A Theory of Thermo-Elastohydrodynamic Lubrication of Liquid-Solid Lubricated Cylinders

1990 ◽  
Vol 112 (2) ◽  
pp. 259-265 ◽  
Author(s):  
M. M. Khonsari ◽  
S. H. Wang ◽  
Y. L. Qi
Keyword(s):  
Mechanical Properties ◽  
Solid Lubricant ◽  
Elastohydrodynamic Lubrication ◽  
Solid Lubricants ◽  
Theoretical Development ◽  
Rheological Characteristics ◽  
Combined Effects ◽  
Line Contact ◽  
The Coefficient Of Friction ◽  
Bounding Surfaces

The purpose of this research is to extend the theory of the concentrated thermo-elastohydrodynamic line contact to include the influence of the existence of solid lubricant dispersed in liquid-base lubricant. The combined effects of the rheological characteristics of the oil and the mechanical properties of the particles and those of the bounding surfaces are taken into consideration in theoretical development. Results are presented for the pressure distribution, the oil film thickness, the temperature rise, and the coefficient of friction for two commonly used solid lubricants namely MOS2 and graphite.

Effect of Thermal Properties of a Coated Elastohydrodynamic Lubrication Line Contact Under Various Slide-to-Roll Ratios

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Huaiju Liu ◽  
Caichao Zhu ◽  
Zonglin Gu ◽  
Zhanjiang Wang ◽  
Jinyuan Tang
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Elastohydrodynamic Lubrication ◽  
Temperature Fields ◽  
Line Contact ◽  
Oil Film ◽  
Line Contacts ◽  
Energy Equations ◽  
Thermal Conductivities

A numerical thermal elastohydrodynamic lubrication (EHL) model is developed for coated line contacts by considering both the mechanical properties and the thermal properties of the coating and the substrate. The temperature fields within the oil film and within the solids are solved by deriving the energy equations for the solids and the oil film. Heat continuity conditions are satisfied at the interfaces between the solids and the oil film, and the coating/substrate interfaces. Effects of the slide-to-roll ratio (SR), the thermal conductivities of the coating bodies, and the oil film on temperature fields are studied.

Enhancing the tribological and mechanical properties of M50 steel using solid lubricants – A detailed review

2017 ◽  
Vol 232 (5) ◽  
pp. 619-642 ◽  
Author(s):  
FA Essa ◽  
Qiaoxin Zhang ◽  
Xingjiu Huang ◽  
Ahmed Mohamed Mahmoud Ibrahim ◽  
Mohamed Kamal Ahmed Ali ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tribological Properties ◽  
Solid Lubricant ◽  
Tribological Behavior ◽  
Solid Lubricants ◽  
Industrial Applications ◽  
Solid Lubricant Additives ◽  
Wide Range ◽  
Future Work ◽  
M50 Steel

Recent strides in contact mechanics of M50 steel offer unique opportunities for better and more control of its tribological behavior and mechanical properties under different contact and surrounding conditions. Most researchers have focused on the solid lubricants on M50 steel as the key strategy for improving the tribological properties. In this paper, we have selected a wide range of previous late studies to discuss the different mechanisms leading to an improvement in the tribological properties of M50 steel via solid lubricants. A discussion of M50 steel industrial applications is also reviewed. The main objective is to develop an exhaustive understanding of the tribological behavior of M50 steel with solid lubricant additives under different conditions and also provide some prospects to be considered for future work.

Development of Fe-P Matrix Composites Containing Embedded Solid Lubricants

2014 ◽  
Vol 802 ◽  
pp. 96-101
Author(s):  
Antonio Itamar Ramos Filho ◽  
Renan Schroeder ◽  
Cristiano Binder ◽  
Aloisio N. Klein
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Solid Lubricant ◽  
Hexagonal Boron Nitride ◽  
Solid Lubricants ◽  
Alloy Element ◽  
Alpha Phase ◽  
Mechanical Resistance ◽  
The Matrix ◽  
P Matrix

In this work the processing of composites containing graphite or hexagonal boron nitride dispersed in a ferrous matrix alloyed with phosphorous was addressed, with the goal of developing self-lubricating sintered materials with high mechanical resistance. Phosphorous is an alloy element characteristic in powder metallurgy for promoting the formation of liquid phase and alpha phase at high temperature, wherein both phenomena are densification inducers. It is expected therefore with that to rearrange volumetrically the solid lubricant reservoirs, so permitting the composites to present better mechanical properties. In order to understand what really occurs at high temperature, sintering was studied in situ in a dilatometer. Furthermore, microstructural and mechanical properties were carried out to characterize the sintered parts. The main remark was that graphite reacts with the matrix going into solid solution and therefore not being disposed as solid lubricant after sintering. On the other hand, h-BN remains insoluble in the Fe-P matrix and without reducing drastically the strength of the composite.

scholarly journals Optimization of Mechanical Properties of Cr3C2-Ni20Cr/Graphite Cold Sprayed Coatings

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3458
Author(s):  
Wojciech Żórawski ◽  
Anna Góral ◽  
Medard Makrenek ◽  
Dominika Soboń ◽  
Anna Trelka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Coefficient Of Friction ◽  
Solid Lubricant ◽  
Gas Composition ◽  
Graphite Content ◽  
Process Gas ◽  
The Coefficient Of Friction ◽  
Parameter Values ◽  
Sprayed Coatings ◽  
Friction Analysis

This study analyzed the mechanical properties of cold-sprayed Cr3C2-25(Ni20Cr) blended with Ni-graphite as a solid lubricant deposited on 7075 aluminum alloy substrate. To optimize the coating properties, different sets of parameters (graphite content in feedstock, process gas composition, spraying distance, and traverse gun speed) were tested in the frame of the Taguchi experiment. The cold-sprayed coatings were evaluated for their chromium carbide and graphite content, hardness, and coefficient of friction. Analysis of the microstructure of the deposited coatings revealed that graphite as a soft and brittle component fills all voids in the coating and its quantity depends on its content in the feedstock. The experimental results show that the composition of the process gas has the greatest impact on the Cr3C2 content in the coating and the proportion of graphite in the sprayed blend directly affects its hardness. In the case of the coefficient of friction, the most significant parameters were the graphite content in the sprayed blend, the spraying distance, and process gas composition. The conducted verification experiment with the optimum parameter values allowed a coating with the highest hardness and the lowest coefficient of friction to be obtained.

Feasible strategies to promote the sensing performances of spinel MCo2O4 (M = Ni, Fe, Mn, Cu and Zn) based electrochemical sensors: A review

2021 ◽  
Author(s):  
Josué M. Gonçalves ◽  
Diego Pessoa Rocha ◽  
Murillo N.T. Silva ◽  
Paulo Roberto Martins ◽  
Edson Nossol ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physicochemical Properties ◽  
Electrochemical Sensors ◽  
Combined Effects ◽  
Cu And Zn

Spinel MCo2O4 (M = Ni, Fe, Mn, Cu and Zn) demonstrates excellent physicochemical properties due to combined effects of M2+ and Co2+ cations. Their inimitable optical, electronic, and mechanical properties...

Stress Optical Behavior of Rubber Networks at Large Deformations

1966 ◽  
Vol 39 (5) ◽  
pp. 1436-1450
Author(s):  
K. J. Smith ◽  
D. Puett
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Statistical Theory ◽  
Natural Rubber ◽  
Large Deformations ◽  
Strong Support ◽  
Theoretical Development ◽  
Statistical Parameters ◽  
Strain Behavior ◽  
Optical Behavior

Abstract The birefringence of natural rubber networks at large deformations has been investigated experimentally and compared with the simultaneously determined stress—strain behavior. Our data is analyzed using a statistical theory of flexibly jointed chains, derived herein, which is believed to be more significant for the particular range of deformation used than the theories of Treloar and of Kuhn and Grün. In addition, the experimental data of Saunders is commented on in light of our theoretical development. We find that for network extensions exceeding those of the Gaussian region there is little correlation between the observed and theoretical behavior of the stress and birefringence (based upon the theory of flexibly jointed chains) and this lack of agreement is attributed to the fact that the statistical parameters needed for the description of the optical chain properties differ in magnitude from those required for the mechanical properties. Furthermore, by considering the points of incipient crystallization the strain behavior of the stress-optical coefficient is highly indicative of nonGaussian behavior rather than crystallization, and therefore yields strong support for the position that nonGaussian behavior does exist in rubber networks.

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