Effects of Structured Fibre on Mechanical and Tribological Properties of Phenolic Composites for Application to Friction Brakes

2018 ◽  
Vol 26 (4) ◽  
pp. 315-324
Author(s):  
Yunhai Ma ◽  
Yucheng Liu ◽  
Chunyu Mao ◽  
Junwei Li ◽  
Jiangtao Yu ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Test Temperature ◽  
Compression Moulding ◽  
Obvious Effect ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Treatment Tank ◽  
Heat Treated ◽  
Surface Morphologies ◽  
Wear Tests

Jute fibres were processed with different types of structures, and these fibres were applied to prepare friction composites through compression moulding. The Structured Jute fibres reinforced Friction composites (SJF) were heat-treated using a heat treatment tank, and the mechanical and tribological properties of the SJF were investigated with a friction-wear tester. The surface morphologies of friction composites were observed using Scanning Electron Microscopy (SEM). The experimental results showed that structured jute fibres could improve impact strength of SJF, but they had no obvious effect on their density and hardness. The friction-wear tests revealed the specimens to present a remarkable fade phenomenon when the test temperature was above 200°C. The presence of the structured jute fibres could decrease the wear rates (V) of SJF when the temperatures were in the range of 250 to 350°C, especially for specimens containing beaded jute fibres and specimens containing dumbbell-shaped jute fibres. They also increased the friction stability and decreased the wear rates of the friction composites. For all specimens, wear rates of the SJF increased with the test temperature. The results of this study could be useful in many applications, such as automobile brake system, clutches and friction gearings.

Tribological Properties of Fe-Cu-MoS2 and Self-Lubricating Behaviors

2011 ◽  
Vol 268-270 ◽  
pp. 389-394 ◽  
Author(s):  
Chuan Qi Fu ◽  
Jun Cai Sun ◽  
Zhou Wang
Keyword(s):  
Tribological Properties ◽  
Testing Machine ◽  
High Wear Resistance ◽  
Solid Solution Alloy ◽  
Wear Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Temperature Load ◽  
Surface Morphologies ◽  
Hot Press Sintering

The Fe-Cu-MoS2composites with different adding amount of MoS2as lubricant were prepared by induction sintering method. Their mechanical and tribological properties from room temperature (RT) to 800°C were tested by universal testing machine and high temperature tribometer. The effects of amounts of MoS2, temperature, load and sliding distance on the friction and wear properties of composite were discussed. The structure of the composite was analyzed by XRD and worm surface morphologies were observed by SEM. It was found that MoS2was decomposed during the hot-press sintering process. Meanwhile, solid solution alloy of Mo and Fe, and sulfides were formed in composite, which were responsible for low-friction and high wear-resistance at elevated temperature, respectively. Hardness and anti-compress strength can be improved by adding 8 wt. % MoS2. The friction coefficients and wear rates of composites decrease with the increase of adding amount of MoS2until a critical value of 8 wt. %. The composite with 8 wt. % MoS2shows the optimum tribological properties over the temperature range of RT~800°C.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

Carbon Nanotubes Improves the Tribological Properties of Ni60/Al2O3 Coatings

2013 ◽  
Vol 785-786 ◽  
pp. 864-871
Author(s):  
Shu Xiao ◽  
Xi Yun Cheng ◽  
De Gui Ma
Keyword(s):  
Carbon Nanotubes ◽  
Tribological Properties ◽  
Microstructural Characterization ◽  
Flame Spraying ◽  
Dual Roles ◽  
Wear Rates ◽  
Transmission Electron ◽  
Pin On Disk ◽  
Wear Tests ◽  
Original Coating

Carbon nanotubes (CNTs) was introduced into Ni60/Al2O3coating by flame spraying. The effect of adding CNTs on the tribological properties of the coating was studied by varying the CNTs content as 0.0, 1.5, 3.0 and 4.5 wt% in the Ni60/Al2O3powders. The microhardness tester was used to measure the microhardness of the coating. Wear tests were performed on a pin-on-disk tribometer, to evaluate the tribological properties of the Ni60/Al2O3/CNTs coatings. Microstructural characterization was performed using scanning and transmission electron microscopy. Ni60/Al2O3/CNTs coatings revealed a lower wear rate and friction coefficient compared with the original coating, and their wear rates and friction coefficients showed a decreasing trend with increasing mass fraction of CNTs within the range from 0 to 3.0 wt% due to the effects of the reinforcement and reduced friction of CNTs. The results showed that the CNTs played dual roles in improving the tribological performance of the coating, indirectly by influencing the microstructure and mechanical properties of the coating and directly by acting as a lubricating medium.

The effect of environmental humidity/water absorption on tribo-mechanical performance of polymers and polymer composites – a review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kawaljit Singh Randhawa ◽  
Ashwin Patel
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Tribological Properties ◽  
Fiber Reinforced Polymer ◽  
Content Type ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Water Conditions

Purpose The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of humidity/water conditions on various polymers and polymer composites' mechanical properties and tribological behaviors. Design/methodology/approach The influence of humidity and water absorption on mechanical and tribological properties of various polymers, fillers and composites has been discussed in this paper. Tensile strength, modulus, yield strength, impact strength, COF and wear rates of polymer composites are compared for different environmental conditions. The interaction between the water molecules and hydrophobic polymers is also represented. Findings Pure polymer matrices show somewhat mixed behavior in humid environments. Absorbed moisture generally plasticizes the epoxies and polyamides and lowers the tensile strength, yield strength and modulus. Wear rates of PVC generally decrease in humid environments, while for polyamides, it increases. Fillers like graphite and boron-based compounds exhibit low COF, while MoS2 particulate fillers exhibit higher COF at high humidity and water conditions. The mechanical properties of fiber-reinforced polymer composites tend to decrease as the rate of humidity increases while the wear rates of fiber-reinforced polymer composites show somewhat mixed behavior. Particulate fillers like metals and advanced ceramics reinforced polymer composites exhibit low COF and wear rates as the rate of humidity increases. Originality/value The mechanical and tribological properties of polymers and polymer composites vary with the humidity value present in the environment. In dry conditions, wear loss is determined by the hardness of the contacting surfaces, which may not effectively work for high humid environments. The tribological performance of composite constituents, i.e. matrix and fillers in humid environments, defines the overall performance of polymer composite in said environments.

Effect of glass fibers length on the properties of polytetrafluoroethylene composites reinforced by glass fibers and graphite: Experimental and simulation study

2021 ◽  
pp. 095400832110594
Author(s):  
Wei Xiao ◽  
Xin Ji ◽  
Lei Gao
Keyword(s):  
Tribological Properties ◽  
Sliding Friction ◽  
Mechanical Performance ◽  
Glass Fibers ◽  
Frictional Heat ◽  
Matrix Composites ◽  
Theoretical Simulation ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Ptfe Composites

Polytetrafluoroethylene (PTFE)-based matrix composites filled with glass fibers (GF) and graphite (GR) were prepared by an internal mixer and molded using a compression mold to produce test samples. The objective was to study the mechanical and tribological properties of PTFE composites filled with different lengths of GF. The fillers of GR and GF were 5 and 15 wt.%, respectively, with the lengths of the GF of 15, 20, 25, 30, and 35-μm in the work. The mechanical performance tests and tribological tests were carried out under the same conditions. The experimental results revealed that the mechanical properties and tribological properties of the PTFE composites filled with GF and GR were associated with the lengths of GF. When the length of GF increased from 15 to 20 μm, GF could be homogeneously dispersed in the PTFE-based matrix composites and the tensile strength reached the maximum value of 21.7 ± 3.3% MPa. Also, with 20-μm long GF, the composites exhibited the lowest coefficient of friction values and wear rates compared to PTFE with GF of the other lengths. The changes in frictional heat generation and frictional force of the composites during sliding friction were simulated using the finite element method. The theoretical simulation results matched with the experimental values, which proved the accuracy of the theoretical simulations.

Influence of h-BN fillers on mechanical and tribological properties of PP/PA6 blend

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abhishek Vyas ◽  
Kawaljit Singh Randhawa
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Wear Rate ◽  
Tribological Properties ◽  
Hexagonal Boron Nitride ◽  
Polyamide 6 ◽  
Content Type ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Lubricating Film

Purpose The purpose of this study is to improve the mechanical and tribological performance of polypropylene (PP) material. The influence of hexagonal boron nitride (h-BN) microparticles on mechanical and tribological properties of PP/polyamide 6 (nylon 6) (PA6) blend has been investigated in this paper. Design/methodology/approach Tensile strength, elongation, elastic modulus and Rockwell hardness were measured to identify the mechanical properties of materials. Coefficient of friction (COF) and wear rates of materials were measured with the help of a pin-on-disc tribometer to check the tribological behavior of blend and composite materials. Findings As a result, a small decrease in tensile strength and elongation and improvement in elastic modulus were found for PP/PA6 and PP/PA6/h-BN composite compared to pure PP. The wear rate of PP/PA6 blend and PP/PA6/h-BN composite was found low compared to pure PP matrix, while the COF of PP/PA6 blend was found slightly higher owing to the presence of harder PA6 matrix which was then improved by the h-BN filler reinforcement in PP/PA6/h-BN composite. The addition of PA6 in PP improved the wear rate of PP by 8–24%, whereas the addition of h-BN microparticles improved the wear rate by 22–50% and 24–44% compared to pure PP and PP/PA6 blend, respectively, in different parameters. Originality/value Modulus of elasticity and hardness of pure PP was enhanced by blending with PA6 and was further improved by h-BN fillers. The addition of PA6 in PP improved the wear rate, while h-BN fillers were found effective in reducing the COF by generating smooth thin lubricating film.

The Research on the Tribological Properties of C/C Composites

2011 ◽  
Vol 287-290 ◽  
pp. 675-678 ◽  
Author(s):  
Wen Xia Wang
Keyword(s):  
Carbon Fiber ◽  
Tribological Properties ◽  
Thermal Gradient ◽  
High Performance ◽  
Sliding Wear ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Three Point Bending ◽  
Mechanical And Tribological Properties ◽  
Wear Tests

The mechanical and tribological behaviors of the carbon/carbon (C/C) composites were evaluated by three-point bending and sliding wear tests. The effect of carbon fiber content on their mechanical behavior was also investigated. To produce the C/C composites, the precursor was introduced to the preforms by impregnating with phenolic solution. The C/C preforms were densified by thermal gradient chemical vapor infiltration. Results indicated that, the C/C composites show excellent mechanical and tribological properties. A kind of high performance brake materials was obtained.

Microstructure, Mechanical and Tribological Properties of Reactive Magnetron Sputtered Titanium Carbide Coatings

2007 ◽  
Author(s):  
Kyriaki Polychronopoulou ◽  
Claus Rebholz ◽  
Nicholaos G. Demas ◽  
Andreas A. Polycarpou ◽  
Lefki Theodorou ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Carbon Content ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Reactive Magnetron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Carbide Coatings

This study describes the correlation between the microstructure, mechanical and tribological properties of Ti1−xCx coatings (with x being in the range of 0–0.5), deposited by reactive magnetron sputtering from a Ti target in Ar/C2H2 mixtures at ∼200 °C. The mechanical and tribological properties were found to strongly depend on the chemical composition and the microstructure present. Very dense structures and highest hardness and elastic modulus, combined with low wear rates, were observed for films with chemical composition close to TiC. X-ray diffraction (XRD) studies showed that the coating deposited at high C2H2 flow rates composed of randomly oriented TiC crystallites. Morphological investigations by scanning electron microscopy (SEM) indicate that the morphology is strongly dependent on the carbon content of the coating. Coatings composition and bonding environment was investigated using X-ray photoelectron spectroscopy (XPS). Both the mechanical properties and tribological performance of the coatings were found to be dependent on carbon content.

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