Artificial Aging Experiments of Neat and Contaminated Engine Oil Samples

Nagy, Á.; Rohde-Brandenburger, Jan; Zsoldos, Ibolya

doi:10.3390/lubricants9060063

Cited by 12 publications

(10 citation statements)

References 22 publications

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“…The aging of lubricants in combustion engines was frequently analyzed and a multitude of publications was released to the public. 28,29,30,31,32,33,34,8,35,36,37,38,39,40,41 The combustion engine oils are additionally burdened with the combustion process, so they cannot be compared with the transmission oils.…”

Section: Introductionmentioning

confidence: 99%

Test method for determining the scuffing capacity of oils with reduced oil volume

Gerges,

Heipl,

Pfeifer

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part J:

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Previous studies by several researchers have shown that the aging of the transmission fluid in dual clutch transmissions has a major impact on the wear protection of the highly loaded tribological contacts. Depending on the transmission design, oil sump temperature, transmitted torque, rotational speed and oil volume, the scuffing ability decreases significantly. Since typically only limited quantities of oil from gearbox tests are available to evaluate oil condition with respect to wear protection properties, available analytical standards are currently limited to methods such as viscometry, TAN, elemental analysis, and IR. A test method is presented that can be used to determine the gear scuffing load capacity of transmission fluids with a reduced oil volume. For this purpose, a standard test rig is modified to reduce the test oil volume from 1.25 liters, as specified in the public standards, to 0.5 liters. The applicability of the reduced test oil volume is demonstrated and the remaining scuffing wear protection of several used oil samples from durability testing is presented. A comparison of the tribological results with the chemical oil analysis results shows the advantage of direct testing of the oil's service properties.

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Section: Introductionmentioning

confidence: 99%

Test method for determining the scuffing capacity of oils with reduced oil volume

Gerges,

Heipl,

Pfeifer

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part J:

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show abstract

“…This ushered in a surge of research work concerned with reducing (or optimizing) the use of ZDDPs or replacing them altogether with different oil additives [14]. Of late, the oncoming turn to electric or hybrid drive systems, as well as alternative fuel concepts, has become a further incentive to improve the understanding of ZDDP-based wear protection, in order to be able to adapt its use appropriately or develop appropriate replacements [7,15].…”

Section: Introductionmentioning

confidence: 99%

“…Nagy et al [15] compared an artificial ageing procedure with aged samples of a commercial engine oil collected from vehicles. Based on conventional oil analysis, they determined the validity of the artificial ageing procedure.…”

Section: Introductionmentioning

confidence: 99%

Influence of Artificially Altered Engine Oil on Tribofilm Formation and Wear Behaviour of Grey Cast Cylinder Liners

Jech,

Hofer,

Tomastik

et al. 2023

Lubricants

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This work investigates the influence of altered engine oil on the tribological performance, focusing in particular on wear and interconnected tribofilm formation. For this purpose, Zinc dialkyldithiophosphate (ZDDP) additivated engine oils of different degradation levels, produced in an artificial oil alteration process, were used in tribometer tests with a nitride steel piston ring against a grey cast iron cylinder liner model contact. Parameters were chosen to simulate the boundary and mixed lubrication regime typical for the top dead centre conditions of an internal combustion engine of a passenger car. Wear of the cylinder liner specimens was continuously monitored during the tribometer tests by the radio-isotope concentration (RIC) method, and tribofilms were posteriorly investigated by X-ray photoelectron spectroscopy (XPS). The results clearly show that the steady-state wear rates for experiments with altered lubricants were significantly lower than for the experiments with fresh lubricants. XPS analysis on the formed tribofilms revealed a decrease in sulphide and an increase in sulphate states for altered oils evaluated at 120 °C oil temperature, correlating with a decrease in steady-state wear rate. This finding emphasizes the role of sulphate species in the tribofilm formation process and its anti-wear capabilities, in contrast to the sulphide species and the (poly-)phosphate species, as outlined in most of the ZDDP literature. Moreover, the RIC signal that represents the amount of wear in the engine oil showed a decrease over time for specific altered lubricants and test conditions. These “negative” trends in the wear signal are remarkable and have been identified as an incorporation of wear particles from the lubricant into the tribofilm. This finding is supported by XPS results that detected an iron-oxide layer with a remarkably similar quantity within the tribofilm on the surface. Based on these findings, an assessment of the minimum film formation rate and particle incorporation rate was achieved, which is an important basis for adequate tribofilm formation and wear models.

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“…These artificially aging methods and equipment simulate the lubricant's high-temperature load and fuel dilution, which influences the tribological properties of the engine oil under real operating conditions. Nagy et al [6] have designed a unique oil aging machine, and methodology and their artificially aged lubricant samples correlate with the aging properties of the engine oils taken from real vehicles according to the chemical and tribological measurements of the samples.…”

Section: Introductionmentioning

confidence: 99%

Detection of the possible engine damages in case of a continuous track military vehicles with tribological investigations

Kuti¹,

Könczöl²,

Csapó³

et al. 2022

FME Transactions

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Detecting the engine failures of the continuous track military vehicles is challenging because their engines are always built-in narrow places covered with armored plates. In the case of the older engines, modern computer diagnostics cannot be used for failure analysis; the solution for these tasks is the visual analysis with the engine disassembly. A possible cost-effective failure analysis method can be the tribological and chemical analysis of the used oil from the engine, which can eliminate the engine disassembly work and as the results of the chemical oil analysis can also provide information about possible fuel or cooling water dilution or the increased wear of engine components. The main goal of this article is to present the failure analysis method through the tribological investigation of the engines of two PTSZ-M type medium-tracked amphibious military transport vehicles.

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Artificial Aging Experiments of Neat and Contaminated Engine Oil Samples

Cited by 12 publications

References 22 publications

Test method for determining the scuffing capacity of oils with reduced oil volume

Test method for determining the scuffing capacity of oils with reduced oil volume

Influence of Artificially Altered Engine Oil on Tribofilm Formation and Wear Behaviour of Grey Cast Cylinder Liners

Detection of the possible engine damages in case of a continuous track military vehicles with tribological investigations

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