Study on the Lubrication and Antifriction Mechanism of Low Frictional Self-Lubricating Wear-Resisting Coating

2011 ◽  
Vol 339 ◽  
pp. 477-482 ◽  
Author(s):  
Yun Cai Zhao ◽  
Shu Feng Huang ◽  
Xiao Mei Liu
Keyword(s):  
Friction Coefficient ◽  
Friction Factor ◽  
Room Temperature ◽  
Abrasive Particle ◽  
Surface Texturing ◽  
Laser Remelting ◽  
Third Body ◽  
The Third ◽  
Abrasion Loss ◽  
Supersonic Plasma

This paper is about the lubricating wear-resisting coating KF301/WS2 and round pit texturing modified coating KF301/WS2 which are prepared by supersonic plasma spraying, laser remelting and surface texturing technology, tribological characteristics of two kinds of coatings are studied under room temperature, according to this, it is discussed for lubrication antifriction mechanism. The research shows: round pit texture has a certain influence on friction factor of coating’s surface and abrasion loss. Friction coefficient of untextured surface is about 0.0138 in the initial stages, while friction coefficient of round pit texture is about 0.01, compared with the former, the latter decreases 27%; when wear time reaches to 1 hour, abrasion loss of untextured surface is 0.0026mg, while abrasion loss of round pit texture is about 0.013mg, compared with the former, the latter decreases 50%. The lubricant antifriction performance of round pit texture is higher than untextured surface, this is because friction coefficient of coating is decreased as the change of the third-body bed, and round pit micro moulding can collect abrasive particle, decreasing the influence of abrasive particle.

Experiment Study on Tribological Properties of the Coating with Different Surface Textures

2011 ◽  
Vol 121-126 ◽  
pp. 2735-2740
Author(s):  
Yun Cai Zhao ◽  
Fang Ping Hu ◽  
Xiao Mei Liu ◽  
Chun Ming Deng ◽  
Wen You Ma
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Room Temperature ◽  
Surface Texturing ◽  
Tribological Characteristic ◽  
Laser Remelting ◽  
Experiment Study ◽  
Surface Textures ◽  
Abrasion Loss ◽  
Supersonic Plasma

This paper is about the KF301/WS2 modified lubricating wear-resisting coating which is prepared by supersonic plasma spraying, laser remelting and surface texturing technology, tribological characteristic of KF301/WS2 lubricating wear-resisting coating of four different (round pit, diamond, parallel and intermittence) tracks and part laser remelting is studied under room temperature. Research shows: textures of different tracks have a certain influence on friction factor of coating’s surface and abrasion loss. Friction coefficient of mouldling surface of broken texture is about 0.012 in the initial stages, while friction coefficient of round pit texture is about 0.0085. Round pit, diamond and parallel microtopography make friction state enter stabilization quickly, effectively restraining the wave of abrasion loss. When wear time reaches to 1 hour, abrasion loss of broken texture is 0.03mg, while abrasion loss of round pit texture is about 0.015mg. Tribological properties, from high to low, in turn, are round pits, diamond, parallel and broken texture.

The Influence of Rhombus Cross Track Laser Remelting on Tribological Properties of Lubricating Wear-Resisting Coating Prepared Plasma Spraying

2011 ◽  
Vol 121-126 ◽  
pp. 1830-1835
Author(s):  
Yun Cai Zhao ◽  
Gao Jie Hao ◽  
Xiao Mei Liu ◽  
Chun Ming Deng ◽  
Wen You Ma
Keyword(s):  
Surface Modification ◽  
Friction Factor ◽  
Plasma Spraying ◽  
Room Temperature ◽  
Textured Surface ◽  
Tribological Characteristic ◽  
Laser Remelting ◽  
Abrasion Loss ◽  
Supersonic Plasma ◽  
Cross Track

This paper is about the KF301/WS2 lubricating wear-resisting coating of diamond textured surface modification which is prepared by supersonic plasma spraying, laser remelting coating and surface micro moulding, and coating’s tribological characteristic is studied under room temperature. It indicates that the diamond texture has a certain influence on abrasion loss and friction factor of coating’s surface. In the initial stages, fiction coefficient of untextured surface is about 0.0138, while fiction coefficient of textured surface is about 0.0115, compared with the former, the latter is obviously better and decreases 17%; When wear time reaches to 1 hour, abrasion loss of untextured surface is 0.03mg, and which of diamond textured surface is about 0.018, compared with the former, the latter is obviously better and decreases 40%. Tribological characteristic of diamond textured surface is higher than untextured surface.

Friction Coefficient as a Macroscopic View of Local Dissipation

2007 ◽  
Vol 129 (4) ◽  
pp. 829-835 ◽  
Author(s):  
D. Richard ◽  
I. Iordanoff ◽  
Y. Berthier ◽  
M. Renouf ◽  
N. Fillot
Keyword(s):  
Friction Coefficient ◽  
Dry Friction ◽  
Three Dimensional ◽  
Third Body ◽  
The Third ◽  
Dynamic Friction Coefficient ◽  
Approaches To Study ◽  
Set Up ◽  
Method Approach ◽  
Simple Interaction

This paper presents an overview of a discrete element method approach to dry friction in the presence of a third body. Three dimensional computer simulations have been carried out to show the influence of the third body properties (and more specifically their adhesion) on friction coefficient and profiles of dissipated power. Simple interaction laws and a cohesive contact are set up to uncouple the key parameters governing the contact rheology. The model is validated through a global energy balance. As it is shown that dynamic friction coefficient can be explained only in terms of local energy dissipation, this work also emphasizes the fact that mechanism effects and third body rheology have important consequences on the energy generation and dissipation field. Therefore, asymmetries can arise and the surface temperature of first bodies can be significantly different even for the same global friction coefficient value. Such investigations highlight the fact that friction coefficient cannot be considered in the same way at the mechanism scale as at the contact scale where the third body plays a non-negligible role, although it has been neglected for years in thermal approaches to study of surfaces in contact.

Modeling of Friction Induced Vibration due to Third-Body Effects

2001 ◽  
Author(s):  
David S. Xu ◽  
Hooshang Heshmat
Keyword(s):  
Friction Coefficient ◽  
Normal Load ◽  
System Response ◽  
Viscous Damping ◽  
Third Body ◽  
The Third ◽  
Damping Material ◽  
Variable Friction ◽  
Semi Empirical ◽  
Friction Induced Vibration

Abstract Friction induced vibration at contact interfaces is still a big challenging problem and not well understood how to affect the high cycle fatigue (HCF) failures in gas turbine engine and other machinery. Most researchers conducted on the subject of only two bodies in contact with the Coulomb’s friction law only. In this paper, the interface friction phenomena and induced vibration are investigated by means of the improved third-body composite interface micro-slip model which includes a variable friction coefficient and a flexible contact, represented as effective stiffness and equivalent viscous damping elements. The third-body considered herein is almost always present at contacting interfaces and is comprised of generated wear debris or a soft intermediate anti-fretting coating applied to the mating surfaces. This kind of third-body can be viewed as a thin factional damping material layer to provide shear energy dissipation in order to mitigate the destructive effects of high frequency vibrations in components with highly stressed contacts. A properly engineered third-body can also play the role of both a damping material and a lubricant to decrease wear rate. For the study presented, a semi-empirical formula for the third-body powder properties was employed, depending on the experimental data and the non-linear regression approach. The experimental powder TiO2 data included density, shear strength, frictional coefficients, loss factor as a function of normal load, shear strain, speed and frequency. The results in this paper indicate that the third body semi-empirical equivalent stiffness / viscous damping representation of a flexible contact with variable friction coefficient does indeed have merit and does have influence on overall system response. It has been shown that the third body effects should be considered in the friction and damping induced vibration on the contact interfaces. Such a model may be used to assess designs and material coating approaches to counter fretting in highly stressed contacts as well as assessing the interaction of contact kinematics on HCF failures. Further experimental investigation of specified friction contact configuration of the components needs to be conducted in order to evaluate their friction characteristics and move this technology toward a practical engineering applications.

Friction Coefficient as a Macroscopic View of Local Dissipation

2007 ◽  
Author(s):  
I. Iordanoff ◽  
D. Richard ◽  
M. Renouf ◽  
Y. Berthier
Keyword(s):  
Friction Coefficient ◽  
Dry Friction ◽  
Three Dimensional ◽  
Global Scale ◽  
Contact Interface ◽  
Third Body ◽  
The Third ◽  
Dynamic Friction Coefficient ◽  
Set Up ◽  
Method Approach

This paper presents an overview of a Discrete Element Method approach used to study the dry friction (global scale) taking into account local discontinuity with the presence of third body at the contact interface. Three dimensional computer simulations have been carried out to show the influence of the third body properties (and more specifically its adhesion) on the resulting friction coefficient as well as the dissipated power profiles. The physics of the interface is described by a simple cohesive contact law which is set up to uncouple the key parameters governing the contact rheology. The model is validated through a global energy balance. As it is shown that dynamic friction coefficient can be explained in term of local energy dissipation, the work also emphasizes the fact that mechanism effects and third body rheology have important consequences on the energy generation and dissipation field. The friction coefficient cannot be considered the same way at the mechanism scale than at the contact one where the third body plays a non-negligible role despite the fact that it has been neglected for years in thermal approaches of the contact.

The role of the third body in the fretting wear of 690 alloy

2020 ◽  
Vol 34 (09) ◽  
pp. 2050077
Author(s):  
Xue Mi ◽  
Xiao-Ming Bai ◽  
Pan Tang ◽  
Hai Xie ◽  
Jin-Fang Peng ◽  
...  
Keyword(s):  
Room Temperature ◽  
Normal Force ◽  
Fretting Wear ◽  
Wear Particles ◽  
Third Body ◽  
Experimental Conditions ◽  
The Third ◽  
The Coefficient Of Friction ◽  
Friction Energy

In this work, to investigate the role of the third body in the fretting behavior of 690 alloy, the fretting capabilities of 690 alloy against 405 stainless steel have been performed under various experimental conditions. The testing normal force and temperature varied from 10 N to 40 N and from room-temperature (RT) to [Formula: see text]C, respectively, at 5 Hz and 200 [Formula: see text]m. The results demonstrated that the profile shape of wear scar was dependent on the action of the wear particles. Three typical profile shapes were examined in this work: “U” shape, “W” shape and “M” shape. The balance of the formation and ejection of wear particles led to a steady value of the coefficient of friction (COF) and friction energy.

scholarly journals Temperature Effects on the Friction and Wear Behaviors of SiCp/A356 Composite against Semimetallic Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Like Pan ◽  
Jianmin Han ◽  
Zhiyong Yang ◽  
Jialin Wang ◽  
Xiang Li ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Debris ◽  
Friction And Wear ◽  
Brake Disc ◽  
Third Body ◽  
Braking Performance ◽  
The Third ◽  
Braking Process ◽  
Disc Configuration ◽  
Worn Surface

Due to the low density and high temperature resistance, the SiCp/A356 composites have great potential for weight reduction and braking performance using the brake disc used in trains and automobiles. But the friction coefficient and braking performance are not stable in the braking process because of temperature rising. In this paper, friction and wear behaviors of SiCp/A356 composite against semimetallic materials were investigated in a ring-on-disc configuration in the temperature range of 30°C to 300°C. Experiments were conducted at a constant sliding speed of 1.4 m/s and an applied load of 200 N. Worn surface, subsurface, and wear debris were also examined by using SEM and EDS techniques. The third body films (TBFs) lubricated wear transferred to the third body abrasive wear above 200°C, which was a transition temperature. The friction coefficient decreased and weight of semimetallic materials increased with the increase of temperature and the temperature had almost no effect on the weight loss of composites. The dominant wear mechanism of the composites was microploughing and slight adhesion below 200°C, while being controlled by cutting grooves, severe adhesion, and delamination above the 200°C.

Effect of Graphite Content on the Tribological Performance of Copper-Matrix Composites Under Different Friction Speeds

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Han Xiao-Ming ◽  
Gao Fei ◽  
Su Lin-Lin ◽  
Fu Rong ◽  
Zhang En
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
High Speed ◽  
Copper Matrix ◽  
Tribological Performance ◽  
Matrix Composites ◽  
Third Body ◽  
H13 Steel ◽  
Copper Matrix Composites ◽  
The Third

The effect of graphite (Gr) content on tribological performance of copper-matrix composites against H13 steel was investigated using a pin-on-disk test in the range of 3.14–47.1 m/s. The composites with different weight fractions of Gr (up to 18%) were fabricated by powder metallurgy technique. The results showed that the friction coefficient and wear rate generally decreased with the increase in Gr content. However, the friction coefficient and wear rate differ at various speeds. At 200 and 500 r/min, the friction coefficient and wear rate kept lower with the increase in Gr content, because the third body of Cu–Al–3%Gr specimen had strong fluidity and plasticity. By contrast, the particle third body of Cu–Al–12%Gr specimen, which contained higher content of Gr, could roll easily. Increased Gr feeding to the third body was reasonable for the decreasing of friction coefficient and wear with the increasing of the amount of Gr content at the speed in the range of 1000–2000 r/min. Under the high-speed, the friction coefficient showed slight change because the friction temperature induced all the third bodies to extend and flow effortlessly without componential influence. However, wear decreased significantly because the third body possessed more metal, which favored attachment to the counter disk.

scholarly journals Extended analytical formulae for the perturbed Keplerian motion under low-thrust acceleration and orbital perturbations

2021 ◽  
Vol 133 (3) ◽  
Author(s):  
Marilena Di Carlo ◽  
Simão da Graça Marto ◽  
Massimiliano Vasile
Keyword(s):  
Gravitational Perturbation ◽  
Low Thrust ◽  
Orbital Elements ◽  
Third Body ◽  
The Third ◽  
Orbital Perturbations ◽  
Analytical Formulae ◽  
Numerical Orbit ◽  
Body Potential

AbstractThis paper presents a collection of analytical formulae that can be used in the long-term propagation of the motion of a spacecraft subject to low-thrust acceleration and orbital perturbations. The paper considers accelerations due to: a low-thrust profile following an inverse square law, gravity perturbations due to the central body gravity field and the third-body gravitational perturbation. The analytical formulae are expressed in terms of non-singular equinoctial elements. The formulae for the third-body gravitational perturbation have been obtained starting from equations for the third-body potential already available in the literature. However, the final analytical formulae for the variation of the equinoctial orbital elements are a novel derivation. The results are validated, for different orbital regimes, using high-precision numerical orbit propagators.

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