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Articles 1 - 30 of 1318

Full-Text Articles in Engineering Science and Materials

Transformation Between Polar And Rectangular Coordinates Of Stiffness And Dampness Parameters In Hydrodynamic Journal Bearings, Zhuxin Tian, Yu Huang Nov 2020

Transformation Between Polar And Rectangular Coordinates Of Stiffness And Dampness Parameters In Hydrodynamic Journal Bearings, Zhuxin Tian, Yu Huang

Friction

The stiffness and dampness parameters of journal bearings are required in rectangular coordinates for analyzing the stability boundary and threshold speed of oil film bearings. On solving the Reynolds equation, the oil film force is always obtained in polar coordinates; thus, the stiffness and dampness parameters can be easily obtained in polar coordinates. Therefore, the transformation between the polar and rectangular coordinates of journal bearing stiffness and dampness parameters is discussed in this study.


A Finite Element Analysis (Fea) Approach To Simulate The Coefficient Of Friction Of A Brake System Starting From Material Friction Characterization, Gabriele Riva, Francesco Varriale, Jens Wahlström Nov 2020

A Finite Element Analysis (Fea) Approach To Simulate The Coefficient Of Friction Of A Brake System Starting From Material Friction Characterization, Gabriele Riva, Francesco Varriale, Jens Wahlström

Friction

The coefficient of friction (COF) is one of the most important parameters to evaluate the performance of a brake system. To design proper brake systems, it is important to know the COF when estimating the brake force and resulting torque. It is challenging to simulate the COF since friction in disc brakes is a complex phenomenon that depends on several parameters such as sliding velocity, contact pressure, materials, and temperatures, etc. There is a lack of studies found in the literature focusing on simulation of the COF for a full brake system based on tribometer material characterization. The aim of ...


Grease Film Evolution In Rolling Elastohydrodynamic Lubrication Contacts, Xinming Li, Feng Guo, Gerhard Poll, Yang Fei, Ping Yang Nov 2020

Grease Film Evolution In Rolling Elastohydrodynamic Lubrication Contacts, Xinming Li, Feng Guo, Gerhard Poll, Yang Fei, Ping Yang

Friction

Although most rolling element bearings are grease lubricated, the underlying mechanisms of grease lubrication has not been fully explored. This study investigates grease film evolution with glass disc revolutions in rolling elastohydrodynamic lubrication (EHL) contacts. The evolution patterns of the grease films were highly related to the speed ranges and grease structures. The transference of thickener lumps, film thickness decay induced by starvation, and residual layer were recognized. The formation of an equilibrium film determined by the balance of lubricant loss and replenishment was analyzed. The primary mechanisms that dominate grease film formation in different lubricated contacts were clarified.


Tribological Behavior Of Ammonium-Based Protic Ionic Liquid As Lubricant Additive, Hong Guo, Patricia Iglesias Nov 2020

Tribological Behavior Of Ammonium-Based Protic Ionic Liquid As Lubricant Additive, Hong Guo, Patricia Iglesias

Friction

In this study, the tribological behavior of an ammonium-based protic ionic liquid (PIL) as an additive in a base mineral oil (MO) is investigated on a steel-steel contact at room temperature and 100 °C. Tri-[bis(2-hydroxyethylammonium)] citrate (DCi) was synthesized in a simple and low-cost way, and the ionic structure of DCi was confirmed by proton nuclear magnetic resonance (1H NMR). The stability measurement of 1 wt% DCi to a MO was investigated, and the lubricating ability and anti-wear properties of DCi as an additive in MO were also examined using a custom-designed reciprocating ball-on-flat tribometer. Optical microscope ...


Influence Of Lubrication, Tool Steel Composition, And Topography On The High Temperature Tribological Behaviour Of Aluminium, Justine Decrozant-Triquenaux, Leonardo Pelcastre, Braham Prakash, Jens Hardell Nov 2020

Influence Of Lubrication, Tool Steel Composition, And Topography On The High Temperature Tribological Behaviour Of Aluminium, Justine Decrozant-Triquenaux, Leonardo Pelcastre, Braham Prakash, Jens Hardell

Friction

The use of high strength aluminium alloys, such as 6XXX and 7XXX series, is continuously increasing for automotive applications in view of their good strength-to-weight ratio. Their formability at room temperature is limited and they are thus often formed at high temperatures to enable production of complex geometries. Critical challenges during hot forming of aluminium are the occurrence of severe adhesion and material transfer onto the forming tools. This negatively affects the tool life and the quality of the produced parts. In general, the main mechanisms involved in the occurrence of material transfer of aluminium alloys at high temperature are ...


Modified Graphene As Novel Lubricating Additive With High Dispersion Stability In Oil, Pu Wu, Xinchun Chen, Chenhui Zhang, Jiping Zhang, Jianbin Luo, Jiyang Zhang Nov 2020

Modified Graphene As Novel Lubricating Additive With High Dispersion Stability In Oil, Pu Wu, Xinchun Chen, Chenhui Zhang, Jiping Zhang, Jianbin Luo, Jiyang Zhang

Friction

Graphene is a promising material as a lubricant additive for reducing friction and wear. Here, a dispersing method which combines chemical modification of graphene by octadecylamine and dicyclohexylcarbodiimide with a kind of effective dispersant has been successfully developed to achieve the remarkable dispersion stability of graphene in base oil. The stable dispersion time of modified graphene (0.5 wt%) with dispersant (1 wt%) in PAO-6 could be up to about 120 days, which was the longest time reported so far. At the same time, the lubricant exhibits a significant improvement of tribological performance for a steel ball to plate tribo-system ...


Electroadhesion Between A Flat Touchscreen And The Human Finger With Randomly Self-Affine Fractal Surface, M. Feshanjerdi Nov 2020

Electroadhesion Between A Flat Touchscreen And The Human Finger With Randomly Self-Affine Fractal Surface, M. Feshanjerdi

Friction

In this study, the effects of finger roughness on the electrostatic potential, electrostatic field, and average effective squeezing pressure between a human finger and a touchscreen are calculated by the perturbation method. This theory is an extension of an earlier work by Persson. It is found that an additional potential <ϕ(2)> will appear between the solids when the roughness effect is considered in calculating the perturbation potential. This additional potential is still proportional to the distance u¯ from the bottom surface. Therefore, the effect of the roughness increases the effective potential <ϕ> between the two solids. As a result, the average electrostatic ...


Multiscale Analysis Of Friction Behavior At Fretting Interfaces, Zhinan Zhang, Shuaihang Pan, Nian Yin, Bin Shen, Jie Song Nov 2020

Multiscale Analysis Of Friction Behavior At Fretting Interfaces, Zhinan Zhang, Shuaihang Pan, Nian Yin, Bin Shen, Jie Song

Friction

Friction behavior at fretting interfaces is of fundamental interest in tribology and is important in material applications. However, friction has contact intervals, which can accurately determine the friction characteristics of a material; however, this has not been thoroughly investigated. Moreover, the fretting process with regard to different interfacial configurations have also not been systematically evaluated. To bridge these research gaps, molecular dynamics (MD) simulations on Al-Al, diamond-diamond, and diamond-silicon fretting interfaces were performed while considering bidirectional forces. This paper also proposes new energy theories, bonding principles, nanoscale friction laws, and wear rate analyses. With these models, semi-quantitative analyses of coefficient ...


Tribological And Anti-Corrosion Performance Of Epoxy Resin Composite Coatings Reinforced With Differently Sized Cubic Boron Nitride (Cbn) Particles, Zhiping Huang, Wenjie Zhao, Wenchao Zhao, Xiaojing Ci, Wentao Li Nov 2020

Tribological And Anti-Corrosion Performance Of Epoxy Resin Composite Coatings Reinforced With Differently Sized Cubic Boron Nitride (Cbn) Particles, Zhiping Huang, Wenjie Zhao, Wenchao Zhao, Xiaojing Ci, Wentao Li

Friction

A series of high solid content (30 wt%) epoxy resin (EP) composite coatings reinforced with differently sized cubic boron nitride (CBN) particles were fabricated successfully on 304L stainless steel. Polydopamine (PDA) was used to improve the dispersibility of CBN particles in EP. The structural and morphological features of the CBN particles and the composite coatings were characterized by Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Moreover, a UMT-3 tribometer and surface profiler were used to investigate the tribological behaviors of the as-prepared composite coatings. Electrochemical impedance spectroscopy (EIS) and Tafel analysis were used to investigate the ...


A New Kind Of Resin-Based Wet Friction Material: Non-Woven Fabrics With Isotropic Fiber Networks As Preforms, Yewei Fu, Le Zhou, Tao Yin, Zhongyao Luo, Hejin Li, Lehua Qi Nov 2020

A New Kind Of Resin-Based Wet Friction Material: Non-Woven Fabrics With Isotropic Fiber Networks As Preforms, Yewei Fu, Le Zhou, Tao Yin, Zhongyao Luo, Hejin Li, Lehua Qi

Friction

As an alternative to short fibers, non-woven fabrics (NWFs) were made using different types of long fibers to optimize the performance of paper-based friction materials and their technology. In this investigation, the fillers and resin were impregnated into these NWFs to prepare three kinds of wet friction material. The tribological, mechanical, and thermal properties of the new wet friction material were studied. The results indicate that the dynamic friction coefficient of the new friction material is approximately 0.12 and the static friction coefficient is approximately 0.15; the better wear rate is 0.81334 × 10−14 m3·(N ...


Comparative Study On Corrosion Resistance And Lubrication Function Of Lithium Complex Grease And Polyurea Grease, Guanlin Ren, Pengfei Zhang, Xiangyuan Ye, Wen Li, Xiaoqiang Fan, Minhao Zhu Nov 2020

Comparative Study On Corrosion Resistance And Lubrication Function Of Lithium Complex Grease And Polyurea Grease, Guanlin Ren, Pengfei Zhang, Xiangyuan Ye, Wen Li, Xiaoqiang Fan, Minhao Zhu

Friction

In this study, lithium complex grease (LCG) and polyurea grease (PUG) were synthesized using mineral oil (500SN) and polyalphaolefin (PAO40) as base oil, adsorbed onto lithium complex soap and polyurea as thickeners, respectively. The effects of grease formulation (thickener and base oil with different amounts (80, 85, and 90 wt%) on the corrosion resistance and lubrication function were investigated in detail. The results have verified that the as-prepared greases have good anti-corrosion ability, ascribed to good salt-spray resistance and sealing function. Furthermore, the increase in the amount of base oil reduces the friction of the contact interface to some extent ...


Effects Of Magnetic Ionic Liquid As A Lubricant On The Friction And Wear Behavior Of A Steel-Steel Sliding Contact Under Elevated Temperatures, Jiajia Jia, Guangbin Yang, Chunli Zhang, Shengmao Zhang, Yujuan Zhang, Pingyu Zhang Nov 2020

Effects Of Magnetic Ionic Liquid As A Lubricant On The Friction And Wear Behavior Of A Steel-Steel Sliding Contact Under Elevated Temperatures, Jiajia Jia, Guangbin Yang, Chunli Zhang, Shengmao Zhang, Yujuan Zhang, Pingyu Zhang

Friction

A magnetic ionic liquid (abridged as MIL) [C6mim]5[Dy(SCN)8] was prepared and used as the magnetic lubricant of a steel-steel sliding pair. The tribological properties of the as-prepared MIL were evaluated with a commercially obtained magnetic fluid lubricant (abridged as MF; the mixture of dioctyl sebacate and Fe3O4, denoted as DIOS-Fe3O4) as a control. The lubrication mechanisms of the two types of magnetic lubricants were discussed in relation to worn surface analyses by SEM-EDS, XPS, and profilometry, as well as measurement of the electric contact resistance of the rubbed ...


The Correlation Between Friction Coefficient And Areal Topography Parameters For Aisi 304 Steel Sliding Against Aisi 52100 Steel, Deepak K. Prajapati, Mayank Tiwari Nov 2020

The Correlation Between Friction Coefficient And Areal Topography Parameters For Aisi 304 Steel Sliding Against Aisi 52100 Steel, Deepak K. Prajapati, Mayank Tiwari

Friction

Dry wear experiments provide an insight detail on how severely contacting surfaces change under unlubricated sliding condition. The theory of dry sliding wear is used for understanding mixed-lubrication regime in which asperity interactions play a significant role in controlling of the friction coefficient (f). The purpose of this work is to study the tribological behavior of AISI 304 steel in contact with AISI 52100 steel during wear. Both materials are used in rolling element bearings commanly. Experiments are carried out using a pin-on-disc tribometer under dry friction condition. The areal (three dimensional, 3D) topography parameters are measured using a 3D ...


Ultralow Friction Polymer Composites Incorporated With Mono-Dispersed Oil Microcapsules, Lin Zhang, Guoxin Xie, Shuai Wu, Shiguang Peng, Xiaoqing Zhang, Dan Guo, Shizhu Wen, Jianbin Luo Nov 2020

Ultralow Friction Polymer Composites Incorporated With Mono-Dispersed Oil Microcapsules, Lin Zhang, Guoxin Xie, Shuai Wu, Shiguang Peng, Xiaoqing Zhang, Dan Guo, Shizhu Wen, Jianbin Luo

Friction

Ultralow friction polymer composites were prepared by adding oil-loaded microcapsules into epoxy (EP) resin. Mono-dispersed polystyrene (PS)/poly alpha olefin (PAO) microcapsules with a diameter of ~2 μm and a shell thickness of ~30 nm were prepared by solvent evaporation method in an oil-in-water emulsion. The lubrication behaviors of the EP resin composites with oil-loaded microcapsules have been investigated under different loads and sliding speeds. As compared with the pure EP resin, the friction coefficient of the composite could be reduced to 4% (from 0.71 to 0.028) and the wear rate could be decreased up to two orders ...


Role Of Interfacial Water In Adhesion, Friction, And Wear—A Critical Review, Lei Chen, Linmao Qian Nov 2020

Role Of Interfacial Water In Adhesion, Friction, And Wear—A Critical Review, Lei Chen, Linmao Qian

Friction

Surficial water adsorption and interfacial water condensation as natural phenomena that can alter the contact status of the solid interface and tribological performances are crucial in all length scales, i.e., from earthquakes to skating at the macroscale level and even to micro/nano-electromechanical systems (M/NEMS) at the microscale/nanoscale level. Interfacial water exhibits diverse structure and properties from bulk water because of its further interaction with solid surfaces. In this paper, the evolutions of the molecular configuration of the adsorbed water layer depending on solid surface chemistry (wettability) and structure, environmental conditions (i.e., relative humidity and temperature ...


Superlubricity Achieved With Two-Dimensional Nano-Additives To Liquid Lubricants, Hongdong Wang, Yuhong Liu Oct 2020

Superlubricity Achieved With Two-Dimensional Nano-Additives To Liquid Lubricants, Hongdong Wang, Yuhong Liu

Friction

The topic of superlubricity is attracting considerable interest around the world while humanity is facing an energy crisis. Since various liquid superlubricity systems can be commonly achieved on the macroscale in ambient conditions, it is considered an effective solution to reduce unnecessary energy and material losses. However, certain practical problems such as low load-bearing pressure, dependence on hydrogen ions, and relatively long running-in processes still limit its widespread application. Two- dimensional (2D) nano-additives with ultrathin longitudinal dimensions can lower the shear resistance between sliding solid surfaces, and thus further optimize the applied conditions. In this review, the latest studies on ...


Influence Of White Etching Layer On Rolling Contact Behavior At Wheel-Rail Interface, Qinglin Lian, Guanyu Deng, Hongtao Zhu, Huijun Li, Xi Wang, Zhiming Liu Oct 2020

Influence Of White Etching Layer On Rolling Contact Behavior At Wheel-Rail Interface, Qinglin Lian, Guanyu Deng, Hongtao Zhu, Huijun Li, Xi Wang, Zhiming Liu

Friction

The existence of narrow and brittle white etching layers (WELs) on the rail surface is often linked with the formation of rail defects such as squats and studs, which play the key roles in rail surface degradation and tribological performance. In the present study, a systematic investigation on stress/strain distribution and fatigue life of the WEL during wheel-rail rolling contact was conducted based on a numerical model considering the realistic wheel geometry. This is the first study considering the influence of rail materials, loading pressure, frictional condition, WEL geometry (a/b), and slip ratio (Sr) in the practical service ...


Effect Of Friction On The Contact Stress Of A Coated Polymer Gear, Su-Min Bae, Kuk-Jin Seo, Dae-Eun Kim Oct 2020

Effect Of Friction On The Contact Stress Of A Coated Polymer Gear, Su-Min Bae, Kuk-Jin Seo, Dae-Eun Kim

Friction

Polymer gears are used extensively in various applications. However, durability issues have been emerging because of friction at gear tooth contact areas. To extend the lifetime of polymer gears, a low-frictional coating has been considered as a possible strategy. In this study, a finite element simulation method was performed to investigate the contact stress between a pair of coated polymer gears. The simulation included various friction coefficients (COFs) for studying the effects of friction during the operation. Numerical results revealed that the friction causes the contact stress to shift over the roll angle, which is attributed to the direction of ...


Tribological Response Of Waste Tire Rubber As Micro-Fillers In Automotive Brake Lining Materials, Anand Pai, Sayikumar Subramanian, Tribhuvan Sood Oct 2020

Tribological Response Of Waste Tire Rubber As Micro-Fillers In Automotive Brake Lining Materials, Anand Pai, Sayikumar Subramanian, Tribhuvan Sood

Friction

Elastomeric materials show promise as potential micro-fillers in brake linings. They can provide vibration damping and acoustic advantages in intermittent and abrupt impact applications such as braking. The elastomeric material can be salvaged from non-biodegradable automotive tires, thereby providing an opportunity to reuse materials that will otherwise be discarded in landfills. Both tribological and thermomechanical performances of the waste tire rubber were assessed to determine their potential for use as micro-fillers in the brake linings of commercial vehicles with a gross weight less than 16 tons. Accordingly, the brake lining materials were fabricated with fine waste tire rubber particulates (WTRPs ...


Running-In Friction Of Hip Joint Replacements Can Be Significantly Reduced: The Effect Of Surface-Textured Acetabular Cup, David Nečas, Hatsuhiko Usami, Tatsuya Niimi, Yoshinori Sawae, Ivan Křupka, Martin Hartl Oct 2020

Running-In Friction Of Hip Joint Replacements Can Be Significantly Reduced: The Effect Of Surface-Textured Acetabular Cup, David Nečas, Hatsuhiko Usami, Tatsuya Niimi, Yoshinori Sawae, Ivan Křupka, Martin Hartl

Friction

Hip joint replacements represent the most effective way of treatment for patients suffering from joint diseases. Despite the rapid improvement of implant materials over the last few decades, limited longevity associated with wear-related complications persists as the main drawback. Therefore, improved tribological performance is required in order to extend the service life of replacements. The effect of surface texturing of ultra- high molecular weight polyethylene (UHMWPE) acetabular cup was investigated in the present study. Unique tilling method was utilized for manufacturing the dimples with controlled diameter and depths on the contact surface of the cup. The experiments with four commercial ...


Tribological Performance And Microstructural Evolution Of Α-Brass Alloys As A Function Of Zinc Concentration, Zhilong Liu, Philipp Messer-Hannemann, Stephan Laube, Christian Greiner Oct 2020

Tribological Performance And Microstructural Evolution Of Α-Brass Alloys As A Function Of Zinc Concentration, Zhilong Liu, Philipp Messer-Hannemann, Stephan Laube, Christian Greiner

Friction

Tailoring a material’s properties for low friction and little wear in a strategic fashion is a long-standing goal of materials tribology. Plastic deformation plays a major role when metals are employed in a sliding contact; therefore, the effects of stacking fault energy and mode of dislocation glide need to be elucidated. Here, we investigated how a decrease in the stacking fault energy affects friction, wear, and the ensuing sub-surface microstructure evolution. Brass samples with increasing zinc concentrations of 5, 15, and 36 wt% were tested in non-lubricated sphere-on-plate contacts with a reciprocating linear tribometer against Si3N4 ...


Microstress Cycle And Contact Fatigue Of Spiral Bevel Gears By Rolling-Sliding Of Asperity Contact, Wei Cao, Si Ren, Wei Pu, Ke Xiao Oct 2020

Microstress Cycle And Contact Fatigue Of Spiral Bevel Gears By Rolling-Sliding Of Asperity Contact, Wei Cao, Si Ren, Wei Pu, Ke Xiao

Friction

The rolling contact fatigue (RCF) model is commonly used to predict the contact fatigue life when the sliding is insignificant in contact surfaces. However, many studies reveal that the sliding, compared to the rolling state, can lead to a considerable reduction of the fatigue life and an excessive increase of the pitting area, which result from the microscopic stress cycle growth caused by the sliding of the asperity contact. This suggests that fatigue life in the rolling-sliding condition can be overestimated based only on the RCF model. The rubbing surfaces of spiral bevel gears are subject to typical rolling-sliding motion ...


Measurement Of Bit-Rock Interface Temperature And Wear Rate Of The Tungsten Carbide Drill Bit During Rotary Drilling, Vijay Kumar Shankar, Bijay Mihir Kunar, Chivukula Suryanarayana Murthy, M R. Ramesh Oct 2020

Measurement Of Bit-Rock Interface Temperature And Wear Rate Of The Tungsten Carbide Drill Bit During Rotary Drilling, Vijay Kumar Shankar, Bijay Mihir Kunar, Chivukula Suryanarayana Murthy, M R. Ramesh

Friction

Rock drilling is an essential operation in mining industries. Temperature at the bit-rock interface plays a major role in the wear rate of the drill bit. This paper primarily focuses on the wear rate of tungsten carbide (WC) drill bit and the interrelationship between temperature and wear rate during rotary drilling operations conducted using a computer numerical control (CNC) machine. The interrelationship between the temperature and wear rate was studied with regard to three types of rock samples, i.e., fine-grained sandstone (FG) of uniaxial compressive strength (UCS) that is 17.83 MPa, medium-grained sandstone (MG) of UCS that is ...


Friction And Wear Behavior Of Carbon Fiber Reinforced Lithium Aluminosilicate Composites Sliding Against Gcr15 Steel, Haibao Ma, Xin Wu, Long Xia, Longnan Huang, Li Xiong, Hua Yang, Bo Zhong, Tao Zhang, Zhiwei Yang, Feng Gao, Guangwu Wen Oct 2020

Friction And Wear Behavior Of Carbon Fiber Reinforced Lithium Aluminosilicate Composites Sliding Against Gcr15 Steel, Haibao Ma, Xin Wu, Long Xia, Longnan Huang, Li Xiong, Hua Yang, Bo Zhong, Tao Zhang, Zhiwei Yang, Feng Gao, Guangwu Wen

Friction

Carbon fibers reinforced lithium aluminosilicate matrix composites (Cf/LAS) were prepared by slurry infiltration combined with a hot press procedure. The friction, wear behavior, and wear mechanisms of Cf/LAS composites under dry sliding conditions were investigated. The results show that the coefficient of friction (COF) initially increased with the increase in carbon fiber content, and reached the maximum value of 0.20 for the 33%Cf/LAS composite. The COF increased sharply with increasing sample temperature from RT to 300 °C. The COF remained stable in the temperature range of 300-500 °C. The two wear mechanisms ...


Assessment Of Water-Based Cutting Fluids With Green Additives In Broaching, Jing Ni, Kai Feng, Lihua He, Xiaofan Liu, Zhen Meng Oct 2020

Assessment Of Water-Based Cutting Fluids With Green Additives In Broaching, Jing Ni, Kai Feng, Lihua He, Xiaofan Liu, Zhen Meng

Friction

In order to improve the cutting performance in broaching, the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing. Therefore, water-based solutions with castor oil, surfactant (linear alkylbenzene sulfonate, LAS), and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via atomization. The performances of the cutting fluids, in terms of the viscosity, specific heat, wetting angle, and droplet size, were evaluated to discuss their effects on the broaching load. Among the fluids, the addition of LAS into oil-in-water (WO-S), where its cutting ...


Evaluation Of Contact Fatigue Risk Of A Carburized Gear Considering Gradients Of Mechanical Properties, Wei Wang, Huaiju Liu, Caichao Zhu, Jinyuan Tang, Chenxu Jiang Oct 2020

Evaluation Of Contact Fatigue Risk Of A Carburized Gear Considering Gradients Of Mechanical Properties, Wei Wang, Huaiju Liu, Caichao Zhu, Jinyuan Tang, Chenxu Jiang

Friction

Carburized gears are widely used in geared machines such as wind turbines. Contact fatigue problems occur in engineering practice, reducing reliabilities of machines. Contact fatigue failures are related to many factors, such as gradients of mechanical properties of the hardening layer. In this work, an elastic-plastic contact model of a carburized gear is developed based on the finite element method to evaluate contact fatigue failure risk, considering variations in hardness and strength. The Dang Van multiaxial equivalent stress is calculated via Python coding within the Abaqus framework. The gradient of yield strength along the depth from case to core is ...


Effective Sugar-Derived Organic Gelator For Three Different Types Of Lubricant Oils To Improve Tribological Performance, Ruochong Zhang, Xuqing Liu, Zhiguang Guo, Meirong Cai, Lei Shi Oct 2020

Effective Sugar-Derived Organic Gelator For Three Different Types Of Lubricant Oils To Improve Tribological Performance, Ruochong Zhang, Xuqing Liu, Zhiguang Guo, Meirong Cai, Lei Shi

Friction

In this study, the gelling ability and lubrication performance of N-octadecyl-D-gluconamides (NOG) in liquid paraffin (LP), pentaerythritol oleate (PE-OA), and polyethylene glycol (PEG) oils were systemically investigated. The NOG, which could gelate the investigated oils, was successfully synthesized by a one-step method. The prepared gel lubricants were completely thermoreversible and exhibited improved thermal stability, according to the thermogravimetry analysis (TGA) reports. Rheological tests confirmed that the NOG gelator could effectively regulate the rheological behavior of the base oils. Tribological evaluation suggested that NOG, as an additive in the three types of base oils, could remarkably reduce the friction and wear ...


A New Approach For Prediction Of The Wear Loss Of Pta Surface Coatings Using Artificial Neural Network And Basic, Kernel-Based, And Weighted Extreme Learning Machine, Mustafa Ulas, Osman Altay, Turan Gurgenc, Cihan Özel Oct 2020

A New Approach For Prediction Of The Wear Loss Of Pta Surface Coatings Using Artificial Neural Network And Basic, Kernel-Based, And Weighted Extreme Learning Machine, Mustafa Ulas, Osman Altay, Turan Gurgenc, Cihan Özel

Friction

Wear tests are essential in the design of parts intended to work in environments that subject a part to high wear. Wear tests involve high cost and lengthy experiments, and require special test equipment. The use of machine learning algorithms for wear loss quantity predictions is a potentially effective means to eliminate the disadvantages of experimental methods such as cost, labor, and time. In this study, wear loss data of AISI 1020 steel coated by using a plasma transfer arc welding (PTAW) method with FeCrC, FeW, and FeB powders mixed in different ratios were obtained experimentally by some of the ...


Mechanical And Tribological Properties Of Nanocomposites Incorporated With Two-Dimensional Materials, Zhengjia Ji, Lin Zhang, Guoxin Xie, Wenhu Xu, Dan Guo, Jianbin Luo, Braham Prakash Oct 2020

Mechanical And Tribological Properties Of Nanocomposites Incorporated With Two-Dimensional Materials, Zhengjia Ji, Lin Zhang, Guoxin Xie, Wenhu Xu, Dan Guo, Jianbin Luo, Braham Prakash

Friction

In recent years, attempts to improve the mechanical properties of composites have increased remarkably owing to the inadequate utilization of matrices in demanding technological systems where efficiency, durability, and environmental compatibility are the key requirements. The search for novel materials that can potentially have enhanced mechanical properties continues. Recent studies have demonstrated that two-dimensional (2D) nanomaterials can act as excellent reinforcements because they possess high modulus of elasticity, high strength, and ultralow friction. By incorporating 2D nanomaterials in a composite, 2D nanomaterial-based composites (2DNBCs) have been developed. In view of this, a critical review of recent mechanical and tribological studies ...


Ftir Analysis And Monitoring Of Used Synthetic Oils Operated Under Similar Driving Conditions, Artur Wolak, Wojciech Krasodomski, Grzegorz Zając Oct 2020

Ftir Analysis And Monitoring Of Used Synthetic Oils Operated Under Similar Driving Conditions, Artur Wolak, Wojciech Krasodomski, Grzegorz Zając

Friction

The processes of degradation of engine oils operated in passenger cars of a uniform fleet of 25 vehicles were analyzed for oxidation content using infrared (IR) spectroscopy. As part of the experiment, the changes in engine oils occurring during actual operation (under conditions which can be described as "harsh", i.e., short distance driving, frequent starting of the engine, and extended engine idling) have been observed. An evaluation of the Fourier transform infrared spectroscopy (FTIR) spectrum of an engine oil sample was presented. The infrared spectra of both fresh and used oils were recorded with the Thermo Nicolett IS5. The ...