scholarly journals Tribological Effects of Graphene Oxide on Brake Friction Materials

2020 ◽  
Vol 9 (5) ◽  
pp. 414-416
Keyword(s):  
Graphene Oxide ◽  
Tribological Behavior ◽  
Testing Machine ◽  
Tribological Performance ◽  
Brake Pad ◽  
Friction Materials ◽  
Thickness Loss ◽  
Friction Performance ◽  
Frictional Composites

Many times in past Brake friction composites and their various combinations have been filled with graphene oxide made-up and tested many times for their tribological performance. Various changes in tribological behavior of testing materials of the frictional composites have been tested and evaluated on the setup of krauss testing machine During these testing’s a high amount of enhancement in the friction performance (μP), frictions fade (μF) and friction recovery (μR) were found with the proper addition of graphene oxide in various amounts. The changes and the decrement in the wear performances and brake pad thickness loss were found with the increase in graphene oxide contents.

Effect of size and shape of copper alloys particles on the mechanical and tribological behavior of friction materials

2020 ◽  
Vol 21 (6) ◽  
pp. 613
Author(s):  
Amira Sellami ◽  
Nesrine Hentati ◽  
Mohamed Kchaou ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Riadh Elleuch
Keyword(s):  
Tribological Behavior ◽  
Copper Alloys ◽  
Physical And Mechanical Properties ◽  
Friction Material ◽  
Material Behavior ◽  
Brake Pad ◽  
Friction Materials ◽  
Physical Density ◽  
Pin On Disc ◽  
Young Module

Friction materials are composed of numerous ingredients which differ from nature and particles size. Each ingredient has its own impact on the mechanical and tribological behavior of the material. Brass ingredients have a great impact on the thermal gradient dissipation in the sliding contact between disc and brake pad material. In this research, the influence of different sizes and forms of brass ingredient was studied on the friction material behavior. The physical (density), mechanical (yield strength, young module) and thermal (thermal conductivity and specific heat) properties of the considered composites were characterized. Results proves that only physical and mechanical properties are sensitive to the changes in size and form of brass particles. The tribological behavior of the brake friction materials was also assessed using a pin-on-disc tribometer. The results show that bigger brass particles and their elongated shape allows it to be well embedded on the pad surface during braking application, and thus decreased wear rate . In contrast, the smaller particle decrease the friction stability and it rounded shape increase wear of the material since it tearing from the surface by abrasive wear.

scholarly journals A review of the bio-tribology of medical devices

Friction ◽  
2021 ◽  
Author(s):  
Xiaogang Zhang ◽  
Yali Zhang ◽  
Zhongmin Jin
Keyword(s):  
Service Life ◽  
Medical Devices ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Dental Restoration ◽  
Surgical Instruments ◽  
Cardiovascular Devices ◽  
Artificial Joints ◽  
Future Developments ◽  
Fixation Devices

AbstractNumerous medical devices have been applied for the treatment or alleviation of various diseases. Tribological issues widely exist in those medical devices and play vital roles in determining their performance and service life. In this review, the bio-tribological issues involved in commonly used medical devices are identified, including artificial joints, fracture fixation devices, skin-related devices, dental restoration devices, cardiovascular devices, and surgical instruments. The current understanding of the bio-tribological behavior and mechanism involved in those devices is summarized. Recent advances in the improvement of tribological properties are examined. Challenges and future developments for the prospective of bio-tribological performance are highlighted.

Effect of filler content on scratch behavior and tribological performance of polyester/graphene oxide nanocomposite coating

2021 ◽  
Author(s):  
Nedia Gafsi ◽  
Raquel Verdejo ◽  
Mohamed Kharrat ◽  
Massimiliano Barletta ◽  
Miguel Ángel López-Manchado ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Filler Content ◽  
Nanocomposite Coating ◽  
Tribological Performance ◽  
Scratch Behavior

scholarly journals High-Tribological-Performance Polymer Nanocomposites: An Approach Based on the Superlubricity State of the Graphene Oxide Agglomerates

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2237
Author(s):  
Eder H. C. Ferreira ◽  
Angela Aparecida Vieira ◽  
Lúcia Vieira ◽  
Guilhermino J. M. Fechine
Keyword(s):  
Graphene Oxide ◽  
High Viscosity ◽  
Tribological Performance ◽  
Multilayer Graphene ◽  
High Concentration ◽  
Scanning Calorimetry ◽  
Mechanical Reinforcement ◽  
Transmission Electron ◽  
Twin Screw ◽  
Mechanical Tensile

Here, nanocomposites of high-molecular-weight polyethylene (HMWPE) and HMWPE-UHMWPE (80/20 wt.%) containing a low amount of multilayer graphene oxide (mGO) (≤0.1 wt.%) were produced via twin-screw extrusion to produce materials with a higher tribological performance than UHMWPE. Due to the high viscosity of both polymers, the nanocomposites presented a significant concentration of agglomerates. However, the mechanical (tensile) and tribological (volumetric loss) performances of the nanocomposites were superior to those of UHMWPE. The morphology of the nanocomposites was investigated using differential scanning calorimetry (DSC), microtomography, and transmission electron microscopy (TEM). The explanation for these results is based on the superlubricity phenomenon of mGO agglomerates. It was also shown that the well-exfoliated mGO also contained in the nanocomposite was of fundamental importance as a mechanical reinforcement for the polymer. Even with a high concentration of agglomerates, the nanocomposites displayed tribological properties superior to UHMWPE’s (wear resistance up to 27% higher and friction coefficient up to 57% lower). Therefore, this manuscript brings a new exception to the rule, showing that agglomerates can act in a beneficial way to the mechanical properties of polymers, as long as the superlubricity phenomenon is present in the agglomerates contained in the polymer.

scholarly journals Tribological Performance Investigation of a Commercial Engine Oil Incorporating Reduced Graphene Oxide as Additive

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 386
Author(s):  
Hakan Kaleli ◽  
Selman Demirtaş ◽  
Veli Uysal ◽  
Ioannis Karnis ◽  
Minas M. Stylianakis ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tribological Behavior ◽  
Control Sample ◽  
Protective Layer ◽  
Steel Ball ◽  
Carbon Accumulation ◽  
Engine Oil ◽  
Wear Scar Diameter ◽  
Reduced Graphene

We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P were detected on the rubbing surfaces of both the ball and the block through energy-dispersive X-ray spectroscopy. Finally, it was shown that the wear scar diameter on the surface of the steel ball was lower by 3%, upon testing the engine oil sample containing reduced graphene oxide at concentration 0.02 wt %, compared to the control sample.

scholarly journals Effect of Graphene Oxide and Graphite on Dry Sliding Wear Behavior of Polyester Composites

2018 ◽  
Vol 55 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Marian Bastiurea ◽  
Dumitru Dima ◽  
Gabriel Andrei
Keyword(s):  
Graphene Oxide ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Wear Behavior ◽  
Positive Influence ◽  
Tribological Performance ◽  
Dry Sliding Wear ◽  
Melt Mixing ◽  
Polyester Composites ◽  
All Speeds

Graphene oxide and graphite filled polyester composites were prepared by using conventional melt-mixing methods in order to improve tribological performance of polyester. It was investigated friction stability, microhardness, friction coefficient, and specific wear rate of the composites in details. It was found that the presence of graphite and graphene oxide influenced friction coefficient and wear rate of the composites. Graphene oxide decreased wear rate with increasing of test speed and graphite decreased wear rate for composite for all speeds. Tribological performance of the polyester/graphene composites is mainly attributed to bigger thermal conductivity for graphene, which can easily dissipate the heat which appears during the friction process at bigger forces. The positive influence of graphite on coefficient of friction (COF) of the composites is the result of the clivage of graphite layers during the loadings due to van der Waals weak bonds between the graphite layers.

Polymer mechanics and tribology

2018 ◽  
Vol 70 (4) ◽  
pp. 764-772 ◽  
Author(s):  
Nikolai K. Myshkin ◽  
Alexander Kovalev
Keyword(s):  
Polymer Composites ◽  
Contact Mechanics ◽  
Tribological Behavior ◽  
Tribological Performance ◽  
Memory Storage ◽  
Polymer Mechanics ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Storage Devices ◽  
Functional Additives

Purpose The purpose of this paper is to review the advances in mechanics and tribology of polymers and polymer-based materials. It is focused on the understanding of the correlation of contact mechanics and the tribological behavior of polymers and polymer composites by taking account of surface forces and adhesion in the contact. Design/methodology/approach Mechanical behavior of polymers is considered a viscoelasticity. Tribological performance is estimated while considering the parts of deformation and adhesion in friction arising in the contact. Surface energy, roughness, load and temperature effects on the tribological behavior of polymers are evaluated. Polymer composites produced by reinforcing and by the addition of functional additives are considered as materials for various applications in tribology. Particular attention is given to polymer-based nanocomposites. Findings A review of studies in tribology has shown that polymer-based materials can be most successfully used as self-lubricating components of sliding bearings. The use of the fillers provides changes in the tribological performance of neat polymers and widens their areas of application in the industry. Thin polymer films were found to be prospective lubricants for memory storage devices, micro-electro-mechanical systems and precision mechanisms. Further progress in polymer tribology should be achieved on solving the problems of contact mechanics, surface physics and tribochemistry by taking account of the scale factor. Originality/value The review is based on the experience of the authors in polymer mechanics and tribology, their research data and on data of many other literature sources published in this area. It can be useful for specialists in polymer research and industrial engineers working in tribology and industrial lubrication.

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