scholarly journals Study on the Tribological Properties of F-T DS/ZnFe-LDH Composite Lubricating Material

2022 ◽  
Vol 12 (2) ◽  
pp. 599
Author(s):  
Jian Wang ◽  
Tianxia Liu
Keyword(s):  
Friction Coefficient ◽  
Friction Pair ◽  
Carbon Chain ◽  
Wear Scar ◽  
Wear Properties ◽  
Tribochemical Reaction ◽  
Lubricating Material ◽  
Combined Action ◽  
Fe Hydroxide ◽  
High Degree

The homemade soot capture device was used to burn Fischer-Tropsch synthetic diesel (F-T diesel) in order to simulate the combustion of F-T diesel in the engine and collect its soot (F-T DS, FS). The zinc-iron hydrotalcite (ZnFe-LDH) and the composite materials of FS and ZnFe-LDH (F-T DS/ZnFe-LDH, FS/ZnFe-LDH) were prepared by hydrothermal synthesis, and the similarities and differences in tribological characteristics of the above three lubricating materials such as 10# white oil (10# WO) lubricant additives were investigated. FS is an aggregation composed of amorphous carbon and graphite microcrystals. ZnFe-LDH is mainly composed of nanosheets, Zn, and Fe hydroxide particles, with a high degree of crystallization, while FS/ZnFe-LDH is a “sandwich layer” composed of nanosheets and soot particles. Because of the addition of cetyltrimethylammonium bromide and the grafting of a long carbon chain lipophilic group in the preparation process, FS/ZnFe-LDH has better anti-wear properties than the FS and ZnFe-LDH Effect. When FS/ZnFe-LDH is added at 0.2 wt.%, the average friction coefficient (AFC) and average wears scar diameter (AWSD) are at their lowest. Compared with pure 10# WO, the minimum values of AFC and AWSD have dropped by 36.84% and 22.58%, respectively. XPS analysis of the wear scar surface shows that when ZnFe-LDH and FS/ZnFe-LDH are used as lubricating additives of 10# WO, together with the organic matter in the white oil and the iron element in the friction pair, tribochemistry occurs under the combined action of the adsorption force and the tribochemical reaction, a friction protection film containing four elements of C, O, Fe, and Zn is formed on the surface of the wear scar, which effectively reduces the wear and reduces the friction coefficient.

Frictional Performance of an Ionic Liquid/Graphene Composite Additive in Lubricating Oil

NANO ◽  
2021 ◽  
pp. 2150111
Author(s):  
Shengli You ◽  
Ming Zhou ◽  
Mingyue Wang ◽  
Xin Chen ◽  
Long Jin ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Pair ◽  
Testing Machine ◽  
Steel Ball ◽  
Wear Scar ◽  
Wear Testing ◽  
Lubricating Oil ◽  
Wear Scar Diameter ◽  
Base Oil ◽  
Frictional Performance

In this study, we used a four-ball friction and wear testing machine to test the tribological properties of [HPy]BF4 ionic liquids (ILs), low-layer graphene (G), and IL and G compounds (IL/G) as lubricant additives at variousconcentrations, loads, and speeds. The morphology of the wear scar was characterized by a white-light interferometer and a scanning electron microscope (SEM). The results showed that the optimal concentrations of IL and G were 0.10[Formula: see text]wt.% and 0.05[Formula: see text]wt.%, respectively. When the IL concentration was 0.10[Formula: see text]wt.%, the friction coefficient and the wear scar diameter (WSD) reduced by approximately 18% and 8%, respectively, compared to the base oil. When the concentration of G was 0.05[Formula: see text]wt.%, the friction coefficient and WSD reduced by approximately 23% and 12%, respectively, compared to the base oil. After adding the optimal concentration of the IL/G composite additive under the same test conditions, the average friction coefficient of the steel ball reduced by approximately 30%, and the average WSD reduced by approximately 18%. IL/G nanoadditives could be easily attached to the pit area on the friction surface of the steel ball, which made the contact surface of the friction pair smoother and the area of the oil film bearing the load larger, compared to those using the base oil. These two combined phenomena promoted synergistic antifriction and antiwear effects, which significantly improved the frictional performance of the base oil.

Effect of Ultrasonic Vibration on the Friction and Wear Properties of GCr15/45# Steel Frictional Pairs Lubricated by n-Al2O3 Additives

2012 ◽  
Vol 538-541 ◽  
pp. 1920-1923
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Xin Yu Dong ◽  
Qing Sheng Cui
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Photoelectron Spectroscopy ◽  
Friction And Wear ◽  
Ball Bearing ◽  
Wear Scar ◽  
Friction Reduction ◽  
Wear Volume ◽  
Wear Properties ◽  
Friction And Wear Properties

The friction and wear properties of GCr15/45# steel frictional pairs lubricated by n- Al2O3 additives under ultrasonic vibration or not were studied. The scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS) and energy dispersive spectrometer (EDS) were carried out to analyse the wear scar surface. The effect mechanism of ultrasonic vibration on friction pairs was discussed. The results indicated that ultrasonic vibration could decrease the friction and wear of GCr15/45# friction pairs, when the content of n-Al2O3 was 0.5wt%, the effect of ultrasonic vibration on friction pairs was most obvious. The friction coefficient, wear volume and wear scar depth under ultrasonic vibration decreased 10%, 34% and 13%, respectively. The friction reduction and anti-wear mechanism of n-Al2O3 was single “micro ball bearing” without ultrasonic vibration, and it changed to “micro ball bearing” and adsorption penetration film with ultrasonic vibration, so the friction coefficient and wear volume was reduced.

Wear Properties of Anode Oxidation Coating in the Surface of ZL101 Aluminium Alloy

2011 ◽  
Vol 393-395 ◽  
pp. 499-502
Author(s):  
Zhi Ping Wang ◽  
Feng Yuan
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Friction Pair ◽  
Wear Test ◽  
Wear Properties ◽  
Low Friction ◽  
Wear Performance ◽  
Anode Oxidation ◽  
Adhesion Wear ◽  
Adhesion Effect

The oxidation film was prepared by anode oxidation method on ZL101 aluminium surface, its morphologies, compositions and phases were characterized with SEM (Scanning Electron Microscope), optical profiler, EDS (Energy Disperse Spectroscopy), respectively, its friction coefficient and abrasion performance were analyzed by wear test, and its wear mechanism was discussed. The results show that the thickness of anode oxidation layer is about 35-40m, under dry friction condition, sliding friction coefficient is 0.65-0.72, the wear forms are abrasive attrition and adhesion wear, the low friction pair between furrows effect and adhesion effect improves the wear performance of anode oxidation film on ZL101 aluminum alloy surface.

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.

Water Absorption, Friction and Wear Behaviors of Polypropylene Composites Filled with Hydroxyapatite

2017 ◽  
Vol 733 ◽  
pp. 60-64
Author(s):  
Munir Tasdemir ◽  
Ozkan Gulsoy
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Water Absorption ◽  
Polymer Composites ◽  
Friction And Wear ◽  
Wear Properties ◽  
Polypropylene Composites ◽  
Friction And Wear Properties

In the present work, the friction and wear properties of Polypropylene (PP) based composites filled with Hydroxyapatite (HA) particles were studied. Fillers contents in the PP were 10, 20, and 30 wt%. The effects of hydroxyapatite ratio on the water absorption, friction and wear properties of the polymer composites is presented. The result showed that the addition of HA to the composite changed the water absorption, friction coefficient and wear rate.

Wear Properties and Scuffing Resistance of the Cr–Al2O3 Coated Piston Rings: The Effect of Convexity Position on Barrel Surface

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Siqi Ma ◽  
Wenbin Chen ◽  
Chengdi Li ◽  
Mei Jin ◽  
Ruoxuan Huang ◽  
...  
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Surface Morphology ◽  
Pressure Distribution ◽  
Cylinder Liner ◽  
Wear Loss ◽  
Wear Properties ◽  
Piston Rings ◽  
Oil Film ◽  
Influencing Mechanism

This work investigates the effect of convexity position of ring barrel surface on the wear properties and scuffing resistance of the Cr–Al2O3 coated piston rings against with the CuNiCr cast iron cylinder liner. The scuffed surface morphology and elements distribution as well as the oil film edge were analyzed to explore the influencing mechanism of the convexity position on the scuffing resistance. The results show that the convexity offset rate on the barrel surface of the ring has no noticeable influence on both friction coefficient and wear loss near the dead points, but a suitable convexity position will result in the improved scuffing resistance. The shape of the barrel face not only affects the worn area on the ring, but also determines the oil film wedge and pressure distribution, consequently influences the scuffing resistance.

scholarly journals Microstructures and high-temperature self-lubricating wear-resistance mechanisms of graphene-modified WC-12Co coatings

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 315-331 ◽  
Author(s):  
Haoliang Tian ◽  
Changliang Wang ◽  
Mengqiu Guo ◽  
Yongjing Cui ◽  
Junguo Gao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Friction Coefficient ◽  
Adhesive Strength ◽  
Friction And Wear ◽  
Resistance Mechanisms ◽  
High Temperature Treatment ◽  
Wear Properties ◽  
Powder Preparation ◽  
Wear Resistant

AbstractTo reduce the friction coefficient of cobalt-cemented tungsten carbide (WC-12Co) wear-resistant coatings, graphene was compounded into WC-12Co powder via wet ball milling and spray granulation. Self-lubricating and wear-resistant graphene coatings were prepared via detonation gun spraying. The presence, morphologies, and phase compositions of graphene in the powders and coatings that are obtained through different powder preparation processes were analyzed. The analysis was performed using the following technologies: energy-dispersive X-ray-spectroscopy (EDXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The mechanical properties of the coatings were studied using a microhardness tester and a universal drawing machine. The friction and wear properties of the coatings were studied using an SRV-4 friction and wear tester. The results showed that the graphene content in the WC-12Co coating modified with graphene was higher than that without modification; graphene was embedded in the structure in a transparent and thin-layer state. The adhesive strength of this coating at approximately 25 °C was approximately 60.33 MPa, and the hardness was approximately 984 HV0.3. After high-temperature treatment, the adhesive strength and hardness of the graphene oxide (GO)/WC-12Co coating decreased slightly (the lowest adhesive strength of 53.16 MPa was observed after treatment at 400 °C, and the lowest hardness of approximately 837 HV0.3 was observed after treatment at 300 °C). Compared to the friction coefficient (0.6) of the WC-12Co coating obtained at room temperature, the friction coefficient of the GO/WC-12Co coating was decreased by approximately 50% of that value. The graphene-modified coating was continuously exposed to the wear tracks on the surface of the contacting materials during friction, and a lubricating film was formed in the microareas in which the wear tracks were present. The coating exhibited improved self-lubricating and wear-resistant effects compared to the unmodified WC-12Co coating. The results of this study demonstrated that graphene could be effective in self-lubrication and wear-reduction in a temperature range of 100–200 °C, as a friction coefficient of 0.3 was maintained.

Experimental investigation on Stribeck curves of different elastic modulus materials under oil and water lubrication conditions

2020 ◽  
Vol 72 (6) ◽  
pp. 805-810
Author(s):  
Hua Zhang ◽  
Guangwu Zhou ◽  
Ping Zhong ◽  
Kepeng Wu ◽  
Xingwu Ding
Keyword(s):  
Elastic Modulus ◽  
Friction Coefficient ◽  
Friction Pair ◽  
Water Lubrication ◽  
Contact Friction ◽  
Friction Coefficients ◽  
Content Type ◽  
Low Viscosity ◽  
Stribeck Curves ◽  
Lubrication Conditions

Purpose The purpose of this paper is to study the influence of friction coefficient of materials with different elastic modulus on the variation of velocity and load under water lubrication and oil lubrication conditions. Design/methodology/approach Low-viscosity lubricating oil and water were used as lubricants to test the friction performance of the ball-disc contact friction pair in the lubrication state on the universal micro-tribometer multi-functional friction and wear test system. Findings In the same speed range, the lubrication states from soft to rigid materials are not necessarily similar to each other. Generally, the material with low elastic modulus is suitable in low-viscosity lubricant environments, while the material with high elastic modulus has relatively smaller friction coefficients in oil-lubricated environments compared with water lubrication. However, the coefficients of polyethylene, polytetrafluoroethylen and polyoxymethylene are exceeded by rubber’s coefficients under water lubrication in the same experiment environments, and their lubrication states are not affected by lubricants. The friction coefficient of the friction pair decreases with the increase of loads; however, it does not apply to all materials. The friction coefficients of materials with smaller elastic modulus such as rubber under high loads are rather large. Therefore, the elastic modulus of the material under high loads is a factor to be considered. Originality/value The Stribeck curves study of the ball-disk contact friction pair comprising soft and rigid materials, whose elastic modulus is from hundreds of GPa to a few of MPa, was carried out. The influence of different speeds, loads and lubricants on the friction coefficient of the friction pair was revealed, which provided a research basis for the selection and matching of friction pair materials.

Microstructure, nano-mechanical characterization, and fretting wear behavior of plasma surface Cr-Nb alloying on γ-TiAl

2020 ◽  
pp. 135065012093983
Author(s):  
Dongbo Wei ◽  
Fengkun Li ◽  
Xiangfei Wei ◽  
Tomasz Liskiewicz ◽  
Krzysztof J Kubiak ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Behavior ◽  
Wear Test ◽  
Wear Scar ◽  
Fretting Wear ◽  
Friction Behavior ◽  
Plasma Surface ◽  
Nb Alloying

In this study, surface Cr-Nb alloying was realized on γ-TiAl using double glow plasma hollow cathode discharge technique. An inter-diffusion layer was generated under the surface, composed of Cr2Nb intermetallic compounds. After Cr-Nb alloying, the surface nanohardness of γ-TiAl increased from 5.65 to 11.61 GPa. The surface H/E and H3/E2 increased from 3.37 to 5.98 and from 0.64 to 4.15, respectively. Cr-Nb alloying and its effect on fretting wear were investigated. The surface treatment resulted in improved plastic deformation and fretting wear resistance of γ-TiAl. The fretting wear test showed that an average friction coefficient of γ-TiAl against Si3N4 ball was significantly decreased after Cr-Nb alloying. The fluctuation of friction coefficient during running-in stage was significantly improved. The friction behavior of both γ-TiAl before and after Cr-Nb alloying could be divided into distinctive stages including formation of debris, flaking, formation of crack, and delamination. It was observed that the high hardness, resistance to plastic deformation, and fatigue resistance of γ-TiAl after Cr-Nb alloying could inhibit the formation of debris and delamination during friction test. The fretting wear scar area and the maximum wear scar depth were decreased, indicating that the wear resistance of γ-TiAl has been greatly improved after Cr-Nb alloying. The results indicated that plasma surface Cr-Nb alloying is an effective way for improving the fretting wear resistance of γ-TiAl in aviation area.

scholarly journals Evaluation of the effectiveness of anti-turbulent additives in the oil pipeline transportation

2020 ◽  
Vol 157 ◽  
pp. 02005
Author(s):  
Aleksei Balabukha ◽  
Valentina Zvereva
Keyword(s):  
Friction Coefficient ◽  
Experimental Studies ◽  
Computer Application ◽  
Eastern Siberia ◽  
Practical Application ◽  
Pipeline Transportation ◽  
Pressure Losses ◽  
Oil Pipeline ◽  
Oil Pipelines ◽  
High Degree

The authors of the article have developed the computer application allows to determine the value of the friction coefficient λ and anti-turbulent additives efficiency with a high degree of accuracy. The program can be used in the calculations and design of oil pipelines. The paper presents experimental studies of the effect anti-turbulent additives on the magnitude of pressure losses during fluid movement through pipes. The data gained by the developed computer program has been proved by the data of practical application of additives in the real oil pipeline transportation system called Eastern Siberia-Pacific Ocean oil pipeline.

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