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.

scholarly journals High Temperature Friction and Wear Performance of PVD Coatings under Press Hardening Contact Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Sergej Mozgovoy ◽  
Jens Hardell ◽  
Braham Prakash
Keyword(s):  
Coefficient Of Friction ◽  
Elevated Temperatures ◽  
Adhesive Wear ◽  
Work Piece ◽  
Pvd Coatings ◽  
Tribological Behaviour ◽  
Press Hardening ◽  
Coated Tools ◽  
22Mnb5 Steel ◽  
Forming Tools

Press hardening is widely employed to produce automotive structural and safety components from advanced high-strength steels. This process depends on friction between the forming tools and the work piece. Wear of the forming tools affects the dimensional accuracy of produced components and reduces their service life. It is therefore desirable to reduce wear of forming tools for press hardening applications. One way to achieve this is by applying hard physical vapour deposited (PVD) coatings on the tool. In this work, the tribological behaviour of PVD coated tool-work piece material pairs has been studied at elevated temperatures in an experimental set-up simulating the tribological conditions in press hardening. Four different PVD coatings deposited on tool steel and uncoated tools as reference were studied during sliding against uncoated and Al-Si coated 22MnB5 steel. Results show that uncoated tools exhibited the lowest coefficient of friction when sliding against uncoated 22MnB5 steel. A CrWN coating initially showed low coefficient of friction but it increased with increasing sliding distance. A TiAlN coating and one of two AlCrN coatings showed similar frictional behaviour when sliding against uncoated 22MnB5 steel. During sliding against uncoated 22MnB5 steel, adhesive wear has been found to be the dominant wear mechanism. Adhesive wear was considerably reduced in the case of hard PVD coated tools in comparison to that of uncoated tools. During sliding against Al-Si coated 22MnB5 steel, no clear advantage in terms of friction behaviour of uncoated or PVD coated tools was observed. However, the transfer of Al-Si coating material from the work piece to the tools was significantly reduced for PVD coated tools. Frictional instabilities in all cases involving Al-Si coated work piece material further confirmed the occurrence of adhesive material transfer.

Mechanical Behaviour of Sputtered Aluminium Thin Films under High Sliding Loads

2019 ◽  
Vol 796 ◽  
pp. 67-73 ◽  
Author(s):  
Fredrick M. Mwema ◽  
Esther Titilayo Akinlabi ◽  
Oluseyi Philip Oladijo
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Coefficient Of Friction ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Rf Magnetron Sputtering ◽  
Wear Behaviour ◽  
Material Loss ◽  
Significant Coefficient ◽  
The Coefficient Of Friction

In this work, the wear behaviour of thin aluminium films deposited on stainless-steel substrate through rf magnetron sputtering is studied. The coefficient of friction and material loss are characterised as functions of the substrate temperature (Ts) of the deposited aluminium thin films. It was observed that due to the evolving microstructural and roughness properties of the films with the substrate temperature, the material behaviour of the films under extremely high wear loads significantly depend on the substrate temperature. The most significant coefficient of friction was observed at 60oC and 80oC, and highest material loss was recorded at 100oC. The material loss and variation of coefficient of friction were related to the morphology (porosity and roughness) of the sputtered aluminium thin films.

The Size of the Friction Coefficient Depending on the Size and Course of Normal Load

2014 ◽  
Vol 474 ◽  
pp. 303-308 ◽  
Author(s):  
Eva Labašová
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Testing Machine ◽  
Constant Load ◽  
Current Component ◽  
Rectangular Shape ◽  
The Coefficient Of Friction ◽  
Ring Method ◽  
Run Up

The coefficient of friction for the bronze material (CuZn25Al6) with inset graphite beds is investigated in the present paper. Friction coefficient was investigated experimentally by the testing machine Tribotestor`89 which uses the principle of the ring on ring method. Tribotestor`89 machine may be classed to the rotary tribometers. The tested sliding pairs were of the same material. The internal bushing performed a rotational movement with constant sliding speed (v = 0.8 m s-1). The external fixed bushing was exposed to the normal load, which was of different sizes and different variations. Process of load was increased from level 50 N to 200 N (400 N, 600 N) during run up 600 s, after the run up the appropriate level of load was held.The forth test had a rectangular shape of loading with direct current component 400 N and the amplitude 200 N period 600 s, the whole test took 1800 s. The obtained results reveal that friction coefficient decreases with the increase of normal load. Further, that the coefficient of friction was found smaller at constant load, as compared to rectangular shape of loading.

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.

Formation of a High-speed Mode of Vibration Displacement of Grain During Heat Treatment

2020 ◽  
pp. 88-96
Author(s):  
Roman Kalinichenko ◽  
◽  
Serhii Stepanenko ◽  
Boris Kotov ◽  
◽  
...  
Keyword(s):  
Heat Treatment ◽  
Differential Equations ◽  
Coefficient Of Friction ◽  
High Speed ◽  
Air Flow ◽  
Support Surface ◽  
System Of Differential Equations ◽  
Vibration Displacement ◽  
The Coefficient Of Friction ◽  
Speed Mode

The article compiled and solved a system of differential equations of motion of a material point along a porous (air-permeable) surface, which is inclined at an angle to the horizon. Based on the analysis of solutions to this system of differential equations, it is proposed to change the speed of grain movement by the frequency of oscillations of the support surface, the angle of inclination of the support surface to the horizon and the coefficient of friction. Also, the graphical dependences of the speed of grain movement on the angle of inclination of the support surface to the horizon, the coefficient of friction and the frequency of oscillations were obtained. The possibility of decelerating the vibration movement of grain by an air flow, which is fed from the bottom of the porous support surface against (at an angle) the direction of grain movement, as well as using an asymmetrically corrugated support surface with vertical perforations, is theoretically substantiated. A linear regression dependence of the change in the vibration displacement speed has been experimentally determined, which makes it possible to form the required speed mode of vibration displacement of grain by changing the parameters: the inclination of the vibrating plane is 50 ÷ 90, the vibration frequency is 45 ÷ 55 s-1, the air flow speed is 0.1 ÷ 2 m/s in optimal operating modes. installations for high-intensity heat treatment of grain with a vibratory conveyor.

scholarly journals RF Power and Thermal Annealing Effect on the Properties of Zinc Oxide Films Prepared by Radio Frequency Magnetron Sputtering

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Chaoyang Li ◽  
Mamoru Furuta ◽  
Tokiyoshi Matsuda ◽  
Takahiro Hiramatsu ◽  
Hiroshi Furuta ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Thermal Annealing ◽  
Annealing Temperature ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
Zinc Oxide Films ◽  
Deposition Power ◽  
Comparison Measurements

Polycrystalline zinc oxide (ZnO) films were prepared by radio frequency (RF) magnetron sputtering under different powers. The XRD results showed that ZnO crystallite size along c-axis decreased by 43% with deposition power increased from 60 W to 300 W, increased 36% with annealing temperature rising to400∘C. TDS measurement revealed that the desorption peaks of both atomic Zn (60 W-deposited) and oxygen molecule (180 W and 300 W-deposited) obtained from ZnO films were originated from300∘C. When annealing temperature was higher than300∘C, the sheet resistance dramatically decreased, and compressive stress in the (002) plane changed to tensile stress as well. The comparison measurements of ZnO films crystallinity strongly suggested that both lower deposition power and certain thermal annealing temperature over300∘Cwould contribute to the formation of high quality ZnO films.

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.

scholarly journals The Influence of Surface Texturing on the Frictional Behaviour in Starved Lubricated Parallel Sliding Contacts

Lubricants ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 68 ◽  
Author(s):  
Bijani ◽  
Deladi ◽  
Rooij ◽  
Schipper
Keyword(s):  
Coefficient Of Friction ◽  
Surface Texturing ◽  
Geometrical Parameters ◽  
Textured Surfaces ◽  
Tribological Behaviour ◽  
Sliding Contacts ◽  
Cavitation Effect ◽  
The Coefficient Of Friction ◽  
Starved Lubrication ◽  
Frictional Behaviour

Starvation occurs when the lubricated contact uses up the lubricant supply, and there is not enough lubricant in the contact to support the separation between solid surfaces. On the other hand, the use of textures on surfaces in lubricated contacts can result in a higher film thickness. In addition, a modification of the surface’s geometrical parameters can benefit the tribological behaviour of the contacts. In this article, for parallel sliding surfaces in starved lubricated conditions, the effect of surface texturing upon the coefficient of friction is investigated. It is shown that surface texturing may improve film formation under the conditions of starvation, and as a result, the frictional behaviour of the parallel sliding contact. Furthermore, the effect of starved lubrication on textured surfaces with different patterns in the presence of a cavitation effect, and its influence on frictional behaviour, is investigated. It is shown that surface texturing can reduce the coefficient of friction, and that under certain conditions, the texturing parameter could have an influence on the frictional behaviour of parallel sliding contacts in the starved lubrication regime.

Correlating the Features of Topography to Friction by Sliding Experiments

2008 ◽  
Author(s):  
Anirudhan Pottirayil ◽  
Pradeep L. Menezes ◽  
Satish V. Kailas
Keyword(s):  
Sheet Metal ◽  
Coefficient Of Friction ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Work Piece ◽  
Manufacturing Processes ◽  
Experimental Procedure ◽  
The Coefficient Of Friction ◽  
Soft Metal

Friction can influence the quality of the finished product to a large extent in certain manufacturing processes. Sheet metal forming is a particular case, where the friction between the hard-die and the relatively soft work-piece can be extremely important. Under such conditions, topography of the harder surface can influence the resistance to traction at the interface. This paper discusses about the correlation between certain features of the surface topography and coefficient of friction based on experiments involving sliding of a few soft metal pins against a harder material. A brief description of the experimental procedure and the analysis are presented. A hybrid parameter which encapsulates both the amplitude features as well as the relative packing of peaks is shown to correlate well with the coefficient of friction.

scholarly journals Determination of the Coefficient of Friction Under Cold Tube Drawing Using FEM Simulation and Drawing Force Measurement

2018 ◽  
Vol 26 (42) ◽  
pp. 29-34 ◽  
Author(s):  
Martin Necpal ◽  
Maroš Martinkovič ◽  
Štefan Václav
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Tensile Testing ◽  
Force Measurement ◽  
Testing Machine ◽  
Fem Simulation ◽  
Tensile Testing Machine ◽  
Additional Equipment ◽  
The Coefficient Of Friction ◽  
Cold Draw

Abstract The purpose of this article is to describe the methodology to define coefficient of friction between a tool and a forming material during tube cold draw technology process. In this regard, an experimental drawing process was done by using the tensile testing machine. The tensile testing machine was modified by additional equipment that allows drawing the tube. During the drawing, the force was recorded. Subsequently, the finite element simulation of cold draw forming was used to generate load-stroke curves with different friction coefficient. The friction coefficient was estimated by comparing the load stroke and the force recorded curves.

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