The Effect of Surface Finishing on the Tribological Behavior of a 94% Alumina Ceramic Material

AbstractThe effect of surface finish on the unlubricated sliding wear behavior of a 94% A12O3 ceramic material has been investigated using a reciprocatingright cylinder-on-flat tribometer. The surface finishes evaluated were produced using a combinationof SiC and diamond abrasive particles.Profilometry was employed to characterize surface topography and x-ray diffraction was used to determine the residual stress associated with each finishing process.The coefficients of friction and controlling wear mechanisms varied dramatically as the maximum asperity height was altered by different finishing techniques. Below a peak profile of 0.25 μm, the coefficient of friction varied between 0.60 and 0.75 due to preferential shearing of the siliceous binder phase which segregated at surfacial pores and grain boundaries. Binder adhesion in the sliding contact produced stick-slip frictional behavior. Surfaces with asperity heights in excess of 10 μin exhibited intergranularfracture or grain “pluck-out”. These surfaces contained minimal real areas of contact and yielded friction coefficients of 0.30 - 0.35. Removed alumina grains actedas hard abrasives in the contact zone and enhanced transgranular fracture by a lateral cracking mechanism. Evidence of crack propagation as a result of Mode II and Mode III shearloading was discovered at subsurface pore sites. The influences of microindentation hardness and fracture toughness are discussed in terms of their relative importances on the observed wear behavior.

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Brush Dynamics: Models and Characteristics

Volume 3: Dynamic Systems and Controls, Symposium on Design and Analysis of Advanced Structures, and Tribology ◽

10.1115/esda2006-95565 ◽

2006 ◽

Cited By ~ 6

Author(s):

Libardo V. Vanegas Useche ◽

Magd M. Abdel Wahab ◽

Graham A. Parker

Keyword(s):

Surface Roughness ◽

Coefficient Of Friction ◽

Rotational Speed ◽

Surface Finishing ◽

Stick Slip ◽

Street Sweeping ◽

The Coefficient Of Friction ◽

Dynamics Models ◽

Frictional Behaviour ◽

Duct Cleaning

This paper reviews investigations into the dynamics and modelling of brushes. They include brushes for surface finishing operations, removal of fouling, post-CMP brushing processes, air duct cleaning, and street sweeping. The methods that have been proposed to model brush dynamics are described, and the results of the research into brush mechanics are presented and discussed. Some conclusions of the paper are as follows: brush dynamics is very complex, as it depends on the interaction among many phenomena and variables. The bristle oscillations that occur in some brushes constitute a complexity for modelling brush behaviour and are not normally addressed. Additionally, the literature reveals that the coefficient of friction is not a constant value that depends only on the materials and surface roughness of the two contacting bodies. Frictional behaviour strongly depends on many variables, such as brush setup angles and rotational speed, which play a part in the development of stick-slip friction cycles. Finally, it is concluded that brush behaviour and the phenomena involved in brushing have not been fully studied or understood and more research into this field is needed.

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Correlation of 3-D Precision Machined Surface Topography With Frictional Response

Manufacturing Engineering and Materials Handling Engineering ◽

10.1115/imece2004-59534 ◽

2004 ◽

Author(s):

Ramesh Singh ◽

Rick Kalil ◽

Shreyes N. Melkote ◽

Fukuo Hashimoto

Keyword(s):

Three Dimensional ◽

Surface Characteristics ◽

Trial And Error ◽

Machined Surface ◽

Topographic Analysis ◽

Amplitude Parameter ◽

Surface Finishes ◽

Rolling Elements ◽

The Coefficient Of Friction ◽

Effect Of Surface

Precision surface finishes are used in a wide variety of applications. From bearing races and rolling elements to parallel slide ways, the functional characteristics of these surfaces are critical to their performance. Experimental trial and error has shown that certain surfaces outperform others in certain applications, but the specific surface characteristics that make this true are yet to be fully understood. The present paper addresses this issue through a detailed three-dimensional topographic analysis of different precision finished surfaces and correlation with their frictional response. Experiments are conducted to investigate the effect of surface type (Isotropic Finished, Ground, Hard Turned and Honed) and relative surface speed on the coefficient of friction in rolling/sliding contact. Utilizing white light interferometry measurement of the surfaces, different 3-D topographic parameters such as RMS deviation, density of summits and texture direction are obtained and their correlation with the experimentally obtained coefficients of friction is examined. Results show that the 3-D amplitude parameter Sq (RMS deviation of surface) and spatial parameter Sds (density of summits) play an important role in determining the frictional behavior of the surfaces studied.

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Sliding friction and wear behavior of Al–Ni–Co–Si quasicrystalline coatings deposited by the high-velocity oxy-fuel spraying technique

Journal of Materials Research ◽

10.1557/jmr.2002.0069 ◽

2002 ◽

Vol 17 (2) ◽

pp. 492-501 ◽

Cited By ~ 12

Author(s):

Eric Fleury ◽

Yu-Chan Kim ◽

Jae-Soo Kim ◽

Hyo-Sok Ahn ◽

Sang-Mok Lee ◽

...

Keyword(s):

Coefficient Of Friction ◽

High Velocity ◽

Wear Debris ◽

Friction And Wear ◽

Sliding Friction ◽

Wear Behavior ◽

Stick Slip ◽

Friction And Wear Behavior ◽

Test Conditions ◽

The Coefficient Of Friction

The sliding friction and wear performance of Al–Ni–Co–Si quasicrystalline coatings deposited by the high-velocity oxy-fuel technique were investigated under dry sliding conditions. This study indicated that changes in the imposed sliding test conditions modified the friction and wear behavior of quasicrystalline coatings. Qualitative analysis of the contact interface and wear debris were performed with the aim of understanding the role of the third body on the friction and wear processes. The dependence of the coefficient of friction on the sliding velocity and counterpart material was explained by the stick-slip behavior. It was also shown that test conditions favorable for the formation of thick intermediate layers and the densification of the coating subsurface led to low wear rates. Large cylindrical particles, formed by agglomeration of small wear debris, were suggested as a beneficial factor for the reduction of the coefficient of friction.

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Reciprocating Friction and Wear Behavior of WC-Co Based Cemented Carbides Manufactured by Electro-Discharge Machining

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.2025 ◽

2007 ◽

Vol 561-565 ◽

pp. 2025-2028 ◽

Cited By ~ 7

Author(s):

Koenraad Bonny ◽

Patrick de Baets ◽

Omer Van der Biest ◽

Jef Vleugels ◽

Bert Lauwers

Keyword(s):

Wear Debris ◽

Wear Behavior ◽

Wear Behaviour ◽

Surface Finishing ◽

Cemented Carbides ◽

Small Scale ◽

Wear Loss ◽

Binder Phase ◽

Wear Performance ◽

Electro Discharge Machining

Tungsten carbide based hardmetals with cobalt binder phase are widely used in engineering industries for their excellent mechanical properties and outstanding wear performance. Reciprocative sliding wear behaviour of a number of WC-Co based hardmetal grades was investigated using a small-scale pin-on-plate tribometer. Test samples were manufactured by electro-discharge machining (EDM) with various surface finishing regimes. SEM topographies and cross-section views of the cemented carbides were obtained both before and after dry friction tests, revealing distinctive wear mechanisms. The generated wear loss was quantified topographically using surface scanning equipment. Wear debris particles were collected and examined by EDX and TEM analysis. Based on experimental results, the execution of consecutive gradually finer EDM cutting steps was found to considerably enhance wear performance. Furthermore, a significant influence of contact load, sliding movement duration, application of lubricant and wear debris formation on wear rate and friction was established.

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Effects of Ambient Gases on Friction and Interfacial Resistance

Journal of Tribology ◽

10.1115/1.3261660 ◽

1988 ◽

Vol 110 (3) ◽

pp. 508-515 ◽

Cited By ~ 7

Author(s):

Y.-J. Chang ◽

D. Kuhlmann-Wilsdorf

Keyword(s):

Contact Resistance ◽

Coefficient Of Friction ◽

Wear Behavior ◽

Copper Surface ◽

Surface Films ◽

Electric Contact ◽

Interfacial Resistance ◽

Stick Slip ◽

The Coefficient Of Friction ◽

Ambient Gases

As is well known, ambient atmospheres can greatly affect the friction and wear behavior of metals sliding on each other, as well as the electric contact resistance between the metals. In order to better understand the mechanisms of those effects of ambient atmospheres, the coefficient of friction and the electric contact resistance have been studied for bundles of 50 micrometer thick copper wires, sliding on a polished copper surface in a specialized apparatus, called the hoop apparatus. The ambient gas was cycled between laboratory air and carbon dioxide, and between laboratory air and argon, respectively. The results indicate a reversible build-up and removal of surface films whose nature as well as speed of formation and removal depends on the gas present. Fiber bundles are used in order to eliminate the constriction resistance, so that the contact resistance is directly proportional to the specific film resistivity. The following properties were found to be affected by the ambient gases. (i) The average level of the contact resistance. (ii) The amplitude of the electric “noise.” (iii) The coefficient of friction. (iv) The difference between the static and the dynamic coefficients of friction in stick-slip motion. The results were found to be consistent with previous measurements in which the mechanism of forming wear particles was deduced from a wear chip analysis. Correspondingly they were interpreted in terms of the same wear model. This led to a further advance in the understanding of the interfacial processes accompanying sliding in this sample/substrate combination.

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Wear Behavior Analysis of Al2O3 Coatings Manufactured by APS and HVOF Spraying Processes Using Powder and Suspension Feedstocks

Coatings ◽

10.3390/coatings11080879 ◽

2021 ◽

Vol 11 (8) ◽

pp. 879

Author(s):

Monika Michalak ◽

Paweł Sokołowski ◽

Mirosław Szala ◽

Mariusz Walczak ◽

Leszek Łatka ◽

...

Keyword(s):

Plasma Spraying ◽

Wear Behavior ◽

Ceramic Coatings ◽

Suspension Plasma Spraying ◽

Atmospheric Plasma ◽

Hvof Spraying ◽

The Coefficient Of Friction ◽

Wear Mode ◽

Α Al2o3 ◽

Plasma Sprayed

Thermally sprayed ceramic coatings are applied for the protection of surfaces that are exposed mainly to wear, high temperatures, and corrosion. In recent years, great interest has been garnered by spray processes with submicrometric and nanometric feedstock materials, due to the refinement of the structure and improved coating properties. This paper compares the microstructure and tribological properties of alumina coatings sprayed using conventional atmospheric plasma spraying (APS), and various methods that use finely grained suspension feedstocks, namely, suspension plasma spraying (SPS) and suspension high-velocity oxy-fuel spraying (S-HVOF). Furthermore, the suspension plasma-sprayed Al2O3 coatings have been deposited with radial (SPS) and axial (A-SPS) feedstock injection. The results showed that all suspension-based coatings demonstrated much better wear resistance than the powder-sprayed ones. S-HVOF and axial suspension plasma spraying (A-SPS) allowed for the deposition of the most dense and homogeneous coatings. Dense-structured coatings with low porosity (4 vol.%) and good cohesion to the metallic substrate, containing a high content of α–Al2O3 phase (56 vol.%) and a very low wear rate (0.2 ± 0.04 mm3 × 10−6/(N∙m)), were produced with the S-HVOF method. The wear mechanism of ceramic coatings included the adhesive wear mode supported by the fatigue-induced material delamination. Moreover, the presence of wear debris and tribofilm was confirmed. Finally, the coefficient of friction for the coatings was in the range between 0.44 and 0.68, with the highest values being recorded for APS sprayed coatings.

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Colour stability of surface finishes on thermally modified beech wood

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0015.2391 ◽

2021 ◽

Vol 114 ◽

pp. 116-124

Author(s):

Gabriela Slabejová ◽

MÁRIA ŠMIDRIAKOVÁ

Keyword(s):

Surface Finish ◽

Beech Wood ◽

Surface Finishing ◽

Colour Stability ◽

Colour Difference ◽

Surface Finishes ◽

Before And After ◽

Thermally Modified Wood ◽

Wood Surfaces ◽

Modified Wood

Colour stability of surface finishes on thermally modified beech wood. The paper deals with the influence of the type of transparent surface finish on the change of colour of the surfaces of native beech wood and thermally modified wood. At the same time, the colour stability of three surface finishes on the surfaces of native and thermally modified beech wood was monitored. Beech wood was thermally modified at temperature of 125 °C for 6 hours. The thermal treatment was performed in a pressure autoclave APDZ 240, by the company Sundermann s.r.o in Banská Štiavnica. Three various types of surface finishes (synthetic, wax-oil, water-based) were applied onto the wood surfaces. The colour of the surfaces of native wood and thermally modified wood was measured in the system CIELab before and after surface finishing; the coordinates L*, a*, b*, C*ab and h*ab were measured. From the coordinates measured before and after surface finishing, the differences were calculated and then the colour difference ∆E* was calculated. Subsequently, the test specimens with the surface finishes were exposed to natural sunlight, behind glass in the interior for 60 days. The surface colour was measured at specified time of the exposure (10, 20, 30, 60 days). The results showed that the colour of the wood surfaces changed after application of the individual surface finishes; and the colour difference reached a change visible with a medium quality filter up to a high colour difference. The wax-oil surface finish caused a high colour difference on native wood and on thermally modified wood as well. On native beech wood, the lowest colour difference after exposure to sunlight was noticeable on the synthetic surface finish. On the surface of wood thermally modified, after exposure to sunlight, the lowest colour difference was noticeable on the surface with no surface finish.

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Micro/Nano-Tribological Behavior of Octadecyltrichlorosilane on Silicon as a Coating for MEMS

World Tribology Congress III, Volume 2 ◽

10.1115/wtc2005-63491 ◽

2005 ◽

Author(s):

J. Barriga ◽

B. Ferna´ndez ◽

E. Abad ◽

B. Coto

Keyword(s):

Liquid Phase ◽

Vapour Phase ◽

Stick Slip ◽

Force Microscopy ◽

Angle Measurements ◽

Atomic Force ◽

Contact Angle Measurements ◽

Assembled Monolayers ◽

The Coefficient Of Friction ◽

Semicontact Mode

Despite progresses achieved in the technology of MEMS, the tribological problem continues being an unresolved matter. Wear and stick-slip phenomena are many times the origin of failure of these devices. The application of self-assembled monolayers (SAMs) in liquid phase seems to be a solution to this problems. SAMs of octadecyltrichlorosilane (CH3(CH2)17SiCl3, OTS) were attached to Si(100) oxidized in liquid phase. Contact angle measurements were used for characterizing the grade of hydrophobicity. The topography of the coating was obtained with an Atomic Force Microscopy (AFM) in semicontact mode. The images showed the presence of particles related to the polymerization of the precursor molecule during the formation process of the SAMs. Creating the film of lubricant in vapour phase would avoid this undesirable effect. Tribological tests were carried out with a microtribometer in linear reciprocating movement with a ball of 2 mm of diameter (100Cr6 and Si3N4) and load of some milinewtons. Results were compared with those obtained for silicon oxidized without any coating. The coefficient of friction (COF) and wear (substrate and ball) were studied under different test conditions.

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Review of Superfinishing by the Magnetic Abrasive Finishing Process

High Speed Machining ◽

10.1515/hsm-2017-0004 ◽

2017 ◽

Vol 3 (1) ◽

Cited By ~ 8

Author(s):

Lida Heng ◽

Yon Jig Kim ◽

Sang Don Mun

Keyword(s):

High Surface ◽

Processing Parameters ◽

Engineering Industry ◽

Advanced Materials ◽

Surface Finishing ◽

Magnetic Abrasive Finishing ◽

Surface Finishes ◽

Abrasive Finishing ◽

Recent Developments ◽

Finishing Processes

AbstractRecent developments in the engineering industry have created a demand for advanced materials with superior mechanical properties and high-quality surface finishes. Some of the conventional finishing methods such as lapping, grinding, honing, and polishing are now being replaced by non-conventional finishing processes. Magnetic Abrasive Finishing (MAF) is a non-conventional superfinishing process in which magnetic abrasive particles interact with a magnetic field in the finishing zone to remove materials to achieve very high surface finishing and deburring simultaneously. In this review paper, the working principles, processing parameters, and current limitations for the MAF process are examined via reviewing important work in the literature. Additionally, future developments of the MAF process are discussed.

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