THE INFLUENCE OF SILICON-DOPED DIAMOND-LIKE CARBON COATING ON THE WEAR OF IONIC LIQUID LUBRICATED FRICTION PAIRS

Tribologia ◽  
2018 ◽  
Vol 282 (6) ◽  
pp. 97-106 ◽  
Author(s):  
Krystian MILEWSKI ◽  
Monika MADEJ ◽  
Joanna KOWALCZYK ◽  
Dariusz OZIMINA

This article reports the results of the study of an a-C:H:Si coating doped with silicon and produced by chemical deposition (PACVD). The effect of the coating on the tribological behaviour of IL-lubricated friction pairs was evaluated. The properties of the 100Cr6 steel specimens with and without the coating were compared. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis were used for imaging the morphology of the coating surfaces and cross-sections and for identifying the elements in the coating composition. The contact angle of the investigated surfaces was measured with an optical tensiometer. Friction tests were performed on a ball-on-disc tribometer under dry friction and when lubricated with trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl) amide ionic liquid. The geometrical structure of the surfaces before and after the tribological tests was measured using an optical profilometer. The ionic liquid used with the silicon-doped diamond-like coating under friction conditions reduced the coefficient of friction and wear. The results obtained from the tests and analysis allow for the conclusion that the use of DLC coatings a-C:H:Si lubricated with trihexyltetradecylphosphonium Bis(trifluoromethylsulfonyl) amide contributes towards the improvement of tribological properties of sliding surfaces under friction.

Author(s):  
J. Palmers ◽  
K. Vanhollebeke ◽  
J. P. Celis ◽  
T. Van der Donck

The aim of this study was the investigation of the fretting wear of industrial and newly developed multi-layered coatings. The tribological behaviour of flat DLC coated specimens was investigated in fretting mode I and fretting mode II against different ball counterbodies namely, corundum, 100Cr6, and DLC coated 100Cr6 using a broad range of strokes, frequencies, and loads. From Fretting I a dependency of the wear behaviour with the type of DLC coating, and an influence of the normal load with the coefficient of friction was observed. Using Fretting mode II, an attempt was made to study the fatigue and toughness properties of the coatings.


Author(s):  
P.A. Crozier

Absolute inelastic scattering cross sections or mean free paths are often used in EELS analysis for determining elemental concentrations and specimen thickness. In most instances, theoretical values must be used because there have been few attempts to determine experimental scattering cross sections from solids under the conditions of interest to electron microscopist. In addition to providing data for spectral quantitation, absolute cross section measurements yields useful information on many of the approximations which are frequently involved in EELS analysis procedures. In this paper, experimental cross sections are presented for some inner-shell edges of Al, Cu, Ag and Au.Uniform thin films of the previously mentioned materials were prepared by vacuum evaporation onto microscope cover slips. The cover slips were weighed before and after evaporation to determine the mass thickness of the films. The estimated error in this method of determining mass thickness was ±7 x 107g/cm2. The films were floated off in water and mounted on Cu grids.


2017 ◽  
Vol 1 (21) ◽  
pp. 49-63
Author(s):  
Zdzisław Kaliniewicz ◽  
Piotr Markowski ◽  
Andrzej Anders ◽  
Paweł Tylek ◽  
Zbigniew Krzysiak ◽  
...  

The basic dimensions and the mass of common beech nuts and seeds from five nut batches, harvested from tree stands in northern Poland, were determined. Environmental conditions had a greater influence on seed plumpness than the age of tree stands. The results of measurements were analyzed statistically by analysis of variance, correlation analysis and linear regression analysis. Despite differences in their plumpness, nuts were characterized by nearly identical cross-sections which resembled an equilateral triangle. The thickness of nuts and seeds was highly correlated with their mass, and this information can facilitate seed husking and separation into mass categories. Before and after husking, seeds should be separated with the use of a mesh screen with longitudinal openings. Medium-sized (most numerous) seeds were separated into the following plumpness categories using a screen separator with ≠6 mm and ≠7 mm openings: 84% of moderately plump seeds, 3% of seeds with reduced plumpness, and 13% of plump seeds.


2013 ◽  
Vol 561 ◽  
pp. 125-129 ◽  
Author(s):  
Ying Ying Ding ◽  
Ya Mei Zhao ◽  
Chang Zheng Zheng ◽  
Dong Huai Tu

Introducing ionic liquid [n-C16mim][BF4] as a new structure-controlled additive, Polysulfone (PSf) membranes were prepared by the wet-phase-inversion using [n-C16mim][BF4] into the casting solution (PSf/NMP). The scanning electron microscope and the atomic force microscopy were utilized to visualize the cross-sections of the membranes to gain more better understanding the structure-controlled ability of [n-C16mim][BF4] and surface morphologies of the membrane. The results indicate that the structures of the membranes were typical bilayer asymmetric finger-pores structure. [n-C16mim][BF4] has stronger ability of the pore-forming. Especially, at the 4:76 ratio of [n-C16mim][BF4]/NMP in the polymer solution ,the membrane has the asymmetric structure and good separation properties of the solution flux. The PSf membrane has the 0.45~0.65μm dimpling close to surface layer, and the retention rate and solution flux of the prepared membrane are 95.2% and 137.5 L•h-1•m-2. Meanwhile, [n-C16mim][BF4] partially retained in the prepared Polysulfone membrane reduced the contact angles of Polysulfone membranes, improving the hydrophilic properties of the membranes.


Author(s):  
Avinash V Borgaonkar ◽  
Ismail Syed ◽  
Shirish H Sonawane

Molybdenum disulphide (MoS2) is a popularly used solid lubricant in various applications due to its superior tribological behaviour. However, it possesses poor wear resistance which requires further improvement. In the present study efforts have been made to enhance the tribological properties of pure MoS2 coating film by doping TiO2 nanoparticles as a reinforcement material. The Manganese phosphating is selected as a pre-treatment method to improve the bond strength between coating and substrate. The coating is bonded with the substrate material employing sodium silicate as a binder. The effects of wt. % of TiO2 onto the mechanical properties of composite MoS2-TiO2 coating such as hardness and bond strength have been studied. In addition coating microstructure before and after experimental test was studied using optical microscope and scanning electron microscope. It was also found that with increase in wt. % addition of TiO2 upto 15% into MoS2 base matrix, the hardness of coating increases proportionally. Beyond 15 wt. % addition of TiO2, the coating becomes brittle in nature. This leads to reduction in the scratch resistance.


2021 ◽  
pp. 1-19
Author(s):  
Xinyu Wang ◽  
Xudong Sui ◽  
Shuaituo Zhang ◽  
Mingming Yan ◽  
Yan Lu ◽  
...  

Abstract For improving the wear resistance, thick silicon doped hydrogenated amorphous carbon (a-SiC:H) coatings were deposited on cold working tool steels by Plasma Enhanced Chemical Vapor Deposition (PECVD) technology. The increase of the acetylene (C2H2) flow rate distinctly tuned the microstructure of a-SiC:H coatings, including an increase in the coating thickness (>15 μm), a decrease in the silicon content, a greater sp2/sp3 ratio and higher degree of graphitization. The highest hardness of 19.61 GPa and the greatest critical load of 50.7 N were obtained. The coating showed low wear rates against different friction pairs and presented excellent abrasive wear resistance at high applied load and the wear rates decreased with increasing loads, which exhibited an outstanding application prospect in cold working tool steels.


2021 ◽  
Vol 1038 ◽  
pp. 93-99
Author(s):  
Alexander Levterov ◽  
Julia Nechitailo ◽  
Tatyana Plugina ◽  
Oleg Volkov

In the article, the issues of using the methods of thermo-frictional and chemical-thermal treatments for surface strengthening of steel tools were disclosed. 65G steel and U8A steel were considered. A flat graver and a cylindrical root roller were considered to be tools in need of hardening. The nature of the jewellery work using such a tool has been described. Hardening techniques, experimental studies and macro photographs of the samples were presented in this article. A detailed metallographic analysis and measurement of the microhardness of the cross-sections of the prototypes after their strengthening using various methods was carried out. The metallographic nature of the reinforcement with the formation of surface "white layers" was shown. Comparison of the properties of the samples before and after strengthening was carried out. Conclusions about the strengthening effect of the thermo-frictional and chemical-thermal methods of strengthening were made.


1999 ◽  
Vol 15 (4) ◽  
pp. 301-306 ◽  
Author(s):  
A. Varma ◽  
V. Palshin ◽  
E.I. Meletis ◽  
C. Fountzoulas

Author(s):  
J. Quintelier ◽  
P. Samyn ◽  
P. De Baets ◽  
J. Degrieck

On a Pin-on-Disc test rig with composite disc and steel pin tribological experiments were done on pultruded glass fiber reinforced polymer matrix composites plates. The wear and frictional behavior strongly depends on the structure. Also the normal load plays an important role in the frictional behavior, which is of greater importance than the speed. The formation of a thin polymer film onto the wear track results in a lowering of the coefficient of friction with 20%.


Author(s):  
Jerzy Nowaczewski ◽  
Milena Kita ◽  
Justyna Świeczak ◽  
Jacek Rudnicki

The paper describes methods for the explosive hardening of metals which were performed with a view to increasing the hardness of previously obtained composites, as well as treatment of their surface layers to increase the efficiency of further thermochemical treatment. Typical systems for explosive hardening of metals and the construction of current systems, are discussed. The resulting effects of explosive hardening are illustrated with before and after diagrams of microhardness distributions in cross-sections of the processed composites hardening. In a further processing stage, the tested composite samples were subjected to ion nitriding. As a result of this process, in addition to the typical increase in hardness of the individual layers, an intermediate phase with a distinctly higher hardness was observed in the junction zone. Preliminary analysis of the photographs and the results from a scanning electron microscope (SEM) with an energy dispersive spectroscopy (EDS) attachment suggests that the particularly beneficial properties of the composites are attributed to the presence of the intermetallic layer.


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