scholarly journals Tribological Properties of Si3N4-hBN Composite Ceramics Bearing on GCr15 under Seawater Lubrication

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.

Author(s):  
Xianghua Zhan ◽  
Peng Yi ◽  
Yancong Liu ◽  
Peifa Xiao ◽  
Xiaoye Zhu ◽  
...  

Textural morphology is an important factor influencing dry friction, and few studies have been conducted regarding the effects of single- and multi-shape textures on dry tribological properties. In this work, six types of textures including single- and multi-shape textures were produced on 40Cr steel samples by using a nanosecond laser. Reciprocating sliding tests under dry friction were conducted using a pin-on-disc friction tester. The influences of textured surfaces with different textures on tribological properties were investigated. Results showed that tribological properties were affected by different textural morphologies. The dimple-textured surface had the highest friction coefficient, followed by the groove-textured surface. The sinusoidal-textured surface had the lowest friction coefficient. The friction coefficients of multi-shape textured surfaces were lower than those of non-textured surfaces but higher than those of sinusoidal-textured surfaces. The wear properties of the tested surfaces were consistent with the friction-coefficient results. The sinusoidal- and sinusoidal–groove-textured surfaces can be considered as the optimum choices for dry reciprocating friction.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 660
Author(s):  
Dariusz Jędrzejczyk ◽  
Elżbieta Szatkowska

The analyzed topic refers to the wear resistance and friction coefficient changes resulting from heat treatment (HT) of a hot-dip zinc coating deposited on steel. The aim of research was to evaluate the coating behavior during dry friction after HT as a result of microstructure changes and increase the coating hardness. The HT parameters should be determined by taking into consideration, on the one hand, coating wear resistance and, on the other hand, its anticorrosion properties. A hot-dip zinc coating was deposited in industrial conditions (according EN ISO 10684) on disc-shaped samples and the chosen bolts. The achieved results were assessed on the basis of tribological tests (T11 pin-on-disc tester, Schatz®Analyse device, Sindelfingen, Germany), microscopic observations (with the use of optical and scanning microscopy), EDS (point and linear) analysis, and microhardness measurements. It is proved that properly applied HT of a hot-dip zinc coating results in changes in the coating’s microstructure, hardness, friction coefficient, and wear resistance.


2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.


2015 ◽  
Vol 75 (11) ◽  
Author(s):  
N. Nuraliza ◽  
S. Syahrullail ◽  
M.N. Musa

The use of vegetable oil-based lubricant as a lubricant in various applications has increased and it is eyed by the industry due to its superior tribological properties, besides possessing the potential to replace petroleum-based lubricants. Palm olein is one of alternative lubricants that could be suitable and attractive as a lubricant to be studied due to its advantages and large production in the country. Thus, in this study, the behavior of palm olein characteristics was investigated by using pin-on-disc experiment, in which a hemispherical pin was loaded against the rotating grooved disc. The experiments via sliding were performed with pin-on-disc tester using pure aluminum as the material for hemispherical pin and SKD11 for disc. The test was implemented by dropping continuous flow of palm olein as lubricating oil on sliding surface at different loads applied, which were 10N, 50N, and 100N. The wear rate of the pin and the friction coefficient were also investigated. Moreover, the surface roughness before and after the experiment was analyzed as well. All the results obtained were compared to hydraulic oil and engine oil-SAE 40. From the analysis, the friction coefficient acquired from lubricated with palm olein was the lowest for both conditions. The wear rate obtained for the three lubricants increased from 10N to 100N load for palm oil, but decreased for hydraulic and engine oil-SAE 40. Meanwhile, the wear rate obtained for lubrication with hydraulic oil showed the lowest value compared to Engine oil-SAE 40 and double fractionated palm olein. 


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3452 ◽  
Author(s):  
Mihai Tiberiu Lates ◽  
Radu Velicu ◽  
Cornel Catalin Gavrila

The tribological properties of PA66, PA46, and PTFE-mixed PA46 were investigated. The tests were achieved on a pin-on-disc tribometer. Before tests with different sets of parameters, a running-in-type test (with constant parameters) was performed for all the materials, under lubricated and dry conditions. The tests parameters were variable referring on load, velocity, and temperature. The results are referring on the value of the wear developed during the run-in period and on the variation of friction coefficient with the testing parameters. The results show that the PTFE-mixed PA46 polyamide has better tribological properties than the PA66 and the PA46 polyamide.


2012 ◽  
Vol 591-593 ◽  
pp. 1054-1057 ◽  
Author(s):  
Li Li Yan ◽  
Cheng Biao Wang ◽  
Wen Yue ◽  
Bo Xu

The development of environment-friendly water-based lubricants has been paid more and more attention in modern manufacturing due to environmental concern and human health. In this paper, several water-soluble molybdenum-containing additives (WMCAs) were synthesized, and characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The tribological properties of WMCAs in water were evaluated by a four-ball tester. The results indicated that WMCAs exhibited beneficial effect on the anti-wear and friction-reducing properties of water under all tested concentrations, which could be attributed to organic nitrogen compound, iron oxides and MoO3 in WMCAs tribofilm.


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.


2021 ◽  
Author(s):  
Hai Wang ◽  
Xiaowen Qi ◽  
Yu Dong ◽  
Bingli Fan ◽  
Changxin Liu ◽  
...  

Abstract Polytetrafluoroethylene (PTFE), as one of the most widely used solid lubricating materials, is thought to be very efficient at forming transfer film because of terrific low intermolecular force. This work investigates the tribological properties of PTFE transfer film under dry friction, and further explores its formation process and evolution mechanism. The friction coefficient is the lowest when the transfer film thickness is in range of 8-12 μm. An evaluation method for transfer film is proposed. The results show that the quality of the transfer film is closely related to the test load and velocity. This method is expected to be a general evaluation method for polymer transfer film, which can further directly evaluate the wear state of polymers, and even directly predict the tribological properties of polymers and abrasion life.


2021 ◽  
pp. 1-13
Author(s):  
Jian Liu ◽  
Xudong Sui ◽  
Zhen Yan ◽  
Guosheng Huang ◽  
Junying Hao

Abstract Cr doped MoS2 films were deposited by magnetron sputtering. The tribological properties of Cr doped MoS2 films under vacuum (VC) and air (AR) environments were investigated. The results show that Cr doped MoS2 film with Cr target power of 0.2 A (0.2 A Cr:MoS2 film) exhibits low friction coefficient and long wear life under both VC and AR environments. The chemical compositions of the films were analyzed by energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). With the increases of Cr target power, the content of Cr increases. The cross-sectional FESEM morphologies show that the structure of the films changed from granular particles to column when the Cr target power increases from 0.2A to 0.4A. The wear mechanism has also been discussed based on the characteristics of worn surface. The 0.4 A Cr:MoS2 film has the lowest wear volume among these films, which can be attributed to the compact microstructure. The bandgap of Cr doped MoS2 films were measured by XPS and the tribological performance of the film is found to be best when there is a modest bandgap. It can be speculated that the tribological performance of Cr doped MoS2 films are closely related to the width of bandgap.


2012 ◽  
Vol 512-515 ◽  
pp. 2097-2100
Author(s):  
Xin Feng ◽  
Yan Qiu Xia

Abstract. Two fluorosilicone oils as additives were evaluated using an Optimol SRV reciprocating friction and wear tester by gray cast iron disc against AISI 52100 steel ball at 20 N and sliding speed of 0.20 m/s, respectively. The morphologies of worn surface of the disc were examined using a scanning electron microscope (SEM). In addition, the elemental compositions and chemical states of several typical elements on the worn surfaces of the gray cast iron discs were examined by means of X-ray photoelectron spectroscopy (XPS). Results indicate that PAO(Poly-alpha-olefin)+F-Si-E exhibite excellent tribological properties. This is partly attributed to material properties and tribological reaction between the lubricant and the sliding surface.


Sign in / Sign up

Export Citation Format

Share Document