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Article
Publication date: 3 June 2014

Alicja Laber

The purpose of this paper is to present the results of research into using an additive to SAE 15W/40 engine oil during operation and its influence on lubricating properties…

Abstract

Purpose

The purpose of this paper is to present the results of research into using an additive to SAE 15W/40 engine oil during operation and its influence on lubricating properties (normalised tests) on weld point Pz, non-seizure load Pn, load wear index Ih and on seizure load Pt. The friction pair consisted of a group of four balls and the tested lubricant. Moreover, the author tested the influence of an additive to engine oil (non-normalised tests) on tribological properties, including friction force, wear and the temperature of friction area for the C45 steel/210Cr12 steel friction joint. She also determined the influence of an additive to engine oil on the formation of the operating surface layer. The research results helped to build the model of the boundary layer that was formed as a result of adding an additive to engine oil.

Design/methodology/approach

The lubricant properties of engine oil and engine oil to which an additive was added during operation were determined according to PN-76/C-04147. The following are the indexes of lubricant properties: weld point Pz, load wear index Ih, non-seizure load Pn, seizure load and average scar diameter. The Pz, Pn and Ih indexes were determined at abruptly increasing load to the moment of welding of the friction pair. The Pt index was determined at the increasing load of the friction pair from 0 to 800 daN at the speed of 408.8 N/s. The tests of tribological properties (friction force, wear and the temperature of friction area) were conducted for the C45/210 Cr12 friction pair in the presence of a lubricant and a lubricant with an additive.

Findings

The modification of SAE 15W/40 engine oil with the additive added during operation resulted in improved indexes of lubricant properties Pz, Pn, Ih and Pt and average scar diameter. The boundary layer for the modified oil breaks after a longer time and at lesser friction force. The modification of the engine oil reduced the wear of the friction pair. After the friction process, element composition in the surface layer of the wear trace and its distribution were determined in relation to applied lubricants. A significant amount of sulphur, phosphorus and oxygen, as well as an insignificant amount of copper, was observed in the wear trace after the friction process in the presence of the lubricant medium. The distribution of elements in the wear trace when the engine oil with the additive was used is steady in the wear trace and outside it. Some sulphur, phosphorus and chlorine were found in the wear trace.

Originality/value

The results of tests on tribological properties (non-normalised tests) confirmed the positive affect of the additive to engine oil on lubricant properties (normalised tests). The modification of the engine oil caused reduced friction force and the reduced wear of the friction pair. The reduction of friction force and wear was the result of the formation of the surface of a greater amplitude density of unevenness tops in the friction process. Moreover, the operating surface layer, created in the friction process when the additive was added to the engine oil, had greater load participation at 50 per cent C. This operational surface layer improved tribological properties, i.e. it reduced value of friction force and wear. The test results were used to build a model of the boundary layer created as a result of the additive added to engine oil.

Details

Industrial Lubrication and Tribology, vol. 66 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 17 August 2023

Yinkai Niu, Heyun Bao, Wei Huang, Wuzhong Tan and Rupeng Zhu

During the operation of a wet clutch, there are fluctuations in speed and torque, which have an impact on the stability of the clutch and the strength of the friction plate and…

88

Abstract

Purpose

During the operation of a wet clutch, there are fluctuations in speed and torque, which have an impact on the stability of the clutch and the strength of the friction plate and the spline pair of the dual steel plate. The purpose of this study is to investigate the vibration characteristics of the wet clutch and the dynamic load characteristics of the spline pairs.

Design/methodology/approach

The spline pair model is established by the piecewise linear function method, and on this basis, dynamic equations considering the spline pair of dual steel plates and friction plates are established. Considering that the wet clutch has multiple spline pairs, an equivalent model of the number of teeth and the equivalent model of the tooth width were proposed, and the Runge-Kutta numerical method was used for the wet clutch for these two models.

Findings

The research results show that the equal tooth number model has greater meshing stiffness and smaller fluctuation than the constant tooth width model, which shows that increasing the meshing stiffness of the system is beneficial to reduce system fluctuation and improve system stability.

Research limitations/implications

The friction plate has the system that multiple splines are independent of each other, which is relatively complicated. Therefore, an equivalent calculation is performed on multiple pairs of steel plates (friction plates) to simplify the calculation of the spline pairs.

Social implications

This paper provides a theoretical basis for further dynamic characteristics analysis of wet clutch and reducing fluctuation of speed and torque.

Originality/value

Dynamic equation considering the spline pair of the dual steel plates and the friction plates is established to study the vibration characteristics of the wet clutch and the dynamic load characteristics of the spline pair, etc.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2023-0078/

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 4 December 2018

Bingjing Qiu, Jiyun Zhao and Jiaxiang Man

Aiming at improving the mechanical efficiency, the applicability and the working life of high water-based hydraulic motor (HWBHM) under working conditions at low speed and high…

Abstract

Purpose

Aiming at improving the mechanical efficiency, the applicability and the working life of high water-based hydraulic motor (HWBHM) under working conditions at low speed and high pressure, the friction performance of different matching materials for piston slipper – crankshaft pair with high water-based hydraulic fluid (HWBHF) under working conditions at low speed and high pressure – were studied.

Design/methodology/approach

The friction experiments for different materials (316L, 316L with surface coating OVINO – tetrahedral amorphous carbon [TAC; 316L-TAC] – 316L with surface coating OVINO-graphite intercalated compound [GIC; 316L-GIC] and polyetheretherketone [PEEK] reinforced with 30 per cent carbon fiber [PEEK-30CF]) under HWBHF lubrication were implemented on a pin-disk friction abrasion machine to determine the variations of coefficient of friction (CoF) and wear rate for each matching materials. In addition, the roughness and the morphology of worn surface of different matching materials were quantitatively characterized.

Findings

The study revealed that material combinations have different friction performances. Test results showed that the abrasion of matching type stainless steel (SS) and SS is rather serious, and the method of surface coating could improve the friction performance of SS when friction with other materials. For matching type of SS with surface treatment (SS-ST) and SS-ST, 316L-GIC and 316L-GIC have relatively stable CoF, and the wear rate was smaller than other matching materials, while 316L-TAC and 316L-TAC has the smaller CoF than that of 316L-GIC. Matching materials 316L-GIC with PEEK-30CF of matching type SS-ST and PEEK-30CF has more stable COF and better wear resistance than those of other matching materials.

Originality/value

This research has laid a foundation for the improvement of service life and working efficiency of friction pair in HWBHM under working conditions at low speed and high pressure.

Details

Industrial Lubrication and Tribology, vol. 71 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 4 March 2020

Hua Zhang, Guangwu Zhou, Ping Zhong, Kepeng Wu and Xingwu Ding

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…

Abstract

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.

Details

Industrial Lubrication and Tribology, vol. 72 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 2 August 2018

Fanjing Meng, Kun Liu and Tao Qin

Granular lubrication is a new lubrication method and can be used in extreme working conditions; however, the obstacle of force transmission characteristics needs to be urgently…

Abstract

Purpose

Granular lubrication is a new lubrication method and can be used in extreme working conditions; however, the obstacle of force transmission characteristics needs to be urgently solved to fully understand the mechanical and bearing mechanisms of granular lubrication.

Design/methodology/approach

A flat sliding friction cell is developed to study the force transmission behaviors of granules under shearing. Granular material, sliding velocity, granule size and granule humidity are considered in these experiments. The measured normal and shear force, which is transmitted from the bottom friction pair to the top friction pair via the granular lubrication medium, reveals the influence of these controlling parameters on the force transmission characteristics of granules.

Findings

Experimental results show that a low sliding velocity, a large granule size and a low granular humidity increase the measured normal force and shear force. Besides, a comparison experiment with other typical lubrication styles is also carried out. The force transmission under granular lubrication is mainly dependent on the force transmission path, which is closely related to the deconstruction and reconstruction of the force chains in the granule assembly.

Originality/value

These findings reveal the force transmission mechanism of granular lubrication and can also offer the helpful reference for the design of the new granular lubrication bearing.

Details

Industrial Lubrication and Tribology, vol. 70 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 4 September 2017

Fangwei Xie, Diancheng Wu, Yaowen Tong, Bing Zhang and Jie Zhu

The purpose of this paper is to study the influence of structural parameters of oil groove (such as central angle number, depth and so on) on pressure, flow, load capacity and…

Abstract

Purpose

The purpose of this paper is to study the influence of structural parameters of oil groove (such as central angle number, depth and so on) on pressure, flow, load capacity and transmitted torque between friction pairs of hydro-viscous clutch.

Design/methodology/approach

According to the working process of friction pairs of hydro-viscous clutch, mathematical models of hydrodynamic load capacity and torque transmitted by the oil film were built based on viscosity-temperature property. Then analytical solutions of pressure, flow, load capacity and transmitted torque were obtained; effects of central angle of oil groove zone and friction contact zone, oil film thickness, number of oil grooves on pressure, flow, load capacity and torque were studied theoretically.

Findings

The research found that the central angle of oil groove zone, number of oil grooves and oil groove depth have similar effects on flow, which means that with the increase of central angle, number or depth of oil grooves, the flow also increases; pressure in friction contact zone and oil groove zone drops along radial direction, whereas its value in oil groove zone is higher. With the increase of the central angle of oil groove zone, pressure in friction contact zone and friction contact zone rises, and the load capacity increases, whereas the transmitted torque drops. Number of oil grooves has little effect on load capacity. When the oil film thickness increases, its flow increases accordingly, whereas the pressure, load capacity and transmitted torque drops. Meanwhile, the transmitted torque decreases with the increase of number of oil grooves, whereas the oil groove depth nearly has no effects on transmitted torque.

Originality/value

In this paper, mathematical models of hydrodynamic load capacity and torque transmitted by oil film were built based on viscosity-temperature property in the working process of hydro-viscous clutch, and their analytical solutions were obtained; effects of structural parameters of oil groove on transmission characteristics of hydro-viscous clutch based on viscosity-temperature property were revealed. The research results are of great value to the theory development of hydro-viscous drive technology, the design of high-power hydro-viscous clutch and relative control strategy.

Details

Industrial Lubrication and Tribology, vol. 69 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 29 September 2021

Gang Wang, Wei Wang, Yi Zhang, Xu Zhang, Zhaowen Hu, Kun Liu and Daogao Wei

This paper aims to investigate the micro-plastic behavior of granular material in three-body friction interface and its effect on friction characteristics.

Abstract

Purpose

This paper aims to investigate the micro-plastic behavior of granular material in three-body friction interface and its effect on friction characteristics.

Design/methodology/approach

A numerical model of particle breakage in friction contact was constructed based on the discrete element method. The influence of friction pair working condition and internal bonding strength on the micro-plastic behavior of particulate matter was analyzed. A reciprocating linear tribometer was used to verify the simulation results.

Findings

The results show that when the granular materials are squeezed and sheared by the friction pair, a shear zone inclined to the left is gradually formed, which leads to particle breakage. The breakage of the particle leads to the reduction of load-bearing capacity and the increase of friction coefficient. Due to the differences in bond strength and friction pairs working conditions, the particle plastic behavior is divided into the following three states: elastic deformation, breakage and plastic rheology.

Originality/value

This study is helpful to understand the effect of the micro-plastic behavior of particles on the three-body friction characteristics.

Details

Industrial Lubrication and Tribology, vol. 73 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 21 January 2022

Raimondas Kreivaitis, Milda Gumbytė and Jolanta Treinytė

This paper aims to investigate the tribological properties of two protic ionic liquids used as lubricity-improving additives in the water. Their concentration was optimized for…

Abstract

Purpose

This paper aims to investigate the tribological properties of two protic ionic liquids used as lubricity-improving additives in the water. Their concentration was optimized for different metal friction pairs including bearing steel, stainless steel and aluminum alloy.

Design/methodology/approach

In this study tribological properties were investigated by using a ball-on-plate reciprocating tribometer. Three different friction pairs were selected: bearing steel-bearing steel; bearing steel-stainless steel; bearing steel-aluminum alloy. To optimize the concentration of investigated protic ionic liquids four concentrations were selected. Wettability was investigated using the droplet method. The corrosiveness of additive-loaded water was investigated using the iron chip method.

Findings

The results show that by using protic ionic liquids the lubricity of water could be greatly improved. However, the friction pair material and additive concentration play a significant role. The positive tribological effect was attributed to the polarity of the additive molecule which tends to form an adsorption layer. The polarity of molecules also leads to better surface wettability. It was also found that both investigated protic ionic liquids can improve the anticorrosion properties of water.

Originality/value

To the best of the authors’ knowledge, this is the first study to present a complex investigation of tribological properties of two protic ionic liquids as additives in the water. In this case, three different metal friction pairs and four additive concentrations were investigated. The results could be interesting to those who are working in the field of water-based lubricants and luck for multipurpose lubricity-improving additives.

Details

Industrial Lubrication and Tribology, vol. 74 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 13 March 2017

Wengang Chen, Xueyuan Liu and Lili Zheng

This paper aims to clarify the friction properties of 304 steel surface modification. The surface modification includes laser texturing processing and nitriding treatment on 304…

168

Abstract

Purpose

This paper aims to clarify the friction properties of 304 steel surface modification. The surface modification includes laser texturing processing and nitriding treatment on 304 steel surface, and then the friction properties’ test was conducted on different friction directions and different upper test samples by using microfriction and wear testing machine.

Design/methodology/approach

The diameter and spacing of 100-, 150-, 200-, 300-μm pit array on the surface of 304 steel were calculated using a M-DPSS-50 semiconductor laser device. Then, the textured surface was nitriding-treated using a nitriding salt bath device. The chemical composition, surface morphology and surface microhardness of the composite-modified surface were measured by X-ray diffraction and by using an optical microscope and a microhardness tester. The tribological characteristics of the composite-modified surface were tested by MRTR microcomputer-controlled multifunctional friction and wear testing machine.

Findings

The result showed that a rule pit texture surface was obtained by the texture processing. The microhardness of nitriding treatment surface reached 574.27HV0.1, which significantly higher than 222.58HV0.1 of 304 steel. The composite-modified surface has excellent anti-friction and wear resistance properties when the upper specimen was GCr15 steel and ZrO2, respectively. The composite-modified surface has excellent anti-friction and anti-wear properties after long time friction under different angles. However, the friction coefficient and wear morphology of the friction pairs are not affected by the friction angle.

Research limitations/implications

Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further.

Practical implications

The paper conducted a systematic study of the tribological characteristics of 304 steel composite modification surface and provided a good basis for the extensive application of 304 steel.

Social implications

The study provides a good basis for the extensive application of 304 steel.

Originality/value

This paper fulfils an identified need to study the extensive application of 304 steel.

Details

Industrial Lubrication and Tribology, vol. 69 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 August 2000

I.I. Garbar E. Sher and R. Shneck

Antiwear mechanism of action of some chemical elements added to lubricant is studied. These elements are transferred from the lubricant into the surface layers of the sliding pair

Abstract

Antiwear mechanism of action of some chemical elements added to lubricant is studied. These elements are transferred from the lubricant into the surface layers of the sliding pair during friction. The mechanism is based on the influence of these elements on the stacking fault energy (SFE) of the materials in the friction pair and leads to changes in the fragmented structure formed in the metals under plastic deformation. Work hardening of the metal surface layers and their predisposition to wear are changed accordingly. Copper and Armco iron, as typical FCC and BCC metals, were chosen for the friction pair materials. Si, Ni, Zn, Co and Ti were used as the additive components to the lubricant. It was found that the addition of different elements to the lubricant leads to alloying by these elements of the surface layers of the metal during the process of friction. It was found that alloying by elements which decreases the SFE of the metal, the average size of surface layer fragments formed during friction increases and the wear rate decreases. The possibility of controlling the wear resistance of metals during friction through the use of appropriate additives is discussed.

Details

Industrial Lubrication and Tribology, vol. 52 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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