Engine Oil Additives Research Articles

Influence of crystal grain structure of steel surface on formation of chemical reaction film derived from engine oil additives

This study investigated the relationship between the chemical reaction film formation derived from engine oil additives and crystal grain structure of a steel surface. Variations in the contact area between a rotating sapphire disc and a stationary steel pin were captured by a monochromatic high-speed camera. A fully formulated low viscosity engine oil was used as the lubricant. After friction tests, the elements on the surface were analysed using energy dispersive X-ray spectroscopy and the crystal grain structure of the top surface layer by electron backscatter diffraction. In-situ and ex-situ analyses revealed that plastic flow changed the crystal grain structure of the surface, inhibiting the formation of the chemical reaction film derived from additives.

Determination of Diphenylamine Antioxidants in Wastewater/Biosolids and Sediment

Diphenylamine derivatives are widely used as antioxidant additives in vehicle engine oils, commercial/industrial lubricants, and products composed of rubber. Their presence in the environment resul...

Preliminary results on nano-diamond and nano-graphite testing as additive for an engine lubrication oil

An important amount of the fuel energy burned in an internal combustion engine is used to overcome the friction losses inside the engine. Developing advanced lubricants is one of the ways to improve the fuel efficiency and reducing the pollution caused by internal combustion engines. This paper presents tests done with 1% v/v nano-diamond and nano-graphite additives in engine oils, with bench tests on an air-cooled spark ignition engine (Honda GX 160) with a displacement of 118 cubic centimeters. Using the raw lubrication oil laboratory, tests were done to determine the viscosity, density and viscosity index using an Anton Paar SVM 3000 viscometer in comparison to the oil with nano-diamond and nano-graphite additives. The tests also revealed an average reduction in fuel consumption of 21% for the single cylinder engine in case of the oil with additives, for the entire speed range of the engine, showing a decrease of the fuel efficiency as the speed increases. The temperature of the exhaust manifold, outer side of the cylinder and the temperature of the oil pan were measured. By adding nano-diamond and nano-graphite additives to the lubricant oil, tests have revealed a reduction of the temperature of the exhaust manifold (with 11%), temperature on the outer side of the cylinder was reduced with 21% showing a clear friction reduction within the cylinder and piston-rings assembly. The temperature of the oil pan was reduced with 20%, showing a general reduction of the lubricating oil temperature which means a substantial reduction of the friction losses.

Potassium deactivation of Cu-SSZ-13 catalyst for NH3-SCR: Evolution of salts, zeolite and copper species

Cu-SSZ-13, as an efficient catalyst for NOx removal, has been commercialized in diesel exhaust aftertreatments. However, SCR catalysts in practical applications may suffer from alkali deactivation due to the introduction of engine oil additives and biodiesel. In this study, the poisoning effect of different potassium salts (K2CO3, K2SO4 and K3PO4) on the Cu-SSZ-13 catalyst was systematically investigated. Deactivation effect of potassium salts follows the order of K2CO3 > K2SO4 > K3PO4, resulting from the transformation of isolated Cu2+ into other copper species. The loss of isolated Cu2+ is considered as the main reason for the low-temperature deactivation while the formed copper oxides, copper sulfate and copper phosphate related species are mainly responsible for the different catalytic behaviors of the poisoned catalysts at high temperatures (>400 °C). The CuOx clusters induced by K2CO3 promote NH3 oxidation while the copper salts derived from K2SO4 and K3PO4 are relative inactive for this competitive reaction. As a balance between the consumption of NH3 by the side reaction and loss of Brønsted acid sites, the K2CO3 poisoned catalyst shows significantly dropped high-temperature SCR activity, while the reaction is promoted over those catalysts impregnated with K2SO4 and K3PO4 at high temperatures.

Study of impact of tribotechnical composition on rubber technical products to assess its applicability in wheeled transport engine

Tribotechnical coating helps to reduce the friction factor and improves the performance of the internal-combustion engine, but in the process, the generic components of the engine oil and other additives interfuse together. Besides, the coating mixture excretes acids and can destroy general mechanical rubber goods and metals. For this research the oil-gasoline-resistant rubber was used which is half-disk shaped with the dimensions of 27x7x2 mm. These samples of rubber have been heated to 110°C and exposed to generic components of engine oil, tribotechnical coating «ACTIVE PLUS» and strong acid H2SO4. In the total, the volume of the tribotechnical coating and engine oil was approximately 1 % of strong acid H2SO4. The article describes most common properties of aged rubbers such as rubber hardness, resilience, elasticity after exposure to generic components of engine oil and its additives. Results were obtained in the laboratory where samples of rubber were exposed to heat, engine oil, tribotechnical coating in conditions of absence of mechanical load. This study has identified an important issue according to which sulfuric acid destroys the system of oil-ultrafine particles in the absence of swelling of rubber.

Effect of engine oil additives reduction on the tribofilm structure of a cylinder liner model surface

PurposeThe purpose of this paper is to provide a general picture for describing the formed tribofilm, including chemical and physical aspects in the micro-scale and the nano-scale. In a previous study, the durability of zinc dialkyl dithiophosphate (ZDDP) tribofilms on cylinder liner samples has been investigated in a tribometer model system by using fresh and aged fully formulated oils and replacing them with PAO8 without additives. Analyses of the derived tribofilms by means of X-ray photoelectron spectroscopy and scanning electron microscopy could give some hints about the underlying mechanisms of the tribofilm build-up and wear performance, but a final model has not been achieved.Design/methodology/approachThus, characterisation of these tribofilms by means of focused ion beam-transmission electron microscopy (FIB-TEM) and energy dispersive X-ray spectroscopy is presented and a concluding model of the underlying mechanisms of tribofilm build-up is discussed in this paper.FindingsFor tribotests running first with fresh fully formulated engine oil, a rather homogeneous ZDDP-like tribofilm is found underneath a carbon rich tribofilm after changing to non-additivated PAO8. However, when the tests run first with aged fully formulated engine oil, no ZDDP-like tribofilm has been found after changing to non-additivated PAO8, but a wear protective carbon rich tribofilm.Originality/valueThe obtained results provide insights into the structure and durability of tribofilms. Carbon-based tribofilms are built up on the basis of non-additivated PAO8 because of the previously present ZDDP tribofilms, which suggests an alternative way to reducing the consumption of antiwear additives.

Tests of energy-saving additives to engine oils on gasoline engine stand

The influence of energy-saving engine oil additives on the parameters of the internal combustion engine has been studied. The tests were carried out on a stand with a 4-stroke gasoline engine. The additives contained a pentaerythritol ester and a complex compound of copper or molybdenum. It is shown that the introduction of additives in motor oils SAE 10W40, SAE 30 reduces fuel consumption, reduces the content of CO and CH in the exhaust gases. The resulting effect is explained by the formation on the conjugate surfaces of a tribopolymer antifriction film, which reduces the gap between the piston and the cylinder. This leads to an increase in compression and a more complete combustion of fuel.

Impact of Diesel Engine Oil Additives–Soot Interactions on Physiochemical, Oxidation, and Wear Characteristics of Soot

Carbonaceous soot accumulated in crankcase oil is known to have an adverse effect on diesel engine performance, durability, and fuel efficiency. The current study is focused on determining the infl...

Effects of waste engine oil additive on the pelletizing and pyrolysis properties of wheat straw

This study focused on the reuse of wheat straw and waste engine oil by producing pellets with mixtures of the two products. Oxidative thermogravimetric experiments were carried out after blending the wheat straw with different amounts of the waste engine oil additive. Based on the results of these experiments, the effects of additive contents on the pyrolysis properties were obtained. Based on a single pellet unit, experiments were conducted to make pellets from wheat straw blended with the waste engine oil additive under different moisture content, temperature, and pressure conditions. The influences of additive content on the specific energy consumption, pellet density, tensile strength, and higher heating value (HHV) were investigated based on the experimental data. Finally, comparisons were made between the effects of waste engine oil additive and the additives used in other studies. The results showed that the use of waste engine oil additives had few effects on the pellet density but increased the HHV, and decreased the ignition temperature, specific energy consumption, and tensile strength.

Tribology of Wire Arc Spray Coatings under the Influence of Regenerative Fuels

In order to further optimize the efficiency of today’s internal combustion engines, specific coatings are used on functional surfaces to reduce internal engine friction and wear. In the current research project, oxymethylene ether (OME) is discussed because it is CO2 neutral and has a strong soot-reducing effect as a fuel or fuel additive. In some operational regimes of the internal combustion engine a dilution of engine oil by fuel must be assumed. In this paper, the frictional contact between piston ring and cylinder raceway is modelled using a pin-on-disk tribometer and the friction and wear behavior between a diamond-like carbon coating (DLC) and a thermal spray coating is characterized. The wear of the spray layer could be continuously detected by radionuclide technology (RNT). With the aid of photoelectron spectroscopic measurements (XPS), the steel thermal spray coating was chemically analyzed before and after the tribometer tests and the oxidative influence of OME was investigated. In addition, confocal microscopy was used to assess the topographies of the specimens. The measurements showed that the addition of OME to the lubricant reduced the viscosity and load-bearing capacity of the lubricating film, which led to an increase in the coefficient of friction. While almost no wear on the pin could be detected at 10% OME, the first visible material removal occurs at an OME content of 20% and the layer delaminated at 30% OME. The evaluation of the RNT wear tests showed that both the tests with engine oil and with engine oil plus 20% OME achieved very low wear rates. No corrosion of the thermal spray coating could be detected by XPS. Only the proportion of engine oil additives in the friction track increased with increasing OME concentration.

自動車排出粒子に含まれるエンジンオイル添加剤由来微量無機元素の リアルタイム計測へ向けたICP-TOFMS 技術の応用

自動車排出粒子に含まれるエンジンオイル添加剤由来微量無機元素の リアルタイム計測へ向けたICP-TOFMS 技術の応用

Importance of Emulsification in Calibrating Infrared Spectroscopes for Analyzing Water Contamination in Used or In-Service Engine Oil

Using Fourier transform infrared (FT-IR) spectroscopy we investigated the water content of SAE 15W–40 diesel engine lubricating oil at various levels of contamination to establish instrument calibration standards for measuring water contamination in used or in-service engine oil by the standards of ASTM International. Since some known additives in consumer grade engine oil possess slightly hydrophilic properties, this experiment avoided changing the sample matrix with supplemental additives, such as adding surfactants, to achieve homogeneity of the original sample. The impact of sampling time after contamination on the spectral absorption signature was examined in an attempt to improve the accuracy of water contamination quantification and determine if water-soluble potassium bromide (KBr) windows were suitable for analyzing water in oil emulsions. Analysis of variance (ANOVA) modeling and limit of detection calculations were used to predict the ability to discriminate contamination levels over time. Our results revealed that the amount of water concentration in engine oil could be misinterpreted depending on the timing of the FT-IR measurement of the calibration standard after initial water contamination. Also, KBr windows are not sufficiently etched due to the limited window interaction with water molecules within micelles of emulsions to alter FT-IR spectral signatures.

Colloidal Stability of Metal Nanoparticles in Engine Oil under Thermal and Mechanical Load

AbstractExtended colloidal stability and high dispersion degree of nanolubricants are required to avoid nanoparticle deposition in combustion engines and to reduce friction and wear. The simple and rapid one‐step technique of pulsed laser ablation in liquids is employed to synthesize precursor‐free and highly dispersed gold nanoparticles in lubricants while the colloidal stability is measured by optical spectroscopy and transmission electron microscopy. A remarkable colloidal stability is determined under engine‐like and ambient conditions for nine months in terms of constant primary particle size. In contrast to additive‐free oils, almost no agglomeration is observed, which might be attributed to the attachment of engine oil additives or pyrolyzed/oxidized molecules to the nanoparticles preventing attractive nanoparticle interactions.

Experimental Investigation on the Influence of Engine Oil Additives on Silicone Rubber

Experimental Investigation on the Influence of Engine Oil Additives on Silicone Rubber

Supercritical Fluid Synthesis and Tribological Applications of Silver Nanoparticle-decorated Graphene in Engine Oil Nanofluid

Silver nanoparticle-decorated graphene nanocomposites were synthesized by a facile chemical reduction approach with the assistance of supercritical CO2 (ScCO2). The silver nanoparticles with diameters of 2–16 nm are uniformly distributed and firmly anchored on graphene nanosheets. The tribological properties of the as-synthesized nanocomposites as lubricant additives in engine oil were investigated by a four-ball tribometer. The engine oil with 0.06~0.10 wt.% Sc-Ag/GN nanocomposites displays remarkable lubricating performance, superior than the pure engine oil, the engine oil containing zinc dialkyl dithiophosphate (ZDDP), as well as the oil dispersed with the single nanomaterial of graphene oxides (GOs) and nano-Ag particles alone. The remarkable lubricating behaviors of Sc-Ag/GN probably derive from the synergistic interactions of nano-Ag and graphene in the nanocomposite and the action of the formed protective film on the contact balls. The anchored nano-Ag particles on graphene expand the interlamination spaces of graphene nanosheets and can prevent them from restacking during the rubbing process, resulting in the full play of lubricating activity of graphene. The formed protective film on the friction pairs significantly reduces the surface roughness of the sliding balls and hence preventing them from direct interaction during the sliding process.

Friction, Wear, and Scuffing Characteristics of Marine Engine Lubricants with Nanodiamond Particles

ABSTRACTMany kinds of additives are generally added to engine lubricants to improve performance. These chemical additives are harmful to both humans and the environment. For this reason, the research trend in the lubricant industry is to reduce the use of chemical additives in engine oils. Carbon materials like nanodiamonds are candidates among many physical additives. Nanodiamond particles are round, very hard, chemically stable, and highly heat conductible. In this research, nanodiamond particles were uniformly dispersed in marine engine lubricants. A matrix synthesis method was used for dispersion with various concentrations. Friction and wear tests were performed to measure the friction and wear amounts, and scuffing tests were performed. The friction coefficients were decreased with the addition of nanodiamond particles. Due to their octagonal and almost spherical shape, the particles could act as rolling contact elements between two lubricated sliding surfaces. In addition, it was found that there was a proper concentration of nanodiamond to minimize the wear amounts, which was 0.3 wt%. From the scanning electron microscopy (SEM) analysis many agglomerated particles were found on the sliding surfaces with a high concentration of particles over 0.3%. The excessive amount of nanodiamonds acted as abrasive debris and ploughed the contact surfaces. Finally, as the concentration of nanodiamonds increased, the scuffing life increased due to a reduction in friction, and the rate of temperature increase was reduced due to the high heat conductivity of nanodiamonds.

Tribological Properties of the Lubricant Containing Titanium Dioxide Nanoparticles as an Additive

To improve the oil-solubility of nanoparticles, a new technology was used to prepare a kind of lubricant containing titanium dioxide (TiO2) nanoparticles. The microstructures of the prepared nanoparticles were characterized via transmission electron microscope (TEM) and infrared spectroscopy (IR). Tribological properties of TiO2 nanoparticles used as an additive in base oil were evaluated using four-ball tribometer and ball-on-disk tribometer. In addition, the worn surface of the steel ball was investigated via polarized microscopy (PM) and X-ray photoelectron spectroscopy (XPS). The TiO2 nanoparticles can be completely well-dispersed in the base oil under a new process (NP), which has no significantly negative effect on the anti-oxidation property. The results of the tribological tests show that TiO2 nanoparticles under the NP show a better anti-wear property and friction-reducing property in base oil compared to TiO2 nanoparticles under the tradition process (TP). The main aim of this paper lies in solving with the oil-solubility problem through the combination effect of surface modification and special blend process of lubricating oil. This method was first used to prepare lubricant containing TiO2 nanoparticles and then used as additives in engine oil, gear oil, and other industrial lubricants. At the same time, tribological properties of TiO2 nanoparticles in base oil as a lubricating additive were also studied.

Effect of a new phosphate compound (BAFDP) addition on the lubricating performance of engine oils at elevated temperatures

A new phosphate compound bisphenol AF bis(diphenyl phosphate) (BAFDP) has been synthesized, characterized, and its tribological behaviours as a potential additives in aircraft engine oil were investigated at elevated temperature. BAFDP has high solubility in synthetic polyol esters and it is noteworthy that BAFDP exhibited effective friction reduction and antiwear characteristics when blended with trimethylolpropyl trioleate (TMPTO) and pentaerythritol oleate (PETO). The tribological properties of BAFDP were generally superior to the traditionally used tricresyl phosphate (TCP) in TMPTO and PETO. The antiwear mechanism is tentatively proposed on the basis of the morphology features and the chemical composition of the worn surfaces by SEM and XPS.

Titanium oxide nanoparticles as additives in engine oil

This research study investigates the tribological behaviour of titanium oxide (TiO2) nanoparticles as additives in mineral based multi-grade engine oil. All tests were performed under variable load and varying concentrations of nanoparticles in lubricating oil. The friction and wear experiments were performed using pin-on-disc tribotester. This study shows that mixing of TiO2 nanoparticles in engine oil significantly reduces the friction and wear rate and hence improves the lubricating properties of engine oil. The dispersion analysis of TiO2 nanoparticles in lubricating oil using UV spectrometer confirms that TiO2 nanoparticles possess good stability and solubility in the lubricant and improve the lubricating properties of the engine oil.

Influence of Ca-, Mg- and Na-Based Engine Oil Additives on Abnormal Combustion in a Spark-Ignition Engine

<div class="section abstract"><div class="htmlview paragraph">One issue of downsized and supercharged engines is low-speed pre-ignition (LSPI) that occurs in the low-speed and high-load operating region. One proposed cause of LSPI is the influence of the engine oil and its additives. However, the effect of engine oil additives on pre-ignition and the mechanism involved are still not fully understood. This study investigated the influence of engine oil additives on abnormal combustion in a spark-ignition engine. A four-stroke air-cooled single-cylinder engine with a side valve arrangement was used in conducting combustion experiments. The research methods used were in-cylinder pressure analysis, in-cylinder visualization and absorption spectroscopic analysis. Engine oil additives were mixed individually at a fixed concentration into a primary reference fuel with an octane number of 50 and their effect on knocking was investigated.</div></div>