scholarly journals Composite Coatings with Ceramic Matrix Including Nanomaterials as Solid Lubricants for Oil-Less Automotive Applications

2016 ◽  
Vol 61 (2) ◽  
pp. 1039-1043 ◽  
Author(s):  
A. Posmyk ◽  
J. Myalski ◽  
B. Hekner

Abstract The paper presents the theoretical basis of manufacturing and chosen applications of composite coatings with ceramic matrix containing nanomaterials as a solid lubricant (AHC+NL). From a theoretical point of view, in order to reduce the friction coefficient of sliding contacts, two materials are required, i.e. one with a high hardness and the other with low shear strength. In case of composite coatings AHC+NL the matrix is a very hard and wear resistant anodic oxide coating (AHC) whereas the solid lubricant used is the nanomaterial (NL) featuring a low shear strength such as glassy carbon nanotubes (GC). Friction coefficient of cast iron GJL-350 sliding against the coating itself is much higher (0.18-0.22) than when it slides against a composite coating (0.08-0.14). It is possible to reduce the friction due to the presence of carbon nanotubes, or metal nanowires.

Author(s):  
Jianliang Li ◽  
Dangsheng Xiong ◽  
Yongkun Qin ◽  
Rajnesh Tyagi

This chapter illustrates the effect of the addition of solid lubricants on the high temperature friction and wear behavior of Ni-based composites. Ni-based composites containing solid lubricant particles both in nano and micrometer range have been fabricated through powder metallurgy route. In order to explore the possible synergetic action of a combination of low and high temperature solid lubricant, nano or micro powders of two or more solid lubricants were added in the composites. This chapter introduces the fabrication of the Ni-based self-lubricating composites containing graphite and/or MoS2, Ag and/or rare earth, Ag and/or hBN as solid lubricants and their friction and wear behavior at room and elevated temperatures. The chapter also includes information on some lubricating composite coatings such as electro-deposited nickel-base coating containing graphite, MoS2, or BN and graphene and their tribological characteristics.


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.


2010 ◽  
Vol 152-153 ◽  
pp. 580-586
Author(s):  
Zheng Xi Hu ◽  
Xiao Hua Jie ◽  
Guo Hui Lu

Multi-walled carbon nanotube (MWCNT)/Pb-Sn composite coatings were prepared by electrodeposition technique. Friction coefficient and wear weight losses were investigated on a double rings apparatus using carbon steel (C: 0.45%) rings as counterparts under wet friction condition. Tribological characteristics were compared among the samples as carbon nanotubes concentration was changed in the bath. The results indicate that the composite coatings had smaller friction coefficient and weight loss than that of ordinary Pb-Sn coatings under the same work conditions. In addition, the wear performance of Pb-Sn-CNTs composite coating was optimized when the CNTs concentration in bath was 2 g L-1.


2015 ◽  
Vol 778 ◽  
pp. 168-173
Author(s):  
Zheng Xi Hu ◽  
Xiao Hua Jie

In order to get homogeneously dispersed carbon nanotubes suspension for composite plating, carbon nanotubes were ball milled for different times and polycyclic acid (PA) was used as dispersant in this work. Sedimentation ratio was calculated by measuring the absorbance of suspensions and friction coefficient of the composite coatings was measured by friction tester. Dispersant content and ball milling time on the dispersive stability of suspension were studied. The dispersion mechanisms were discussed. The results showed that PA could effectively disperse carbon nanotubes in Pb-Sn electroplating solution. When the volume percent of PA was 0.3%, milling time was 6h and the milling speed was 300r/min, the sedimentation ratio was the smallest. The composite coatings had the smallest friction coefficient. Besides, the mechanism of PA effectively dispersing CNTs in Pb-Sn electro plating solution was electrostatics stabilization.


2021 ◽  
Vol 875 ◽  
pp. 272-279
Author(s):  
Wan Farhana Mohamad ◽  
Amir Azam Khan ◽  
Pierre Barroy ◽  
Olivier Durand-Drouhin ◽  
Clement Puille ◽  
...  

High temperature applications of self-lubricated sliding surfaces have gained industrial importance during the recent years. One popular system is based on sintered Ni-Cr composites with addition of solid lubricants. In the present work these composites were prepared under controlled sintering conditions with different combinations of solid lubricants (MoS2, Ag and CaF2) at 1200 °C under flowing argon. The physical properties such as sintered density, relative density and porosity were studied. The microstructures and phase studies of the Ni-Cr based composites were conducted using SEM analysis while the hardness of the composites was measured by Vickers Micro Hardness Tester. The friction tests were conducted with ball on disc configuration following ASTM G-99-95a standard. The MoS2 solid lubricant provides best lubrication at room temperature which is demonstrated by a low friction coefficient compared to pure Ni-Cr composites. The SEM pictures of worn out tracks show solid debris distribution, and filling of pores with solid lubricant phases. The time taken for stabilization of friction coefficient also varies with the type of solid lubricant. Dual and multiple additions of solid lubricants are also able to reduce the friction of coefficient compared to pure Ni-Cr composite.


Author(s):  
Patrick S. M. Dougherty ◽  
Cecily M. Sunday ◽  
C. Fred Higgs

The success of solid lubricants to exhibit ultra-low friction and wear behaviors in oil-prohibiting environments, has led to a major effort to optimize their performance and enhance their applicability. Depending on the operating conditions, solid lubricants may take on a plethora of forms including fabricated composite coatings, thick-film powder lubricants, nano-particle additives for hard surfaces or liquid lubricants, and self-replenishing transfer films. One of the benefits of transfer films are their freedom from the complex deposition techniques required for most other solid lubricant systems. In this work, the potential for adaptive self-replenishing transfer films was explored by creating composite powders of well-known powder lubricants and electrically conductive or anti-oxidation materials. MoS2, WS2, and Graphite Powders were mixed in varying composition with Cu, Sb2O3, and BO3 additives and compacted to form “tuned” or adaptive powder pellets. Relationships between friction, wear, electrical resistance, tribo-induced oxidation and powder composition, will be presented in order to investigate the potential of composite property optimization for lubricious, highly conductive, and oxidation resistant transfer films.


Author(s):  
Koshi Adachi ◽  
Hisakazu Sato ◽  
Koji Kato

Solid lubrication film formed by tribo-coating, which deposits a solid lubricant by evaporation to the contact interface during friction in vacuum, gives low friction coefficient below 0.03 that can not be observed by any other solid lubricants of soft metals. The tribo-coating film formed on the pin has nano-order composite structure which the crystalline indium of nano size are distributed in an amorphous matrix of silicon oxide and chromium oxide. Because of the nano composite structure, a very thin indium film is formed without break down like conventional pre-coated thin film. The thinner indium film can give smaller value of friction coefficient than that of conventional solid lubricant.


1996 ◽  
Vol 11 (11) ◽  
pp. 2749-2756 ◽  
Author(s):  
Wei Zhao ◽  
Jinke Tang ◽  
Ashok Puri ◽  
Ray L. Sweany ◽  
Yuxin Li ◽  
...  

The frictional behaviors of fullerenes C60 and C70 were studied because they were speculated to be solid lubricants. For the sublimated pure C60 films on Si(001), a high friction coefficient (0.55–0.8) was observed under different loads and pin materials. For the C70 film, the friction coefficient showed a pin dependence, which changed from 0.5 with an Al2O3 pin to about 0.9 with a 440 stainless steel pin. The relatively high friction coefficients of C60 and C70 films were due to the tendency of the C60 and C70 particles to clump and compress into high shear strength layers rather than due to the impurities in the fullerenes. The benzene-solvated C60 · 4C6H6 and C70 ·xC6H6 showed a lowered friction coefficient (0.25 for C60 · 4C6H6 and 0.3 for C70 · xC6H6), which might result from the lowered shear strength of the hcp structure of C60 · 4C6H6 and C70 ·xC6H6 molecular crystals in which the benzene molecules were intercalated.


2013 ◽  
Vol 561 ◽  
pp. 585-590 ◽  
Author(s):  
Tong Kun Cao ◽  
Chun Sheng Shan ◽  
Jun Peng Ge

For friction design, the antifriction model of self-lubricating tool was built. Al2O3/TiC/CaF2was prepared, and the chemical compatibility of Al2O3/TiC/CaF2was analyzed and calculated and the results were verified by X-ray diffraction patterns. The microstructure design of self-lubricating tool material was discussed. The results show that it can reduce the friction coefficient if solid lubricating film can be produced on the friction interface, even the lubricating film can't completely be formed on the friction interface. Under high temperature, there were no reactions in Al2O3/TiC/CaF2. To form continuous net structure of matrix and reduce the friction, the solid lubricants content should be moderate. According to analysis of the particle packing ways, the radius ratio between solid lubricant particles and ceramic matrix particles was confirmed and it should be within the scope of 0.225 r / R 0.414.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hadi Pourpasha ◽  
Saeed Zeinali Heris ◽  
Yaghob Mohammadfam

AbstractThis research aims of compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes include the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. The pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Increasing 0.3 wt.% of TiO2 and MWCNTs into the oil caused to improvement in viscosity index. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.


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