Unified Physical Concept of Friction and Wear of Rubber Part 1: Strong Adhesion and High Frictional Force caused by the Surface Characteristics of Cross-linked Rubber

2020 ◽  
Vol 93 (9) ◽  
pp. 312-319
Author(s):  
Yoshihide FUKAHORI
Keyword(s):  
Frictional Force ◽  
Friction And Wear ◽  
Surface Characteristics ◽  
Physical Concept ◽  
Rubber Part ◽  
Strong Adhesion

Ambiguous Transition from Fretting to Sliding of Biomedical Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 2343-2348
Author(s):  
Hisao Fukui ◽  
W. Yang ◽  
Shozo Tsuruta ◽  
K. Kaikawa ◽  
A. Sugimura ◽  
...  
Keyword(s):  
Friction Force ◽  
Friction And Wear ◽  
Lower Threshold ◽  
The Self ◽  
Ti Alloy ◽  
Hybrid Mechanism ◽  
Strong Adhesion

An intensive amplitude arrangement for reciprocal tribocontact of biomedical alloys, Ag-20.0Pd-14.5Cu-12.0Au, Au-5.0Pt-2.0Pd-9.2Ag-15.0Cu and Ti-29Nb-13Ta-4.6Zr was conducted in order to check the details of friction and wear alterations around the transition from fretting to sliding. It is shown that the friction force exhibits stagnation for the Ag alloy and decrease for the Au alloy and the Ti alloy in certain domain of oscillating amplitude. Beyond the domain the friction force increases with the amplitude, and below the lower threshold and above the upper threshold triboevent is complete fretting and sliding respectively. Observation of friction-force waveform and SEM topography found, a hybrid mechanism of fretting and sliding is dominant in the amplitude domain, and the strong adhesion between the self-mated alloys is responsible to this exhibition.

What Causes Low Friction? — What Causes High Friction?

2005 ◽  
Author(s):  
Y. Elaine Zhu ◽  
Steve Granick
Keyword(s):  
Friction Coefficient ◽  
Recent Work ◽  
Frictional Force ◽  
Friction And Wear ◽  
Normal Load ◽  
Low Friction ◽  
Strategic Design ◽  
Modern Methods ◽  
Design Requirements ◽  
The Many

The design of tribological interfaces is often motivated by a quest to minimize friction and wear. Among the many strategic design principles that have been developed to this end, the simple idea of decoupling frictional force from normal load is especially attractive. Recent work from this laboratory demonstrates that under certain conditions, it is possible to reduce this coupling significantly with the result that the friction coefficient appears to be very low. However, the materials design requirements to achieve this end are rather stringent. Furthermore, modern methods enable one under some conditions to measure directly the structure and motions of lubricants during tribological sliding.

Towards minimizing wear by improving antiwear additives and surface characteristics using reduced phosphorus plain ZDDP oil under boundary lubrication

2016 ◽  
Vol 68 (1) ◽  
pp. 16-29 ◽  
Author(s):  
Gabi N Nehme ◽  
Saeed Ghalambor
Keyword(s):  
Boundary Lubrication ◽  
Friction And Wear ◽  
Water Drop ◽  
Heavy Traffic ◽  
Surface Characteristics ◽  
Heating Time ◽  
Contact Angles ◽  
Antiwear Additives ◽  
Sem Images ◽  
Content Type

Purpose – This study aims to examine the effect of the antiwear resistance of plain zinc-dialkyldithiophosphate (ZDDP) oil in the presence of Titanium-fluoride/iron-fluoride/polytetrafluoroethylene (TiF3/FeF3/PTFE) in the time to tribofilm breakdown and extent of wear under extreme boundary lubrication using a contact load of 317 Newton and a rotational speed of 700 rpm to simulate the cold start of a car engine. The mechanism of tribofilm formation and breakdown was followed carefully by monitoring the friction coefficient for different surface roughnesses over the duration of several reproducible tests that were performed in a ball on cylinder tribometer. Design/methodology/approach – The heating time of the cylinder dipped in the specified lubricant blend then set for one minute before testing and the break in period of 2 minutes to cool the contacting metal to metal surfaces during tribological testing played important roles in minimizing friction and wear, and are directly proportional to the durability and time for breakdown of the tribofilm. This article addresses the improvement of water drop contact angles for different surfaces during heat treatment and the tribological enhancement of antiwear additives when optimum concentration of fluorinated catalysts and PTFE is used in connection with reduced surface roughness and break in period. Findings – Design of Experiment software, scanning electron microscopy, energy dispersive spectroscopy and nanoindentation were used in this study to evaluate the antiwear resistance films when using 0.05 per cent phosphorus ZDDP plain oil with 0.5 weight per cent TiF3 + 0.5 weight per cent FeF3 + 2 weight per cent PTFE and when applying 2 minutes break in time to cool down the contacting bodies when temperature rises. Results indicated that the coated film on the thermally treated surfaces that is reflected as white patches on the SEM images is a function of the antiwear additives contribution; it is also shown to have positive influence on the friction and wear performances during tribological testing. Originality/value – This research involved the study of lubricant and surface interactions with antiwear additives under boundary lubrication and extreme pressure loading. Several researchers studied these effects and submitted articles to the journal. This is the first time that a break in period was used with surface conditions to simulate car stops in heavy traffic conditions.

The Friction and Wear of Rubber Part 1: Effects of Dynamically Changing Slip Direction and the Damage Orientation Distribution Function

2002 ◽  
Vol 75 (1) ◽  
pp. 29-48 ◽  
Author(s):  
David P. Gerrard ◽  
Joe Padovan
Keyword(s):  
Distribution Function ◽  
Orientation Distribution Function ◽  
Friction And Wear ◽  
Analytical Study ◽  
Orientation Distribution ◽  
Slip Direction ◽  
Wear Performance ◽  
Model Predictions ◽  
Rubber Surface ◽  
Rubber Part

Abstract In Part 1, results of an experimental and analytical study are offered which examined the effects of a dynamically changing slip direction on a rubber surface's friction and wear performance and on the properties of an industrial abrasive. For a filled SBR compound, it was found that a dynamically changing slip direction had a small effect on the friction/traction performance, but a substantial beneficial effect on the surface's wear performance. The abrasive's ability to generate wear was found to be strongly dependent on the accumulation of side slip over the life of the abrasive. Conceptualization of the Damage Orientation Distribution Function is offered to describe the statistical nature of the oriented damage generated on a slipping rubber surface. The experimental results are shown to be in excellent agreement with model predictions based on several simple assumptions regarding the effects that changing slip orientation has on the response of the Distribution Function.

Friction and abrasion of hard solids at high sliding speeds

1962 ◽  
Vol 269 (1338) ◽  
pp. 368-384 ◽  
Keyword(s):  
High Speed ◽  
Friction And Wear ◽  
Thermal Transformation ◽  
Fused Silica ◽  
Temperature Gradients ◽  
Supporting Evidence ◽  
Small Particles ◽  
Anomalous Effect ◽  
Strong Adhesion ◽  
Very High

An investigation has been made of the friction and wear of hard solids such as sapphire (Al 2 O 3 ), rutile (TiO 2 ), TiC, SiC, diamond and fused silica (SiO 2 ) sliding on metal surfaces at very high speed (700 m/s). It is shown that hard solids can undergo extensive wear when rubbed against metals of much lower hardness. There is evidence that this apparently anomalous effect is due partly to the abrading effect of small particles of the harder material which becomes dislodged and dragged across the surfaces. This disintegration may be caused by therm al shock due to the high temperature gradients produced, while in some cases chemical reactions or solid solutions may lead to strong adhesion between the metal and the non-metal. With diamond there is supporting evidence that the abrasion process is accompanied by a thermal transformation into amorphous carbon.

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