scholarly journals Study of Tribological Properties of Fullerenol and Nanodiamonds as Additives in Water-Based Lubricants for Amorphous Carbon (a-C) Coatings

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 139
Author(s):  
Shuqing Chen ◽  
Qi Ding ◽  
Yan Gu ◽  
Xin Quan ◽  
Ying Ma ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Tribological Properties ◽  
Size Range ◽  
Friction Pair ◽  
Asperity Contact ◽  
Low Concentration ◽  
Contact Loads ◽  
Water Based ◽  
The Coefficient Of Friction ◽  
Sufficient Concentration

The tribological performances of fullerenol and nanodiamonds (NDs) as additives in water-based lubricants for amorphous carbon (a-C) coatings are investigated to avoid disadvantage factors, such as chemical reactions and deformation of particles. The effects of size and additive amount on tribological properties of nanoparticles are studied by rigid nanoparticles within the dot size range. The results show that owing to its small particle size (1–2 nm), fullerenol cannot prevent direct contact of the friction pair at low concentration conditions. Only when the quantity of fullerenol increased to support the asperity contact loads in sufficient concentration did nano-bearings perform well in anti-friction and anti-wear effects. Unlike fullerenol, nanodiamond particles with a diameter of about 5–10 nm show friction-reducing effect based on the nano-bearing effects at ultra-low concentration (0.01 wt.%), whereas particles at higher concentration block the rolling movement, hence increasing the coefficient of friction (COF) and wear. As a result of the effect of difference in size, fullerenol provides a better overall lubrication, but it is hard to reach a friction coefficient as low as NDs even under the optimal conditions.

scholarly journals Analysis and Comparative Assessment of Basic Tribological Properties of Selected Polymer Composites

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 75 ◽  
Author(s):  
Jerzy Jozwik ◽  
Krzysztof Dziedzic ◽  
Marcin Barszcz ◽  
Mykhaylo Pashechko
Keyword(s):  
Polymer Composites ◽  
Friction Force ◽  
Tribological Properties ◽  
Friction Pair ◽  
Computer Software ◽  
Operating Conditions ◽  
The Coefficient Of Friction ◽  
Cast Polyamide ◽  
Friction Path ◽  
Materials Used

Phenomena occurring in the contact area between two mating bodies are characterised by high complexity and variability. Comparisons are usually made between parameters such as the coefficient of friction, friction force, wear and temperature in relation to time and friction path. Their correct measurement enables the proper evaluation of tribological properties of materials used in the friction pair. This paper concerns the measurements of basic tribological parameters in the friction of selected polymer composites. Knowing the tribological properties of these composite materials, it will be possible to create proper operating conditions for kinematic friction pairs. This study investigated the coefficients of friction, friction force and temperatures of six polymer composites: cast polyamide PA6 G with oil, PA6 G with MoS2, polyoxymethylene POM with aluminium, polyethylene terephthalate PET with polytetrafluoroethylene PTFE, PTFE with bronze, and PTFE with graphite. The friction surface was also examined using an optical system and computer software for 3D measurements. As a result, PA6-G with oil was found to be the best choice as a composite material for thin sliding coatings.

Tribological modification of high-density polyethylene by using carbon soot from diesel combustion

2016 ◽  
Vol 68 (5) ◽  
pp. 603-610 ◽  
Author(s):  
X.A. Cao ◽  
G.Q. Shao ◽  
K.H. Hu
Keyword(s):  
Abrasive Wear ◽  
Amorphous Carbon ◽  
Tribological Properties ◽  
High Density Polyethylene ◽  
Friction Pair ◽  
High Density ◽  
Exhaust Emission ◽  
Content Type ◽  
Transmission Electron ◽  
Carbon Soot

Purpose The purpose of this paper is to explore the tribological properties of high-density polyethylene (HDPE) modified by carbon soot from the combustion of No. 0 diesel. Design/methodology/approach Carbon soot is characterized using X-ray diffraction, transmission electron microscopy and scanning electronic microscopy. The tribological properties of HDPE samples with carbon soot are investigated on a materials surface tester with a ball-on-disk friction pair. Findings The collected carbon soot mainly comprises amorphous carbon nanoparticles of 50-100 nm in diameter. The main wear behaviours of pure HDPE include abrasive wear and plastic deformation. After adding carbon soot nanoparticles to HDPE, HDPE wear decreases. The appropriate carbon soot content is 8 per cent in HDPE under the selected testing conditions. Compared with other HDPE samples, HDPE with 8 per cent carbon soot has higher melting temperature, lower abrasive wear and better wear resistance. The lubrication of HDPE with carbon soot is due to the formation of a transferring film composed of HDPE, amorphous carbon and graphite carbon. Originality/value The paper reveals the HDPE modification and lubrication mechanisms by using carbon soot from the combustion of diesel. Related research can perhaps provide a potential approach for the treatment of carbon soot exhaust emission.

scholarly journals Preparation and Tribological Properties of Dual-Coated TiO2Nanoparticles as Water-Based Lubricant Additives

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yue Gu ◽  
Xiuchen Zhao ◽  
Ying Liu ◽  
Yunxia Lv
Keyword(s):  
Tribological Properties ◽  
Titanium Dioxide Nanoparticles ◽  
Pure Water ◽  
Lubricant Additives ◽  
Wear Scar ◽  
Drilling Process ◽  
Wear Scar Diameter ◽  
Water Based ◽  
The Coefficient Of Friction ◽  
Worn Surface

Titanium dioxide nanoparticles (TiO2) were synthesized and then dual-coated with silane coupling agent (KH-570) and OP-10 in sequence in order to be dispersed stably in water as lubricant additives. The tribological properties and the application performance in Q235 steel machining of the nanoparticles as water-based lubricant additives were investigated on an MSR-10D four-ball tribotester and on a bench drilling machine, respectively. Scanning electron microscope (SEM) and atomic force microscope (AFM) were used to analyze the worn surface. The results show that the surface-modified TiO2nanoparticles can remarkably improve the load-carrying capacity, the friction reducing, and anti wear abilities of pure water. The wear scar diameter and the coefficient of friction of the water-based lubricating fluids with TiO2nanoparticles decreased, and the thick deep furrows on the surface of wear scar also decreased obviously with the increase of TiO2concentration. The power consumption in drilling process was lower and the cutting surface was smoother using the water-based lubricating fluids added TiO2nanoparticles compared to the fluid without addition. The reason for nanoparticles improving tribological properties of water based lubricating fluid might be the formation of a dynamic deposition film during rubbing process according to analysis of the worn surface.

THE INFLUENCE OF SELECTIVE LASER SINTERING PARAMETERS ON TRIBOLOGICAL PROPERTIES OF PA 3200 GF POLYAMIDE

Tribologia ◽  
2018 ◽  
Vol 277 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Czesław KUNDERA ◽  
Tomasz KOZIOR
Keyword(s):  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Glass Fibre ◽  
Friction Pair ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Preliminary Results ◽  
The Coefficient Of Friction ◽  
Polyamide Powder

The paper presents the preliminary results of tribological research on the material used in the selective laser sintering technology, SLS. The samples in the shape of rings were manufactured of PA 3200 GF polyamide powder additionally reinforced with glass fibre, which is based on pure PA 2200 polyamide. The tests were carried out on a tribological T-15 tester, ring-on-disc type imitating the cooperation conditions of elements, e.g., the rings of the contact active seal. The main objective of the research was to determine the influence of the direction of the positioning of the models on the construction platform on the coefficient of friction and the wear of the cooperating friction pair components.

Lubrication adaptability to the variations of combustion modes by texturing cylinder liner in engines

2017 ◽  
Vol 232 (7) ◽  
pp. 946-957 ◽  
Author(s):  
Bifeng Yin ◽  
Bo Xu ◽  
Yanqiang Qian ◽  
Jinghu Ji ◽  
Yonghong Fu
Keyword(s):  
Tribological Properties ◽  
Friction Pair ◽  
Cylinder Liner ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Frictional Loss ◽  
Compression Stroke ◽  
Combustion Modes ◽  
Lubrication Performance ◽  
Micro Dimples

The application of different combustion modes in engines has placed greater demands on the lubrication of cylinder liners and piston rings. In this study, a mixed lubrication model was built to investigate the tribological properties of a liner textured with micro-dimples. The simulation results indicate that surface texturing can improve the lubrication and friction properties of the ring/liner pair and adapt to different combustion modes in an engine. Due to the significant differences in external loads around top dead center of the compression stroke under pre-mixed charge combustion ignition, conventional combustion and retarded injection modes, when the liner remains untextured, the lubrication performance of the friction pair appears to be unstable in a mixed lubrication region. For the textured liner, micro-dimples enhance the hydrodynamic effects between the ring and liner, increasing the oil film thickness and its bearing capacity. As a result, the mixed lubrication interval shrinks and the micro asperity contact is reduced, thus improving the tribological properties of the friction pair. The numerical fluctuation ranges of parameters, the maximum asperity pressure, the average friction force and the frictional loss, are narrowed by 21.6%, 27.8% and 24.5%, respectively, under the three different combustion modes around top dead center of the compression stroke.

scholarly journals Impact of Operating Time on Selected Tribological Properties of the Friction Material in the Brake Pads of Passenger Cars

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 884
Author(s):  
Andrzej Borawski
Keyword(s):  
Tribological Properties ◽  
Operating Time ◽  
Friction Material ◽  
Operating Conditions ◽  
Direct Impact ◽  
Passenger Cars ◽  
Wear Factor ◽  
Brake Pads ◽  
Road Users ◽  
The Coefficient Of Friction

Braking systems have a direct impact on the safety of road users. That is why it is crucial that the performance of brakes be dependable and faultless. Unfortunately, the operating conditions of brakes during their operating time are affected by many variables, which results in changes in their tribological properties. This article presents an attempt to develop a methodology for studying how the operating time affects the value of the coefficient of friction and the abrasive wear factor. The Taguchi method of process optimization was used to plan the experiment, which was based on tests using the ball-cratering method. The results clearly show that the degree of wear affects the properties of the friction material used in the production process of brakes.

scholarly journals Tribological performance of various metal-doped carbon dots as water-based lubricant additives and their potential application as additives of poly(ethylene glycol)

Friction ◽  
2021 ◽  
Author(s):  
Weiwei Tang ◽  
Xuejun Zhu ◽  
Yufeng Li
Keyword(s):  
Ethylene Glycol ◽  
Tribological Properties ◽  
Carbon Dots ◽  
Lubricant Additives ◽  
Poly Ethylene Glycol ◽  
Wear Properties ◽  
Water Based ◽  
Friction Reducing ◽  
Poly Ethylene ◽  
Metal Doped

AbstractAdvances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development. Carbon dots (CDs) have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties, in particular, their friction-reducing and anti-wear properties. Metal-doped CDs are a new type of CDs, and their friction-reducing and anti-wear properties are attracting increasing attention. Therefore, a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis. The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order: Zn-CDs > Cu-CDs ≫ Mg-CDs > Fe-CDs > U-CDs. Specifically, adding 1.0 wt% of Zn-CDs into water-based lubricant results in 62.5% friction and 81.8% wear reduction. Meanwhile, the load-carrying capacity of the water-based lubricant increases from 120 N to at least 500 N. Zn-CDs as an additive have long service life. Additionally, anion-tuned Zn-CDs fabricated via anion exchange exhibit promise as lubricant additives for poly(ethylene glycol). Based on the results of wear scar surface analyses, it is discovered that tribochemical films, primarily composed of iron oxides, nitrides, metal carbonates, zinc oxides, zinc carbonates, organic compounds, and embedded carbon cores, formed on the rubbing surfaces with a thickness of approximately 270 nm when Zn-CDs are used as additives. This film combined with the “ball-bearing” and third-particle effects of Zn-CDs contributed to excellent lubrication performance.

Amorphous Carbon Coatings for Locally Adjusted Tribological Properties in Sheet Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 969-974 ◽  
Author(s):  
Harald Hetzner ◽  
Stephan Tremmel ◽  
Sandro Wartzack
Keyword(s):  
Amorphous Carbon ◽  
Tribological Properties ◽  
Metal Forming ◽  
Friction And Wear ◽  
Wear Properties ◽  
Carbon Coatings ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Friction And Wear Properties ◽  
Amorphous Carbon Coatings

In sheet bulk metal forming, locally adapted friction properties of the contact tool/workpiece are an appropriate means for the targeted enhancement of the material flow, enabling an improved form filling and lowered forming forces. However, the implementation of desirable friction conditions is not trivial. And further, friction is inseparably linked to wear and damage of the contacting surfaces. This calls for a methodological approach in order to consider tribology as a whole already in the early phases of process layout, so that tribological measures which allow fulfilling the requirements concerning local friction and wear properties of the tool surfaces, can already be selected during the conceptual design of the forming tools. Thin tribological coatings are an effective way of improving the friction and wear properties of functional surfaces. Metal-modified amorphous carbon coatings, which are still rather new to the field of metal forming, allow tackling friction and wear simultaneously. Unlike many other types of amorphous carbon, they have the mechanical toughness to be used in sheet bulk metal forming, and at the same time their friction properties can be varied over wide ranges by proper choice of the deposition parameters. Based on concrete research results, the mechanical, structural and special tribological properties of tungsten-modified hydrogenated amorphous carbon coatings (a-C:H:W) are presented and discussed against the background of the tribological requirements of a typical sheet bulk metal forming process.

Experimental study on the relationship between the friction coefficient and interference in locomotive axle press-fitting

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ting Wang ◽  
Hanfei Guo ◽  
Jianjun Qiao ◽  
Xiaoxue Liu ◽  
Zhixin Fan
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Friction Pair ◽  
Rolling Stock ◽  
Content Type ◽  
Press Fitting ◽  
The Press ◽  
The Coefficient Of Friction ◽  
The Relationship ◽  
Locomotive Wheels

PurposeTo address the lack of data in this field and determine the relationship between the coefficient of friction and the interference between locomotive wheels and axles, this study evaluates the theoretical relationship between the coefficient of friction and the interference under elastic deformation.Design/methodology/approachWhen using numerical analyses to study the mechanical state of the contacting components of the wheels and axle, the interference between the axle parts and the coefficient of friction between the axle parts are two important influencing factors. Currently, as the range of the coefficient of friction between the wheel and axle in interference remains unknown, it is generally considered that the coefficient of friction is only related to the materials of the friction pair; the relationship between the interference and the coefficient of friction is often neglected.FindingsA total of 520 press-fitting experiments were conducted for 130 sets of wheels and axles of the HXD2 locomotive with 4 types of interferences, in order to obtain the relationship between the coefficient of friction between the locomotive wheel and axle and the amount of interference. These results are expected to serve as a reference for selecting the coefficient of friction when designing axle structures with the rolling stock, research on the press-fitting process and evaluations of the fatigue life.Originality/valueThe study provides a basis for the selection of friction coefficient and interference amount in the design of locomotive wheels and axles.

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