared to the values of neat cactus oil. Finally, it is concluded, the blends of cactus oil with commercial lubricant oil have better performance compared to commercial lubricant oil or neat cactus oil.

Quantitative comparison of tribological performance of chromium- and zinc-phosphate-coated piston rings in tribotest rig

The main purpose of this paper is to investigate the tribological performance of the zinc-phosphate- and chromium-coated spheroidal cast iron piston rings in reciprocating tribotest rig with conventional commercial lubricant. Results of the experiments showed that tribofilm was formed both on ring and liner surfaces. Zinc phosphate coating was removed from the ring surface after the experiments. Wear rate of liner-chromium-coated ring pair was lower than the liner-phosphate-coated ring. The friction coefficient of the liner-phosphate-coated ring pair ranged from 0.104 to 0.124, lower than the liner-chromium-coated ring, which ranged from 0.114 to 0.129. Change of average surface roughness was also lower in chromium-coated ring (31%) than the phosphate-coated ring (72%). Test results showed that hard chromium-coated ring had better tribological performance and coating efficiency than the phosphate-coated ring due to wear resistance and lower change of average surface roughness.