Development of Porous Films Based on Polyanionic Cellulose to Form Functional Coatings

2022 ◽  
Vol 1049 ◽  
pp. 130-137
Author(s):  
Natalia Antonova

New porous films based on polyanionic cellulose with AlOOH nanoparticles have been developed. The morphology of the films has been studied by electron microscopy: the size of the formed pores is 1000-500 microns; the total surface porosity of the films is 30%. Using infrared microscopy, it was shown that during the formation of porous films, their chemical composition remains unchanged. Differential scanning calorimetry was used to determine the threshold for thermal destruction of porous films: 306 С. The possibility of using the obtained materials as antifriction coatings when filling the pores with solid lubricant MoS2 is considered. It is shown that for a steel sample protected by a porous coating with MoS2, the friction coefficient decreases by 50% compared to the friction coefficient for a steel surface under a load of up to 450 MPa.

2018 ◽  
Vol 788 ◽  
pp. 59-67 ◽  
Author(s):  
Alexander Urbahs ◽  
Konstantins Savkovs ◽  
Margarita Urbaha ◽  
Darja Andrejeva

A modern method of processing steel parts by ion-plasma sputtering in vacuum is proposed as a solution to the problem of friction and wear. An ion-plasma coating based on Ti-Cu has been developed. Such parameters as microhardness, roughness, friction coefficient of the intermetallic, conglomerate and nitride coatings have been studied


2013 ◽  
Vol 815 ◽  
pp. 574-578
Author(s):  
Xiao Zhen Liu ◽  
Yu Zhen Li ◽  
Ling Ling Song ◽  
Xiao Dong Yu ◽  
Wei Ting Lu

TiB2and Gd2O3were used as codeposited particles for the first time in preparing Ni-TiB2-Gd2O3composite coatings to improve its performance. Ni-TiB2-Gd2O3composite coatings were prepared by electrodeposition method from a nickel cetyltrimethylammonium bromide and hexadecylpyridinium bromide solution containing TiB2and Gd2O3particles. The content of codeposited TiB2and Gd2O3in the composite coatings was controlled by the addition of different TiB2and Gd2O3particles concentrations in the solution, respectively. The effects of TiB2and Gd2O3content on microhardness, wear weight loss, and friction coefficient of composite coatings were investigated, respectively. Ni-TiB2-Gd2O3composite coatings shows higher microhardness and lower wear weight loss, friction coefficient than those of the pure Ni coating and Ni-TiB2composite coatings. The wear weight loss of Ni-TiB2-Gd2O3composite coatings is lower 9.13 and 1.59 times than that of the pure Ni coating and Ni-TiB2composite coatings, respectively. The friction coefficients of pure Ni coating, Ni-TiB2and Ni-TiB2-Gd2O3composite coatings are 0.723, 0.815 and 0.43, respectively. Ni-TiB2-Gd2O3composite coatings shows the least friction coefficient among the three coatings. Gd2O3particles in composite coatings serves as solid lubricant between contact surfaces, decreases the friction coefficient, abates the wear and increases the corrosion resistance of the composite coatings. The loading-bearing capacity and the wear-reducing effect of the Gd2O3particles in the composite coatings are closely related to the content of Gd2O3particles in the composite coatings.


Author(s):  
Masanori Iwaki ◽  
Thierry Le Mogne ◽  
Julien Fontaine ◽  
Jean-Michel Martin

Among diamond-like carbon (DLC) coatings, hydrogenated amorphous carbon (a-C:H) coatings are of great interest since some of them may exhibit coefficients of friction in the millirange, so-called “superlow friction” in ultrahigh vacuum. However, there are still many points to be clarified and improved to employ them as solid lubricant for actual vacuum applications. For example, in space environment solid lubricants are required to function at both low and high temperature ranging from −150 to 100°C. To apply them as solid lubricant in such an extreme environment, it is necessary to know the evolution of the tribological behavior in temperature, leading to their application limit. Furthermore, tribological behavior of a-C:H coatings is known to depend on tribochemistry and on mechanical properties like viscoplasticity. Since both could be affected by temperature, a better understanding of superlow friction mechanisms is expected from experiments at various temperatures. In this present work, pin-on-disk reciprocating friction tests were conducted at various temperature conditions ranging from −130 to 300°C under ultrahigh vacuum (10−7Pa) to study the effect of temperature on the coefficient of friction of an a C:H coated flat mated against steel (AISI 52100) pins. For all temperatures, superlow friction regime could be reached, as it was observed usually at room temperature for this sample. However, an effect of temperature is evidenced on the duration of “running-in” phase, i.e. the number of cycles required to reach a superlow friction regime. The duration becomes shorter at higher temperatures and longer at lower temperatures. Also, the application limit in temperature is found between 200 and 300°C, at which the friction coefficient slowly increases after running-in, to reach values above 0.01. In light of these results, the mechanisms of superlow friction are discussed in terms of tribochemistry and mechanical properties of the coating.


2016 ◽  
Vol 36 (3) ◽  
pp. 279-286
Author(s):  
Huseyin Unal ◽  
Ugur A. Kaya ◽  
Kadir Esmer ◽  
A. Mimaroglu ◽  
Bayram Poyraz

Abstract In this study, the influence of wax content on the electrical, thermal and tribological properties of a polyamide 6 composite filled with 15% wt. graphite was investigated. The wax filler contents of the composite were by 2, 4 and 6 wt.%. Characterisation of the composites was obtained using a Fourier transform infrared spectroscopy test. Electrical performance tests were carried out, and the dielectric real values (ε′) and imaginary values (ε″) were recorded. Thermal differential scanning calorimetry tests were carried out, and the glassy and melting temperatures of the composite materials were recorded. Furthermore, tribological tests were carried out and the friction coefficient and wear rate of the composites were recorded. The results show that the increase in wax content led to the increase in the permittivity values (ε′ and ε″) of the composites. The increase in wax content also led to the decrease in the friction coefficient and wear rates of the composite materials. Furthermore, the glassy and melting temperatures of the composite materials showed a sensitivity to the wax content. Finally, it is concluded that optimum properties, in total, were obtained in the composite filled with 6 wt.% wax.


2021 ◽  
Vol 871 ◽  
pp. 176-188
Author(s):  
Ben Yuan Wang ◽  
Guang Chun Xiao ◽  
Zhao Qiang Chen ◽  
Ming Dong Yi ◽  
Jing Jie Zhang ◽  
...  

In this paper, the dry cutting performance of Al2O3/TiC-based ceramic composites with nanoCaF2 was studied. Compared with the Al2O3/TiC ceramic tool, the Al2O3/TiC/CaF2 ceramic tool has lower cutting force, cutting temperature and surface roughness when milling 40Cr hardened steel. Three cutting parameters of cutting speed, feed per tooth, and cutting depth were used to conduct orthogonal experiments to study its changing trend. Through testing of cutting force, cutting temperature and surface roughness, and by comparison with ceramic tools without nanosolid lubricant added, the order of influence of three cutting parameters on cutting force, cutting temperature and surface roughness was obtained. The experimental results showed that the cutting force, cutting temperature and surface roughness of Al2O3/TiC/CaF2 ceramic tools containing nanoCaF2 werebetter than those of Al2O3/TiC ceramic tools. The cutting force, the cutting temperature, and the surface roughness were respectively reduced by 16.5%, 25.8% and 43% compared to when no solid lubricant was added. In addition, after adding solid lubricant, the effect of cutting depth on cutting force was significantly reduced. The average friction coefficient of the tool rake surface was 31.1% lower than that of ceramic tools without solid lubricant. In order to explain this phenomenon, through scanning electron microscopy (SEM) scanning and energy spectroscopy (EDS) elemental analysis, the wear reduction mechanism of solid lubricants was analyzed, that is, during the cutting process, nanosolid lubricants precipitated and formed lubricating film on the rake surface of the tool to reduce the friction coefficient. This was also the main reason for reducing the cutting temperature.


2011 ◽  
Vol 148-149 ◽  
pp. 778-784
Author(s):  
Rattapasakorn Sountaree ◽  
Panichakorn Jesda ◽  
Mongkolwongrojn Mongkol

This paper presents the performance characteristics of two surfaces in line contact under isothermal mixed lubrication with non-Newtonian liquid–solid lubricant base on Power law viscosity model. The time dependent Reynolds equation, elastic equation and viscosity equation were formulated for compressible fluid. Newton-Raphson method and multigrid technique were implemented to obtain film thickness profiles, friction coefficient and load carrying in the contact region at various roughness amplitudes, applied loads, speeds and the concentration of solid lubricant. The simulation results showed that roughness amplitude has a significant effect on the film pressure, film thickness and surface contact pressure in the contact region. The film thickness decrease but friction coefficient and asperities load rapidly increases when surface roughness amplitude increases or surface speed decreases. When the concentration of solid lubricant increased, friction coefficient and asperities load decrease but traction and film thickness increase.


2011 ◽  
Vol 80-81 ◽  
pp. 667-672
Author(s):  
Yun Cai Zhao ◽  
Gao Jie Hao ◽  
Chun Ming Deng ◽  
Wem You Ma

This paper is about the study of the KF301/WS2 composite lubricating wear-resisting coatings prepared by supersonic plasma spraying. Basing on the research of the tribological characteristics, it has been discussed that the thermal stress of lubricating wear-resisting coating prepared by supersonic plasma spraying in the high-heat tribological process. Research shows that the wear rate of the coating increases with the increase of the temperature. At 300°C, the wear rate is 1.02×10-4mg/m; At 750°C, the wear rate is 2.61×10-4 mg/m. With the increase of temperature, friction coefficient of the coatings shows gradually increasing. When the temperature falls below 600°C, friction coefficient keeps around 0.08; At 750°C, the friction coefficient is 0.12. The thermal stress σ1max mainly is controlled by temperature, with the increase of temperature, the warping phenomena of solid lubricant film and the combined effects of heat stress and friction contact stress, which causes the insecure combination of the lubricant film and substrate, lubricant film’s warp, break, local direct contact between the metals, which is one of reasons to lead to decrease of the tribological properties of self-lubricating composite coating.


2014 ◽  
Vol 1025-1026 ◽  
pp. 32-36 ◽  
Author(s):  
Khanittha Wongseedakaew ◽  
Jesda Panichakorn

This paper presents the performance characteristics of thermo-elastohydrodynamic lubrication (TEHL) in line contact with non-Newtonian liquid–solid lubricant. The time independent Reynolds equation, energy equation, elastic equation and load carrying with solid particle equation were formulated for compressible fluid. Newton-Raphson method and multigrid technique were implemented to obtain film thickness, film pressure, film temperature, friction coefficient and load carrying with solid particle equation in the contact region at various concentrations of solid lubricant and applied loads. The simulation results showed that film thickness and film temperature increase but film pressure decreases when solid particles are added into liquid lubricant. The maximum film temperature and load carrying of solid particle increased but friction coefficient decreased when concentration of solid particle increased. For increasing applied loads, the minimum film thickness decreases but maximum film temperature and friction coefficient increase for all liquid lubricant and liquid-solid lubricants.


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