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.

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.

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.

Low friction states for thin solid lubricant film of MoS2

2018 ◽  
Vol 70 (4) ◽  
pp. 639-644 ◽  
Author(s):  
Kwang-Hua R. Chu
Keyword(s):  
Thin Films ◽  
Solid Lubricant ◽  
Activation Volume ◽  
High Vacuum ◽  
Low Friction ◽  
Friction Behavior ◽  
Stick Slip ◽  
Content Type ◽  
Term Operation

Purpose During the operation of Wendelstein 7-X (W7-X), any mechanical disturbance such as stick-slip may cause quenching of superconducting (SC) coils. The friction behavior of MoS2 lubrication (thin film) for narrow support elements between the SC coils in W7-X is rather important, as there is a design requirement for a coefficient of friction (COF) 0.05 between the sliding surfaces to control the stress contribution (from friction). Design/methodology/approach The author has carried out intensive calibrations or verifications using verified models considering previous friction tests on various samples which measured the COF in 4.2 K, 77 K and room temperature conditions (at high vacuum) to simulate the actual working condition. Findings The author has given useful explanations and diagnosis for previous anomalous scattered data. To improve the performance of MoS2, the author has predicted its better COF (0.002 via tuning of the activation volume), which could be a superlubricating state for MoS2 thin films considering the long-term operation requirement W7-X. Originality/value In this paper, the author has adopted Eyring’s approach to predict the low COF (0.002 via tuning of the activation volume), which could be a superlubricating state for MoS2 thin films considering the long-term operation requirement W7-X. Finally, some recent progresses about the possible few-layer MoS2 role in the electromagnetic loads have been provided.

scholarly journals Ultralow Interlayer Friction of Layered Electride Ca2N: A Potential Two-Dimensional Solid Lubricant Material

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2462 ◽  
Author(s):  
Jianjun Wang ◽  
Lin Li ◽  
Ziting Shen ◽  
Peng Guo ◽  
Meng Li ◽  
...  
Keyword(s):  
Density Functional ◽  
Solid Lubricant ◽  
Interlayer Space ◽  
Solid Lubricants ◽  
Two Dimensional ◽  
Friction Behavior ◽  
Friction Mechanism ◽  
Functional Theory ◽  
Ultralow Friction ◽  
Conduction Electrons

Dispersion-corrected density functional theory (DFT) calculations reveal that the layered electride of dicalcium nitride (Ca2N) exhibits stronger interlayer binding interactions but lower interlayer friction behavior than that of traditional layered lubricants weakly bonded by van der Waals (vdW) interactions, such as graphite, h-BN, and MoS2. These results are attributed to the two-dimensional (2D) homogeneous conduction electrons distribution in the middle of the interlayer space of Ca2N, which yields a smooth sliding barrier and hence ultralow friction behavior. The interesting results obtained in this study have not only broadened the scope of 2D solid lubricants but also enriched the physical understanding of ultralow friction mechanism for 2D systems.

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.

An Experimental Evaluation of Solid Lubricant Based Nanofluids in Small Quantity Cooling and Lubrication during Grinding

2017 ◽  
Vol 890 ◽  
pp. 98-102 ◽  
Author(s):  
Sourabh Paul ◽  
Amitava Ghosh
Keyword(s):  
Boron Nitride ◽  
Solid Lubricant ◽  
Hexagonal Boron Nitride ◽  
Solid Lubricants ◽  
Metallic Alloys ◽  
Grinding Wheel ◽  
Metal Working ◽  
Maximum Reduction ◽  
Cooling And Lubrication ◽  
Ball On Disc

Small quantity cooling lubrication (SQCL) with commercially available metal working fluids (MWF) and nanofluids has been attempted successfully in machining and grinding. Solid lubricants also provided some benefits in grinding of metallic alloys. However, there are very few studies using molybdenum di-sulphide (MoS2) and hexagonal boron nitride (hBN) dispersed nanofluids applied in SQCL mode in grinding. The aim of the present work is to experimentally study improvement in grinding of EN31 steel using alumina grinding wheel with aqueous MoS2 and hBN nanofluids. The grinding study is supported by detailed tribometry at 1 m/s sliding speed to reveal the possible reasons behind such improvement. MoS2 dispersed nanofluids provided minimum coefficient of friction in ball-on-disc test. It also provided the maximum reduction in specific grinding energy and improvement in surface finish with respect to flood cooling. hBN dispersed nanofluids could not match the performance of MoS2 dispersed nanofluids both in ball-on-disc and grinding experiments.

Friction and Wear Behaviors of WC-Co/WC-Co Pairs in Air

2007 ◽  
Vol 534-536 ◽  
pp. 1193-1196
Author(s):  
Hiroyuki Hosokawa ◽  
Takeshi Nakajima ◽  
Koji Shimojima
Keyword(s):  
Friction Coefficient ◽  
Diffraction Pattern ◽  
Wear Debris ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Wear Test ◽  
Wear Volume ◽  
Grain Sizes ◽  
Ball On Disc

To investigate sliding friction and wear behaviors of WC–Co/WC–Co pairs containing different WC grain sizes, the ball-on-disc test in air were carried out for WC-Co containing WC grain sizes of 0.5 μm (F.G.) and 1.5 μm (C.G.). The results show that the wear volume of F.G. pin for F.G. pin/C.G. disc is larger than that of F.G. pin for F.G. pin/F.G. disc due to higher friction coefficient, and the surfaces after wear test are richer in oxygen compared to those before test. Furthermore, the wear debris, which is composed of nona-scale grains, after the wear test are remarkably richer in oxygen than to those before test. The diffraction pattern reveals sharp ring

Rolling-Friction Behavior of Sub-Micron Polystyrene-Sphere Arrays under Very Light Loads

2013 ◽  
Vol 321-324 ◽  
pp. 174-178
Author(s):  
Jiao Qu ◽  
Shi Rong Ge
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Self Assembly ◽  
Sliding Friction ◽  
Rolling Friction ◽  
Polystyrene Sphere ◽  
Si Substrate ◽  
Friction Behavior ◽  
Layer Film ◽  
Colloidal Spheres

The uniform sub-micron colloidal spheres were arrayed on the surface of a Si substrate via self-assembly to forming a sphere-layer film (monolayer), with emphasis on the application of rolling friction in the presence of rolling spheres on the surface of micro- or nano-equipment. It was found that the arrayed spheres on the substrate are mobile arising from rolling, and they can significantly reduce the friction force through changing the sliding friction to rolling one, thus exhibiting a smaller friction coefficient value than that of pure substrate. On the other hand, the elastic deformation of polystyrene (PS) spheres also contributes to the reduced friction force. In the absence of lubricant, the optimal friction coefficient of sphere-layer film was found to be 0.059 at the load of 3500 µN, at which the friction force of sphere-layer film was only 68% that of substrate. The friction coefficient of sphere-layer film decreases with increasing the applied load up to 3500 µN, followed by an increase with a further enhanced load, which has been ascribed to the transition from elastic contact to plastic one.

Sliding Friction Behavior of Bulk Ti3SiC2 under Difference Normal Pressures

2007 ◽  
Vol 280-283 ◽  
pp. 1353-1356 ◽  
Author(s):  
Zhen Ying Huang ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Yi Fan Wang ◽  
Zhi Li Zhang
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Transition Period ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Low Carbon ◽  
Friction Behavior ◽  
Steady Stage ◽  
Initial Stage ◽  
Friction Surfaces

The friction behavior of Ti3SiC2 sliding against low carbon steel was studied. Tests were carried out on a block-on-disk type friction tester, with the normal pressures from 0.2 MPa to 0.8 MPa and the sliding speed of 20 m/s. The results showed that, irrespective of the normal pressure, the friction coefficient exhibits a transition period in the initial stage of a sliding friction process, in which the friction coefficient increases from an initial value and tends to a saturation value, and then enters into a relatively steady stage. The results also showed that, the friction coefficient of the steady stage decreases gradually from 0.35 to 0.26 with increase in normal pressure from 0.2 MPa to 0.8 MPa. The friction surfaces were observed by using SEM. It was found that all the surfaces were covered by a layer consisting of the frictional products with antifriction effect, and that the denseness and the thickness of the layer were increased with increase in normal pressure applied.

scholarly journals Mathematical Model of Friction Coefficient Determination for Lubricated Surfaces

2015 ◽  
Vol 1 ◽  
pp. 121
Author(s):  
Armands Leitans ◽  
Janis Lungevics
Keyword(s):  
Mathematical Model ◽  
Friction Coefficient ◽  
Sliding Friction ◽  
Material Surface ◽  
Roughness Parameters ◽  
Lubricating Material ◽  
Model Of Friction ◽  
Rough Surface Contact ◽  
Ball On Disc

<p class="R-AbstractKeywords"><em><span lang="EN-GB">This article reviews mathematical model for the determination of friction coefficient for lubricated surfaces which operate works at sliding friction pairs in boundary lubrication case. In the particular model an absolutely smooth ball and rough surface contact is viewed taking into account properties of the material, surface roughness parameters, lubricating material kinematic viscosity and density. The model refers to widely spread ball-on-disc type tribometer where ball is in the contacts with plane.</span></em></p>

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