Measuring the coefficient of friction of a low-friction cart

1998 ◽  
Vol 36 (8) ◽  
pp. 464-465 ◽  
Author(s):  
Roger F. Larson
Keyword(s):  
Coefficient Of Friction ◽  
Low Friction ◽  
The Coefficient Of Friction

Study of the micro/nano-texture design to improve the friction properties of DLC thin films

2021 ◽  
pp. 2140027
Author(s):  
Young Woo Kwon ◽  
Mun Ki Bae ◽  
Ri-Ichi Murakami ◽  
Tae Hwan Jang ◽  
Tae Gyu Kim
Keyword(s):  
Thin Film ◽  
Coefficient Of Friction ◽  
Surface Friction ◽  
Low Friction ◽  
Frictional Wear ◽  
The Coefficient Of Friction ◽  
Surface Contact Area ◽  
Photolithography Process ◽  
Texture Design ◽  
Pattern Width

In this study, a DLC pattern was fabricated through a photolithography process that constitutes a part of the semiconductor process, to investigate the frictional wear characteristics. The photolithography was used to produce negative patterns with a pattern width of 10 [Formula: see text]m or 20 [Formula: see text]m and a pattern depth of 500 nm on the DLC surface. The change in the coefficient of friction of the surface was investigated through a ball-on-disk tribology test on the fabricated micro/nano-sized DLC pattern. The DLC pattern fabricated by the photolithography process showed a superior coefficient of friction to that of the general DLC sample. These results show that the decrease in the surface friction coefficient of the patterned DLC thin film is due to the reduction in the surface contact area owing to the modification of the micro/nano-texture of the surface as well as the low friction characteristics of the DLC.

Multiscale Modeling of Frictional Behavior of Highly-Ordered Carbon Nanotube/Ceramic Nanocomposites

2006 ◽  
Vol 978 ◽  
Author(s):  
Zhenhai Xia ◽  
William A Curtin ◽  
Pradeep Guduru
Keyword(s):  
Carbon Nanotube ◽  
Coefficient Of Friction ◽  
Md Simulation ◽  
Interaction Force ◽  
Thick Wall ◽  
Low Friction ◽  
Frictional Behavior ◽  
The Coefficient Of Friction ◽  
Cnt Arrays ◽  
Ceramic Nanocomposites

AbstractMicromechanics model incorporating with molecular dynamics (MD) simulation is developed to simulate the frictional behavior of carbon nanotube (CNT) arrays in ceramic nanocomposites. MD model is used to compute the interaction force and simulate failure mechanisms of individual nanotube at atomic length scale. The force and deformation calculated from MD simulation are passed to the continuum model to simulate the interaction between nanotube arrays and AFM tips. The coefficient of friction is determined at different load levels. The simulation shows that the low friction in the thick-wall CNT systems occurs because the stiffer CNTs are more resistant to collapse under the applied loads. The predictions for the coefficient of friction are consistent with nanoscale tests.

Friction of a Steel Ball on a Single Crystal of Ice

1977 ◽  
Vol 19 (81) ◽  
pp. 225-235 ◽  
Author(s):  
Katutosi Tusima
Keyword(s):  
Single Crystal ◽  
Coefficient Of Friction ◽  
Contact Area ◽  
Steel Ball ◽  
Low Friction ◽  
Prismatic Plane ◽  
Ice Friction ◽  
The Coefficient Of Friction ◽  
Pressure Melting ◽  
Definite Temperature

Abstract This paper presents the results of a study carried out to explain the low friction on ice. Friction of a steel ball on a single crystal of ice was measured as a function of load, velocity, temperature, and diameter of slider. It was found that even when the velocity was very small (1.5 - 10-7 to 1.8-10–3 m/s) the coefficient of friction was very small ranging from 0.005 to 0.2, although friction on the prismatic plane was twice as large as that on the basal plane. The coefficient of friction increased with load, which means that Amonton’s classical law of friction is not applicable to ice. The coefficient of friction increased with decreasing velocity, which may result from the creep of ice in the contact area. The friction strongly increased as the temperature became close to °C. A minimum friction was observed for a definite temperature. It was found that the explanation of the results obtained is given satisfactorily neither by the classic pressure-melting theory nor by the friction-melting theory, but only by adhesion theory.

scholarly journals Friction of a Steel Ball on a Single Crystal of Ice

1977 ◽  
Vol 19 (81) ◽  
pp. 225-235 ◽  
Author(s):  
Katutosi Tusima
Keyword(s):  
Single Crystal ◽  
Coefficient Of Friction ◽  
Contact Area ◽  
Steel Ball ◽  
Low Friction ◽  
Prismatic Plane ◽  
Ice Friction ◽  
The Coefficient Of Friction ◽  
Pressure Melting ◽  
Definite Temperature

AbstractThis paper presents the results of a study carried out to explain the low friction on ice. Friction of a steel ball on a single crystal of ice was measured as a function of load, velocity, temperature, and diameter of slider. It was found that even when the velocity was very small (1.5 - 10-7 to 1.8-10–3 m/s) the coefficient of friction was very small ranging from 0.005 to 0.2, although friction on the prismatic plane was twice as large as that on the basal plane. The coefficient of friction increased with load, which means that Amonton’s classical law of friction is not applicable to ice. The coefficient of friction increased with decreasing velocity, which may result from the creep of ice in the contact area. The friction strongly increased as the temperature became close to °C. A minimum friction was observed for a definite temperature. It was found that the explanation of the results obtained is given satisfactorily neither by the classic pressure-melting theory nor by the friction-melting theory, but only by adhesion theory.

scholarly journals Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3791
Author(s):  
Pantcho Stoyanov ◽  
Rolf Merz ◽  
Markus Stricker ◽  
Michael Kopnarski ◽  
Martin Dienwiebel
Keyword(s):  
Coefficient Of Friction ◽  
Wear Track ◽  
High Vacuum ◽  
Extreme Environments ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Low Friction ◽  
The Coefficient Of Friction ◽  
On Line ◽  
Low Wear

In the search for achieving ultra-low friction for applications in extreme environments, we evaluate the interfacial processes of diamond/tungsten sliding contacts using an on-line macro-tribometer and a micro-tribometer in an ultra-high vacuum. The coefficient of friction for the tests with the on-line tribometer remained considerably low for unlubricated sliding of tungsten, which correlated well with the relatively low wear rates and low roughness on the wear track throughout the sliding. Ex situ analysis was performed by means of XPS and SEM-FIB in order to better understand the underlying mechanisms of low friction and low-wear sliding. The analysis did not reveal any evidence of tribofilm or transferfilm formation on the counterface, indicating the absence of significant bonding between the diamond and tungsten surfaces, which correlated well with the low-friction values. The minimal adhesive interaction and material transfer can possibly be explained by the low initial roughness values as well as high cohesive bonding energies of the two materials. The appearance of the wear track as well as the relatively higher roughness perpendicular to the sliding indicated that abrasion was the main wear mechanism. In order to elucidate the low friction of this tribocouple, we performed micro-tribological experiments in ultra-high vacuum conditions. The results show that the friction coefficient was reduced significantly in UHV. In addition, subsequently to baking the chamber, the coefficient of friction approached ultra-low values. Based on the results obtained in this study, the diamond/tungsten tribocouple seems promising for tribological interfaces in spacecraft systems, which can improve the durability of the components.

Experimental Investigation of aluminum doping crumb rubber/epoxy composite in reciprocating motion

2015 ◽  
Vol 3 ◽  
pp. 1
Author(s):  
Goutam Chandra Karar ◽  
Nipu Modak
Keyword(s):  
Experimental Investigation ◽  
Coefficient Of Friction ◽  
Epoxy Composite ◽  
Normal Load ◽  
Crumb Rubber ◽  
The Other ◽  
Reciprocating Motion ◽  
Molding Process ◽  
Friction Tester ◽  
The Coefficient Of Friction

The experimental investigation of reciprocating motion between the aluminum doped crumb rubber /epoxy composite and the steel ball has been carried out under Reciprocating Friction Tester, TR-282 to study the wear and coefficient of frictions using different normal loads (0.4Kg, 0.7Kgand1Kg), differentfrequencies (10Hz, 25Hz and 40Hz).The wear is a function of normal load, reciprocating frequency, reciprocating duration and the composition of the material. The percentage of aluminum presents in the composite changesbut the other components remain the same.The four types of composites are fabricated by compression molding process having 0%, 10%, 20% and 30% Al. The effect of different parameters such as normal load, reciprocating frequency and percentage of aluminum has been studied. It is observed that the wear and coefficient of friction is influenced by the parameters. The tendency of wear goes on decreasing with the increase of normal load and it is minimum for a composite having 10%aluminum at a normal load of 0.7Kg and then goes on increasing at higher loads for all types of composite due to the adhesive nature of the composite. The coefficient of friction goes on decreasing with increasing normal loads due to the formation of thin film as an effect of heat generation with normal load.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

scholarly journals Influence of Beam Power on Young’s Modulus and Friction Coefficient of Ti–Ta Alloys Formed by Electron-Beam Surface Alloying

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1246
Author(s):  
Stefan Valkov ◽  
Dimitar Dechev ◽  
Nikolay Ivanov ◽  
Ruslan Bezdushnyi ◽  
Maria Ormanova ◽  
...  
Keyword(s):  
Electron Beam ◽  
Young’S Modulus ◽  
Coefficient Of Friction ◽  
Young's Modulus ◽  
Beam Power ◽  
Surface Alloying ◽  
Surface Alloys ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Beam Surface

In this study, we present the results of Young’s modulus and coefficient of friction (COF) of Ti–Ta surface alloys formed by electron-beam surface alloying by a scanning electron beam. Ta films were deposited on the top of Ti substrates, and the specimens were then electron-beam surface alloyed, where the beam power was varied from 750 to 1750 W. The structure of the samples was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Young’s modulus was studied by a nanoindentation test. The coefficient of friction was studied by a micromechanical wear experiment. It was found that at 750 W, the Ta film remained undissolved on the top of the Ti, and no alloyed zone was observed. By an increase in the beam power to 1250 and 1750 W, a distinguished alloyed zone is formed, where it is much thicker in the case of 1750 W. The structure of the obtained surface alloys is in the form of double-phase α’and β. In both surface alloys formed by a beam power of 1250 and 1750 W, respectively, Young’s modulus decreases about two times due to different reasons: in the case of alloying by 1250 W, the observed drop is attributed to the larger amount of the β phase, while at 1750 W is it due to the weaker binding forces between the atoms. The results obtained for the COF show that the formation of the Ti–Ta surface alloy on the top of Ti substrate leads to a decrease in the coefficient of friction, where the effect is more pronounced in the case of the formation of Ti–Ta surface alloys by a beam power of 1250 W.

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