Tribological behavior of various ceramic materials sliding against CF/PTFE/graphite-filled PEEK under seawater lubrication

In order to select appropriate antifriction and wear resistance material combinations for key frictional pairs in seawater hydraulic components, tribological characteristics of SiC, Si3N4, Al2O3, and ZrO2 ceramics sliding against carbon fiber/polytetrafluoroethylene/graphite-filled polyetheretherketone composite lubricated with seawater were comparatively investigated with a ring-on-ring test rig. The results show that the nonoxide ceramics (Si3N4 and SiC), especially the Si3N4 ceramic, exhibited lower friction coefficients and smaller wear rates than those of oxide ceramics (Al2O3 and ZrO2). And the tribological behaviors of polyetheretherketone/Si3N4 tribopair under dry friction, pure water, and seawater lubrications are further comparatively studied to explore the effect of lubricating medium on the tribological characteristics of Si3N4 ceramic. It is found that the lubricating effect of SiO2 and Si(OH)4 films generated by tribo-chemical reaction between Si3N4 and water is the main factor for the relatively low friction coefficient and wear rate of polyetheretherketone/Si3N4 tribopair under aqueous lubrication. Under seawater lubrication, the Mg(OH)2 and CaCO3 deposition layers caused by the chemical reaction of Mg2+ and Ca2+ in seawater could inhibit the generation of SiO2 and Si(OH)4 films and increase the counterface roughness. As a result, the tribological behaviors of polyetheretherketone/Si3N4 tribopair are worse under seawater lubrication than that of pure water lubrication.

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

Materials ◽

10.3390/ma13030635 ◽

2020 ◽

Vol 13 (3) ◽

pp. 635 ◽

Cited By ~ 1

Author(s):

Fang Han ◽

Huaixing Wen ◽

Jianjian Sun ◽

Wei Wang ◽

Yalong Fan ◽

...

Keyword(s):

Friction Coefficient ◽

Tribological Properties ◽

Photoelectron Spectroscopy ◽

Dry Friction ◽

Pure Water ◽

Water Environment ◽

Surface Films ◽

Seawater Lubrication ◽

Pin On Disc ◽

Worn Surface

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.

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Tribological Performance of CF‐PEEK Sliding Against 17‐4PH Stainless Steel with Various Cermet Coatings for Water Hydraulic Piston Pump Application

Coatings ◽

10.3390/coatings9070436 ◽

2019 ◽

Vol 9 (7) ◽

pp. 436 ◽

Cited By ~ 3

Author(s):

Nie ◽

Lou ◽

Ji ◽

Yin

Keyword(s):

Stainless Steel ◽

Test Bench ◽

Ring Test ◽

High Rotational Speed ◽

Cermet Coatings ◽

Tribological Behaviors ◽

Peek Composite ◽

Water Hydraulic ◽

Resistance Performance ◽

Better Than

To improve the abrasion resistance performance of the critical tribopairs within water hydraulic piston pumps, tribological characteristics of the stainless steel 17‐4PH and 17‐4PH coated with Cr3C2‐NiCr, WC‐10Co‐4Cr, Cr2O3 and Al2O3‐13%TiO2 sliding against carbon fiber reinforced polyetheretherketone (CF‐PEEK) composite under water‐lubricated condition were experimentally studied using a pin‐on‐ring test bench with different working conditions. It has been demonstrated by the experimental results that the tribological behaviors of CF‐PEEK/cermet coatings tribipairs were better than that of CF‐PEEK/17‐4PH tribopair under water lubrication. However, the Cr3C2‐NiCr coating could be damaged under high rotational speed. Due to the reaction film produced by the Al2O3‐13%TiO2 and water, the CF‐PEEK/Al2O3‐13%TiO2 material combination exhibits more excellent tribological behaviors than other tribopairs lubricated with water, and could preferentially be used in water hydraulic piston pumps.

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Exploration of Chemical Reaction Effects on Entropy Generation in Heat and Mass Transfer of Magneto-Jeffery Liquid

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2018-0005 ◽

2018 ◽

Vol 16 (9) ◽

Author(s):

R. Mohapatra ◽

B. Mahanthesh ◽

B.J. Gireesha ◽

S.R. Mishra

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Chemical Reaction ◽

Chemical Engineering ◽

Numerical Solutions ◽

Ceramic Materials ◽

Transverse Magnetic ◽

Cross Diffusion ◽

Order Chemical Reaction ◽

First Order Chemical Reaction

AbstractIn many chemical engineering processes, a chemical reaction between a foreign mass and the fluid does occur. These processes find relevance in polymer production, oxidation of solid materials, ceramics or glassware manufacturing, tubular reactors, food processing, and synthesis of ceramic materials. Therefore, an exploration of homogeneous first-order chemical reaction effects on heat and mass transfer along with entropy analysis of Jeffrey liquid flow towards a stretched isothermal porous sheet is performed. Fluid is conducting electrically in the company of transverse magnetic field. Variations in heat and mass transfer mechanisms are accounted in the presence of viscous dissipation, heat source/sink and cross-diffusion aspects. The partial differential equations system governing the heat transfer of Jeffery liquid is reformed to the ordinary differential system through relevant transformations. Numerical solutions based on Runge-Kutta shooting method are obtained for the subsequent nonlinear problem. A parametric exploration is conducted to reveal the tendency of the solutions. The present study reveals that the Lorentz force due to magnetism can be used as a key parameter to control the flow fields. Entropy number is larger for higher values of Deborah and Brinkman numbers. It is also established that the concentration species field and its layer thickness of the Jeffery liquid decreases for a stronger chemical reaction aspect. To comprehend the legitimacy of numerical results a comparison with the existing results is made in this exploration and alleged an admirable agreement.

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Basic Experiment on Lithium Removal Technique

Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles ◽

10.1115/icone20-power2012-54209 ◽

2012 ◽

Author(s):

Tomohiro Furukawa ◽

Yasushi Hirakawa

Keyword(s):

High Temperature ◽

Low Temperature ◽

Dissolution Rate ◽

Chemical Reaction ◽

Pure Water ◽

Preliminary Investigation ◽

Testing Temperature ◽

Temperature Range ◽

Removal Technique ◽

Good Agreement

As a preliminary investigation into the establishment of a lithium removal technique for the components used at the International Fusion Materials Irradiation Facility (IFMIF), experiments were performed on the dissolution of lithium in three solvents: ethanol, pure water, and ethanol–water. In these experiments, hemispherical lithium was immersed in the solvents at constant temperatures, and the degree of dissolution was measured continuously from the height of the sample. From the obtained data, the average dissolution rate in the solvents at each testing temperature (10–90 °C) and the amount of hydrogen generated by the chemical reaction were calculated. The average dissolution rates in ethanol, pure water, and ethanol–water at 30 °C were 0.01, 1.6, and 0.43 mm/min, respectively. Although the average dissolution rate increased with the testing temperature in the low-temperature range (10–50 °C) for all solvents, this increase was saturated in the high-temperature range (50–90 °C) in experiments with pure water and ethanol–water as solvents. The volume of gas collected during each experiment was in good agreement with the volume of hydrogen assumed to be generated from the chemical reaction of lithium with the solvents.

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The Effect of Tribofilm Formation and Humidity on the Friction and Wear Properties of Ceramic Materials

Journal of Tribology ◽

10.1115/1.2920851 ◽

1992 ◽

Vol 114 (1) ◽

pp. 131-140 ◽

Cited By ~ 42

Author(s):

K. Komvopoulos ◽

H. Li

Keyword(s):

Steady State ◽

Wear Debris ◽

Friction And Wear ◽

Ceramic Materials ◽

Composition Analysis ◽

Wear Properties ◽

Qualitative Comparison ◽

Wear Rates ◽

Subsurface Material ◽

Friction And Wear Properties

The processes of tribofilm formation and disruption and the predominant tribo-mechanisms of unlubricated ceramic materials were investigated experimentally. Sliding experiments in humidity controlled atmospheres revealed that the formation of interfacial tribofilms significantly affects the steady-state friction and wear properties of ceramics. Scanning electron microscopy and various composition analysis techniques demonstrated that although tribochemical reactions might occur, the principal mechanisms of tribofilm formation were the generation, agglomeration, and compaction of fine wear debris produced from both sliding surfaces. The tribofilms exhibited different tribological characteristics, depending on their elemental compositions and the humidity. For all the ceramic pairs tested, the steady-state coefficients of friction decreased with relative humidity. In contrast to the conventional fracture toughness approach, surface profilometry and microscopy studies showed that the highest wear rates were encountered with the toughest ceramic. Plowing grooves parallel to the direction of sliding, fine wear debris of round and cylindrical shapes, microcracking, and localized delamination of the tribofilms were identified. Microscopic observations suggested that damage of the subsurface material adjacent to the interface of the tribofilms was immeasurable. Qualitative comparison of the topographical features of worn surfaces indicated that, depending on the humidity and the type of ceramic, microplasticity, microfracture, and delamination of the tribofilms were the prevailing steady-state tribomechanisms.

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Wear Characteristics of Binder-Less Nano-Polycrystalline Diamond and Cubic Boron Nitride

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1017.406 ◽

2014 ◽

Vol 1017 ◽

pp. 406-410 ◽

Cited By ~ 4

Author(s):

Hitoshi Sumiya ◽

Katsuko Harano

Keyword(s):

Boron Nitride ◽

Chemical Reaction ◽

High Speed ◽

Single Phase ◽

Cubic Boron Nitride ◽

Polycrystalline Diamond ◽

Wear Characteristics ◽

Wear Process ◽

Wear Rates ◽

Starting Condition

Wear characteristics of binder-less (single-phase) nanopolycrystalline diamond (NPD) and cubic boron nitride (BL-PcBN) were investigated by rubbing them against various ceramics such as SiO2, Si3N4, Al2O3 and SiC. The wear rates of NPD and BL-PcBN against SiO2 and Si3N4 at high speed rubbing (280-360 m/min) at a loading pressure of 55 MPa (starting condition) were considerably high, indicating the main wear process is a chemical reaction. BL-PcBN specimens were found to be worn at much higher (more than ten times) rates than NPD, suggesting that cBN highly reacts with these ceramics in comparison with diamond under the experiment condition.

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Tribological behaviors of Gra./Cu and CNTs/Cu composites with and without electric current

MATEC Web of Conferences ◽

10.1051/matecconf/201817501031 ◽

2018 ◽

Vol 175 ◽

pp. 01031

Author(s):

Wei Xu ◽

Binghong Li

Keyword(s):

Powder Metallurgy ◽

Electric Current ◽

Tribological Properties ◽

High Speed ◽

Friction Coefficients ◽

Wear Rates ◽

Tribological Behaviors ◽

Testing Condition ◽

Worn Surfaces

Gra./Cu composites and CNTs/Cu composites were respectively fabricated by powder metallurgy techniques. The experiments of high speed sliding with and without electric current were carried out to investigate their tribological behaviors. The results show that the friction coefficients and wear rates with electric current are higher than without electric current; under the same testing condition the friction coefficients and wear rates of CNTs/Cu are lower and the worn surfaces are more planar than Gra./Cu. CNTs can debase the effect of heat generating during sliding process on the composites. The tribological properties of CNTs/Cu composites are more excellent than Gra./Cu composites.

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