Árpád Tóth

57219185178

Publications - 16

Tribological Investigation of the Surface Protective Layer-Forming Effect of a Nano-Sized Yttria–Silica Mixture as a Lubricating Oil Additive

Publication Name: Lubricants

Publication Date: 2025-01-01

Volume: 13

Issue: 1

Page Range: Unknown

Description:

Nanoparticles exhibit diverse effects when added as additives to oily medium, enhancing tribological properties and surface characteristics. Studies have shown that many oxide ceramic nanoparticles improve friction and wear, while mixtures also demonstrate favorable tribological properties. This study explores the tribological effect of an yttria–silica (Y2O3, SiO2) nanoparticle mixture in a Group III base oil medium. The results reveal that the yttria–silica mixture significantly reduces friction (−8–17%), mean wear scar diameter (−32%), and wear volume (−94%), while increasing load-bearing capacity (+114%) by creating a durable boundary layer. Observations from scanning electron microscopy revealed the original surface is protected. EDX analyses highlight the boundary layer’s elemental composition, which is high in yttrium, silicon, and oxygen and found in higher areas. XRD analysis could not detect the yttria nanoparticle additive within the boundary layer, suggesting that it fragmented due to sliding stress, resulting in an amorphous structure for the new boundary layer. TEM imaging confirmed that the boundary layer thickness is 40–45 nm. These findings demonstrate significant potential for industrial applications in developing advanced, high-performance lubricants for demanding mechanical systems.

Open Access: Yes

DOI: 10.3390/lubricants13010028

Tribological Investigation of the Effects of Engine Oil Additives for Vintage Gasoline Engines

Publication Name: Fme Transactions

Publication Date: 2025-01-01

Volume: 53

Issue: 1

Page Range: 31-37

Description:

Restoration of vintage vehicles is becoming more and more popular nowadays. Conditions of usage and operation changed throughout recent years, factory recommended lubricants and fuels are no longer available. The usage of improper lubricants can lead to severe engine damages. The aim of our research is to conduct the analytical and tribological investigation of the lubricant used in a Triumph SC 1300 type four-stroke gasoline engine assembled with two carburetors. Our further task is to conduct analytical and tribological investigation of engine oil that we infused with MoS2 to compare it with the oil in accordance with factory parameters after defined test operation. After the analysis and evaluation of results we serve with recommendations in connection with the given engine to operate it with the most appropriate engine oil regarding operation conditions.

Open Access: Yes

DOI: 10.5937/FME2501031K

Investigation of Lubrication Capability of Zinc Oxide-Reinforced Nanolubricants in Automotive Applications †

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

This article aims to introduce the tribological investigation of nanoscale zinc oxide particles as friction and wear reduction additives in the automotive industry and to present the results of the measurements. The surface-activated nanoparticles were homogenized into a neat Group-III-type base oil at five different concentrations, and their tribological properties were tested using a simplified ball-on-disc tribosystem. The arising wear scar images were investigated, and the occurred wear volume values were also calculated using a confocal microscope. The evaluation presented excellent friction and wear reduction properties, especially at higher concentrations (0.4 and 0.5 wt%). The authors would like to highlight the tribological decreasing potentials provided by such nanoparticles. Nanoparticle-reinforced lubricants can be one of the future solutions to developing operating machines with an achievable maximum energy efficiency.

Open Access: Yes

DOI: 10.3390/engproc2024079087

Selection of Engine Oils with Tribological Examinations Applicable to Specially Operated Diesel Engines

Publication Name: Fme Transactions

Publication Date: 2024-01-01

Volume: 52

Issue: 2

Page Range: 335-342

Description:

In recent times, many specially engineered diesel engines built in the 1980s are still used in different areas, for which the suggested engine oils are no longer available. These engines are operated reliably in military combat vehicles, electricity generators, and tracked machinery, thus it is essential to examine what engine oils are suitable for their operating conditions and may be used as their engine oil. The aim of our research is to conduct the tribological examination of an oil sample taken from a V-6M type naturally aspirated Diesel engine and the oil prescribed by the manufacturer. After evaluating the results, we determine which type of oil is applicable in the engine to achieve safe operation and a long lifetime.

Open Access: Yes

DOI: 10.5937/fme2402335K

Experimental Wear Analysis of Nano-Sized Titania Particles as Additives in Automotive Lubricants

Publication Name: Micro

Publication Date: 2023-09-01

Volume: 3

Issue: 3

Page Range: 715-727

Description:

This study focuses on the wear effects of nano-sized titania as a potential engine lubricant additive. Titanium dioxide nanoparticles have promising wear-reducing properties and significant tribological potential. In this article, titania nanoparticles were homogenized in Group III automotive oil at five different concentrations (0.1; 0.2 … 0.5 wt%). The nanodoped oil samples were tested on a linear oscillating tribometer with oil circulation. Based on the tribological results, titania nanoparticles increased friction by 20–32% but can reduce the wear area by up to 32%. According to the confocal microscopic examination, wear volume can be reduced by up to 57% with titania nanoparticles. Titania nanoparticles improved the repeatability of tribological measurements. A scanning electron microscopy examination of the wear track revealed that the characteristic wear of the tribological system was abrasive, but a significant amount of adhesive wear was also observed. Energy dispersive X-ray spectroscopy analysis found that the nanoparticles fill the deeper trenches of the wear. The worn surface uniformly contains TiO2 particles and the quantified normalized titanium concentration was between 0.56 and 0.62%.

Open Access: Yes

DOI: 10.3390/micro3030050

Tribological Investigation of the Effect of Nanosized Transition Metal Oxides on a Base Oil Containing Overbased Calcium Sulfonate

Publication Name: Lubricants

Publication Date: 2023-08-01

Volume: 11

Issue: 8

Page Range: Unknown

Description:

In this study, copper(II) oxide, titanium dioxide and yttrium(III) oxide nanoparticles were added to Group III-type base oil formulated with overbased calcium sulfonate. The nanosized oxides were treated with ethyl oleate surface modification. The tribological properties of the homogenized oil samples were tested on a linear oscillating tribometer. Friction was continuously monitored during the tribological tests. A surface analysis was performed on the worn samples: the amount of wear was determined using a digital optical and confocal microscope. The type of wear was examined with a scanning electron microscope, while the additives adhered to the surface were examined with energy-dispersive X-ray spectroscopy. From the results of the measurements, it can be concluded that the surface-modified nanoparticles worked well with the overbased calcium sulfonate and significantly reduced both wear and friction. In the present tribology system, the optimal concentration of all three oxide ceramic nanoadditives is 0.4 wt%. By using oxide nanoparticles, friction can be reduced by up to 15% and the wear volume by up to 77%. Overbased calcium sulfonate and oxide ceramic nanoparticles together form a lower friction anti-wear boundary layer on the worn surfaces. The results of the tests represent another step toward the applicability of these nanoparticles in commercial engine lubricants. It is advisable to further investigate the possibility of formulating nanoparticles into the oil.

Open Access: Yes

DOI: 10.3390/lubricants11080337

Surface Modification of Silica Nanoparticles with Ethyl Oleate for the Purpose of Stabilizing Nanolubricants Used for Tribological Tests

Publication Name: Ceramics

Publication Date: 2023-06-01

Volume: 6

Issue: 2

Page Range: 980-993

Description:

Long-term sustainability and decreasing amount of fossil oil reserves require a partial or complete transformation of traditional lubricating oils. The use of silica nanoparticles as a lubricant additive has a huge tribological potential, which has already been discussed in numerous articles. Nanosized silica shows excellent results in reducing friction and preventing wear, but they quickly aggregate and settle after homogenization in oils. For long-term stable dispersion of lubricating oils containing nanoceramics, the surface of the particles was modified with ethyl oleate. The surface modification, the ethyl oleate applied to the surface of the nanosilica, was confirmed by Fourier-transform infrared spectroscopy. Group III based lubricating oil was prepared using the surface-modified nanosilica. The particle size of the nanoparticles in the lubricating oil dispersion was examined by dynamic light scattering. Oscillating tribometer measurements were performed with different concentrations (0.1; 0.2; 0.3 wt%) of nanolubricants. Based on the tribological results, the friction coefficient of the surface-modified nanosilica is more stable, its wear is 15% lower compared to the reference. There is no significant change in the magnitude of the friction coefficient. It can be concluded that the ethyl oleate surface modification method may be suitable for tribological investigations of the acting mechanisms of nanoparticles.

Open Access: Yes

DOI: 10.3390/ceramics6020058

Experimental Investigation of Tribological Properties of Two Fully Formulated Engine Oils with Additional Nanoscale Spherical Zirconia Particles

Publication Name: Lubricants

Publication Date: 2022-10-01

Volume: 10

Issue: 10

Page Range: Unknown

Description:

Decreasing harmful emissions of vehicle engines is becoming more and more challenging due to stricter standards. A possible solution is to improve the tribological attributes of lubricants, which can be achieved through the application of appropriate additives. According to preliminary studies conducted by the authors, ZrO2 (zirconium-dioxide) nano-sized ceramic particles as lubricant additives have overwhelmingly positive tribological attributes in the presence of non-metallic superficial materials. Additive concentration, as well as cross-effects with other additives were investigated in order to determine a formulation resulting in optimal tribological attributes. In this paper, the experimental investigation of ZrO2 nano-ceramic powder as a lubricant additive is presented. The tribological performance of individually samples were experimentally investigated on a ball-on-disc translational tribometer. The experiments revealed an optimal additive content of 0.3 wt%. Increasing the quantity of additives further ruined friction and wear properties of the examined tribological system.

Open Access: Yes

DOI: 10.3390/lubricants10100246

Investigation of the Applicability of Y2O3–ZrO2 Spherical Nanoparticles as Tribological Lubricant Additives

Publication Name: Lubricants

Publication Date: 2022-07-01

Volume: 10

Issue: 7

Page Range: Unknown

Description:

Long-term environmental goals will motivate the automotive industry, component suppliers, and lubricating oil developers to reduce the friction of their tribosystems to improve overall efficiency and wear for increased component lifetime. Nanoscale ceramic particles have been shown to form a protective layer on components’ surface that reduces wear rate with its high hardness and chemical resistance. One such ceramic is yttria (Y2O3), which has an excellent anti-wear effect, but due to its rarity it would be extremely expensive to produce engine lubricant made from it. Therefore, part of the yttria is replaced by zirconia (ZrO2) with similar physical properties. The study presents the result of the experimental tribological investigation of nanosized yttria–zirconia ceramic mixture as an engine lubricant additive. Yttria-stabilized zirconia (YSZ) nanoparticle was used as the basis for the ratio of the ceramic mixture, so that the weight ratio of yttria–zirconia in the resulting mixture was determined to be 11:69. After the evaluation of the ball-on-disc tribological measurements, it can be stated that the optimal concentration was 0.4 wt%, which reduced the wear diameter by 30% and the wear volume by 90% at the same coefficient of friction. High-resolution SEM analysis showed a significant amount of zirconia on the surface, but no yttria was found.

Open Access: Yes

DOI: 10.3390/lubricants10070152

Tribological Properties of the Nanoscale Spherical Y2O3 Particles as Lubricant Additives in Automotive Application

Publication Name: Lubricants

Publication Date: 2022-02-01

Volume: 10

Issue: 2

Page Range: Unknown

Description:

The continuous tribological development of engine lubricants is becoming more and more vital due to its fuel efficiency improvement and lifetime increasing potential. The antiwear additives play a high role in the lubricants to protect the contacting surfaces even in the presence of thinner oil film. Nanoscale spherical particles in the lubricant may increase the necessary protecting effect. This paper presents the results of the experimental tribological investigation of nanoscale spherical Y2O3 (yttria) ceramic particles as an engine lubricant additive. The ball-on-disc tribological measurements have revealed an optimum concentration at 0.5 wt% with about 45% wear scar diameter and 90% wear volume decrease, compared to the reference, neat Group III base oil. The high-magnitude SEM analysis revealed the working mechanisms of yttria: the particles collected in the roughness valleys resulted in a smoother contacting surface, they were tribo-sintered and they have also caused slight plastic deformation of the outer layer of the metallic surface.

Open Access: Yes

DOI: 10.3390/lubricants10020028

Applicability of nanoscale ceramic particles as tribological lubricant additives

Publication Name: 2022 IEEE 1st International Conference on Cognitive Mobility Cogmob 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 31-36

Description:

Lubricants play a critical role in the energy losses of an engine. Several engineering solutions are existing to reduce the frictional and wear losses caused by the lubricant such as ultra-low-viscosity lubricants. With the spread of low-viscosity engine oils like 0W-20 and below, the importance of tribological lubricant additives is increasing. To ensure the necessary protection of the rubbing surfaces against friction and wear, new lubricant additive materials should be researched and investigated. Next to the tribological performance of the additives, their impact on the price is a strong influencing factor. No financial information of the investigated additive materials is available in the current scientific articles and so no rentable decision can be defined which additive worth to invest as an engine oil additive in the future mass production engine oils. This article presents the tribological potential of selected nanoscale ceramic particles (zirconia, cupric oxide and yttria) as lubricant additives and compares them according to their financial impact. According to the results it can be stated that not always the additive with the best tribological properties will be the one be used in mass production manufactured lubricants.

Open Access: Yes

DOI: 10.1109/CogMob55547.2022.10117843

Detection of the Possible Engine Damages in Case of a Continuous Track Military Vehicles with Tribological Investigations

Publication Name: Fme Transactions

Publication Date: 2022-01-01

Volume: 50

Issue: 3

Page Range: 526-534

Description:

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.

Open Access: Yes

DOI: 10.5937/fme2203526K

Tribological Investigation of Applicability of Nano-Sized Cupricoxide (CuO) Ceramic Material in Automotive Vehicles

Publication Name: Fme Transactions

Publication Date: 2021-01-01

Volume: 49

Issue: 2

Page Range: 335-343

Description:

Due to the continuously increasing requirements of the internal combustion engines, the lubricants and their additives have to be further developed. One possible solution is the application of ceramic nanoparticles as friction modifier and wear decreaser additives. This paper presents the tribological investigation of cupricoxide (CuO) nanoparticle mixed in neat Group 3 base oil. To analyse its properties, simplified ball-on-disc friction experiments were carried out in the tribological laboratory in the Széchenyi István University in Győr, Hungary. The arisen wear scars were analysed with different, highresolution microscopes to understand the working mechanism of the nanoparticles. The results have indicated an optimum concentration of nanoparticles at 0.5wt% where both the average friction coefficient and the wear scar diameter were reduced by 15%. The microscopical investigation revealed the reduction of copper material from the CuO material, and it has mended to the rubbing surface forming a protective film on the metal surface.

Open Access: Yes

DOI: 10.5937/fme2102335T

Tribological Properties of Nano-Sized ZrO2 Ceramic Particles in Automotive Lubricants

Publication Name: Fme Transactions

Publication Date: 2021-01-01

Volume: 49

Issue: 1

Page Range: 36-43

Description:

The demand for decreasing CO2-emission and harmful material content of the exhaust gas of passenger cars requires the improvement of the entire powertrain including the applied lubricants. One of the possible future engines lubricant can be the nano-sized ceramic particles, which can provide positive tribological properties also in the presence of nonmetallic surface materials. This paper presents the experimental investigation of ZrO2 nanoceramic powder as a lubricant additive. The tribological performance of the lubricant samples was experimentally investigated on a ball-on-disc translation tribometer. An optimum concentration was found at 0.4 wt%, where the wear scar diameter on the ball specimen was reduced by more than 40% compared to the reference sample. The SEM-analysis confirmed the mending mechanism theory: nanoparticles were revealed to aggregate between the asperities resulting in a significantly smoother contact surface.

Open Access: Yes

DOI: 10.5937/FME2101036T

Investigation of the tribological properties of nano-scaled ZrO2 and CuO additive in automotive lubricants

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

To improve the fuel efficiency and the lifetime of the internal combustion engines, the lubricants and their additives have to be developed further. One of the possible future engines lubricants can be the nano-sized ceramic particles, which can provide positive tribological properties also in the presence of non-metallic surface materials. This paper presents the results of investigations with the help of ZrO2 and CuO nano-sized ceramic particles. To define the tribological properties of these additives, lubricant samples with different additive-concentrations were prepared and tribologically analysed. The frictional losses of these lubricant samples were analysed by a ball-on-disk sliding friction machine. The worn surface on the test specimens was analysed by different high-resolution microscopes. To define the functional mechanisms of the nano-additives, the worn surfaces were investigated by high resolution scanning electron microscopes. The ZrO2 additive has experimentally shown an excellent wear reduction property (over 40% wear reduction compared with the neat Group 3 base oil) at the optimum mixing concentration of 0.4wt%. Both frictional and wear reduction properties could be determined at the application of CuO additive (15-15% friction coefficient and wear scar diameter reduction) at its optimum concentration (0.5wt%). A copper-yellow layer can be seen on the worn surface of the disc specimens with CuO, which indicates the mechanism of chemical transformation to elementary copper from the cupric-oxide nanoparticle and this elementary copper can be melted on the surface, because of the applied high temperature and high loads during the experiments.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012015

Fuzzy Flip-Flop based Neural Networks as a novel implementation possibility of multilayer perceptrons

Publication Name: 2012 IEEE I2mtc International Instrumentation and Measurement Technology Conference Proceedings

Publication Date: 2012-07-30

Volume: Unknown

Issue: Unknown

Page Range: 280-285

Description:

Fuzzy Flip-Flop based Neural Networks (FNN) constructed from fuzzy D flip-flops are studied as a novel technique to implement multilayer perceptrons. The starting point of this approach is the concept of fuzzy flip-flop (F 3), as the extension of the binary counterpart. Fuzzy D flip-flop based neurons are viewed, as sigmoid function generators. Their characteristic equations contain simple fuzzy operations, thus enabling easy implementability. FNNs have an interconnected fuzzy neuron structure composed from a large number of neurons acting in parallel which are capable of learning, and are suitable for function approximation. In this paper we propose the FPGA implementation of ukasiewicz operations, furthermore of fuzzy D flip-flop neurons based on Łukasiewicz norms. © 2012 IEEE.

Open Access: Yes

DOI: 10.1109/I2MTC.2012.6229326