Studies on Dynamic Tribology Properties of Friction Materials by Using an Approximate In Situ Observation for Worn Surfaces

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Weitao Sun ◽  
Wenlong Zhou ◽  
Jianfa Liu ◽  
Xuesong Fu ◽  
Guoqing Chen ◽  
...  

This paper primarily focused on the dynamic tribology properties of one certain nonasbestos organic (NAO) friction material by using an approximate in situ method. This study was performed through a pad-on-disk type friction tester under different temperature conditions. Results showed that temperature has a significant effect on the dynamic tribology performance. At 100 °C, friction coefficient and wear rate after the running-in stage varied little with time. At 250 °C, friction coefficient after the running-in stage increased gradually and then tended to be stable, while wear rate decreased gradually. From 100 to 350 °C, friction coefficient increased first as a function of temperature, but decreased sharply when the temperature was over 250 °C. Simultaneously, wear rate also increased sharply over 250 °C. Additionally, three dynamic evolution models of worn surfaces corresponding to different cases were established.

2014 ◽  
Vol 609-610 ◽  
pp. 8-13 ◽  
Author(s):  
Hua Wei Nie ◽  
Yuan Kang Zhou ◽  
Lv Yang ◽  
Yang Cao

Mass fraction of 1.5%, 3% of the nanomontmorillonite (MMT) were separately added in the phenol prepolymer, phenolic resin/ MMT was synthesized by in-situ method (it is called PF/M). The PF/M was carried out TG analysis using thermal analyser, and the synthetic resin PF/M were as new resin matrix to prepare semimetallic friction material, tribological performance test was carried on XD-MSM fixed speed type friction-wear testing machine in accordance with the GB_5763-2008. The results show that the heat resistance of composite PF/M and tribological performance of friction material are best when nanoMMT is 3% in the resin, the Carbon residue rate of PF/M is an increase of 37% compared with PF without nanoparticles at 600°C, thermal recession temperature of sample by the preparation of PF/M increases above 100°C, and it has stable friction coefficient, overall wear rate decreases 26%, especially in high temperature stage at 350°C, the wear rate decreases significantly, its wear rate decreases 30%.


2013 ◽  
Vol 461 ◽  
pp. 415-420
Author(s):  
Jie Peng ◽  
Yu Cheng Liu ◽  
Zhi Feng Yan ◽  
Bao Gang Wang ◽  
Fu Dong Lin ◽  
...  

The friction materials have many species and they are being used widely, but people have higher requests to friction materials along with the development of technology. the friction material of this expermental optimization formula have the advantages of suitable and stable friction coefficient under high temperature, low wear rate, good restoration characteristics and so on. It can effcetively reduce heat fade of friction and wear under high temperature barking. fricton and wear performance of friction material with second adhesive is better than common preparation friction material , it has higher friction coefficient and lower wear rate, It was determined by physical chemical properities of tin and sulfer. while heating or wearing, the temperature of friction material reach melting temperature of tin, it will become molten state, and sulfer has strong oxidation, on the one hand, tin and sulfer occurred chemical reaction, generating sulfide, stannous (one sulfide tin),on the other hand, while the sulfer is being molten state, it will absorb some abrasive dust, at the same time of generating sulfide, abrasive dust will be adsorb and solidify to pits of friction surface, forming abrasive dust membrane, let the friction coefficient of sample become stable rapidly, reducing the wear rate of friction material.


2010 ◽  
Vol 97-101 ◽  
pp. 1134-1137
Author(s):  
Jian Hua Du ◽  
Jian Guo Han ◽  
Jiang Ping Tu ◽  
Cheng Fa Xu

The Cu-based friction material with Ni coated nanometer SiO2 (Ni/n-SiO2) particles was prepared by the powder metallurgy technology. Friction properties of the friction materials were evaluated by a friction tester. The microstructure and worn morphology were characterized by optical microscope (OM) and scanning electric microscope (SEM). The results indicate that the microstructure is uniform. The Ni/n-SiO2 particles can enhance the wear ability of Cu-based friction materials. The wear rate of the friction material with Ni/n-SiO2 is 6.58 times of that without Ni/n-SiO2. The main wear mechanisms are abrasive wear and adhesive wear, and Ni/n-SiO2 particles can reduce the abrasive wear and adhesive wear.


RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64254-64260 ◽  
Author(s):  
Jin Yang ◽  
Hongtao Zhang ◽  
Beibei Chen ◽  
Hua Tang ◽  
Changsheng Li ◽  
...  

The g-C3N4/Cu nanocomposite was prepared by in situ reduction of Cu2+ adsorbed on the surface defects of g-C3N4, and it exhibited the best lubricating behavior with the lowest friction coefficient and wear rate compared to g-C3N4 or Cu nanoparticles.


2011 ◽  
Vol 311-313 ◽  
pp. 473-476
Author(s):  
Jian Hua Du ◽  
Jian Guo Han ◽  
Cheng Fa Xu

The Cu-based friction materials with nano-AlN (n-AlN) and nano-graphite (n-C) were prepared by powder metallurgy technology, respectively. The microstructures and friction performance were studied through scanning electron microscope (SEM) and friction tester rig, respectively. The results indicate that the n-AlN and n-C particles can enhance the properties of Cu-based friction materials remarkably. Compared with the friction materials without any nanometer materials, the wear resistance of the friction materials with n-AlN and n-C has been improved by 25 % and 11 %, respectively. The heat resistance of the materials with n-AlN and n-C has been improved 18 % and 25 %, respectively. The n-AlN and n-C particles can reduce the abrasive wear and enhance the wear resistance of the Cu-based friction materials.


2018 ◽  
Vol 149 ◽  
pp. 01090 ◽  
Author(s):  
Abdelmajid Hamdaoui ◽  
El Houcine Jaddi

The wheels of a railway axle are the most critical components of a train. These wheels are subjected to several forms of deterioration, including wear, which significantly influences the safety of traffic as well as the dynamic stability of railway vehicles and the lifetime of wheelsets. The objective of this work is to compare the effect of two friction materials of brake shoes at the damage and the wear rate of the ER8 steel wheels.


Friction ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 92-103 ◽  
Author(s):  
Yewei Fu ◽  
Le Zhou ◽  
Tao Yin ◽  
Zhongyao Luo ◽  
Hejin Li ◽  
...  

AbstractAs an alternative to short fibers, non-woven fabrics (NWFs) were made using different types of long fibers to optimize the performance of paper-based friction materials and their technology. In this investigation, the fillers and resin were impregnated into these NWFs to prepare three kinds of wet friction material. The tribological, mechanical, and thermal properties of the new wet friction material were studied. The results indicate that the dynamic friction coefficient of the new friction material is approximately 0.12 and the static friction coefficient is approximately 0.15; the better wear rate is 0.81334 × 10-14 m3·(N·m)-1. In addition, the temperature for 10% mass loss yielded 100 °C enhancement and the tensile strength was improved by 200%, compared to previously reported values. Most importantly, the advantages include a simple preparation flow, low cost, and resource conservation. This is a promising approach for the future development of paper-based friction materials.


2020 ◽  
Vol 304 ◽  
pp. 25-32
Author(s):  
Maitri Kamonrattanapisud ◽  
Karuna Tuchinda

The objective of this work is to study the fiber orientation effect on frictional material properties and tribology performance. Effects of orientation on hardness, maximum load capacity under bending, the friction coefficient and surface wear of the composites were investigated. In this research, 3D printing technique was used to create workpieces in order to control fiber arrangement which is random, 0, 45, and 90 degrees. The results suggested that the fiber direction insignificantly affects material hardness with all specimen showing similar value of average hardness of approx. 90 HRC. However, the fiber orientation had a strong influence on material bending strength. The specimen with forced fiber orientation showed lower bending resistance compared to that with random fiber orientation. This may be caused by the non-uniform distribution of fiber which could promote fracture initiation site in some area with low fiber density. The coefficient of friction of the composite material was found to strongly related to it wear behavior, i.e. higher wear rate results in higher value of friction coefficient. The wear resistance was found to be controlled by both the fiber direction and fiber interface. With fiber oriented at 90 degree to sliding direction, higher coefficient was observed. However, as surface wear took place, the effect of wear debris results in an increase in friction coefficient. For 3D printed specimen, wear was increased with fiber interface density resulting in higher wear rate of specimen with 0-degree fiber orientation compared to those with 45-and 90-degree orientation during. Hence, the specimen with 0 degree fiber direction showed similar value of coefficient of friction to those with random and 90 degree fiber orientation.


Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 25
Author(s):  
Jian Wu ◽  
Xiang Yin ◽  
Liwen Mu ◽  
Xin Feng ◽  
Xiaohua Lu ◽  
...  

Polyimide (PI) is one of the most excellent polymers for coating. However, the high friction coefficient and the high wear rate of pure PI limit its further applications. In this work, the hollow inorganic fullerene-like MoS2/reduced graphene oxide (HIF-MoS2/r-GO) nanocomposite filled PI coating is prepared by in situ polymerization. Reinforcement in mechanical strength and thermal stability is realized on the PI composite coating with incorporation of HIF-MoS2/r-GO, which performs better than carbon nanofiber (CNF). Reduced elastic modulus and hardness of HIF-MoS2/r-GO/PI coating is increased by 8.3% and 4.8%, respectively. The addition of HIF-MoS2/r-GO also results in 24% higher residual mass at 800 °C than CNF. Tribological study indicates that, HIF-MoS2/r-GO/PI achieves a wear rate reduction of 79% compared with pure PI under dry sliding condition, which is much more effective than other nanofillers including CNF, r-GO nanosheets and MoS2 nanoparticles. Under ionic liquid-lubricated condition, the presence of HIF-MoS2/r-GO in PI results in a 30% reduction in wear rate and 10% reduction in friction coefficient as compared to pure PI. It is thought that the HIF-MoS2/r-GO in PI can be slowly released to the frictional interface and form a protective film during sliding, in this way the aggregation problem is successfully solved.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaoyang Wang ◽  
Jiusheng Bao ◽  
Jinge Liu ◽  
Yan Yin ◽  
Tonggang Liu ◽  
...  

Purpose This paper aims to develop of magnetic field controlled friction braking technology, a novel brake friction material with magnetic was designed and prepared in this paper. Design/methodology/approach The permalloy, a soft magnetic material, was selected as an additive to design and prepare the magnetic brake material. The friction, wear performance and permeability of each brake pads were investigated by experiments. By choosing the performance of friction coefficient fluctuation, friction coefficient deviation and mean wear rate as optimization parameters, the formulation of the magnetic friction material was optimized based on Fuzzy theory by using analytic hierarchy process methods and SPSS software. Findings The results showed that the developed soft magnetic friction material has not only superior friction coefficient, permeability and inferior wear rate but also good physical and mechanical properties. Originality/value Permalloy powder was added to the formulation of friction material to achieve a new functional friction material with high magnetic permeability. It is believed that this research will be of great theoretical and practical significance to develop both new brake materials and active control technology of the braking process in the future.


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