Effect of load on the tribological properties of Si3N4-hBN composite ceramics sliding against Si3N4

2018 ◽  
Vol 70 (9) ◽  
pp. 1699-1705
Author(s):  
Dong Qiang Gao ◽  
Rui Wang ◽  
Wei Chen

Purpose The effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 were investigated under dry and water lubrication condition. Design/methodology/approach Using a MMU-5G type pin-on-disc friction and wear tester. Findings Under the dry friction, the wear mechanism was dominated by ploughing and abrasive wear, and the contact status was elastic contact under the load less than 25 N. With the increase of the load, the friction coefficient decreased; the main wear mechanism was fatigue fracture, and the contact status turned into plastic contact. Under water lubrication, effective lubrication film could be produced on the worn surface, and it had a function of fluid lubrication under the load less than 15 N. With the increase of the load, the pin and the disc came into direct contact, and the friction and wear of the pairs were aggravated; the wear mechanism changed from chemical wear into abrasive wear and brittle spalling. Originality/value The study on the effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 was investigated under dry and water lubrication condition in the way of contact stress.

2012 ◽  
Vol 472-475 ◽  
pp. 618-621 ◽  
Author(s):  
Li Li Duan ◽  
Xu Ran

Copper-graphite composites were fabricated by spark plasma sintering (SPS) and cold-pressed (CP) processing using a mixture of copper and graphite powders mechanically alloyed. Pin-on-disc wear was used to evaluate the tribological behavior of copper-graphite composites. The results show that the coefficient friction and wear rate decreased considerably with increasing graphite content; with increasing the sintering temperature, the coefficient friction and wear rate just decreased in the same way. XPS analysis of worn surface indicated that better tribological properties are due to a lubricious film covering almost entire worn surface. The presence of this tribolayer improves the friction and wear characteristics when the tribolayer covers almost entire wear surface it effectively restricts metal to metal contact between pin and disc.


2011 ◽  
Vol 704-705 ◽  
pp. 877-885
Author(s):  
San Ming Du ◽  
Yong Zhen Zhang ◽  
Bao Shangguan

Abstract: In this article, the high-speed dry sliding tribological behaviors of CrNiMo steel against brass in nitrogen and oxygen atmospheres are investigated using a pin-on-disc tribometer. The worn surface is characterized by scanning electron microscopy and electron dispersion spectrums analysis. The wear mechanisms of CrNiMo steel are also analyzed. The results indicate that the tribological properties of CrNiMo steel are coincidental with the law of dry sliding of metal, where the friction coefficients decreases with an increase in sliding speed and with normal load. However, the atmosphere has obvious effects on the tribological properties of CrNiMo steel. In the sliding process, friction heat plays an important role on the tribological properties of materials in high-speed dry friction. The high-speed wear mechanism of CrNiMo steel varies at different atmospheres. In a nitrogen atmosphere, the wear mechanism of CrNiMo steel is mainly characterized by adhesion at a lower speed and load. When the speed and load are increased, melting trace is found in the worn surface accompanied by an abrasive wear. In an oxygen atmosphere, the mechanism is characterized by adhesion at a lower speed and load; with an increase in speed and load, it gradually transformed into oxidation wear and abrasive wear. The difference of the wear mechanisms in the different atmospheres and test parameters is primarily due to the transfer films formed on the contact surfaces of the sliding pairs. In our experimental conditions, the surface film is mainly the metal film in nitrogen, whereas, it is the oxide film in oxygen.


2019 ◽  
Vol 71 (7) ◽  
pp. 931-941 ◽  
Author(s):  
Yazhou Mao ◽  
Yang Jianxi ◽  
Xu Wenjing ◽  
Liu Yonggang

Purpose The purpose of this paper is to investigate the effect of round pits arrangement patterns on tribological properties of journal bearing. In this paper, the tribological behaviors of journal bearing with different arrangement patterns under lubrication condition were studied based on M-2000 friction and wear tester. Design/methodology/approach The friction and wear of journal bearing contact surface were simulated by ANSYS. The wear mechanism of bearing contact surfaces was investigated by the means of energy dispersive spectrum analysis on the surface morphology and friction and wear status of the journal bearing specimens by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS). Besides, the wearing capacity of the textured bearing was predicted by using the GM (1,1) and Grey–Markov model. Findings As the loads increase, the friction coefficient of journal bearing specimens decrease first and then increase slowly. The higher rotation speed, the lower friction coefficient and the faster temperature build-up. The main friction method of the bearing sample is three-body friction. The existence of texture can effectively reduce friction and wear. In many arrangement patterns, the best is 4# bearing with round pits cross-arrangement pattern. Its texturing diameters are 60 µm and 125 µm, and the spacing and depth are 200 µm and 25 µm, respectively. In addition, the Grey–Markov model prediction result is more accurate and fit the experimental value better. Originality/value The friction and wear mechanism is helpful for scientific research and engineers to understand the tribological behaviors and engineering applications of textured bearing. The wear capacity of textured bearing is predicted by using the Grey–Markov model, which provides technical help and theoretical guidance for the service life and reliability of textured bearing.


2016 ◽  
Vol 68 (3) ◽  
pp. 308-314 ◽  
Author(s):  
Ming Qiu ◽  
Yanwei Miao ◽  
Yingchun Li ◽  
Long Chen ◽  
Rensong Hu ◽  
...  

Purpose The fabric self-lubricating liners are the key factors impacting the performances of self-lubricating spherical plain bearings. The purpose of this paper is to improve the friction and wear properties of self-lubricating radial spherical plain bearings by modification of the liners. Design/methodology/approach The liners of hybrid woven PTFE/Kevlar fabrics were treated respectively by the LaCl3 and CeO2 solutions. The tribological properties of self-lubricating spherical plain bearings with treated or untreated liners under continuous swaying conditions were investigated with the bearing tester at the swaying frequency of 2.5 Hz and the swaying angle of ±10°. The film formation and wear mechanisms were analyzed based on the observation of worn surfaces with a scanning electron microscope (SEM) and an energy dispersive spectrometer (EDS). Findings Results show that the tribological properties of the bearings treated by the LaCl3 or CeO2 solution were improved compared with those of the untreated bearings. In particular, the wear resistance of bearings treated by the CeO2 solution was remarkably improved under higher swaying cycles, but the anti-friction properties and cooling effects of bearings treated by the LaCl3 solution were better under lower swaying cycles. Through SEM analysis, the reasons were analyzed. The bearings with treated liners only produced slight adhesive and abrasive wear, but the bearings with untreated liners produced more serious adhesive and abrasive wear under higher swaying cycles. Originality/value The paper proposed a new pretreatment process for the self-lubricating liners. The investigation on the friction and wear behaviors of the bearings is beneficial for prolonging the service lives of the radial spherical plain bearings.


2021 ◽  
pp. 089270572110286
Author(s):  
Xinyue Zhang ◽  
Dekun Zhang ◽  
Kai Chen ◽  
Handong Xu ◽  
Cunao Feng

The complex movement of artificial joints is closely related to the wear mechanism of the prosthesis material, especially for the polymer prosthesis, which is sensitive to motion paths. In this paper, the “soft-soft” all-polymer of XLPE/PEEK are selected to study the influence of motion paths on the friction and wear performance. Based on the periodic characteristics of friction coefficient and wear morphology, this paper reveals the friction and wear mechanism of XLPE/peek under multi-directional motion path, and obtains the quantitative relationship between friction coefficient and the aspect ratios of “∞”-shape motion path, which is of great significance to reveal and analyze the wear mechanism of “soft” all-polymer under multi-directional motion path. The results show that the friction coefficient is affected by the motion paths and have periodicity. Morever, under the multi-directional motion paths, the wear of PEEK are mainly abrasive wear and adhesive wear due to the cross shear effect, while the wear of XLPE is mainly abrasive wear with plastic accumulation. In addition, the friction coefficient is greatly affected the aspect ratios Rs-l of “∞”-shape and loads. Meanwhile, the wear morphologies are greatly affected by the aspect ratios Rs-l of “∞”-shape, but less affected by loads.


2017 ◽  
Vol 69 (6) ◽  
pp. 919-924
Author(s):  
Dawit Zenebe Segu ◽  
Pyung Hwang

Purpose This study aims to compare the friction and wear behaviors of Fe68.3C6.9Si2.5 B6.7P8.8Cr2.2Al2.1Mo2.5 bulk metallic glass (BMG) under sliding using dry, deionized water-lubricated and oil-lubricated conditions. The comparison was performed using a unidirectional ball-on-flat tribometer under different applied loads, and the results were compared to the properties of a conventional material, SUJ2. Fe-based BMG materials have recently been attracting a great deal of attention for prospective engineering applications. Design/methodology/approach As a part of the development of Fe-based BMGs that can be cost-effectively produced in large quantities, an Fe-based BMG Fe68.8C7.0Si3.5B5.0P9.6 Cr2.1Mo2.0Al2.0 with high glass forming ability was fabricated. In the present study, the friction and wear properties of Fe-based BMG has been comparatively evaluated under dry sliding, deionized water- and oil-lubricated conditions using a unidirectional ball-on-flat tribometer under different applied loads, and the results were compared to the properties of conventional material SUJ2. Findings The results show that the Fe-based BMG had better friction performance than the conventional material. Both the friction coefficient and wear mass loss increased with increasing load. The sliding wear mechanism of the BMG changed with the sliding conditions. Under dry sliding conditions, the wear scar of the Fe-based BMG was characterized by abrasive wear, plastic deformation, micro-cracks and peeling-off wear. Under water- and oil-lubricated conditions, the wear scar was mainly characterized by abrasive wear and micro-cutting. Originality/value In this investigation, the authors developed a new BMG alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 to improve the friction and wear performance under dry sliding, deionized water- and oil- lubricated conditions.


2017 ◽  
Vol 69 (5) ◽  
pp. 645-654 ◽  
Author(s):  
Juozas Padgurskas ◽  
Raimundas Rukuiža ◽  
Ihor Mandziuk ◽  
Arturas Kupcinskas ◽  
Katerina Prisyazhna ◽  
...  

Purpose The purpose of this paper is to report on the tribological properties of beef tallow grease and improvements therein through modification with special processing, polymeric compounds and additives. Design/methodology/approach Pure original beef tallow grease was used as a biological lubricating grease reference material for the tribological research. Beef tallow was modified and synthesized by adding special biological anti-oxidant additives, LZ anti-wear additives, waste polyethylene terephthalate (PET) polymer compounds and thermally processed graphite. Findings Rheometric measurements indicate that the beef tallow grease modification technology used in this study enables control of the synthesis process to produce lubricants with the required microstructure. Investigation results of the tribological properties of differently modified greases show that beef tallow synthesized with polymer additives efficiently operates together with anti-wear additives to reduce friction and wear. The grease compound with thermally processed graphite has good tribological properties at 300 N load levels. The critical load level of lubricating greases could be significantly increased through the use of anti-wear additives and thermally processed graphite. Originality/value Investigation results of the tribological properties of differently modified beef tallow greases show that beef tallow synthesized with polymer additives efficiently operates together with anti-wear additives to reduce friction and wear. The critical load level of lubricating beef tallow greases could be significantly increased using anti-wear additives and thermally processed graphite.


2018 ◽  
Vol 70 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Ting Xie ◽  
Dan Li ◽  
Ming Xu ◽  
...  

Purpose This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions. Design/methodology/approach Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed. Findings Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings. Originality/value Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 635 ◽  
Author(s):  
Fang Han ◽  
Huaixing Wen ◽  
Jianjian Sun ◽  
Wei Wang ◽  
Yalong Fan ◽  
...  

This paper concerns a comparative study on the tribological properties of Si3N4-10 vol% hBN bearing on GCr15 steel under seawater lubrication and dry friction and fresh-water lubrication by using a pin-on-disc tribometer. The results showed that the lower friction coefficient (around 0.03) and wear rate (10−6 mm/Nm) of SN10/GCr15 tribopair were obtained under seawater condition. This might be caused by the comprehensive effects of hydrodynamics and boundary lubrication of surface films formed after the tribo-chemical reaction. Despite SN10/GCr15 tribopair having 0.07 friction coefficient in the pure-water environment, the wear mechanismsits were dominated by the adhesive wear and abrasive wear under the dry friction conditions, and delamination, plowing, and plastic deformation occured on the worn surface. The X-ray photoelectron spectroscopy analysis indicated that the products formed after tribo-chemaical reaction were Fe2O3, SiO2, and B2O3 and small amounts of salts from the seawater, and it was these deposits on the worn surface under seawater lubrication conditions that, served to lubricate and protect the wear surface.


2010 ◽  
Vol 150-151 ◽  
pp. 1364-1368 ◽  
Author(s):  
Tao Ding ◽  
Guang Xiong Chen ◽  
Ming Xue Shen ◽  
Min Hao Zhu ◽  
Wei Hua Zhang

Friction and wear tests of stainless steel rubbing against copper-impregnated metalized carbon with electric current were carried on the pin-on-disc tester. The result indicates that arc discharge occurs in the process of experiments, and the intensity of arc discharge of interface increases with increasing of electric current and sliding velocity. As increasing of the arc discharge intensity, friction coefficient shows a tendency of slightly increase. While the rate of copper-impregnated metalized carbon material increase significantly with the increase of arc discharge intensity. Through observing the worn surface morphology of pin samples, it is found that the abrasive wear is dominant at small arc discharge due to worn particles and arc ablation craters, but arc erosion and oxidation wear are the main wear mechanisms in condition of large arc discharge due to arc discharge and its producing high temperature. The materials transfer of contact couple occurs in the process of friction and wear.


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