Formation Mechanisms of Tribo-Coating for Low Friction in UHV

2005 ◽  
Author(s):  
Koshi Adachi ◽  
Hisakazu Sato ◽  
Koji Kato
Keyword(s):  
Friction Coefficient ◽  
Composite Structure ◽  
Solid Lubricant ◽  
Silicon Oxide ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Formation Mechanisms ◽  
Coating Film ◽  
Low Friction ◽  
Indium Film

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.

Sliding Friction Behavior of Sintered Ni-Cr Composites with Solid Lubricants

2021 ◽  
Vol 875 ◽  
pp. 272-279
Author(s):  
Wan Farhana Mohamad ◽  
Amir Azam Khan ◽  
Pierre Barroy ◽  
Olivier Durand-Drouhin ◽  
Clement Puille ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Solid Lubricant ◽  
Sliding Friction ◽  
Solid Lubricants ◽  
Sem Analysis ◽  
Low Friction ◽  
Friction Behavior ◽  
Hardness Tester ◽  
Disc Configuration ◽  
Ball On Disc

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.

scholarly journals Understanding the Unique Role of Phospholipids in the Lubrication of Natural Joints: An Interfacial Tension Study

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 264 ◽  
Author(s):  
Aneta D. Petelska ◽  
Katarzyna Kazimierska-Drobny ◽  
Katarzyna Janicka ◽  
Tomasz Majewski ◽  
Wiesław Urbaniak
Keyword(s):  
Interfacial Tension ◽  
Lipid Bilayers ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Phospholipid Bilayer ◽  
Low Friction ◽  
Unique Role ◽  
Lamellar Phases ◽  
Chemical Inertness

Some solid lubricants are characterized by a layered structure with weak (van der Waals) inter-interlayer forces which allow for easy, low-strength shearing. Solid lubricants in natural lubrication are characterized by phospholipid bilayers in the articular joints and phospholipid lamellar phases in synovial fluid. The influence of the acid–base properties of the phospholipid bilayer on the wettability and properties of the surface have been explained by studying the interfacial tension of spherical lipid bilayers based on a model membrane. In this paper, we show that the phospholipid multi-bilayer can act as an effective solid lubricant in every aspect, ranging from a ‘corrosion inhibitor’ in the stomach to a load-bearing lubricant in bovine joints. We present evidence of the outstanding performance of phospholipids and argue that this is due to their chemical inertness and hydrophilic–hydrophobic structure, which makes them amphoteric and provides them with the ability to form lamellar structures that can facilitate functional sliding. Moreover, the friction coefficient can significantly change for a given phospholipid bilayer so it leads to a lamellar-repulsive mechanism under highly charged conditions. After this, it is quickly transformed to result in stable low-friction conditions.

Application of WS2 in Solid Lubricant Coating for Metal

2013 ◽  
Vol 652-654 ◽  
pp. 1904-1907 ◽  
Author(s):  
Suo Xia Hou ◽  
Hui Gao ◽  
Xiao Ming Jia
Keyword(s):  
Friction And Wear ◽  
Solid Lubricant ◽  
Solid Lubricants ◽  
Feasibility Analysis ◽  
Solid Lubrication ◽  
Wear Testing ◽  
Metallic Materials ◽  
Solid Lubricant Coating ◽  
Wide Range ◽  
Performance Research

WS2has excellent tribological properties; it is emerging of lubricating materials. MoS2is commonly used solid lubricants and wide range of applications, but its poor heat resistance. WS2can well make up for the inadequate performance of the MoS2, but uses it as a solid lubricant in performance research on metallic materials. By friction and wear testing, the paper gets feasibility analysis of the application that WS2instead of MoS2in the field of solid lubrication, while exploring the synergies between them, laying the foundations for the manufacture of new types of composite lubrication coatings.

Effect of Sintering Temperature on the Tribological Behavior of Plasma Assisted Debinded and Sintered MIM Self Lubricating Steels

2010 ◽  
Author(s):  
Jose´ Daniel B. de Mello ◽  
Cristiano Binder ◽  
Aloisio Nelmo Klein ◽  
Roberto Binder
Keyword(s):  
Friction Coefficient ◽  
Sintering Temperature ◽  
Metallic Matrix ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Metal Injection Molding ◽  
Processing Route ◽  
Second Phase ◽  
New Processing ◽  
Feedstock Preparation

Solid lubrication and solid lubricants are one of the most promising choices for controlling friction and wear in energy efficient modern systems. The production of self lubrication composites containing second phase particles incorporated into the volume of the material appears to be a promising solution. A new processing route to obtaining a homogeneous dispersion of discrete solid lubricant particles in the volume of sintered steels produced by metal injection molding (MIM) was recently presented. This new route was achieved by in situ formation of graphite nodules due to the dissociation of precursor (SiC particles) mixed with the metallic matrix powders during the feedstock preparation. Nodules of graphite (size ≤ 20μm) presenting a nanostructured stacking of graphite foils a few nanometers thick were obtained. The thermal debinding, as well as the sintering, was performed in a single thermal cycle using a Plasma Assisted Debinding and Sintering (PADS) process. In this work, we present and discuss the effect of sintering temperature on the tribolayer durability and average friction coefficient in the lubricious regime (μ<0.2) of plasma assisted debinded and sintered self lubricating steel produced by metal injection mould technique. Three different temperatures (1100, 1150 and 1200 °C) and six different SiC contents (0–5%) were analyzed. Friction coefficient was little affected by the sintering temperature. However, the durability of the tribo layer formed on the sliding interface was greatly increased (5X) for the lower sintering temperature (1100°C).

Preparations and Properties of Solid Lubricants Coating on High-Speed Steel Tools

2008 ◽  
Vol 392-394 ◽  
pp. 538-542
Author(s):  
Suo Xia Hou ◽  
Xiao Ming Jia ◽  
C. Wu
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Solid Lubricant ◽  
Testing Machine ◽  
High Speed Steel ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Mixture Ratio ◽  
Solid Lubricant Coating ◽  
Cutting Test

This paper presents that the high-speed steel tools with solid lubrication material coating can cut without fluid because it has the quality of self-lubrication. With the help of M-2 friction and wearing testing machine and KYKY2800 scan electron microscope, the coating preparation technology and mixture ratio of solid lubrication material in complex coating can be optimized. The results show: phosphate treatment can increase the power of the tools’ surface adsorbing solid lubricant, and the frictional behaviour of solid lubrication coating is excellent when surface roughness of phosphate coating is Ra 2μm~Ra 4μm; molybdenum bisulfide, graphite and trioxid aluminium are mixed together and form a kind of complex coating which has better antifriction effect. The cutting test shows that the solid lubricant coating on the high-speed steel tools can be helpful in increasing the service life of the tools, decreasing the cutting resistance, and reducing the chip deformation and surface roughness of finished work.

Observing Interfacial Sliding Processes in Solid–Solid Contacts

MRS Bulletin ◽  
2008 ◽  
Vol 33 (12) ◽  
pp. 1159-1167 ◽  
Author(s):  
Kathryn J. Wahl ◽  
W. Gregory Sawyer
Keyword(s):  
Thin Film ◽  
Optical Microscopy ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Low Friction ◽  
Interfacial Sliding ◽  
Moving Contact ◽  
Powerful Approach

AbstractDirectly seeing into a moving contact is a powerful approach to understanding how solid lubricants develop low-friction, long-lived interfaces. In this article, we present optical microscopy and spectroscopy approaches that can be integrated with friction monitoring instrumentation to provide real-time, in situ evaluation of solid lubrication phenomena. Importantly, these tools allow direct correlation of common tribological events (such as variations in friction and wear) with the responsible sliding-induced mechanical and chemical phenomena. We demonstrate the utility of in situ approaches with applications to a variety of thin-film solid lubricants.

Study on Tribological Properties of n-SiO2/FeS Solid Lubrication Composite Coating

2011 ◽  
Vol 694 ◽  
pp. 914-918
Author(s):  
Yu Qiang Zhao ◽  
Yan Zang ◽  
Yu Lin Qiao ◽  
Shan Lin Yang
Keyword(s):  
Friction Coefficient ◽  
Composite Coating ◽  
Tribological Properties ◽  
Treatment Process ◽  
Solid Lubrication ◽  
Vacuum Impregnation ◽  
Comprehensive Treatment ◽  
Low Friction ◽  
Duplex Coating ◽  
Lubrication Mechanisms

The n-SiO2/FeS solid lubrication composite coating is prepared by means of the comprehensive treatment process of gridded laser quenching, low temperature ion sulfuration and vacuum impregnation technology. The tribological properties of n-SiO2/FeS solid lubrication composite coating are investigated under the condition of dry sliding, and the lubrication mechanisms are also preliminary discussed. The experiment results reveal that the friction coefficient of the coating is in the range of 0.065~0.10 when tested in 4067 minutes. Furthermore, its wear rate is only 6% of FeS solid lubrication duplex coating. This is testified that the n-SiO2/FeS solid lubrication composite coating is durable with low friction coefficient and wear resistance.

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
Keyword(s):  
Carbon Nanotubes ◽  
Shear Strength ◽  
Friction Coefficient ◽  
Solid Lubricant ◽  
Composite Coatings ◽  
Ceramic Matrix ◽  
Solid Lubricants ◽  
Metal Nanowires ◽  
Theoretical Point ◽  
Low Shear

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.

Adaptive Solid Lubricant Transfer Films for Conductivity and Oxidation Control

2012 ◽  
Author(s):  
Patrick S. M. Dougherty ◽  
Cecily M. Sunday ◽  
C. Fred Higgs
Keyword(s):  
Solid Lubricant ◽  
Composite Coatings ◽  
Solid Lubricants ◽  
Operating Conditions ◽  
Low Friction ◽  
Composite Powders ◽  
Electrically Conductive ◽  
Transfer Films ◽  
Oxidation Resistant ◽  
Complex Deposition

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.

Characterization of Sintered Bronze–MoS2 Composite With Solid Lubrication Effect

2020 ◽  
Vol 143 (7) ◽  
Author(s):  
L. E. Vieira ◽  
A. L. Gonçalves ◽  
N. I. R. Arraya ◽  
J. B. Rodrigues Neto ◽  
A. Dias ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Metallic Matrix ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Material Loss ◽  
Wear Rates ◽  
Sintered Bronze ◽  
Material Wear ◽  
Self Lubricating Composites

Abstract The most efficient method to reduce material loss and frictional energy losses is by using lubrication. An alternative is the use of solid lubrication, specifically by using solid lubricants evenly distributed in a metallic matrix, thus forming self-lubricating composites, which are capable to induce low coefficients of friction in mechanical systems. Molybdenum disulfide (MoS2) is a very versatile solid lubricant, suitable for lubrication in critical circumstances such as vacuum, high temperatures, and pressures. Therefore, the aim of this study is to produce samples of sintered composites consisting of homogeneously distributed MoS2 in a bronze matrix obtained by cold uniaxial pressing and to compare the wear-rates and friction coefficient between the MoS2-free bronze and the self-lubricating composites. Different MoS2 percentages were used to characterize the tribological properties of the composites as a function of the MoS2 content. At the end of the experiments, it was found that samples with 20% MoS2 did not sinter properly due to the large amount of lubricant between the bronze particles. It was also found that the mixture with 5.0 vol% MoS2 had proper sintering, satisfactory hardness, achieved lower friction coefficient, and better material wear performance due to the optimal amount and good distribution of MoS2 when compared with the rest of conditions studied.

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