A Novel Solid Lubricant Uses the Principles of Tribology to Reduce the Coefficient of Friction COF in Oil- Based Muds OBM for Extended Reach Drilling Applications

Ceramic Base

An analysis of studies conducted under vacuum conditions revealed that MoS2-based solid lubricant coatings applied to a titanium base using magnetron sputtering was virtually unusable. It was established that satisfactory working capacity of the considered couplings could be achieved by preliminary treatment of the base, that is by galvanic chrome plating and nickel plating. It was shown that life of a coupling with solid lubricant coatings sputtered using the magnetron method on a ceramic base was higher than those sputtered on a metal base. However, starting from the middle of operational life, temporary “surges” in the coefficient of friction occurred and subsequently stabilized. The life of coatings sputtered using the magnetron method was 2.51 times lower than that of a coupling with coatings of the BNII NP 212 type obtained using the suspension method, and 3.65 times lower than that of similar types by foreign manufacturers. The coefficient of friction for the considered couplings under vacuum conditions varied from 0.02 to 0.07.

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

Materials ◽

10.3390/ma14133458 ◽

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 ◽

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.

A Fundamental Study on Derailment of Wheel Flange Under Rolling-Sliding and Pure Sliding Conditions

World Tribology Congress III, Volume 1 ◽

10.1115/wtc2005-63422 ◽

2005 ◽

Author(s):

Md. Ziaur Rahman ◽

Takumi Ban ◽

Hideshi Kakishima ◽

Takashi Yamamoto

Keyword(s):

Surface Roughness ◽

Coefficient Of Friction ◽

Solid Lubricant ◽

Contact Point ◽

Testing Machine ◽

Full Scale ◽

Detailed Data ◽

Friction Behavior ◽

Fundamental Study ◽

A newly developed full scale wheel-rail contact testing machine is used to obtain detailed data on flange climb behavior with covering various loads and displacements at the wheel flange and rail contact under both rolling-sliding and pure sliding conditions. The effects of different surface roughness of the wheel flange on coefficient of friction at the contact point in wheel flange climb mechanism were investigated. A correlation between different state of the interface (i.e. surface of dry, wet, rust, oily and different lubricated condition by solid lubricant) and wheel flange surface roughness with rail were drawn. The coefficient of friction was significantly influenced in pure sliding conditions than that of rolling-sliding conditions by the degree of the asperities on the wheel flange surface. Moreover, solid lubricant showed better performance to reduce coefficient of friction. However, the rust on the rail surfaces was one of the important factors to destabilize the friction behavior.

Synthesis of Polymeric Nancocomposites by Infiltration. Applications in 3D (Fused Filament Molding) Printing

MRS Advances ◽

10.1557/adv.2018.617 ◽

2018 ◽

Vol 3 (63) ◽

pp. 3793-3798 ◽

Cited By ~ 1

Author(s):

Kevin Riberi ◽

Jesica Yanina Pereyra ◽

Gabriel A. Planes ◽

Silvestre Bongiovanni Abel ◽

Diego F. Acevedo ◽

...

Keyword(s):

Thermal Properties ◽

Functional Properties ◽

Coefficient Of Friction ◽

Solid Lubricant ◽

Thermoplastic Polyurethane ◽

Solvent Mixtures ◽

Test Pieces ◽

ABSTRACTThe generation of filaments constituted by nanocomposites allows printing pieces with functional properties. A method is proposed for incorporating nanoparticles in plastic filaments (thermoplastic polyurethane, PU) by diffusion in the swollen material. The nanoparticles must be dispersed in solvents (or solvent mixtures) in which the polymer swells but does not dissolve. Nanoparticles are incorporated mainly at the surface as revealed by SEM/EDS mapping. The thermal properties (studied by DSC and TGA) of the PU are only slightly affected by the presence of NPs. Test pieces successfully are printed using the modified filaments. Incorporation of solid lubricant (MoS2) nanoparticles decreases the coefficient of friction of the printed test samples.

Effects of Fabricated Method on the Coefficient of Friction of Al2O3-15 wt% ZrO2-3 wt% Solid Lubricant Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.695.231 ◽

2011 ◽

Vol 695 ◽

pp. 231-234 ◽

Cited By ~ 1

Author(s):

Seung Ho Kim ◽

M. Erkin Cura ◽

Outi Söderberg ◽

Simo Pekka Hannula ◽

Soo Wohn Lee

Keyword(s):

High Temperature ◽

Coefficient Of Friction ◽

Solid Lubricant ◽

Temperature Stability ◽

Atmospheric Plasma Spraying ◽

Atmospheric Plasma ◽

Engine Oil ◽

High Temperature Stability ◽

Pulsed Electric Current ◽

The coefficient of friction was very important factor for the applications of high temperature parts. In vehicles, the coefficient of friction was decreased due to lubricants as like engine oil etc. Lubricant such as oils is difficult to apply at high temperature. To apply high temperature parts, lubricants were demanded for high temperature stability. This work is to use the pulsed electric current sintering (PECS) technique and the atmospheric plasma spraying (APS) method in order to make self-lubricating Al2O3-15wt% ZrO2-solid lubricant composites. We focused on the coefficient of friction for the fabrication method of self-lubricating Al2O3-15wt% ZrO2-solid lubricant composites. We compared with the coefficient of friction of PECSed and APSed composites. The surface roughness of PECSed Al2O3-15wt% ZrO2-solid lubricant composites were 0.06 ~ 0.31 μm of Ra and 10.16 ~ 33.12 μm of Ry. In the case of APSed Al2O3-15wt% ZrO2-solid lubricant composites, as-coated samples were 6.56 ~ 11.42 μm of Ra and 59.68 ~ 81.79 μm of Ry, and polished samples were 1.12 ~ 3.70 μm of Ra and 11.66 ~ 32.22 μm of Ry. The coefficient of friction of PECSed and APSed Al2O3-15wt% ZrO2-solid lubricant composites were 0.19 ~ 0.49 and 0.41 ~ 0.61, respectively.

Light conveyor belts. Determination of the coefficient of friction

10.3403/30106633u ◽

2015 ◽

Keyword(s):

Coefficient Of Friction ◽

Conveyor Belts

Experimental Investigation of aluminum doping crumb rubber/epoxy composite in reciprocating motion

Journal of Communications Technology Electronics and Computer Science ◽

10.22385/jctecs.v3i0.12 ◽

2015 ◽

Vol 3 ◽

pp. 1

Author(s):

Goutam Chandra Karar ◽

Nipu Modak

Keyword(s):

Experimental Investigation ◽

Coefficient Of Friction ◽

Epoxy Composite ◽

Normal Load ◽

Crumb Rubber ◽

The Other ◽

Reciprocating Motion ◽

Molding Process ◽

Friction Tester ◽

The experimental investigation of reciprocating motion between the aluminum doped crumb rubber /epoxy composite and the steel ball has been carried out under Reciprocating Friction Tester, TR-282 to study the wear and coefficient of frictions using different normal loads (0.4Kg, 0.7Kgand1Kg), differentfrequencies (10Hz, 25Hz and 40Hz).The wear is a function of normal load, reciprocating frequency, reciprocating duration and the composition of the material. The percentage of aluminum presents in the composite changesbut the other components remain the same.The four types of composites are fabricated by compression molding process having 0%, 10%, 20% and 30% Al. The effect of different parameters such as normal load, reciprocating frequency and percentage of aluminum has been studied. It is observed that the wear and coefficient of friction is influenced by the parameters. The tendency of wear goes on decreasing with the increase of normal load and it is minimum for a composite having 10%aluminum at a normal load of 0.7Kg and then goes on increasing at higher loads for all types of composite due to the adhesive nature of the composite. The coefficient of friction goes on decreasing with increasing normal loads due to the formation of thin film as an effect of heat generation with normal load.

Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽

10.3390/ma14154217 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4217

Author(s):

Üsame Ali Usca ◽

Mahir Uzun ◽

Mustafa Kuntoğlu ◽

Serhat Şap ◽

Khaled Giasin ◽

...

Keyword(s):

Weight Loss ◽

Wear Rate ◽

Coefficient Of Friction ◽

Applied Load ◽

Practical Significance ◽

Tribological Characteristics ◽

M 10 ◽

Wide Range ◽

Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

Influence of Beam Power on Young’s Modulus and Friction Coefficient of Ti–Ta Alloys Formed by Electron-Beam Surface Alloying

Metals ◽

10.3390/met11081246 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1246

Author(s):

Stefan Valkov ◽

Dimitar Dechev ◽

Nikolay Ivanov ◽

Ruslan Bezdushnyi ◽

Maria Ormanova ◽

...

Keyword(s):

Electron Beam ◽

Young’S Modulus ◽

Coefficient Of Friction ◽

Young's Modulus ◽

Beam Power ◽

Surface Alloying ◽

Surface Alloys ◽

X Ray ◽

Beam Surface

In this study, we present the results of Young’s modulus and coefficient of friction (COF) of Ti–Ta surface alloys formed by electron-beam surface alloying by a scanning electron beam. Ta films were deposited on the top of Ti substrates, and the specimens were then electron-beam surface alloyed, where the beam power was varied from 750 to 1750 W. The structure of the samples was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Young’s modulus was studied by a nanoindentation test. The coefficient of friction was studied by a micromechanical wear experiment. It was found that at 750 W, the Ta film remained undissolved on the top of the Ti, and no alloyed zone was observed. By an increase in the beam power to 1250 and 1750 W, a distinguished alloyed zone is formed, where it is much thicker in the case of 1750 W. The structure of the obtained surface alloys is in the form of double-phase α’and β. In both surface alloys formed by a beam power of 1250 and 1750 W, respectively, Young’s modulus decreases about two times due to different reasons: in the case of alloying by 1250 W, the observed drop is attributed to the larger amount of the β phase, while at 1750 W is it due to the weaker binding forces between the atoms. The results obtained for the COF show that the formation of the Ti–Ta surface alloy on the top of Ti substrate leads to a decrease in the coefficient of friction, where the effect is more pronounced in the case of the formation of Ti–Ta surface alloys by a beam power of 1250 W.

Reducing the Coefficient of Friction for Fast-Absorbing Gut Suture

Dermatologic Surgery ◽

10.1111/j.1524-4725.2009.01322.x ◽

2009 ◽

Vol 35 (12) ◽

pp. 2004 ◽

Cited By ~ 2

Author(s):

Jonathan Lee Bingham ◽

Mariah R. Brown ◽

Julian Ramsey Mellette

Keyword(s):

Coefficient Of Friction ◽