A comparison of the relative friction and wear responses of PTFE and a PTFE-based composite when tested using three different types of sliding wear machines

2015 ◽  
Vol 90 ◽  
pp. 15-21 ◽  
Author(s):  
Luigi Mazza ◽  
Andrea Trivella ◽  
Roberto Grassi ◽  
Giulio Malucelli
Keyword(s):  
Sliding Wear ◽  
Friction And Wear ◽  
Different Types ◽  
Relative Friction

The role of surface topography and normal load in the initiation of ratchetting-peak friction, seizure, scuffing, and elastic shakedown

2021 ◽  
pp. 1-12
Author(s):  
Vimal Edachery ◽  
V. Swamybabu ◽  
Gurupatham Anand ◽  
Paramasamy Manikandan ◽  
Satish V. Kailas
Keyword(s):  
Steady State ◽  
Surface Topography ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Critical Parameter ◽  
Normal Load ◽  
Sliding Direction ◽  
Elastic Shakedown ◽  
Lubrication Conditions

Abstract Surface topography is a critical parameter that can influence friction and wear in engineering applications. In this work, the influence of surface topography directionality on seizure and scuffing initiation during tribological interactions is explored. For this, unidirectional sliding wear experiments were carried out in immersed lubrication conditions for various normal loads. The tribological interactions were studied using EN31-60 HRC flats and SAE52100-60HRC pins in a sphere on flat configuration. The results show that, in some cases, the sliding interactions in the initial cycles lead to a high friction coefficient of up to ∼0.68 in lubricated conditions, which was termed as ‘peak friction’, and this was accompanied by scuffing. The existence of peak friction was found to be dependent on surface topography directionality, especially when the directionality in topography was parallel to the sliding direction. Continuous ratchetting was found to be the cause of peak friction which was accompanied by seizure and scuffing. When the topography directionality was perpendicular or independent of sliding direction, elastic shakedown occurred at earlier cycles and prevented peak friction initiation, scuffing and also facilitated for higher steady-state friction values.

Friction and Wear of Epoxy Composites Containing Silica Nanoparticles Grafted by Hyperbranched Aromatic Polyamide

2012 ◽  
Vol 20 (8) ◽  
pp. 673-682
Author(s):  
Ying Yu ◽  
Min Zhi Rong ◽  
Ming Qiu Zhang
Keyword(s):  
Silica Nanoparticles ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Frictional Coefficient ◽  
Aromatic Polyamide ◽  
Epoxy Composites ◽  
Linear Polymers ◽  
Curing Mechanism ◽  
The Matrix ◽  
Amine Groups

Nano-sized SiO2 particles grafted with hyperbranched aromatic polyamide were employed as fillers for fabricating epoxy based composites. The hyperbranched aromatic polyamide was selected because its terminal amine groups could take part in the curing reaction of epoxy resin and covalently connect silica nanoparticles with the matrix. The experimental results proved the occurrence of this reaction, and indicated that the presence of the grafted SiO2 in epoxy does not change the overall curing mechanism of epoxy. In comparison to the composites filled with untreated nano-SiO2 particles, the composites with the grafted nano-SiO2 exhibited significantly improved sliding wear resistance and reduced frictional coefficient owing to the strong filler/matrix interfacial bonding. Moreover, hyperbranched aromatic polyamide grafted nano-SiO2 was more effective to enhance tribological properties of epoxy than linear polymers grafted versions.

Relating Friction in CMP to Topography Evolution

2005 ◽  
Author(s):  
Xiaolin Xie ◽  
Duane Boning
Keyword(s):  
Surface Topography ◽  
Integrated Circuit ◽  
Friction And Wear ◽  
Shallow Trench Isolation ◽  
Integrated Circuit Manufacturing ◽  
Scale Models ◽  
Trench Isolation ◽  
Model Predictions ◽  
Different Types ◽  
Dual Material

Die-scale models of chemical-mechanical polishing (CMP) have been previously reported for a number of different CMP processes used in integrated circuit manufacturing, including oxide, dual material shallow trench isolation, and dual material copper damascene processes. These models can dynamically predict the evolution of surface topography (e.g., local feature step heights, film thickness nonuniformity across the different pattern density regions of the chip, dishing, and erosion) for any time point during CMP. This topography evolution information can be applied to better understand the basis for observed friction and wear in the CMP process. In this work, we explore models of the macroscopic frictional force based on the surface topography. CMP endpoint measurements, such as those from motor current traces, enable verification of model predictions relating friction to CMP surface topography evolution, for different types of CMP processes and patterned chips.

The Mapping of Metallic Sliding Wear

1988 ◽  
Vol 202 (6) ◽  
pp. 379-395 ◽  
Author(s):  
T H C Childs
Keyword(s):  
Shear Strength ◽  
Abrasive Wear ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Interfacial Shear Stress ◽  
Surface Flow ◽  
Main Attention ◽  
Surface Shear ◽  
Microstructural Effects ◽  
Model Predictions

Mechanisms of machining (abrasive), fatigue and transfer wear are reviewed in the context of the interfacial shear stress (adhesive) and surface roughness (deformation) conditions in which they occur. In the first part it is shown how model predictions of surface flow, friction and wear may be mapped on to a field with surface shear strength and roughness slope as its coordinates and in the second part the response of real metals to these variables is considered. The main attention is given to abrasive wear, with a review of lubricant, geometry, bulk mechanical and microstructural effects on abrasive wear resistance; but briefer reviews of fatigue and transfer wear are also given. Any overview of metallic wear requires consideration to be given to wear not of the metal but by removal of surface reaction films (usually oxides): regimes of oxidational wear do not plot on to a map of surface shear strength and slope but on to a map of nominal contact pressure and sliding speed. The need is argued for two sorts of map on which to classify wear phenomena.

scholarly journals VIBROACOUSTIC TESTING OF TRIBOUNITS ENDURANCE

2017 ◽  
pp. 69-76 ◽  
Author(s):  
Leonid Vladimirovich Efremov ◽  
Andrey Vladimirovich Tikalov ◽  
Lyudmila Sanduovna Baeva
Keyword(s):  
Rotational Speed ◽  
Friction And Wear ◽  
Friction Pair ◽  
Surface Condition ◽  
Theory And Practice ◽  
Band Spectrum ◽  
Rolling Bearings ◽  
Sliding Bearings ◽  
Object State ◽  
Different Types

For the development of standards of timing and amount of shipboard equipment maintenance and repair it is important to study and improve the theory and practice of evaluation of endurance of such friction pairs as sliding bearings. In the diagnosis of rolling bearings vibroacoustic methods are widely used, but, as for sliding bearings, these methods are still at the stage of research with respect to friction. Thereby, the results of testing different types of tribounit samples on friction test machines have been studied. There have been done vibration measurements for given conditions (rotation speed and load), where the root mean square values (RMS) of vibrational acceleration a in m/s2 or dB for acceleration were used as main diagnostic parameters. The authors have investigated dependencies of vibration levels for each band of tri-band spectrum on rotational speed, load, lubrication, surface roughness with respect to temperature, coefficient of friction and wear resistance. It has been proved that the source of VHF vibration of RMS is friction in coupling, depending on the surface condition and lubrication type of the friction pair. Dependency of acceleration RMS level on rotational speed and load of the sample has been stated. The results allow to infer about the effectiveness of the proposed tri-band vibroacoustic characteristics of the tribounits using vibrometer CM-21. This method can be used for diagnostics of sliding bearings, which can require standardization of modes and conditions of measurement and the establishment of zones of maximum permitted levels of the object state.

scholarly journals Molecular Coverage Determines Sliding Wear Behavior of n-Octadecylphosphonic Acid Functionalized Cu–O Coated Steel Disks against Aluminum

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 280
Author(s):  
Stephan Prünte ◽  
Denis Music ◽  
Velislava L. Terziyska ◽  
Christian Mitterer ◽  
Jochen M. Schneider
Keyword(s):  
Sliding Wear ◽  
Friction And Wear ◽  
Surface Coverage ◽  
Wear Behavior ◽  
Coated Steel ◽  
Low Friction ◽  
Phosphonic Acids ◽  
Asperity Contacts ◽  
Sliding Distance ◽  
Octadecylphosphonic Acid

The sliding wear behavior of Cu–O coated steel disks functionalized with n-octadecyl-phosphonic acids was evaluated against aluminum in ball-on-disk tribometer experiments. After 5 m of sliding the friction coefficient of the functionalized sample with maximum molecular coverage is ≤0.3 ± 0.1. Surfaces with lower coverage mitigate friction and wear as well exhibiting initially similar low friction coefficients but reveal the breakdown of lubrication for sliding distances <5 m. The length of the low friction sliding distance before breakdown scales with the coverage of n-octadecylphosphonic acids on the Cu–O surface. Coverage hence determines the tribological behavior of the functionalized surface against sliding aluminum. As the coverage is increased, detrimental asperity contacts between the rubbing surfaces are reduced.

Friction and wear behaviors of the PVD ZrN coated carbide in sliding wear tests and in machining processes

Wear ◽  
2008 ◽  
Vol 264 (3-4) ◽  
pp. 298-307 ◽  
Author(s):  
Deng Jianxin ◽  
Liu Jianhua ◽  
Zhao Jinlong ◽  
Song Wenlong ◽  
Niu Ming
Keyword(s):  
Sliding Wear ◽  
Friction And Wear ◽  
Machining Processes ◽  
Coated Carbide ◽  
Wear Tests

ANN Prediction of Coefficient of Friction and Sliding Wear Rates of Cast Al6061-Si3N4 Composites

2010 ◽  
Vol 159 ◽  
pp. 338-341 ◽  
Author(s):  
C.S. Ramesh ◽  
R. Keshavamurthy ◽  
D. Vineela ◽  
R. Archana
Keyword(s):  
Coefficient Of Friction ◽  
Material Properties ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Tribological Behavior ◽  
Matrix Alloy ◽  
Wide Spread ◽  
Wear Rates ◽  
Cast Composites ◽  
Pin On Disc

This work focuses on the prediction of tribological behavior of cast Al6061-Si3N4 composites using ANN technique owing to its wide spread popularity in accurate predictions of material properties. The cast composites were developed by stir cast method and its tribological behavior were experimentally evaluated using a pin-on-disc tribometer adopting loads and sliding velocities ranging from 20-100N and 0.314-1.574m/s respectively. The predictions of coefficient of friction and wear rates of matrix alloy and the developed cast composites by ANN approach do agree very closely with the experimental data. Keywords: ANN, Composites, coefficient of friction, wear rates.

Friction and wear behaviors of the carbide tools embedded with solid lubricants in sliding wear tests and in dry cutting processes

Wear ◽  
2011 ◽  
Vol 270 (9-10) ◽  
pp. 666-674 ◽  
Author(s):  
Jianxin Deng ◽  
Wenlong Song ◽  
Hui Zhang ◽  
Pei Yan ◽  
Aihua Liu
Keyword(s):  
Sliding Wear ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Dry Cutting ◽  
Cutting Processes ◽  
Wear Tests
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