scholarly journals Study of the structure and frictional properties of a new composite friction material

Author(s):  
О.В. Башков ◽  
А.А. Афанасьева

В статье приведены результаты исследования фрикционных свойств и структуры нового композиционного фрикционного материала (КФМ). В ходе исследования были разработаны восемь перспективных составов КФМ, полученных методом порошковой металлургии. Фрикционные испытания новых материалов проводились на испытательной машине на трение и износ ИИ5018, оснащённой программным комплексом Tester 3.0, позволяющим точно фиксировать изменение момента трения в течение испытания с построением графика и автоматическим расчётом параметров трения. Методика испытаний позволила имитировать условия фрикционного взаимодействия, возникающие в муфтах электроприводов, применяемых в наземном и морском транспорте. По результатам испытаний оценивались величина коэффициента трения и его стабильность на протяжении цикла испытания и в диапазоне рабочих регулировок электропривода, а также износостойкость КФМ. На основании исследований структуры поверхности трения и качественной оценки стабильности коэффициента трения был определён оптимальный состав КФМ, способный обеспечить стабильную и безопасную работу электропривода в диапазоне рабочих регулировок. The article presents the results of a study of the frictional properties and structure of a new composite frictional material (CFM). In the course of the study, eight promising CFM compositions were developed, obtained by the method of powder metallurgy. Friction tests were carried out on a friction and wear testing machine II5018, equipped with the software package Tester 3.0, which allows registering the change in friction moment during the test with plotting and automatic calculation of friction parameters. The test technique made it possible to simulate the conditions of frictional interaction arising in the couplings of electric drives used in land and sea transport. After the tests, the value of the friction coefficient, its stability during the test cycle and in the range of operating adjustments of the electric drive and the wear resistance of the CFM were evaluated. Based on the analysis of the structure of the friction surface and a qualitative assessment of the stability of the coefficient of friction, the optimal composition of the CFM capable of ensuring stable and safe operation of the electric drive in the range of operating adjustments was determined.

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 659 ◽  
pp. 3-6
Author(s):  
Ze Cheng Guo ◽  
Ming Chen ◽  
Dong Bo Zhao ◽  
Fei Meng Zhang

RE nanophase composite material between the grain size 30nm and 100nm are prepared by the method of mechano-chemistry,in which the material’s adsorptive capacity to metal base is checked,and the nature of anti-friction as well as self-repairing effectiveness to the surface of abrasion is tested by four-ball friction wear testing machine. The results show that RE nanophase composite material prepared by the method of mechano-chemistry has a good adsorptive capacity to metal base,and the wear surface can be covered and repaired under dynamic condition;RE nanophase composite material used as anti-friction material is test and verified.


2016 ◽  
Vol 693 ◽  
pp. 653-661 ◽  
Author(s):  
Da Bin Zhang ◽  
Can Li Li ◽  
Yang Cao ◽  
Ze Lu ◽  
Qi Xiang Cui

This paper makes PF weaving friction material (p0.0) from tung oil, PF weaving friction material (BP) from boric acid, modified PF weaving friction material (SP) of nanopalygorskite by in-situ method, and modified PF weaving friction material (MP) of nanopalygorskite by blending method. The contrast tests of frictional properties are carried out on DMS-1 friction-abrasion tester. Hot recession test is performed on CHASE-M600 testing machine, and surface appearance analysis of friction sample is made on electronic probe. The result shows that after modification, the heat resistance and thermal stability of PF are all improved to different extent. SP friction material has best thermal stability and strongest braking ability under high temperature; while BP takes second place, and P0.0 is the worst. The heat resistance of BP, SP and MP is stronger than P0.0. The critical temperature of hot recession for weaving friction material on the base of nanopalygorskite/tung oil PF raises by 40~50°C. On the aspect of frictional properties, friction coefficients of SP, BP, and MP show quite stable. Among these samples, SP has the most stable friction coefficient, and P0.0 the worst. The wear rate of SP, BP and MP has the same trend with the temperature changes. However, the wear rate of P0.0 is getting intense with temperature rise. Its wear rate is much higher than SP, BP, and MP’s under same temperature.


2016 ◽  
Vol 17 (9) ◽  
pp. 755-761 ◽  
Author(s):  
Abhishek Nagpal ◽  
Gaurav Issar

ABSTRACT Introduction In an attempt to minimize wear damage to the enamel of antagonist teeth, new low and medium fusing ceramic materials have been developed. Manufacturers usually claim that these ceramics are wear-friendly because of their lower hardness, lower concentrations of crystal phase, and smaller crystal sizes. This study aimed to quantitatively analyze the wear strength of various commercially available dental porcelain with tooth enamel as well as the surface hardness of these dental porcelain. Materials and methods The basic model was designed as a pin on plate arrangement. The tooth specimens were mounted on the stylus which was centered on the ceramic specimen in a wear testing machine. The dental ceramic specimen was centered in the metal die. A load of 40 N was applied at a rate of 80 cycles/minute for 15 minutes. In the current study, mean wear depth (Ra) value, volumetric loss, and surface hardness were obtained by standard quantification method and were statistically evaluated. Results Ceramco-3 was reported to be most abrasive for enamel; however, Duceram love significantly more abraded itself than the other two, Ceramco-3 and Vita Alpha, and generated the lowest loss of enamel. Also, same abrasive type of wear was revealed for all three variants of tested ceramics. Conclusion Ceramco-3 was the most abrasive for enamel, while surface roughness (mean wear depth) of Duceram love was maximum and for Ceramco-3 it was minimum. The value of surface roughness for Vita Alpha was in between Duceram love and Ceramco-3. Nonetheless, the mean surface hardness of Duceram love was found to be least and maximum for Vita Alpha. Clinical significance In situations of dental wear and wasting tooth disease (Attrition/Abrasion), Duceram can be applied in lieu of Ceramco-3 so as to prevent worsening of existing dentition. However, in younger patients Vita Alpha would offer maximum durability due to its greater surface hardness. How to cite this article Singh A, Nagpal A, Pawah S, Pathak C, Issar G, Sharma P. Qualitative Assessment of Wear Resistance and Surface Hardness of Different Commercially Available Dental Porcelain: An in vitro Study. J Contemp Dent Pract 2016; 17(9):755-761.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 884
Author(s):  
Andrzej Borawski

Braking systems have a direct impact on the safety of road users. That is why it is crucial that the performance of brakes be dependable and faultless. Unfortunately, the operating conditions of brakes during their operating time are affected by many variables, which results in changes in their tribological properties. This article presents an attempt to develop a methodology for studying how the operating time affects the value of the coefficient of friction and the abrasive wear factor. The Taguchi method of process optimization was used to plan the experiment, which was based on tests using the ball-cratering method. The results clearly show that the degree of wear affects the properties of the friction material used in the production process of brakes.


2021 ◽  
pp. 002199832098764
Author(s):  
Mingren Jiang ◽  
Xianhua Cheng

Rare earth modified acidified carbon nanotubes were prepared by functionalization of acidified carbon nanotubes with different concentrations of LaCl3. The modification results were characterized by Fourier-transform infrared and X-ray photoelectron spectroscopy. The rare earth successfully increases the surface activity of the acidified carbon nanotubes. Polymer matrix composites were prepared by using the rare earth modified acidified carbon nanotubes as the reinforcement in epoxy matrix. Mechanical properties were analyzed by Zwick Z100 testing machine and the tribological behaviors were test by multifunctional tribological tester. Compared with pure epoxy (epoxy resin), the mechanical strength of the best composite sample was increased by 50–120%, the coefficient of friction was reduced by 19.4% and the wear rate was reduced by approximately 40 times. The experimental results show that the RE concentration of 0.2–0.3 wt% has the most obvious influence on the properties of polymer composites. The mechanism of rare earth reinforcement in polymer matrix is analyzed and suggested.


2014 ◽  
Vol 693 ◽  
pp. 305-310 ◽  
Author(s):  
Eva Labašová

The coefficient of friction for the bronze material (CuZn25Al6) with insert graphite beds and other bronze material (CuSn12) are investigated in this paper. Friction coefficient was investigated experimentally by the testing machine Tribotestor`89 which uses the principle of the ring on ring method. The external fixed bushing was exposed to the normal load of the same size in all tests. Process of load was increased from level 50 N to 600 N during run up 300 s, after the run up the appropriate level of load was held. The internal bushing performed a rotational movement with constant sliding speed. The value of sliding speed was changed individually for every sample (v = 0.2 (0.3, 0.4) m.s-1). The forth test had a rectangular shape of sliding speed with direct current component 0.3 m.s-1 and the amplitude 0.1 m.s-1 period 300 s, the whole test took 2100 s. The obtained results reveal that friction coefficient increase with the increase of sliding speed.


2017 ◽  
Vol 898 ◽  
pp. 1406-1413
Author(s):  
Yu Long Qi ◽  
Hai Yan Chen ◽  
Chen Yang Shu ◽  
Xuan Zhao ◽  
Li Hua Dong ◽  
...  

Soft and hard FeCrNiSi alloy coatings were obtained on 30CrMo alloy steel surface by laser cladding. The phase constitution, microstructure, frictional wear behavior and corrosion resistance of the composite coating were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), three-dimensional non-contact surface mapping, friction and wear testing machine and electrochemical workstation, separately. XRD analysis showed that the cladding layer was mainly composed of Fe-based alloy composition, accompanied by a small amount of cobalt nickel alloy. There were massive protrusions in the interface of the soft sample, and the coating was regularly dendritic. Hard sample coating lines were cluttered, and there was no bulk deposition. Under the same wear condition, the soft coating exhibited serious abrasive wear, while the hard coating had slight abrasive wear behavior. The polarization curves in 3%NaCl solution revealed that the self-corrosion potential of the soft coating was positive shifted more than that the hard coating. The soft coating has better corrosion resistance than the hard coating.


2021 ◽  
Vol 67 (1-2) ◽  
pp. 27-35
Author(s):  
Idawu Yakubu Suleiman ◽  
Auwal Kasim ◽  
Abdullahi Tanko Mohammed ◽  
Munir Zubairu Sirajo

This paper aims to investigate the mechanical (tensile, hardness, impact, elongation), microstructure and wear behaviours of aluminium alloy reinforced with mussel shell powder (MSP) at different weight percentages (0 wt. % to 15 wt. %) at 3 wt. % interval. The mussel shell powder was characterized by X-ray fluorescence (XRF). The matrix and the composites’ morphology were studied using a scanning electron microscope attached with energy dispersive spectroscopy for the distribution of mussel shell powder particles within the matrix. The wear behaviour of the alloy and composites produced at various reinforcements were carried out using a Taber abrasion wear-testing machine. The XRF showed the compositions of MSP to contain calcium oxide (95.70 %), silica (0.83 %) and others. Mechanical properties showed that tensile values increase with increases in MSP, hardness value increases from 6 wt. % to 15 wt. % of MSP. The impact energy decreased from 42.6 J at 3 wt. % to 22.6 J at 15 wt. %; the percentage elongation also decreased from 37.4 % at 3 wt. % to 20.5 % at 15 wt. % MSP, respectively. The bending stress results increase with increases in the percentage of reinforcement. The morphologies revealed that uniform distribution of MSP within the matrix resulted to improvement in mechanical properties. The wear resistance of the composites increases with increase in the applied load and decreases with increases in the weight percentage of MSP and can be used in the production of brake pads and insulators in the automobile industry.


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