Hakan Kaleli - Academia.edu (original) (raw)
Papers by Hakan Kaleli
This paper considers construction and advantage of modern tribometer conception. Universal Tribom... more This paper considers construction and advantage of modern tribometer conception. Universal Tribometer enables simulation of different contact and test types. Special device enables pin-on-disc (rotational), ball-on-disc and linear reciprocating test types. The main purpose of tribometer was investigation of friction and wear of different materials with or without lubricant according to appropriate standards. Tribometer concept and design solution of same subassemblies that provide defined requests fulfill were described in details. System design and construction with data measurement information are specially described. ROTASYON VE PİSTONLU (DOĞRUSAL) HAREKETİ YAPAN MODERN ÜNİVERSAL TRİBOMETRE TASARIMI ÖZET Bu makale modern Tribometre kavramının tasarım ve avantajını ele almaktadır. Üniversal Tribometre farklı temas ve test tiplerinin simulasyonunu sağlamaktadır. Özel cihaz Pim-Disk (Dönel hareket), Bilya-Disk (Dönel hareket) ve Pim-Plaka (doğrusal git-gel hareketi) olan test tipler...
In this study, the engine cooling system equipment of the rear engine buses produced by Otokar Au... more In this study, the engine cooling system equipment of the rear engine buses produced by Otokar Automotive and Defense Industry were investigated in terms of various radiator, intercooler and fan usage. Experiments were carried out on a specific designed cooling system with a Deutz TCD 2013 4V Euro 5 engine and a Zollner PS1 - 2211 hydraulic dynamometer. 22 data were read, including engine torque and engine speed. Two radiators made from Cu and Al, two intercoolers with different sizes and two fans with different blade numbers were tested. All tests were done with our own design test bench. Studies showed that aluminum radiator has a better engine cooling performance; the CAC (Charge Air Cooler) should be as small as possible, because smaller CAC causes better cooling in the radiator. Also using the 10 blade fan is better for engine cooling and power consumption but it has a higher noise level.
Tribology in Industry, 2021
This work aimed to study the microstructure, wear and corrosion resistance of supermartensitic st... more This work aimed to study the microstructure, wear and corrosion resistance of supermartensitic stainless steel (SMSS). Heat treatment applied to samples consists of quenching after austenitization at elevated temperature (1250 °C) followed by a double tempering at 650 °C. Conventional mechanical properties, scanning electron microscopy (SEM/EDS) analysis and X-ray diffraction methods (XRD) are used to analyze the microstructure and to evaluate the wear mechanisms. The potentiodynamic polarisation and the electrochemical impedance spectroscoopy (EIS) methods are used to evaluate the corrosion resistance in both the 0.5M H2SO4 and 0.5M NaCl aggressive media. The microstructure is mainly composed with tempered lath martensite, small quantity of retained austenite and carbides. Oxidative and abrasive wear dominated the wear process in dry condition. During the corrosion process, the same mechanism of degradation was found in both the 0.5M NaCl and 0.5M H2SO4.
Key Engineering Materials, 2019
Lubricants play a vital role in machine life and performance, reducing friction and wear and prev... more Lubricants play a vital role in machine life and performance, reducing friction and wear and preventing component failure. Performance-enhancing additives are a vital part of today’s modern lubricants. In response to this need, this experimental work presents the development of the new suspended nanoboric acid (nBA) additive added in engine oil that can drastically lowered friction and wear.This is a new invention of nBA additive hold in suspension and added into 5W-40 fully synthetic commercial lubricating oil. This invention is confidential and realized by Tribor ARGE Co. in Teknopark of YILDIZ Technical University in Istanbul-TURKEY.The particle size of nBA is determined with (Transmission Electron Microscopy) (TEM). Turbiscan Tower Stability Analyzer results proved that nBA particles were in suspension in commercial engine oil. Suspended nBA in engine oil is applied between ball and disk system in order to investigate their effect on friction and wear under lubricated conditions...
Key Engineering Materials, 2019
It is well known that nanoparticles affect the interaction between lubricants and surfaces with v... more It is well known that nanoparticles affect the interaction between lubricants and surfaces with various chemical compositions and different chemical and physical properties. In recent years, nanoparticles have started to play more important roles as lubricant additives for their potential in wear, friction and emission reduction and improving lubrication and fuel economy. Although nanolubricants are frequently used for friction tests, little is known about stability and degree of dispersion of these nanoparticles in viscous liquids. Most of them are unstable, agglomerate or aggregate which sediment over time. Boric acid (H3BO3) has always been a very important material due to its broad range of applications such as in medicine, cosmetics, automotive industry, metallurgy and also for miscellaneous purposes in other areas. Literature survey showed that friction between automobile engine parts could be greatly reduced using microscopic particles of boric acid.This study involves the ne...
The present paper contains a description of a new Universal Tribometer design which enables simul... more The present paper contains a description of a new Universal Tribometer design which enables simulation of different contact and test types such as pin-on-disc, ball-on-disc and linear reciprocating tests. There are many models of wear Tribometer in the world market. These devices are manufactured by various companies abroad and are imported to our country. Cost of this devices start from 50.000 euros and goes to hundreds of thousands of euros. One of the most commonly used of this device is Reciprocating Pin-on-Plate Tribo Test Machine. This wear tester is produced at a low limited cost within the KAP (Scientifical Research Project Coordinator) of Yıldız Technical University. The test machine can work including three types of Tribotest rigs (Reciprocating Pin-on-Plate, Pin-on-Disc and Ball-on-Disc). It is designed to operate also at high temperatures up to 500 ˚C. The new piece of equipment allows instrumented tribological testing of piston ring and cylinder liner samples at low and high temperatures and boundary lubrication conditions of any typical gasoline or Diesel engines. Some friction results were shown in boundary lubricating conditions between piston ring and cylinder liner sliding pairs describing Tribotest machine is driven by AC servo motor which is more accurate than DC motor.
This paper considers construction and advantage of modern tribometer conception. Universal Tribom... more This paper considers construction and advantage of modern tribometer conception. Universal Tribometer enables simulation of different contact and test types. Special device enables pin-on-disc (rotational), ball-ondisc and linear reciprocating test types. The main purpose of tribometer was investigation of friction and wear of different materials with or without lubricant according to appropriate standards. Tribometer concept and design solution of same subassemblies that provide defined requests fulfill were described in details. System design and construction with data measurement information are specially described.
Polymers, 2022
Over the past few decades, polyetheretherketone (PEEK) artificial bone joint materials faced prob... more Over the past few decades, polyetheretherketone (PEEK) artificial bone joint materials faced problems of poor wear resistance and easy infection, which are not suitable for the growing demand of bone joints. The tribological behavior and wear mechanism of polyetheretherketone (PEEK)/polytetrafluoroethylene (PTFE) with black phosphorus (BP) nanosheets have been investigated under dry sliding friction. Compared with pure PEEK, the COF of PEEK/10 wt% PTFE/0.5 wt% BP was reduced by about 73% (from 0.369 to 0.097) and the wear rate decreased by approximately 95% (from 1.0 × 10−4 mm3/(N m) to 5.1 × 10−6 mm3/(N m)) owing to the lubrication of the BP transfer film. Moreover, BP can endow the PEEK composites with excellent biological wettability and antibacterial properties. The antibacterial rate of PEEK/PTFE/BP was assessed to be over 99.9%, which might help to solve the problem of PEEK implant inflammation. After comprehensive evaluation in this research, 0.5 wt% BP nanosheet-filled PEEK/...
Tribology in Industry, 2016
The present paper contains a description of a new Universal Tribometer design which enables simul... more The present paper contains a description of a new Universal Tribometer design which enables simulation of different contact and test types such as pin-on-disc, ball-on-disc and linear reciprocating tests. There are many models of wear Tribometer in the world market. These devices are manufactured by various companies abroad and are imported to our country. Cost of this devices start from 50.000 euros and goes to hundreds of thousands of euros. One of the most commonly used of this device is Reciprocating Pin-on-Plate Tribo Test Machine. This wear tester is produced at a low limited cost within the KAP (Scientifical Research Project Coordinator) of Yıldız Technical University. The test machine can work including three types of Tribotest rigs (Reciprocating Pin-on-Plate, Pin-on-Disc and Ball-on-Disc). It is designed to operate also at high temperatures up to 500 ˚C. The new piece of equipment allows instrumented tribological testing of piston ring and cylinder liner samples at low and...
Nanomaterials
We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the ... more We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P we...
Industrial Lubrication and Tribology
Purpose The purpose of this paper is to present an approach to compute accurately the distributio... more Purpose The purpose of this paper is to present an approach to compute accurately the distributions of the frictional heat generated, contact pressure and thermal stresses at any instant during the sliding period (heating phase) of the single-disc friction clutch system works in the dry condition and the complex interaction among them. Design/methodology/approach Numerical work was achieved using the developed elastic and thermal finite element models (axisymmetric models) to simulate the engagement of the single-disc friction clutch system. Findings The change of distribution of contact pressure during the sliding period (heating phase) affects significantly the magnitude and distribution of the produced thermal stress. The high local heat generated appeared in the contacting surfaces because of the non-uniformity of the distribution of contact pressure during the heating phase (sliding time) and this will dramatically increase the thermal stresses. Originality/value Sequentially c...
Industrial Lubrication and Tribology
Purpose This study aims to investigate the tribological characteristics of a Napier-type second p... more Purpose This study aims to investigate the tribological characteristics of a Napier-type second piston ring against a cylinder liner in the presence of graphene nano-additives mixed into 5W40 fully synthetic engine oil. Design/methodology/approach Wear tests were carried out in the boundary lubrication condition using a reciprocating tribometer, and real engine tests were performed using a single spark ignition Honda GX 270 test engine for a duration of 75 h. Findings The experimental results of the tribometer tests revealed that the nano-additives formed a layer on the rubbed surfaces of both the piston ring and the cylinder liner. However, this layer was only formed at the top dead center of the cylinder liner during the engine tests. The accumulation of carbon (C) from the graphene was heavily detected on the rubbed surface of piston ring/cylinder liner, mixed with other additive elements such as Ca, Zn, S and P. Overall, the use of graphene nano-additives in engine oil was found...
Industrial Lubrication and Tribology
Purpose This study aims to find out friction and wear characteristics of graphene and graphene co... more Purpose This study aims to find out friction and wear characteristics of graphene and graphene coating deposited by the Chemical Vapor Deposition (CVD) process on Honda GX270 engine (nodular cast iron) piston rings experimentally investigated under boundary lubricated conditions. Design/methodology/approach This study consists of two stages: tribotest and engine tests. First test was conducted through a reciprocating tribotest machine and second test was conducted through an engine bench with a duration of 75h. Engine piston ring was coated with graphene by two different methods: transfer method and direct CVD method. Findings Graphene has been demonstrated to be a potential and promising candidate for wear- and scratch-resistant coating because it is the thinnest, lightest and strongest known nanomaterial. In this case, the ability of a mono-layer graphene film to withstand high pressure differences (6 atm) indicates its mechanical robustness. It can effectively prevent or reduce m...
International Journal on Interactive Design and Manufacturing (IJIDeM)
Industrial Lubrication and Tribology
Purpose Wear on internal combustion engines is a loss of material that occurs with the rubbing of... more Purpose Wear on internal combustion engines is a loss of material that occurs with the rubbing of the materials in contact with each other and significantly reduces the economic life of the engine. Even the smallest precaution that can be taken to prevent friction and wear in the engines can provide economical savings in very large quantities. Internal combustion engines are widely utilized in modem automobiles. Around 10 per cent of the total fuel energy is dissipated to heat due to mechanical friction, among which 20 per cent is caused by the contact between the cylinder liner and the piston rings. Design/methodology/approach In this study, real piston ring-cylinder specimens were tested with reciprocating tribometer by using five different nanoparticles added to engine oil to investigate their wear and friction behavior. Findings With regard to the experiments, it has been found that the best results were determined by TiO2 and single-walled carbon nanotubes according to boron ni...
Industrial Lubrication and Tribology, 2016
Purpose The purpose of this technical paper is to investigate the friction and wear behavior of i... more Purpose The purpose of this technical paper is to investigate the friction and wear behavior of inexpensive and durable cutting tools, developed for wood machining using duplex treatment. Design/methodology/approach Cr–(WC–Co) coatings were deposited onto carburized low-alloy steel substrate by a reactive magnetron sputtering. The total coating thickness was approximately 2 μm. Unlubricated wear tests have been performed using a disc sample sliding against an alumina ball (Al2O3) and a wood (beech) pin. Findings The paper provides information about the effect of duplex treatment on the surface properties of low-alloy steel against wood and offers practical help for the researchers in coating topic. Originality/value Experimental results showed that sliding wear properties of the selected coatings are strongly dependent on the counter-face material. When tested against alumina balls, the wear mechanisms are oxidative wear followed by a combination of adhesive and abrasive wear, while...
Tribology Series, 2002
Lubricant additives are chemicals which, when present in small amounts, improve the physical, che... more Lubricant additives are chemicals which, when present in small amounts, improve the physical, chemical or tribological properties of the lubricant. They form a tribochemical (antiwear) film on the rubbing surfaces which protect the engine from excessive wear.In this study fully formulated crankcase oil (SAE 20W50) is used to investigate the role of additives and determine the mechanical conditions of the
Industrial Lubrication and Tribology, Feb 28, 1997
The authors wish to thank Shell Oil Company for providing test facilities.
Biodiesel is an alternative fuel for Diesel engines made from new/used vegetable oils and animal ... more Biodiesel is an alternative fuel for Diesel engines made from new/used vegetable oils and animal fats. It is biodegradable and has lower hydrocarbon emission levels and similar performance characteristics compared to conventional Diesel fuel. After modifying its molecular structure through a transesterification process, biodiesel (rapeseed oil methyl ester-RME) can be used as an alternative fuel in compression ignition engines without any modification. Modern internal combustion engines must have longer oil drain periods to decrease operating costs and environmental pollution levels. Related studies indicate that biodiesel fuel has a potential for reducing engine wear. This experimental study investigates the effect of commercial Diesel fuel and RME on lubricating oil performance and the exhaust emissions. Performance, emissions and long-term wear tests were carried out and discussed on a single cylinder marine Diesel engine for both Diesel fuel and 100 % RME. Results indicated that the RME has a deteriorating effect on lubricating oil performance by decreasing oil viscosity degree and base number. Ferrous element is the main evidence of the engine wear and it was increased depending on lowering viscosity relating to the fuel dilution and rising running period. Although carbon monoxide and hydrocarbon pollutants in exhaust gas decreased with RME, nitric oxides raised significantly as well as performance results which remained similar except for specific fuel consumption.
This paper considers construction and advantage of modern tribometer conception. Universal Tribom... more This paper considers construction and advantage of modern tribometer conception. Universal Tribometer enables simulation of different contact and test types. Special device enables pin-on-disc (rotational), ball-on-disc and linear reciprocating test types. The main purpose of tribometer was investigation of friction and wear of different materials with or without lubricant according to appropriate standards. Tribometer concept and design solution of same subassemblies that provide defined requests fulfill were described in details. System design and construction with data measurement information are specially described. ROTASYON VE PİSTONLU (DOĞRUSAL) HAREKETİ YAPAN MODERN ÜNİVERSAL TRİBOMETRE TASARIMI ÖZET Bu makale modern Tribometre kavramının tasarım ve avantajını ele almaktadır. Üniversal Tribometre farklı temas ve test tiplerinin simulasyonunu sağlamaktadır. Özel cihaz Pim-Disk (Dönel hareket), Bilya-Disk (Dönel hareket) ve Pim-Plaka (doğrusal git-gel hareketi) olan test tipler...
In this study, the engine cooling system equipment of the rear engine buses produced by Otokar Au... more In this study, the engine cooling system equipment of the rear engine buses produced by Otokar Automotive and Defense Industry were investigated in terms of various radiator, intercooler and fan usage. Experiments were carried out on a specific designed cooling system with a Deutz TCD 2013 4V Euro 5 engine and a Zollner PS1 - 2211 hydraulic dynamometer. 22 data were read, including engine torque and engine speed. Two radiators made from Cu and Al, two intercoolers with different sizes and two fans with different blade numbers were tested. All tests were done with our own design test bench. Studies showed that aluminum radiator has a better engine cooling performance; the CAC (Charge Air Cooler) should be as small as possible, because smaller CAC causes better cooling in the radiator. Also using the 10 blade fan is better for engine cooling and power consumption but it has a higher noise level.
Tribology in Industry, 2021
This work aimed to study the microstructure, wear and corrosion resistance of supermartensitic st... more This work aimed to study the microstructure, wear and corrosion resistance of supermartensitic stainless steel (SMSS). Heat treatment applied to samples consists of quenching after austenitization at elevated temperature (1250 °C) followed by a double tempering at 650 °C. Conventional mechanical properties, scanning electron microscopy (SEM/EDS) analysis and X-ray diffraction methods (XRD) are used to analyze the microstructure and to evaluate the wear mechanisms. The potentiodynamic polarisation and the electrochemical impedance spectroscoopy (EIS) methods are used to evaluate the corrosion resistance in both the 0.5M H2SO4 and 0.5M NaCl aggressive media. The microstructure is mainly composed with tempered lath martensite, small quantity of retained austenite and carbides. Oxidative and abrasive wear dominated the wear process in dry condition. During the corrosion process, the same mechanism of degradation was found in both the 0.5M NaCl and 0.5M H2SO4.
Key Engineering Materials, 2019
Lubricants play a vital role in machine life and performance, reducing friction and wear and prev... more Lubricants play a vital role in machine life and performance, reducing friction and wear and preventing component failure. Performance-enhancing additives are a vital part of today’s modern lubricants. In response to this need, this experimental work presents the development of the new suspended nanoboric acid (nBA) additive added in engine oil that can drastically lowered friction and wear.This is a new invention of nBA additive hold in suspension and added into 5W-40 fully synthetic commercial lubricating oil. This invention is confidential and realized by Tribor ARGE Co. in Teknopark of YILDIZ Technical University in Istanbul-TURKEY.The particle size of nBA is determined with (Transmission Electron Microscopy) (TEM). Turbiscan Tower Stability Analyzer results proved that nBA particles were in suspension in commercial engine oil. Suspended nBA in engine oil is applied between ball and disk system in order to investigate their effect on friction and wear under lubricated conditions...
Key Engineering Materials, 2019
It is well known that nanoparticles affect the interaction between lubricants and surfaces with v... more It is well known that nanoparticles affect the interaction between lubricants and surfaces with various chemical compositions and different chemical and physical properties. In recent years, nanoparticles have started to play more important roles as lubricant additives for their potential in wear, friction and emission reduction and improving lubrication and fuel economy. Although nanolubricants are frequently used for friction tests, little is known about stability and degree of dispersion of these nanoparticles in viscous liquids. Most of them are unstable, agglomerate or aggregate which sediment over time. Boric acid (H3BO3) has always been a very important material due to its broad range of applications such as in medicine, cosmetics, automotive industry, metallurgy and also for miscellaneous purposes in other areas. Literature survey showed that friction between automobile engine parts could be greatly reduced using microscopic particles of boric acid.This study involves the ne...
The present paper contains a description of a new Universal Tribometer design which enables simul... more The present paper contains a description of a new Universal Tribometer design which enables simulation of different contact and test types such as pin-on-disc, ball-on-disc and linear reciprocating tests. There are many models of wear Tribometer in the world market. These devices are manufactured by various companies abroad and are imported to our country. Cost of this devices start from 50.000 euros and goes to hundreds of thousands of euros. One of the most commonly used of this device is Reciprocating Pin-on-Plate Tribo Test Machine. This wear tester is produced at a low limited cost within the KAP (Scientifical Research Project Coordinator) of Yıldız Technical University. The test machine can work including three types of Tribotest rigs (Reciprocating Pin-on-Plate, Pin-on-Disc and Ball-on-Disc). It is designed to operate also at high temperatures up to 500 ˚C. The new piece of equipment allows instrumented tribological testing of piston ring and cylinder liner samples at low and high temperatures and boundary lubrication conditions of any typical gasoline or Diesel engines. Some friction results were shown in boundary lubricating conditions between piston ring and cylinder liner sliding pairs describing Tribotest machine is driven by AC servo motor which is more accurate than DC motor.
This paper considers construction and advantage of modern tribometer conception. Universal Tribom... more This paper considers construction and advantage of modern tribometer conception. Universal Tribometer enables simulation of different contact and test types. Special device enables pin-on-disc (rotational), ball-ondisc and linear reciprocating test types. The main purpose of tribometer was investigation of friction and wear of different materials with or without lubricant according to appropriate standards. Tribometer concept and design solution of same subassemblies that provide defined requests fulfill were described in details. System design and construction with data measurement information are specially described.
Polymers, 2022
Over the past few decades, polyetheretherketone (PEEK) artificial bone joint materials faced prob... more Over the past few decades, polyetheretherketone (PEEK) artificial bone joint materials faced problems of poor wear resistance and easy infection, which are not suitable for the growing demand of bone joints. The tribological behavior and wear mechanism of polyetheretherketone (PEEK)/polytetrafluoroethylene (PTFE) with black phosphorus (BP) nanosheets have been investigated under dry sliding friction. Compared with pure PEEK, the COF of PEEK/10 wt% PTFE/0.5 wt% BP was reduced by about 73% (from 0.369 to 0.097) and the wear rate decreased by approximately 95% (from 1.0 × 10−4 mm3/(N m) to 5.1 × 10−6 mm3/(N m)) owing to the lubrication of the BP transfer film. Moreover, BP can endow the PEEK composites with excellent biological wettability and antibacterial properties. The antibacterial rate of PEEK/PTFE/BP was assessed to be over 99.9%, which might help to solve the problem of PEEK implant inflammation. After comprehensive evaluation in this research, 0.5 wt% BP nanosheet-filled PEEK/...
Tribology in Industry, 2016
The present paper contains a description of a new Universal Tribometer design which enables simul... more The present paper contains a description of a new Universal Tribometer design which enables simulation of different contact and test types such as pin-on-disc, ball-on-disc and linear reciprocating tests. There are many models of wear Tribometer in the world market. These devices are manufactured by various companies abroad and are imported to our country. Cost of this devices start from 50.000 euros and goes to hundreds of thousands of euros. One of the most commonly used of this device is Reciprocating Pin-on-Plate Tribo Test Machine. This wear tester is produced at a low limited cost within the KAP (Scientifical Research Project Coordinator) of Yıldız Technical University. The test machine can work including three types of Tribotest rigs (Reciprocating Pin-on-Plate, Pin-on-Disc and Ball-on-Disc). It is designed to operate also at high temperatures up to 500 ˚C. The new piece of equipment allows instrumented tribological testing of piston ring and cylinder liner samples at low and...
Nanomaterials
We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the ... more We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P we...
Industrial Lubrication and Tribology
Purpose The purpose of this paper is to present an approach to compute accurately the distributio... more Purpose The purpose of this paper is to present an approach to compute accurately the distributions of the frictional heat generated, contact pressure and thermal stresses at any instant during the sliding period (heating phase) of the single-disc friction clutch system works in the dry condition and the complex interaction among them. Design/methodology/approach Numerical work was achieved using the developed elastic and thermal finite element models (axisymmetric models) to simulate the engagement of the single-disc friction clutch system. Findings The change of distribution of contact pressure during the sliding period (heating phase) affects significantly the magnitude and distribution of the produced thermal stress. The high local heat generated appeared in the contacting surfaces because of the non-uniformity of the distribution of contact pressure during the heating phase (sliding time) and this will dramatically increase the thermal stresses. Originality/value Sequentially c...
Industrial Lubrication and Tribology
Purpose This study aims to investigate the tribological characteristics of a Napier-type second p... more Purpose This study aims to investigate the tribological characteristics of a Napier-type second piston ring against a cylinder liner in the presence of graphene nano-additives mixed into 5W40 fully synthetic engine oil. Design/methodology/approach Wear tests were carried out in the boundary lubrication condition using a reciprocating tribometer, and real engine tests were performed using a single spark ignition Honda GX 270 test engine for a duration of 75 h. Findings The experimental results of the tribometer tests revealed that the nano-additives formed a layer on the rubbed surfaces of both the piston ring and the cylinder liner. However, this layer was only formed at the top dead center of the cylinder liner during the engine tests. The accumulation of carbon (C) from the graphene was heavily detected on the rubbed surface of piston ring/cylinder liner, mixed with other additive elements such as Ca, Zn, S and P. Overall, the use of graphene nano-additives in engine oil was found...
Industrial Lubrication and Tribology
Purpose This study aims to find out friction and wear characteristics of graphene and graphene co... more Purpose This study aims to find out friction and wear characteristics of graphene and graphene coating deposited by the Chemical Vapor Deposition (CVD) process on Honda GX270 engine (nodular cast iron) piston rings experimentally investigated under boundary lubricated conditions. Design/methodology/approach This study consists of two stages: tribotest and engine tests. First test was conducted through a reciprocating tribotest machine and second test was conducted through an engine bench with a duration of 75h. Engine piston ring was coated with graphene by two different methods: transfer method and direct CVD method. Findings Graphene has been demonstrated to be a potential and promising candidate for wear- and scratch-resistant coating because it is the thinnest, lightest and strongest known nanomaterial. In this case, the ability of a mono-layer graphene film to withstand high pressure differences (6 atm) indicates its mechanical robustness. It can effectively prevent or reduce m...
International Journal on Interactive Design and Manufacturing (IJIDeM)
Industrial Lubrication and Tribology
Purpose Wear on internal combustion engines is a loss of material that occurs with the rubbing of... more Purpose Wear on internal combustion engines is a loss of material that occurs with the rubbing of the materials in contact with each other and significantly reduces the economic life of the engine. Even the smallest precaution that can be taken to prevent friction and wear in the engines can provide economical savings in very large quantities. Internal combustion engines are widely utilized in modem automobiles. Around 10 per cent of the total fuel energy is dissipated to heat due to mechanical friction, among which 20 per cent is caused by the contact between the cylinder liner and the piston rings. Design/methodology/approach In this study, real piston ring-cylinder specimens were tested with reciprocating tribometer by using five different nanoparticles added to engine oil to investigate their wear and friction behavior. Findings With regard to the experiments, it has been found that the best results were determined by TiO2 and single-walled carbon nanotubes according to boron ni...
Industrial Lubrication and Tribology, 2016
Purpose The purpose of this technical paper is to investigate the friction and wear behavior of i... more Purpose The purpose of this technical paper is to investigate the friction and wear behavior of inexpensive and durable cutting tools, developed for wood machining using duplex treatment. Design/methodology/approach Cr–(WC–Co) coatings were deposited onto carburized low-alloy steel substrate by a reactive magnetron sputtering. The total coating thickness was approximately 2 μm. Unlubricated wear tests have been performed using a disc sample sliding against an alumina ball (Al2O3) and a wood (beech) pin. Findings The paper provides information about the effect of duplex treatment on the surface properties of low-alloy steel against wood and offers practical help for the researchers in coating topic. Originality/value Experimental results showed that sliding wear properties of the selected coatings are strongly dependent on the counter-face material. When tested against alumina balls, the wear mechanisms are oxidative wear followed by a combination of adhesive and abrasive wear, while...
Tribology Series, 2002
Lubricant additives are chemicals which, when present in small amounts, improve the physical, che... more Lubricant additives are chemicals which, when present in small amounts, improve the physical, chemical or tribological properties of the lubricant. They form a tribochemical (antiwear) film on the rubbing surfaces which protect the engine from excessive wear.In this study fully formulated crankcase oil (SAE 20W50) is used to investigate the role of additives and determine the mechanical conditions of the
Industrial Lubrication and Tribology, Feb 28, 1997
The authors wish to thank Shell Oil Company for providing test facilities.
Biodiesel is an alternative fuel for Diesel engines made from new/used vegetable oils and animal ... more Biodiesel is an alternative fuel for Diesel engines made from new/used vegetable oils and animal fats. It is biodegradable and has lower hydrocarbon emission levels and similar performance characteristics compared to conventional Diesel fuel. After modifying its molecular structure through a transesterification process, biodiesel (rapeseed oil methyl ester-RME) can be used as an alternative fuel in compression ignition engines without any modification. Modern internal combustion engines must have longer oil drain periods to decrease operating costs and environmental pollution levels. Related studies indicate that biodiesel fuel has a potential for reducing engine wear. This experimental study investigates the effect of commercial Diesel fuel and RME on lubricating oil performance and the exhaust emissions. Performance, emissions and long-term wear tests were carried out and discussed on a single cylinder marine Diesel engine for both Diesel fuel and 100 % RME. Results indicated that the RME has a deteriorating effect on lubricating oil performance by decreasing oil viscosity degree and base number. Ferrous element is the main evidence of the engine wear and it was increased depending on lowering viscosity relating to the fuel dilution and rising running period. Although carbon monoxide and hydrocarbon pollutants in exhaust gas decreased with RME, nitric oxides raised significantly as well as performance results which remained similar except for specific fuel consumption.