Base Oil and Additive Effects in the Thermo-oxidation Engine Oil Simulation Test (TEOST)

1996 ◽  
Author(s):  
A J. Stipanovic ◽  
J. P Schoonmaker ◽  
E. F de Paz ◽  
J K Mowlem ◽  
J E Broas ◽  
...  
Keyword(s):  
Engine Oil ◽  
Additive Effects ◽  
Simulation Test ◽  
Base Oil

Study Tribological Properties of MoDTC and Its Interactions With Metal Detergents

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Dongya Zhang ◽  
Zhongwei Li ◽  
Xian Wei ◽  
Liping Wang ◽  
Jinbao Xu ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Elevated Temperatures ◽  
Engine Oil ◽  
Base Number ◽  
Simulation Test ◽  
Detergency Performance ◽  
Wear Performance ◽  
Base Oil ◽  
Tube Test ◽  
Significant Attention

Abstract Recently, the synergistic tribological properties between molybdenum dialkyldithiocarbamate (MoDTC) and metal detergents have been the focus of significant attention due to the high requirements of engine oil. In this study, an SRV tribometer and four-ball machine were used to study the tribological performance of MoDTC combined with three types of metal detergents with different base numbers. Meanwhile, the detergency of the three metal detergents was also investigated using the hot tube test and crankcase simulation test. The results showed that (i) a high-based detergent possessed an excellent detergency performance compared with that of low-based detergents. (ii) The tribological properties of the base oil with a content of 0.75% MoDTC were superior to those of other contents at elevated temperatures. (iii) The metal detergents with a higher base number showed the best thermal stability, detergency performance, and anti-wear performance among the three types of metal detergents. The anti-wear mechanism was that the synergistic action of active elements in MoDTC and metal detergents promoted the generation of a tribological film.

Experimental Study on the Tribological Characteristics of Nanometer WS2 Lubricating Oil Additive Based on Engine Oil

2011 ◽  
Vol 328-330 ◽  
pp. 203-208 ◽  
Author(s):  
Cheng Bin Chen ◽  
Da Heng Mao ◽  
Chen Shi ◽  
Yang Liu
Keyword(s):  
Raw Materials ◽  
Viscosity Index ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Contrast Study ◽  
Base Oil ◽  
Grinding Conditions ◽  
Lubricating Oil Additive ◽  
Great Wall ◽  
Better Than

Nano-WS2(tungsten disulfide nanoparticles)lubricating oil additive, prepared by the nanometer WS2particulates and semi-synthetic engine base oil as raw materials, was added into Great Wall engine oil with different mass ratio. With a contrast study on these oil samples, the results show that it can improve the extreme pressure, antiwear and viscosity-temperature properties of the engine oil effectively by adding a certain amount of nano-WS2additive, and the optimal concentration is 2wt%. The oil film strength, sintering load and viscosity index of this lubricating oil is respectively 1.35 times, 1.58 times and 1.05 times as that of Great Wall engine oil. In addition, when tested under the grinding conditions of 392 N, 1450 r /min and 30 min, the diameter of worn spot reduces 0.018mm, and the average friction coefficients of friction pairs decrease 16.3%, both of which are lubricated by the oil containing nano-WS2additive. Meanwhile, the experiments testify that the tribological and viscosity-temperature properties of the nano-WS2additive are better than that of the Henkel MoS2additive.

Kinetic Study of the Thermo-Oxidative Degradation of Squalane (C30H62) Modelling the Base Oil of Engine Lubricants

2009 ◽  
Author(s):  
Moussa Diaby ◽  
Michel Sablier ◽  
Anthony Le Negrate ◽  
Mehdi El Fassi
Keyword(s):  
Oxidative Degradation ◽  
Engine Oil ◽  
Ongoing Research ◽  
Base Oil ◽  
Rate Law ◽  
Tert Butyl ◽  
Oxidation Rates ◽  
Base Oils ◽  
Wide Range ◽  
Thermo Oxidative Degradation

On the basis of ongoing research conducted on the clarification of processes responsible for lubricant degradation in the environment of piston grooves in EGR diesel engines, an experimental investigation was aimed to develop a kinetic model which can be used for the prediction of lubricant oxidative degradation correlated to endurance test conducted on engines. Knowing that base oils are a complex blend of paraffins and naphtenes with a wide range of sizes and structures, their chemistry analysis during the oxidation process can be highly convoluted. In the present work, investigations were carried out with the squalane (C30H62) chosen for its physical and chemical similarities with the lubricant base oils used during the investigations. Thermo-oxidative degradation of this hydrocarbon was conducted at atmospheric pressure in a tubular furnace, while varying temperature and duration of the tests in order to establish an oxidation reaction rate law. The same experimental procedures was applied to squalane doped with two different phenolic antioxidants usually present in engine oil composition: 2,6-di-tert-butyl-4-methylphenol (BHT), and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (OBHP). Thus, the effect of both antioxidants on the oxidation rate law was investigated. Data analysis of the oxidized samples (FTIR spectroscopy, gas chromatography/mass spectrometry GC/MS) allowed to rationalize the thermo-oxidative degradation of squalane. The resulting kinetic modelling provides a practical analytical tool to follow the thermal degradation processes, which can be used for prediction of base oil hydrocarbon ageing. If experiments confirmed the role of phenolic additives as an affective agent to lower oxidation rates, the main results lay in the observation of a threshold temperature where a reversed activity of these additives was observed.

Effects of phosphorus-free antioxidants on oxidation stability and high-temperature tribological properties of lubricants

2017 ◽  
Vol 231 (12) ◽  
pp. 1527-1536 ◽  
Author(s):  
Wang Liping ◽  
Zhang Dongya ◽  
Wu Hongxing ◽  
Xie Youbai ◽  
Dong Guangneng
Keyword(s):  
Tribological Properties ◽  
Ternary Complex ◽  
Oxidation Stability ◽  
Service Performance ◽  
Engine Oil ◽  
Zinc Dialkyldithiophosphate ◽  
Scanning Calorimetry ◽  
Base Oil ◽  
Hindered Phenol ◽  
Standard Tests

Oxidation stability plays an important role on the engine oil service performance. In this paper, the phosphorus-free antioxidants of diphenylamine, hindered phenol and dibutyldithiocarbamate, combined with zinc dialkyldithiophosphate were added as antioxidants in the base oil and the fully formulated 5W-30 oil, and the oxidation stabilities were evaluated by pressurized differential scanning calorimetry and Romaszewski oil bench oxidation standard tests. Meanwhile, the tribological properties of the fresh and aged oils were evaluated by a SRV tribo-meter. The results indicated that (i) an optimal ternary complex antioxidant of dibutyldithiocarbamate: diphenylamine: hindered phenol (ratio of 2:1:2) displayed good antioxidation property, and (ii) the fully formulated 5W-30 oil containing optimized ratio phosphorus-free antioxidants had better tribological properties than the commercial SN 5W-30 oil.

A Boundary Lubrication Friction Model Sensitive to Detailed Engine Oil Formulation in an Automotive Cam/Follower Interface

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Rupesh Roshan ◽  
Martin Priest ◽  
Anne Neville ◽  
Ardian Morina ◽  
Xin Xia ◽  
...  
Keyword(s):  
Boundary Lubrication ◽  
Fuel Efficiency ◽  
Lubricant Additive ◽  
Friction Model ◽  
Operating Conditions ◽  
Valve Train ◽  
Engine Oil ◽  
Contact Friction ◽  
Boundary Lubrication Friction ◽  
Base Oil

Theoretical studies have shown that in severe operating conditions, valve train friction losses are significant and have an adverse effect on fuel efficiency. However, recent studies have shown that existing valve train friction models do not reliably predict friction in boundary and mixed lubrication conditions and are not sensitive to lubricant chemistry. In these conditions, the friction losses depend on the tribological performance of tribofilms formed as a result of surface–lubricant additive interactions. In this study, key tribological parameters were extracted from a direct acting tappet type Ford Zetec SE (Sigma) valve train, and controlled experiments were performed in a block-on-ring tribometer under conditions representative of boundary lubrication in a cam and follower contact. Friction was recorded for the tribofilms formed by molybdenum dithiocarbamate (MoDTC), zinc dialkyldithiophosphate (ZDDP), detergent (calcium sulfonate), and dispersant (polyisobutylene succinimide) additives in an ester-containing synthetic polyalphaolefin (PAO) base oil on AISI E52100 steel components. A multiple linear regression technique was used to obtain a friction model in boundary lubrication from the friction data taken from the block-on-ring tribometer tests. The model was developed empirically as a function of the ZDDP, MoDTC, detergent, and dispersant concentration in the oil and the temperature and sliding speed. The resulting friction model is sensitive to lubricant chemistry in boundary lubrication. The tribofilm friction model showed sensitivity to the ZDDP–MoDTC, MoDTC–dispersant, MoDTC–speed, ZDDP–temperature, detergent–temperature, and detergent–speed interactions. Friction decreases with an increase in the temperature for all ZDDP/MoDTC ratios, and oils containing detergent and dispersant showed high friction due to antagonistic interactions between MoDTC–detergent and MoDTC–dispersant additive combinations.

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