INFLUENCE OF MOLYBDENUM DISULFIDE PARTICLE SIZE ON FRICTION AND WEAR CHARACTERISTICS OF NON-ASBESTOS-BASED COPPER-FREE BRAKE FRICTION COMPOSITES

2019 ◽  
Vol 27 (01) ◽  
pp. 1950085 ◽  
Author(s):  
R. VIJAY ◽  
D. LENIN SINGARAVELU ◽  
PETER FILIP

Molybdenum disulfide is a successful solid lubricant because of its cleavage of the basal plane at the time of sliding, which helps to retain the lubrication nature in order to reduce wear and to maintain frictional stability. Thus the present study deals with the development of copper-free brake pads using molybdenum disulfide that possesses different grades based on the particle size, namely, technical (coarse), fine and superfine. The brake pads were developed using conventional manufacturing processes and characterized for its physical, chemical, thermal and mechanical properties as per industrial standards. Thermal stability was measured for the varying ingredients and the developed composites using thermogravimetric analyzer instrument. The tribological studies were done using Chase testing following IS2742 Part-4 standards. The results showed that coarse-sized (technical grade) molybdenum disulfide-based brake pads possess better thermal stability with good fade and recovery characteristics in turn leading to less wear when compared with the other two composites. This is because of its better heat dissipation and superior lubricating nature. Scanning electron microscopy and energy dispersive analysis were helpful in studying the wear behavior of the Chase-tested brake friction composite samples.

2012 ◽  
Vol 585 ◽  
pp. 559-563
Author(s):  
M.A. Sai Balaji ◽  
K. Kalaichelvan

Non-Asbestos organic composite friction materials are increasingly used in automotive brake disc pad applications. The present paper deals with the role of various organic fibers Kevlar, Acrylic fibers and the Rock fiber namely the Lapinus fiber on the fade and recovery behavior of friction composites. Three different friction composites were developed with same formulation varying only the percentage of Kevlar, Acrylic and lapinus fibers within the formulation. The formulations containing 13.5% of these fibers were developed as brake pads and designated as NA01, NA02 and NA03 respectively. The chemical and Mechanical properties are tested as per Indian Industrial standards.. The composites are then tested for the tribo-performance using Chase Testing Machine following SAE J661a standards. The fade µ, recovery µ and wear are significantly influenced by the amount and type of fiber combinations. Also the TGA reveals the degradation temperature of these fibers. Composite NA 03 containing Kevlar and lapinus combination is found to have good tribo performance. Worn surface analysis by SEM has proved to be useful in understanding the wear behavior of the composites.


Author(s):  
D. Lenin Singaravelu ◽  
Rahul Ragh M. ◽  
Vijay R. ◽  
S. Manoharan ◽  
Mohamed Kchaou

The present study deals with the effective usage of crab shell, which is a solid waste in the seafood industry. The crab shell was powdered and treated with chemicals to obtain the chemically treated crab shell powder. The crab shell was powdered and heated to the desired conditions to obtain thermally processed crab shell powder. These two powders so obtained were used with other ingredients in the development of brake pads. For comparison crab shell powder free brake pads were also developed. The developed brake pads were tested for various characteristics as per the industrial standards. Thermal stability was found using Thermogravimetric analysis. The fade and recovery behaviours were estimated for the developed brake pads using Chase test following IS2742 Part-4. The test results indicate that the thermally processed crab shell powder based brake pads showed better thermal stability with a char residue of 37%, while the chemically treated crab shell powder based brake pads had better fade and recovery characteristics with a fade rate of 1.71 % and recovery rate of 99.86 % due to its better heat dissipation and coarse structure. Scanning electron microscopy paved the way to study the worn characteristics of the Chase tested samples. An extensive evaluation method was used to rank the developed brake pads based on the Chase test performance; it also ranked chemically treated crab shell powder-based brake pads as the best performer.


Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1637 ◽  
Author(s):  
Wenelska ◽  
Homa ◽  
Popovic ◽  
Maslana ◽  
Mijowska

The fabrication of conventional or biodegradable polymers with improved thermal and fire-resistant properties is an important task for their successful application in various branches of the industry. In this work, few-layered molybdenum disulfide was functionalized with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and introduced into polyethylene and poly(lactic acid) matrixes. The obtained polyethylene composite samples displayed improved thermal stability, significant reduction in CO emissions, improved fire-resistant properties, and over 100% increases in thermal conductivity. Poly(lactic acid) composites displayed less impressive results, but have managed to improve some values, such as CO emissions, peak heat release rate, and total heat release in comparison to pristine polymer.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sundarrajan D. ◽  
Pitchipoo Pandian ◽  
Manoharan Sembian

Purpose This paper aims to deal with the synergistic effect of steel slag-molybdenum disulfide particles on fade-recovery performances of non-asbestos organic friction material. Design/methodology/approach The brake friction materials were developed by using steel slag and molybdenum disulfide particles as individual and combination in the formulation. The brake friction materials were developed in the form of standard brake pads as per the industrial practice. The physical, mechanical and thermal properties of the developed brake pads were tested as per the industrial standards. The tribological properties were analyzed using the Chase test as per IS2742-Part-4. Worn surface analysis was done using a scanning electron microscope. Findings The experimental results indicate that the brake pads filled with a combination of steel slag and molybdenum disulfide showed stable friction and less wear rate due to the synergetic nature of abrasive and lubricant. Originality/value This paper explains the influence of steel slag and molybdenum disulfide particles as individual and combined in brake pads formulation to enhance the tribological performance by producing stabilized friction with undulations. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0216/


2015 ◽  
Vol 659 ◽  
pp. 394-398 ◽  
Author(s):  
Nutthaphon Liawthanyarat ◽  
Sarawut Rimdusit

Polybenzoxazine nanocomposites filled with three different sizes of silica nanoparticles are investigated for their mechanical and thermal properties. In this research, silica nanoparticles with primary particle sizes of 7, 14 and 40 nm were incorporated in polybenzoxazine matrix at a fixed content of 3% by weight. From the experimental results, the storage modulus of the polybenzoxazine nanocomposite was found to systematically increase with decreasing the particle sizes of nanosilica suggesting better reinforcement of the smaller particles. Glass transition temperature was found to slightly increase with the addition of the silica nanoparticles. The uniformity of the composite samples were also evaluated by thermogravimetric analysis to show good dispersion of the silica nanoparticles in the composite samples as a result of high processability of the benzoxazine resin used i.e. low A-stage viscosity with good wetting behaviors. Degradation temperature at 5% weight loss (Td,5) of polybenzoxazine nanocomposites filled with different particle sizes of silica nanoparticles was found to increase from the value of 325 °C of the neat polybenzoxazine to the maximum value of about 340 °C with an addition of the nanosilica of the smallest particle size used. Finally, the smaller nanosilica particle size was also found to show more pronounced effect on Td,5enhancement of the composite samples as a result of greater barrier effect from larger surface area of the smaller particles.


2017 ◽  
Vol 139 (4) ◽  
Author(s):  
V. Srinivas ◽  
R. N. Thakur ◽  
A. K. Jain ◽  
M. Saratchandra Babu

This paper compares the tribological properties of transmission oil dispersed with molybdenum disulfide (MoS2) and tungsten disulfide (WS2) nanoparticles. Lubricant samples are prepared by dispersing MoS2 and WS2 nanoparticles in 0.5 wt.% in transmission oil. The nanoparticles are stabilized in the lubricant by surface modification with surfactant SPAN 80. The stability of the lubricant in terms of size variation of dispersed nanoparticles is evaluated using particle size analyzer. The antiwear, antifriction, and extreme pressure (EP) properties are tested on a four-ball wear tester and a comparison is made to assess the relative performance of MoS2 and WS2 nanoparticles. The friction and wear characteristics of lubricant dispersed with nanoparticles are strongly dependent upon the load taken into consideration. The lubricant dispersed with WS2 nanoparticles gave higher weld load and load wear index (LWI) than that of lubricant dispersed with MoS2 nanoparticles. The metallographic studies show that under high load conditions, the WS2 nanoparticles deposit more than MoS2 nanoparticles, thereby giving better performance at higher load conditions.


2012 ◽  
Vol 55 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Lei Zhang ◽  
Jinkun Xiao ◽  
Kechao Zhou

2021 ◽  
pp. 36-40
Author(s):  
F.F. Yusubov

Tribotechnical indicators of environmentally friendly frictional composite materials with phenol-formaldehyde matrix are studied. Friction tests were carried out on a MMW-1 vertical tribometer according to the pin-on-disk scheme. Keywords: brake pads, composites, friction and wear, plasticizers, degradation, porosity. [email protected]


Sign in / Sign up

Export Citation Format

Share Document