Tribological Parameters of Copper-Alumina Composite

2012 ◽  
Vol 527 ◽  
pp. 191-196
Author(s):  
Pavol Hvizdoš ◽  
Priit Kulu ◽  
Michal Besterci
Keyword(s):  
Coefficient Of Friction ◽  
Structural Characteristics ◽  
Wear Properties ◽  
Wear Rates ◽  
Fine Grained ◽  
Angular Pressing ◽  
The Coefficient Of Friction ◽  
Alumina Composite ◽  
Increasing Temperature ◽  
Pin On Disk

Basic mechanical and wear properties of a commercial copper based composite Glidcop were studied. A Glidcop AL-60 grade (with 1.1 wt.% Al2O3) was used as the initial material. It was further treated by the Equal Channel Angular Pressing (ECAP) process in order to induce massive plastic deformation and to achieve very fine grained microstructure. Both, as-received and ECAP-ed materials were then characterized and the results compared. Hardness and elasticity modulus of the experimental materials were measured by instrumented indentation. Tribological properties were studied by pin-on-disk technique in dry sliding against a steel ball at a various temperatures from room temperature up to 600 °C. For all systems the coefficient of friction and specific wear rates were evaluated. Worn surfaces were studied by scanning electron microscopy and level of oxidation was measured using EDX spectrometry. It was found that above 200 °C the coefficient of friction decreased by about 50 %. The wear resistance with increasing temperature increased due to formation of harder oxide rich surface layer. Damage mechanisms were identified and their relationship with structural characteristics was inferred.

Tribological Characteristics of Copper Based Composites with Al2O3 Particles at Various Temperatures

2013 ◽  
Vol 32 (5) ◽  
pp. 437-442
Author(s):  
P. Hvizdoš ◽  
M. Besterci ◽  
P. Kulu ◽  
T. Kvačkaj
Keyword(s):  
Coefficient Of Friction ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Instrumented Indentation ◽  
Wear Rates ◽  
The Coefficient Of Friction ◽  
Order Of Magnitude ◽  
Pin On Disk ◽  
Equal Channel Angular Pressure ◽  
Scanning Electron

AbstractTwo copper based composites: an experimental Cu-Al2O3 and commercial GlidCop AL-60 grade (with 1.1 wt.% Al2O3) with grains size approximately 1–2 µm were treated by Equal Channel Angular Pressure (ECAP) technique in order to induce severe plastic deformation and to reduce the grain size by about an order of magnitude. Microstructure of the as-received and ECAPed states of both systems were observed. Hardness of the experimental materials was measured by instrumented indentation. Tribological properties were studied by pin-on-disk technique in dry sliding against a steel ball at a various temperatures from room temperature up to 873 K. For all systems the coefficient of friction and specific wear rates were evaluated. Worn surfaces were studied by scanning electron microscopy and level of oxidation was measured using EDX spectrometry. It was found that between 473 K and 673 K the coefficient of friction decreased significantly. At lower temperatures the finer grained systems were more wear resistant than the as-received ones. The wear rate of all systems decreased down to zero at 673 K due to formation of hard oxide rich layers. Damage mechanisms were identified and their relationship with structural characteristics was inferred.

Friction and Wear Properties of Polyamide 66 Composites Filled with Carbon Fiber under Dry Sliding and Oil Lubricated Condition

2011 ◽  
Vol 148-149 ◽  
pp. 612-615 ◽  
Author(s):  
Zhi Yong Cai ◽  
Wen Xia Wang
Keyword(s):  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Applied Pressure ◽  
Tribological Performance ◽  
Dry Sliding ◽  
Polyamide 66 ◽  
Wear Properties ◽  
Wear Rates ◽  
The Coefficient Of Friction ◽  
Friction And Wear Properties

The tribological performance of pure polyamide 66 (PA66) and Carbon fibre (CF) reinforced PA66 composite were studied at dry sliding and oil lubricated conditions. The results show that the coefficient of friction and specific wear rates for pure PA66 and CF/PA66 composite slightly in increase with the increase in applied pressure values. On the other hand the coefficient of friction is in decrease while the specific wear is in increase with the increase in sliding speed values.

Investigation of Surface Roughness on R19 Steel Using PIN on Disc Apparatus

2014 ◽  
Vol 591 ◽  
pp. 81-84
Author(s):  
M. Pradeep ◽  
Packkirisamy Vignesh ◽  
M. Arun ◽  
M. Durairaj
Keyword(s):  
Surface Roughness ◽  
Coefficient Of Friction ◽  
Physical Vapor Deposition ◽  
Normal Load ◽  
Titanium Coating ◽  
Roughness Parameters ◽  
Wear Properties ◽  
Wear Rates ◽  
Pin On Disc ◽  
The Coefficient Of Friction

Influence of surface roughness on coefficient of friction of Titanium coated R19 Steel is investigated in this paper using Pin on Disc Apparatus. Wear properties of R19 Steel are evaluated because it is widely used in making the rail wheel and rail roads over the years. Titanium coating of 100nm thickness was deposited on the R19 Steel by Electron Beam Gun Physical Vapor Deposition method. Wear and friction parameters were evaluated using Pin on Disc apparatus. The Surface morphology plays an important role in affecting the wear rate. Non-contact surface roughness tester was used to examine the surface texture and measure the surface roughness of the specimens. The test was carried out in a pin on disc apparatus for Normal Load of 15N, Sliding Velocity of 3m/s and Time 5 min. The texture and the roughness parameters of the surface affect the coefficient of friction. The experimental values of roughness parameters of uncoated and coated disc and its effect on coefficient of friction are compared and validated. Results show that the Coefficient of friction decreases with lower value of Ra. Lower values of frictional force and coefficient of friction results in lower wear rates.

scholarly journals On the Microstructural, Mechanical and Tribological Properties of Mo-Se-C Coatings and Their Potential for Friction Reduction against Rubber

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1336
Author(s):  
Jorge Caessa ◽  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Albano Cavaleiro
Keyword(s):  
Carbon Content ◽  
Friction And Wear ◽  
Current Mode ◽  
Friction Reduction ◽  
Transition Metal Dichalcogenide ◽  
Butadiene Rubber ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
Pin On Disk

Friction and wear contribute to high energetic losses that reduce the efficiency of mechanical systems. However, carbon alloyed transition metal dichalcogenide (TMD-C) coatings possess low friction coefficients in diverse environments and can self-adapt to various sliding conditions. Hence, in this investigation, a semi-industrial magnetron sputtering device, operated in direct current mode (DC), is utilized to deposit several molybdenum-selenium-carbon (Mo-Se-C) coatings with a carbon content up to 60 atomic % (at. %). Then, the carbon content influence on the final properties of the films is analysed using several structural, mechanical and tribological characterization techniques. With an increasing carbon content in the Mo-Se-C films, lower Se/Mo ratio, porosity and roughness appeared, while the hardness and compactness increased. Pin-on-disk (POD) experiments performed in humid air disclosed that the Mo-Se-C vs. nitrile butadiene rubber (NBR) friction is higher than Mo-Se-C vs. steel friction, and the coefficient of friction (CoF) is higher at 25 °C than at 200 °C, for both steel and NBR countersurfaces. In terms of wear, the Mo-Se-C coatings with 51 at. % C showed the lowest specific wear rates of all carbon content films when sliding against steel. The study shows the potential of TMD-based coatings for friction and wear reduction sliding against rubber.

Tribological and Corrosive Properties of Tin/AlN Multilayer Film

2012 ◽  
Vol 560-561 ◽  
pp. 837-841
Author(s):  
Pu Hong Tang ◽  
Jie Mao ◽  
Chong You Feng
Keyword(s):  
Corrosion Resistance ◽  
Coefficient Of Friction ◽  
Gas Flow ◽  
Multilayer Film ◽  
Corrosion Current ◽  
Multilayer Films ◽  
Nitrogen Gas ◽  
Corrosion Properties ◽  
Wear Rates ◽  
The Coefficient Of Friction

TiN/AlN nanoscale multilayer films were deposited by pulsed laser ablation on silicon, with different argon and nitrogen gas flow rates. The total thickness of the TiN/AlN multilayer film was approximately 1μm. The friction and corrosion properties were studied by tribological and corrosive tests. In tribological tests, ball-on-disc was used to determine coefficients of friction and wear rates. The coefficient of friction against a Si3N4 ball varied considerably between films, as does the wear rate. The lowest coefficient of friction μ=0.97 was shown at sample 1, whereas the other three multilayer films were ranged from 1.0 to 1.5. In corrosion test, the anodic polarization characteristics were measured in a 3.5% NaCl solution at room temperature to examine the corrosion resistance. The potentiodynamic polarization measurements showed that for all the multilayer films the corrosion potential shift to higher values, and the corrosion current density decreased with increasing of nitrogen gas flow rate, which indicate a higher nitrogen partial pressures lead to a better corrosion resistance.

Deformation Characteristics of Ultra-Fine Grained Al6061 Chip in Machining by Finite Element Method

2010 ◽  
Vol 44-47 ◽  
pp. 2931-2934
Author(s):  
Chun Ling Wu ◽  
Bang Yan Ye
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Coefficient Of Friction ◽  
Metal Cutting ◽  
High Hardness ◽  
Rake Angle ◽  
Fine Grained ◽  
The Coefficient Of Friction ◽  
Cutting Velocity ◽  
Element Method

Ultra-fine grained chips with higher hardness and strength than bulk can be produced by severe plastic deformation during orthogonal metal cutting. A finite element method was developed to characterize the distribution of stress, strain, strain rate and temperature in the deformation area at different rake angles and cutting velocities. The coefficient of friction in the tool-chip interface is approximately obtained according model of mean coefficient of friction which is based on experiments in any machining conditions. The formation mechanics of ultra-fine grained chip is discussed and effect of rake angle on microstructure of chips is highlighted. The results of experiment and modeling have shown that chip materials with ultra-fine grained and high hardness can be produced with more negative tool rake angle at some lower cutting velocity.

scholarly journals Tribological Behaviour of Sputter Coated ZnO Thin Films

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ahalaptiya H Jayatissa ◽  
◽  
Omer Ahmed ◽  
Bodhi R Manu ◽  
Adam M Schroeder
Keyword(s):  
Heat Treatment ◽  
Coefficient Of Friction ◽  
Testing Machine ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
Work Piece ◽  
Tribological Behaviour ◽  
Deposition Power ◽  
The Coefficient Of Friction ◽  
Pin On Disk

The tribological properties of ZnO thin film coated on an aluminium work piece by RF magnetron sputtering were studied as a function of deposition power, substrate coating temperature, heat treatment and rotation speed. The variation in the coefficient of friction of ZnO films produced under various levels of coating parameters and conditions were experimentally determined using a pin-on-disk tribometer. The results showed that with change in deposition conditions and heat treatment, there are significant microstructural changes in ZnO films, which affect the coefficient of friction. The hardness of the prepared films was also tested using a Vickers Hardness testing machine. There was a consistent and considerable decrease in the friction coefficient of the aluminium working piece after ZnO coating. It is found that the ZnO can be used as a low friction coating material for components working under oxidative and high temperature environments.

Analysis of the Contribution of Adhesion and Ploughing to Shoe-Floor Lubricated Friction in the Boundary Lubrication Regime

2011 ◽  
Author(s):  
Caitlin Moore ◽  
Kurt Beschorner ◽  
Pradeep L. Menezes ◽  
Michael R. Lovell
Keyword(s):  
Coefficient Of Friction ◽  
Boundary Lubrication ◽  
Ambient Conditions ◽  
Lubrication Regimes ◽  
Lubrication Regime ◽  
Material Hardness ◽  
Lubrication Layer ◽  
The Coefficient Of Friction ◽  
Dry Conditions ◽  
Pin On Disk

Slip and fall accidents cost billions of dollars each year. Shoe-floor-lubricant friction has been shown to follow the Stribeck effect, operating primarily in the boundary and mixed-lubrication regimes. Two of the most important factors believed to significantly contribute to shoe-floor-lubricant friction in the boundary lubrication regime are adhesion and ploughing. Experiments were conducted using a pin-on-disk tribometer to quantify adhesion and ploughing contributions to shoe-floor friction in dry and lubricated conditions. The coefficient of friction between three shoe materials and two floor materials of different hardness and roughness were considered. Experiments were conducted under six lubricants for a sliding speed of 0.01 m/sec at ambient conditions. It was found that the contribution of adhesion and ploughing to shoe-floor-lubricant friction was significantly affected by material hardness, roughness, and lubricant properties. Material hardness and roughness are known to affect adhesion, with increased hardness or increased roughness typically resulting in decreased adhesion. The smoothest shoe material, while also being the hardest, resulted in the greatest adhesional contribution to friction. The roughest material, while also being the softest, resulted in the lowest adhesional contributions under dry conditions. Canola oil consistently resulted in the lowest percent of full adhesion and water consistently resulted in the highest percent of full adhesion, presumably due to the thickness, of the boundary lubrication layer. Ploughing contribution was dependent upon the hardness of the shoe and floor materials. A positive correlation was found between the shoe and floor hardness ratio and ploughing coefficient of friction.

scholarly journals Effect of Micro- and Nano-Sized Carbonous Solid Lubricants as Oil Additives in Nanofluid on Tribological Properties

Lubricants ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 25 ◽  
Author(s):  
Emad Omrani ◽  
Pradeep Menezes ◽  
Pradeep Rohatgi
Keyword(s):  
Coefficient Of Friction ◽  
Canola Oil ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Lubricating Oil ◽  
Oil Additives ◽  
Load Carrying ◽  
The Coefficient Of Friction ◽  
Pin On Disk ◽  
Worn Surface

The tribological behavior of graphene and graphite as additives in canola oil was investigated with a pin-on-disk tribometer. The wear surfaces of the aluminum pins lubricated with the additive-containing canola oil were analyzed by scanning electron microscopy (SEM). It was found that graphene and graphite as additives in oil show a lower coefficient of friction and wear rate in comparison with neat canola oil. The graphene sheets are more effective than graphite flakes to reduce friction and wear. In addition, there is a proper concentration where the coefficient of friction (COF) and wear are in minimum value. The optimal concentration of the additive in canola oil is about 0.7 wt %. Therefore, the load-carrying capacity and antiwear ability of the lubricating oil are improved. Moreover, the worn surface of aluminum pins is smother in the presence of solid lubricant rather than neat oil.

Mechanism of Mild to Severe Wear Transition in Alpha-Alumina

1992 ◽  
Vol 114 (3) ◽  
pp. 403-411 ◽  
Author(s):  
S. Jahanmir ◽  
X. Dong
Keyword(s):  
Coefficient Of Friction ◽  
Threshold Value ◽  
Wear Coefficient ◽  
Wear Rates ◽  
Intermediate Temperature Range ◽  
Mechanics Model ◽  
A Value ◽  
Contact Loads ◽  
The Coefficient Of Friction ◽  
Alpha Alumina

Friction and wear experiments were conducted on high purity alpha-alumina sliding against a similar material in air under different contact loads and at temperatures ranging from 23°C to 900°C. Experimental results indicate that tribochemical reactions between water vapor and alpha-alumina at room temperature produce aluminum hydroxide which results in relatively low coefficients of friction and low wear rates. Both the coefficient of friction and the wear rate of alumina were low at intermediate temperatures (200°C to 800°C), if the contact stress was below a threshold value. Above this load, wear occurred by fracture, the wear coefficient exceeded a value of 10−4, and the coefficient of friction increased to 0.90. At 900°C, the coefficient of friction was 0.40 and the wear coefficient was reduced to a value less than 10−6, because of the formation of a silicon-rich layer on the wear track. A contact mechanics model based on linear elastic fracture mechanics indicated that propagation of cracks from pre-existing flaws controls the onset of catastrophic wear in the intermediate temperature range.

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