THE INFLUENCE OF DEFORMATION OF SELECTED THERMOPLASTICS ON THE FRICTION WITH STEEL

Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 137-144 ◽  
Author(s):  
Maciej KUJAWA ◽  
Aneta NIEMIEC ◽  
Wojciech WIELEBA
Keyword(s):  
Friction Coefficient ◽  
Plastic Strain ◽  
Tensile Stress ◽  
Friction And Wear ◽  
Elastic Limit ◽  
Kinetic Friction ◽  
Scientific Publications ◽  
Friction Coefficients ◽  
Wear And Friction ◽  
Friction Analysis

Friction and wear of materials with additional deformation or stress is not a broadly described case. However, scientific publications considering this issue point out that additional deformation and stress ought to be taken into account during wear and friction analysis. In this article, the influence of strain in thermoplastics (POM, PTFE, PE-HD, PMMA) over the friction coefficient is described. Materials were deformed under tensile stress and examined after 24 hours. For specimens in which plastic strain was maintained, the decline of hardness (PE-HD: approximately 70% decrease, PTFE: approximately 40% decrease) and the reduction of the coefficient of kinetic friction (both PTFE and PE-HD: about 20% decrease) were observed. POM returned to its pre-deformed shape and PMMA was deformed without reaching its elastic limit. In these cases, only small changes in hardness (POM: approximately 10% decrease, PMMA: approximately 6% increase) and friction coefficients (maximum 4% change) occurred.

A Comparative Study on the Friction and Wear Properties of Three Different Copper Alloys

2018 ◽  
Vol 913 ◽  
pp. 205-211
Author(s):  
Dong Mei Liu ◽  
Qiang Song Wang ◽  
Wei Yuan ◽  
Xu Jun Mi
Keyword(s):  
Friction Coefficient ◽  
Comparative Study ◽  
Dry Friction ◽  
Friction And Wear ◽  
Copper Alloys ◽  
Friction Condition ◽  
Al Alloy ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Friction And Wear Properties

A comparative study on the friction and wear properties of three kinds of copper alloys, including Cu-Ni based, Cu-Al and Cu-Be alloys was carried out in this study. The friction pair was stainless steel, and both dry and MoS2 lubrication friction experiments were investigated. During the experiments, different loads were chosen for different alloys. It was found that under dry friction condition, the friction coefficients of both Cu-Ni based and Cu-Al alloys did not change as the loads changes, whereas the friction coefficient of Cu-Be alloy increased as the loads increases. Under lubrication friction condition, the friction coefficients of all three alloys did not change as the load changes. The results show that the dry friction coefficient of Cu-Ni based alloy was the largest (0.74), the Cu-Al alloy next (0.60), and the Cu-Be alloy had the smallest dry friction coefficient (0.54). The lubrication friction coefficient of Cu-Ni based and Cu-Be was equal and relatively smaller (0.12), whereas the Cu-Al alloy had a relative larger lubrication friction coefficient (0.27). The microstructure observations were consistent with the friction and wear performance, and the SEM results show that different wear mechanisms were dominated for different alloys.

scholarly journals Determination of The Rotational Friction Coefficients of Solid Cylinder with Various Inclined Plane Angle

2019 ◽  
Vol 15 (1) ◽  
pp. 52-59
Author(s):  
T. Firdaus ◽  
M. Toifur ◽  
Y. Pramudya
Keyword(s):  
Friction Coefficient ◽  
Learning Activities ◽  
Kinetic Friction ◽  
Plane Angle ◽  
Solid Cylinder ◽  
Inclined Plane ◽  
Friction Coefficients ◽  
Experimental Learning ◽  
Aluminum Cylinder

The layer texture differences of an object have an influence on the friction force caused by both planes. This research aims to determine the static and kinetic friction coefficient on several solid cylinder materials. The benefits of this research can be used to develop experimental learning activities on friction coefficient. This research used experimental method. The research was carried out by rolling samples at various inclined plane angles and measuring the traveled distance traveled in one rotation (D). The results showed that the static and kinetic friction coefficients between aluminum cylinder and glass were 0.146 and 0.097, iron cylinder and glass were 0.136 and 0.096, glass cylinder and brass were 0.132 and 0.094, nylon cylinder and glass were 0.101 and 0.090, and stainsless cylinder and glass were 0.122 and 0.094, respectively.Perbedaan tekstur lapisan sebuah benda mempunyai pengaruh pada gaya gesek yang ditimbulkan oleh kedua bidang. Penelitian ini bertujuan untuk menentukan nilai koefisien gesek statis dan koefisien gesek kinetik pada beberapa bahan silinder pejal. Manfaat yang dapat diambil dari hasil penelitian ini adalah dapat digunakan sebagai mengembangkan kegiatan pembelajaran praktikum koefisien gesekan benda. Penelitian ini menggunakan metode eksperimen. Penelitian dilaksanakan dengan menggelindingkan sampel pada berbagai sudut kemiringan dan mengukur jarak tempuh untuk satu kali putaran (D). Hasil penelitian menunjukkan bahwa nilai koefisien gesek statis dan koefisien gesek kinetik secara berurutan untuk silinder aluminium dengan kaca sebesar 0,146  dan 0,097,  untuk silinder besi dengan kaca sebesar 0,136 dan 0,096, untuk silinder kuningan dengan kaca 0,132 dan 0,094, untuk silinder nylon dengan kaca sebesar 0,101 dan 0,090, dan untuk stainsless dengan kaca sebesar 0,122 dan 0,094.

scholarly journals Friction Coefficients for Arborist Ropes Passing Through Cambium Saver Rings

2007 ◽  
Vol 33 (1) ◽  
pp. 31-42
Author(s):  
Brian Kane
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Physical Models ◽  
Kinetic Friction ◽  
Friction Coefficients ◽  
Ring Material ◽  
Tree Care

Friction is important in tree care operations; climbers encounter friction when ascending into, working in, and descending out of a tree. Twelve commonly used climbing ropes were tested on cambium saver rings made of three different materials to determine rope on ring static and kinetic friction coefficients. All ropes were tested before any field use. In addition, two ropes were tested after they had been used in the field for 2 years and were evaluated to determine the effect of rope wear on friction. Friction coefficients varied among ropes and ring materials, and surface roughness of ring material was the best predictor of friction coefficient. Used ropes exhibited higher friction coefficients than new ropes and, in most cases, superseded the influence of surface roughness of cambium saver rings. Simple physical models were developed to illustrate how friction coefficients can affect different aspects of tree climbing. There are important implications of these results for further studies on rope friction as it relates to reducing climber fatigue.

Analysis on the Friction and Wear Properties of Friction Stir Jointing for 7022 Aluminum Alloy Joining Region

2016 ◽  
Vol 693 ◽  
pp. 718-725 ◽  
Author(s):  
H.F. Wang ◽  
J.L. Wang ◽  
W.W. Song ◽  
Dun Wen Zuo ◽  
D.L. Shao ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Base Metal ◽  
Friction And Wear ◽  
Wear Volume ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Friction Stir ◽  
Friction And Wear Properties ◽  
The Law

The friction and wear properties of the friction stir jointing 7022 aluminum alloy joining region were tested in this paper. The friction coefficients and wearing capacities of the joining regions under different joining process parameters were obtained. The experiment results showed that the friction coefficients and wearing capacities of the joining regions had a certain relationship with the hardness, but not became direct ratio relation. The friction coefficient of the joining region was smaller than that of the base metal. This main reason was base metal was lath-shaped grain, and the joining region was isometric crystal. The wear volume under 400/30 parameters was minimum. The wear volume was greatly influenced by the hardness of the joining region, but was not direct proportion relationship. Due to the random factors influence in friction process, the law of the friction coefficient reflecting friction and wear was not the same with the law of wear volume reflecting friction and wear. The friction form was abrasive wear and adhesive wear.

Anti-Wear and Friction-Reducing Characteristics of Two Kinds of Ceramic Additives

2010 ◽  
Vol 139-141 ◽  
pp. 274-279
Author(s):  
Yu Zhou Gao ◽  
Jiang Tao Wang ◽  
Shi Yong Liu ◽  
Hui Chen Zhang
Keyword(s):  
Thin Film ◽  
Friction Coefficient ◽  
Chemical Analysis ◽  
Direct Contact ◽  
Friction And Wear ◽  
Low Friction ◽  
Initial Stage ◽  
Thin Carbon ◽  
Wear And Friction ◽  
Worn Surface

Two kinds of ceramic additives have been developed that one is the serpentine particles and another is a blend of serpentine particles and catalyst. The tribological properties of the addition of different additives are investigated through a series of friction and wear experiments. Wear surface and the composition of the tribofilm were examined by SEM, EDS and XPS. In case of single serpentine additive, tribo-film can be formed gradually on the worn metal surface. The friction coefficient is about 0.11. The tribofilm mainly consists of Mg and Si elements transferred from the additive. This can compensates part of wear mass loss, avoids the direct contact of the two rubbing surfaces, and thus effectively improves the anti-wear characteristics. In case of the blend oil additive, the tribo-film formed obviously on the worn surface in the initial stage and no obvious film at end of the test. However, the friction coefficient can lower even to 0.007~0.008 compared with the above experiment. The worn surface becomes very smooth. Chemical analysis shows that there is a very thin film of carbon concentration with thickness of 30~50nm on the worn surface. Existence of the very thin carbon-concentrated film and mirror-like surface generates super low friction coefficient.

Friction and Wear of Jatropha curcas Oil Using a Four Balls Tester

2014 ◽  
Vol 902 ◽  
pp. 76-81 ◽  
Author(s):  
M. Figueroa ◽  
E. García ◽  
E.A. Gallardo Hernández ◽  
M. Vite-Torres
Keyword(s):  
Renewable Energy ◽  
Friction Coefficient ◽  
Jatropha Curcas ◽  
Friction And Wear ◽  
Engine Oil ◽  
Test Rig ◽  
Friction Coefficients ◽  
Jatropha Curcas Oil ◽  
Oil Mixtures ◽  
Good Potential

Jatropha curcas oil (JCO) is a good option as renewable energy for biodiesel and as lubricant feedstock. In México, the JCO is widely distributed in more than 15 states. This work describes the characterisation of Jatropha curcas oil as additive in engine oil (EO) blended mixtures. The EO and JCO were separately tested using a four balls test rig at 100%. The JCO was added and mixed as an additive to the EO too at 5%-95%, 10%-90%, 15%-85%, 20%-80%, and 50%-50%. The results have shown a steady friction coefficient for the testes carried out at different loads for the different mixtures. The friction coefficients were lower compare to the friction coefficients from the oil engine. Nevertheless, the wear scars were bigger when JCO was used. The results from the oil mixtures showed good potential for the JCO to be used as an additive.

scholarly journals Developing Smart Measurement Device to Measure Kinetic Friction Coefficients of Bi-Tilt Isolator

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Friction Coefficient ◽  
Image Correlation ◽  
Kinetic Friction ◽  
Measurement Device ◽  
Friction Coefficients ◽  
Measuring Device ◽  
Contact Surfaces ◽  
Relationship Of ◽  
The Relationship ◽  
Smart Measurement

A sliding vibration isolation system, affected by a kinetic friction force, provides a flexible or energy dissipation system for a structure. The kinetic friction coefficient of the contact surfaces between the moving parts changes with the relative moving velocity of the two contact surfaces. In this study, a smart measuring device is proposed to measure the kinetic friction coefficients of materials. The Arduino boards Arduino Nano, Arduino MPU-9250, and Arduino SD modules were combined to create this proposed smart device and mounted on three aluminum extrusions constructed as a horizontal platform. Then, varying amounts of steel gaskets were applied to adjust the various slopes for sliding tests. The time history of the acceleration and displacement responses of test object movements in the sliding process were respectively, recorded and detected by this proposed smart measuring device and the digital image correlation method (DIC). Statistical analyses of all test responses were used to derive the relationship of velocity to kinetic friction coefficient. Test and analysis results showed that (1) the relationship of velocity to kinetic friction coefficient for the conditions of mild lubrication and no lubrication displayed a trend of first decreasing and then increasing with increasing speed, respectively and (2) the relationship of velocity to kinetic friction coefficient for the condition of full lubrication revealed that the kinetic friction coefficient decreased with increasing speed. Test results demonstrated that this proposed smart measurement device, which is low in price and easy to assemble, can easily measure the kinetic friction coefficient of a material under various lubrication conditions.

scholarly journals New Equation for Predicting Pipe Friction Coefficients Using the Statistical Based Entropy Concepts

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 611
Author(s):  
Yeon-Woong Choe ◽  
Sang-Bo Sim ◽  
Yeon-Moon Choo
Keyword(s):  
Friction Coefficient ◽  
Accurate Determination ◽  
Mean Velocity ◽  
Friction Coefficients ◽  
Flow Discharge ◽  
Comparison Results ◽  
Flow Loss ◽  
Key Variables ◽  
New Equation

In general, this new equation is significant for designing and operating a pipeline to predict flow discharge. In order to predict the flow discharge, accurate determination of the flow loss due to pipe friction is very important. However, existing pipe friction coefficient equations have difficulties in obtaining key variables or those only applicable to pipes with specific conditions. Thus, this study develops a new equation for predicting pipe friction coefficients using statistically based entropy concepts, which are currently being used in various fields. The parameters in the proposed equation can be easily obtained and are easy to estimate. Existing formulas for calculating pipe friction coefficient requires the friction head loss and Reynolds number. Unlike existing formulas, the proposed equation only requires pipe specifications, entropy value and average velocity. The developed equation can predict the friction coefficient by using the well-known entropy, the mean velocity and the pipe specifications. The comparison results with the Nikuradse’s experimental data show that the R2 and RMSE values were 0.998 and 0.000366 in smooth pipe, and 0.979 to 0.994 or 0.000399 to 0.000436 in rough pipe, and the discrepancy ratio analysis results show that the accuracy of both results in smooth and rough pipes is very close to zero. The proposed equation will enable the easier estimation of flow rates.

Tribological characterization of all-polymer prosthesis based on multi-directional motion

2021 ◽  
pp. 089270572110286
Author(s):  
Xinyue Zhang ◽  
Dekun Zhang ◽  
Kai Chen ◽  
Handong Xu ◽  
Cunao Feng
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Quantitative Relationship ◽  
Motion Path ◽  
Aspect Ratios ◽  
Directional Motion ◽  
Motion Paths ◽  
Prosthesis Material

The complex movement of artificial joints is closely related to the wear mechanism of the prosthesis material, especially for the polymer prosthesis, which is sensitive to motion paths. In this paper, the “soft-soft” all-polymer of XLPE/PEEK are selected to study the influence of motion paths on the friction and wear performance. Based on the periodic characteristics of friction coefficient and wear morphology, this paper reveals the friction and wear mechanism of XLPE/peek under multi-directional motion path, and obtains the quantitative relationship between friction coefficient and the aspect ratios of “∞”-shape motion path, which is of great significance to reveal and analyze the wear mechanism of “soft” all-polymer under multi-directional motion path. The results show that the friction coefficient is affected by the motion paths and have periodicity. Morever, under the multi-directional motion paths, the wear of PEEK are mainly abrasive wear and adhesive wear due to the cross shear effect, while the wear of XLPE is mainly abrasive wear with plastic accumulation. In addition, the friction coefficient is greatly affected the aspect ratios Rs-l of “∞”-shape and loads. Meanwhile, the wear morphologies are greatly affected by the aspect ratios Rs-l of “∞”-shape, but less affected by loads.

scholarly journals Theoretical Studies of the Interaction between Screw Surface and Material in the Mixer

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 962
Author(s):  
Andrzej Marczuk ◽  
Vasily Sysuev ◽  
Alexey Aleshkin ◽  
Petr Savinykh ◽  
Nikolay Turubanov ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
High Efficiency ◽  
Animal Feed ◽  
Structural Features ◽  
Power Demand ◽  
Friction Coefficients ◽  
Length Unit ◽  
Mixing Chamber ◽  
Size Of Particles ◽  
The Impact

Mixing is one of the most commonly used processes in food, animal feed, chemical, cosmetic, etc., industries. It is supposed to provide high-quality homogenous, nutritious mixtures. To provide appropriate mixing of materials while maintaining the process high efficiency and low energy consumption it is crucial to explore and describe the material flow caused by the movement of mixing elements and the contact between particles. The process of mixing is also affected by structural features of the machine components and the mixing chamber, speed of mixing, and properties of the mixed materials, such as the size of particles, moisture, friction coefficients. Thus, modeling of the phenomena that accompany the process of mixing using the above-listed parameters is indispensable for appropriate implementation of the process. The paper provides theoretical power calculations that take into account the material speed change, the impact of the material friction coefficient on the screw steel surface and the impact of the friction coefficient on the material, taking into account the loading height of the mixing chamber and the chamber loading value. Dependencies between the mixer power and the product degree of fineness, rotational speed of screw friction coefficients, the number of windings per length unit, and width of the screw tape have been presented on the basis of a developed model. It has been found that power increases along with an increase in the value of these parameters. Verification of the theoretical model indicated consistence of the predicted power demand with the power demand determined in tests performed on a real object for values of the assumed, effective loading, which was 65–75%.

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