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 Friction and Wear Characteristics of Rubber Resin-Bonded Metallic Brake Pad Materials

2019 ◽  
Vol 8 (6) ◽  
pp. 1312-1316
Keyword(s):  
Friction And Wear ◽  
Physical And Mechanical Properties ◽  
Friction Material ◽  
Brake Disc ◽  
Brake Pad ◽  
Sliding Velocity ◽  
Wear Characteristics ◽  
Pin On Disc ◽  
Set Up ◽  
Friction And Wear Characteristics

This paper aims to present comparative study of friction and wear characteristics of non-asbestos rubber resin bonded metallic based brake pad material. Friction material was compression moulded and machined to a sample size. Their physical and mechanical properties were studied. Experiments were conducted using Pin-on-disc test set-up against EN31 disc. Coefficient of friction and wear was measured for metallic based brake materials at varying conditions of temperature, sliding velocity, pressure and sliding distance. When brake pads are in contact with brake disc, heat is generated hence thermal behaviour of metallic based brake material and its impact on friction and wear were studied. Experiments, based on Taguchi’s analysis technique, using L9 orthogonal array were performed. On the basis of experimental results and S/N ratio analyses, ranking of the parameters have been done. It was found that temperature (95.37 %) and sliding velocity (2.99 %) are most affecting parameters in friction, However temperature (82.96 %) and pressure (6.80) in wear. The elemental composition of metallic based brake material was measured by EDS technique. SEM micrographs of brake pad samples were tested at different magnifications. Further detailed studies are suggested to evaluate wear rate, stopping distance under simulative test conditions alternate to asbestos based brake pad material.

scholarly journals Tribological and Emission Behavior of Novel Friction Materials

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1050 ◽  
Author(s):  
Ana Paula Gomes Nogueira ◽  
Davide Carlevaris ◽  
Cinzia Menapace ◽  
Giovanni Straffelini
Keyword(s):  
Wear Mechanisms ◽  
Particle Number ◽  
Tribological Behavior ◽  
Airborne Particles ◽  
Emission Measurement ◽  
Bulk Materials ◽  
Friction Materials ◽  
Wear Rates ◽  
Pin On Disc ◽  
Emission Behavior

The tribological behavior and the related airborne particles emission of three copper-free automotive friction materials are investigated. The tests were conducted using a pin-on-disc tribometer equipped with a specifically designed clean-enclosure chamber for the emission measurement. Particle number concentration from particle size 0.3 µm up to 10 µm and the mass of emitted particles between 1 µm to 10 µm were measured. Particular emphasis was given to the chemical composition of the bulk materials, the friction layers and the emissions, in order to explain the acting wear mechanisms, and the recorded emission of airborne particles. The results indicate that the recorded emissions do not correlate with the friction coefficient and the wear rates, since the wear mechanisms exert a different influence on the tribological and emission behavior of the materials under study.

Investigation of the thermal property and tribological behavior of CaSO4 whisker-modified paper-based composite friction materials

2017 ◽  
Vol 231 (12) ◽  
pp. 1583-1594 ◽  
Author(s):  
Xiang Zhang ◽  
Ke-Zhi Li ◽  
He-Jun Li ◽  
Ye-Wei Fu
Keyword(s):  
Tribological Behavior ◽  
Three Dimensional ◽  
Friction Material ◽  
Dynamic Friction ◽  
Friction Materials ◽  
Paper Making ◽  
Dynamic Friction Coefficient ◽  
Secondary Layer ◽  
Surface Profiles ◽  
Dimensional Surface

In this study, CaSO4 whisker was applied to the paper-based composite friction material as the friction layer (secondary layer) by the paper-making process. The tribological and thermal properties were analyzed. Three-dimensional surface profiles were observed to discuss the wear mechanism. The results showed that the samples with higher CaSO4 whisker contents owned better thermal resistance. The sample with 4% CaSO4 whisker content had the highest dynamic friction coefficient. As the CaSO4 whisker content increased from 0% to 16%, the wear rate decreased first and then increased, and the sample with 8% CaSO4 whisker content had the highest wear resistance.

scholarly journals Experimental set-up and the associated model for squeal analysis

2020 ◽  
Vol 21 (2) ◽  
pp. 204 ◽  
Author(s):  
Martin Duboc ◽  
Vincent Magnier ◽  
Jean-François Brunel ◽  
Philippe Dufrénoy
Keyword(s):  
Mechanical Vibration ◽  
High Amplitude ◽  
Friction Material ◽  
Contact Length ◽  
Material Behavior ◽  
Major Influence ◽  
Pin On Disc ◽  
Set Up ◽  
The One ◽  
Improved Model

Brake squeal is commonly defined at frequency upper than 1000 Hz and occurs if the system has a very high amplitude mechanical vibration with sound pressure level above 120 dB. Many studies are devoted to this problem and many of recent ones show that contact conditions and friction material behavior have a major influence on squeal occurrence. To investigate this aspect, an experimental set-up has been developed in this study. It is based on a simplified system in order to focus on the influence of the material in the one hand and surface conditions in the other hand. In this paper, the design of the pin-on-disc is described and an analytical model is also presented in order to understand the dynamic behavior of the system. Macroscopic aspects are investigated by varying the pin geometry. The results show clearly the influence of the variation of the contact length size on squeal occurrence. Comparison with the model shows good agreement and exhibit the necessity of considering an improved model of the friction material behavior. This study also gives information on the comprehension of squeal mechanisms.

Coefficient of friction and wear rate of paper-based composite friction material against 65Mn steel

2020 ◽  
pp. 135065012097229
Author(s):  
Kingsford Koranteng ◽  
Heyan Li ◽  
Biao Ma ◽  
Chengnan Ma
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Tribological Behavior ◽  
Friction Material ◽  
Operating Conditions ◽  
Sliding Speed ◽  
Operating Variables ◽  
Dynamic Friction Coefficient ◽  
Pin On Disc ◽  
High Dynamic

Studies have shown that reinforced paper-based friction material with 600 µm carbon fiber length possesses a high dynamic friction coefficient but is subjected to abrasive wear during sliding contact. This work is devoted to further investigate the effect of operating variables on this friction material subjected to high operating conditions. A pin-on-disc test was carried out to determine the tribological behavior of this friction material sliding against 65Mn steel. The friction and wear rate results from measurements were discussed. The highest friction value of about 0.3 was obtained by varying the applied load at 120 N while the lowest friction value close to 0.02 was obtained when the sliding speed was 0.026 m/s. Increasing the sliding speed above 0.30 m/s caused constant temperature (175 °C) to fluctuate due to high friction heat generation on the sliding surface. The highest wear rate was 1.42 × 10−15m3/Nm by varying the sliding speed at 1.31 m/s. In contrast, the lowest wear rate was 2.1 × 10−16m3/Nm when the temperature was at 400 °C.

scholarly journals Pin-on-disc study of dry sliding behavior of Co-free HVOF-coated disc tested against different friction materials

Friction ◽  
2021 ◽  
Author(s):  
Matteo Federici ◽  
Cinzia Menapace ◽  
Alessandro Mancini ◽  
Giovanni Straffelini ◽  
Stefano Gialanella
Keyword(s):  
Room Temperature ◽  
Friction Material ◽  
Dry Sliding ◽  
High Concentration ◽  
Microstructural Characteristics ◽  
Friction Materials ◽  
Braking System ◽  
Coated Disc ◽  
Particulate Matter Emissions ◽  
Pin On Disc

AbstractThe dry sliding behavior of three commercial friction materials (codenamed FM1, FM2, and FM3) tested against a Co-free cermet coating produced by high-velocity oxy-fuel (HVOF) on gray cast-iron discs is investigated. FM1 is a conventional low-metallic friction material, FM2 is developed for using against HVOF-coated discs, and FM3 is a Cu-free friction material with a low content of abrasives and a relatively high concentration of steel fibers. For the tribological evaluation, they are tested on a pin-on-disc (PoD) test rig against Co-free HVOF-coated discs, with particular attention to the running-in stage, which is fundamental for the establishment of a friction layer between the two mating surfaces, i.e., the pin and disc. The PoD tests are performed at room temperature (RT) and a high temperature (HT) of 300 °C. At RT, all materials exhibit a long running-in stage. At HT, no running-in is observed in FM1 and FM2, whereas a shorter running-in period, with respect to the RT case, is observed in FM3 followed by the attainment of a comparatively high coefficient of friction. At RT, the pin wear is mild in all cases but severe at HT. FM3 shows the lowest wear rate at both temperatures. Moreover, the coated disc shows no wear when sliding against the FM3 friction material. All the results are interpreted considering the microstructural characteristics of the friction layers formed on the sliding surfaces. The findings of the present study provide insights into reducing wear in braking system components and hence reducing environmental particulate matter emissions from their wear, through the use of disc coatings.

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.

scholarly journals Frictional Characteristics of Brake Pad Materials Alternate to Asbestos

2019 ◽  
Vol 9 (2) ◽  
pp. 694-698
Keyword(s):  
Ratio Analysis ◽  
Scanning Electron Micrographs ◽  
Brake Pad ◽  
Sliding Velocity ◽  
Test Set ◽  
Friction Materials ◽  
Stopping Distance ◽  
Test Conditions ◽  
Pin On Disc ◽  
Set Up

Nevertheless, asbestos though having ample physical and tribo-mechanical properties is being banned worldwide due to its health hazardousness. Most importantly, any material replacing asbestos should have comparable friction properties. This paper aims at comparative study of frictional characteristics of asbestos base and asbestos free brake pad materials. A total of three friction materials namely AF-22 (metallic based), CL-3003 (fine brass based) and DM-6 (asbestos based) were compressed and moulded into a sample. Experiments were performed using dedicated test set-up based on Pin-on-disc principle. Coefficient of friction was compared for three materials at different conditions of sliding velocity and pressure. Experiments were performed using Taguchi’s L27 orthogonal array. Ranking of the parameters have been done based on experimental results and S/N ratio analysis. The elemental composition of materials was measured by EDS technique. Scanning electron micrographs of brake pad samples were tested at different magnifications. Further investigations to evaluate wear rate, stopping distance under simulative test conditions are suggested.

Development of fly ash based friction material for wind turbines by liquid phase sintering technology

2020 ◽  
pp. 135065012096399
Author(s):  
K Rajesh Kannan ◽  
M Govindaraju ◽  
R Vaira Vignesh
Keyword(s):  
Fly Ash ◽  
Liquid Phase ◽  
Wind Turbines ◽  
Friction Material ◽  
Comprehensive Analysis ◽  
Liquid Phase Sintering ◽  
Brake Pad ◽  
Friction Materials ◽  
Evolution Of Microstructure ◽  
Sintered Materials

Fly ash based sintered materials are identified as potential brake pad materials for wind turbines. However, fly ash based friction materials fabricated through conventional techniques results in more porosity and undesirable tribological properties. This study attempts to develop liquid phase sintering technology for fly ash using Cu as a liquid phase sintering agent. The study presents a comprehensive analysis of the evolution of microstructure, microhardness, and tribological performance of the specimens sintered in Argon and Air environment.

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