Effect of artificial aging on the tribological properties of an Al-25Zn-1Mg alloy

2021 ◽  
Vol 63 (9) ◽  
pp. 836-841
Author(s):  
Recai Fatih Tunay ◽  
Hayder Isam Abdulzahra Al Saadi
Keyword(s):  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Dry Friction ◽  
Aging Process ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Process Solution ◽  
Test Speed ◽  
The Coefficient Of Friction ◽  
Increasing Load

Abstract The tribological properties of aluminum based Al-25Zn-1Mg alloy was experimentally investigated in an MSc thesis, and the results are presented in this study. To this purpose, Al-25Zn-1Mg was commercially produced by casting. The prepared samples were divided into seven groups: no-process, solution treatment, and artificial aging for 1, 3, 6, 12 and 24 hours. Aged and untreated samples were subjected to tribological experiments under conditions of dry friction under 5 N and 10 N loads at speed of 200 rpm, 400 rpm and 800 rpm for a distance of 500 m. As a result of the tests, it was found that hardness increases in all samples depending on the aging process. It was also found that when the test speed was kept constant, the coefficient of friction increased with increasing load.

scholarly journals Study of tribological properties of epoxy and resins composites under technically dry friction conditions

2018 ◽  
Vol 19 (12) ◽  
pp. 658-661
Author(s):  
Sylwester Stawarz ◽  
Magdalena Stawarz ◽  
Robert Gumiński ◽  
Wojciech Kucharczyk
Keyword(s):  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Dry Friction ◽  
Friction And Wear ◽  
Surface Condition ◽  
Selective Transfer ◽  
X Ray ◽  
Tribological Tests ◽  
Transfer Phenomenon ◽  
The Coefficient Of Friction

The article discusses the results of tribological tests of epoxy and resol composites. There was examined the surface condition of samples of composites operating in sliding nodes. It has been found that it is possible to use cheaper resole resins for sliding composites (instead of Epidian 5). Tests that have been carried out showed that increasing the PTFE content in the composite resulted in lowering both the coefficient of friction and wear. X-ray analysis results con-firmed the occurrence of the selective transfer phenomenon

scholarly journals The Effect of Elemental Composition and Nanostructure of Multilayer Composite Coatings on Their Tribological Properties at Elevated Temperatures

2020 ◽  
Author(s):  
Alexey Vereschaka ◽  
Sergey Grigoriev ◽  
Vladimir Tabakov ◽  
Mars Migranov ◽  
Nikolay Sitnikov ◽  
...  
Keyword(s):  
Elemental Composition ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Elevated Temperatures ◽  
Composite Coatings ◽  
Multilayer Composite ◽  
The Coefficient Of Friction ◽  
The Relationship ◽  
Tribological Parameters ◽  
Adhesion Component

The chapter discusses the tribological properties of samples with multilayer composite nanostructured Ti-TiN-(Ti,Cr,Al,Si)N, Zr-ZrN-(Nb,Zr,Cr,Al)N, and Zr-ZrN-(Zr,Al,Si)N coatings, as well as Ti-TiN-(Ti,Al,Cr)N, with different values of the nanolayer period λ. The relationship between tribological parameters, a temperature varying within a range of 20–1000°C, and λ was investigated. The studies have found that the adhesion component of the coefficient of friction (COF) varies nonlinearly with a pronounced extremum depending on temperature. The value of λ has a noticeable influence on the tribological properties of the coatings, and the nature of the mentioned influence depends on temperature. The tests found that for the coatings with all studied values of λ, an increase in temperature first caused an increase and then a decrease in COF.

Tribological Properties of Polyoxymethylene Composites Against Aluminum

2003 ◽  
Vol 125 (3) ◽  
pp. 661-669 ◽  
Author(s):  
Masaya Kurokawa ◽  
Yoshitaka Uchiyama ◽  
Tomoaki Iwai ◽  
Susumu Nagai
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
High Surface ◽  
Surface Hardness ◽  
Disk Surface ◽  
Optical Microscope ◽  
Transfer Film ◽  
The Other ◽  
The Coefficient Of Friction

Tribological properties of several kinds of polyoxymethylene (POM) composites were evaluated for the purpose of developing a polymeric tribomaterial especially suited for mating with aluminum parts having low surface hardness. POM composites containing small amounts of silicon carbide (SiC), POM/SiC; those containing a small amount of calcium octacosanonoate besides SiC, POM/SiC/Ca-OCA; and the one blended with 24 wt % of polytetrafluoroethylene, POM/PTFE(24); were injection-molded into pin specimens and their tribological properties were tested by means of a pin-on-disk type wear apparatus using an aluminum (A5056) mating disk in comparison with a 303 stainless steel (SUS303) disk. Evaluation was focused on observation of the sliding surfaces of the pin specimens and the mating disks by a scanning electron microscope and an optical microscope together with the measurement of surface roughness. In the case of mating against a SUS303 disk having high surface hardness, all pin specimens did not roughen the disk surfaces even after long time of rubbing. Only POM/PTFE(24) composite obviously made a transfer film on the disk surface, while the other composites made an extremely thin one on it. POM/SiC(0.1)/Ca-OCA(1) composite, containing SiC 0.1 wt. % and Ca-OCA 1 wt. %, was found to show the lowest coefficient of friction and the lowest wear rate forming extremely thin transfer film on the mating disk. On the other hand, against an A5056 disk which has lower surface hardness than that of SUS303 disk, unfilled POM and POM composites except POM/SiC(0.1)/Ca-OCA(1) composite roughened the disk surfaces. However, the sliding surface of the A5056 disk rubbed with POM/SiC(0.1)/Ca-OCA(1) composite was significantly smoother and that of the pin specimen was also quite smooth in comparison with other pin specimens. Further, when each POM composite was rubbed against the A5056 disk, formation of transfer film was not obvious on the disk surfaces. For POM/SiC(0.1)/Ca-OCA(1) composite, the wear rate was the lowest of all POM composites, and the coefficient of friction was as low level as 60 percent of that of unfilled POM, but slightly higher than that of POM/PTFE(24) composite. For POM/SiC(0.1)/Ca-OCA(1) composite, the nucleating effect of SiC and Ca-OCA, which accelerated the crystallization of POM during its injection molding to form a matrix containing fine spherulites, must have resulted in increasing the toughness of the matrix and lowering the wear rate. Also, the lubricant effect of Ca-OCA should have lowered the coefficient of friction of the same matrix for rubbing against aluminum mating disk. POM/SiC(0.1)/Ca-OCA(1) composite was concluded as an excellent tribomaterial for mating with aluminum parts.

Tribometer for Dry Friction Measurement

1999 ◽  
Author(s):  
Marc Brandl ◽  
Friedrich Pfeiffer
Keyword(s):  
Coefficient Of Friction ◽  
Dry Friction ◽  
Stribeck Curve ◽  
Body System ◽  
Friction Measurement ◽  
Detailed Model ◽  
The Coefficient Of Friction ◽  
Simulation Results ◽  
Multi Body

Abstract This paper deals with the measurement of dry friction. A tribometer was developed in order to identify both the sticking and the sliding coefficient of friction. The aim was to determine the so called Stribeck-curve of any material in contact. The design of the plant is presented. Avoiding errors in recalculating the coefficient of friction, a detailed model of the plant as a multi body system with motor feedback was generated. Advantages of the tribometer are shown in simulations. Some results of measurements in comparison with simulation results are presented.

Some Tribological Properties of an Ionic Liquid

2005 ◽  
Author(s):  
Takashi Nogi
Keyword(s):  
Ionic Liquid ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Wear Performance ◽  
Lubrication Regime ◽  
Pin On Disc ◽  
The Coefficient Of Friction

Some tribological properties of an ionic liquid were investigated by using a pin-on-disc friction and wear tester. Due to running-in, the coefficient of friction of the ionic liquid decreased with time to a very low value of 0.02 which suggests that the lubrication regime was hydrodynamic at the end of the tests. Anti-wear performance of the ionic liquid was substantially comparable to a paraffin-based oil.

The Influence of Surface Roughness on the Mechanism of Friction

1970 ◽  
Vol 92 (2) ◽  
pp. 264-272 ◽  
Author(s):  
T. Tsukizoe ◽  
T. Hisakado
Keyword(s):  
Surface Roughness ◽  
Metal Surface ◽  
Coefficient Of Friction ◽  
Dry Friction ◽  
Metal Surfaces ◽  
Roughness Effects ◽  
Real Area Of Contact ◽  
The Coefficient Of Friction ◽  
Tangential Forces ◽  
Soft Metal

A study was made of surface roughness effects on dry friction between two metals, assuming that the asperities are cones of the slopes which depend on the surface roughness. The theoretical explanations were offered for coefficients of friction of the hard cones and spheres ploughing along the soft metal surface. A comparison of calculated values based on these with experimental data shows good agreement. Moreover, theoretical discussion was carried out of surface roughness effects on dry friction between two metal surfaces on the basis of the analyses of the frictional mechanism for a hard slider on the metal surface. The theoretical estimation of the coefficient of friction between two metal surfaces can be carried out by using the relations between the surface roughness and the slopes of the asperities, and the coefficient of friction due to the adhesion at the interface. The experiments also showed that when two metal surfaces are first loaded normally and then subjected to gradually increasing tangential forces, real area of contact between them increases and the maximum tangential microslip of them increases with the increase of the surface roughness.

THE INFLUENCE OF GLASSY CARBON AND ITS FORMS ON TRIBOLOGICAL PROPERTIES OF ALUMINIUM MATRIX COMPOSITES

Tribologia ◽  
2019 ◽  
Vol 285 (3) ◽  
pp. 79-87 ◽  
Author(s):  
Jerzy MYALSKI ◽  
Andrzej Posmyk ◽  
Bartosz HEKNER ◽  
Marcin GODZIERZ
Keyword(s):  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Glassy Carbon ◽  
Amorphous Structure ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Entire Volume ◽  
Carbon Particles ◽  
The Matrix ◽  
The Coefficient Of Friction

Carbon with an amorphous structure was used as a component to modify the tribological properties of engineering plastics. Its construction allows the formation of carbon-based wear products during friction, adhesively bonded to the surface of cooperating machine parts, acting as a solid lubricant. The work compares the tribological properties of two groups of composites with an aluminium alloy matrix in which glassy carbon appeared in the form of particles and an open cell foam fulfilling the role of strengthening the matrix. The use of spatial structures of reinforcement provides, in comparison with the strengthening of particles, homogeneity of carbon distribution in the entire volume of the composite. The tests carried out on a pin-disc tester showed that the use of spatial carbon structures in the composite ensures a greater coefficient of friction stability than when reinforcing with particles, and the coefficient of friction with a small proportion of carbon foams (about 1 wt%) is comparable with the coefficient of friction in the contact with composites containing 5-10% carbon particles in granular form.

Development of Antifriction Materials Based on Polytetrafluoroethylene with Carbon Fibers and Tungsten Disulfide

2020 ◽  
Vol 992 ◽  
pp. 745-750
Author(s):  
A.P. Vasilev ◽  
T.S. Struchkova ◽  
A.G. Alekseev
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Carbon Fibers ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Relative Elongation ◽  
Tungsten Disulfide ◽  
Degree Of Crystallinity ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction

This paper presents the results from the investigation of effect the carbon fibers with tungsten disulfide on the mechanical and tribological properties of PTFE. Is carried out a comparison of mechanical and tribological properties of polymer composites PTFE-based with carbon fibers and PTFE with complex filler (carbon fibers with tungsten disulfide). It is shown that at a content of 8 wt.% CF+1 wt.% WS2 in PTFE, wear resistance increases significantly while maintaining the tensile strength, relative elongation at break and low coefficient of friction at the level of initial PTFE. The results of X-ray analysis and investigation of SEM supramolecular structure and friction surfaces of PTFE and polymer composites are presented. It is shown that the degree of crystallinity of polymer composites increases in comparison with the initial PTFE. The images of scanning electron microscope reveal that particles of tungsten disulfide concentrating on the friction surface is likely responsible to a reduction in the coefficient of friction and increase the wear resistance of PTFE-based polymer composites with complex fillers.

An Empirical Approach to Modeling the Friction Coefficient for Wheel-Rail Contact

2009 ◽  
Author(s):  
HyunWook Lee ◽  
Corina Sandu ◽  
Carvel Holton ◽  
Mehdi Ahmadian
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Dry Friction ◽  
Damping Ratio ◽  
Contact Dynamics ◽  
Nonlinear Dependence ◽  
Accurate Estimation ◽  
Highly Nonlinear ◽  
The Coefficient Of Friction ◽  
Wheel Vibration

The coefficient of friction (CoF) is one of the most important parameters for the contact between the wheel and the rail. Accurate estimation or measurement of the CoF has a very important role, both in terms of modeling the train dynamics and in terms of reducing operational costs in the long-term. For ease of implementation, since the nature of the wheel-rail contact dynamics is very complex, the assumption of a constant CoF is still used in most theoretical studies. Nevertheless, experimental work indicates that the CoF depends on dynamic changes in various wheel-rail conditions, like sliding velocity, contact patch shape and size for stick and sliding region, wheel and rail geometry, wheel vibration, rail surface roughness and/or lubrication, etc. In this paper we present the proposed equation to model the nonlinear dry friction coefficient at the wheel-rail contact. The friction coefficient is calculated at the three different values for change in the damping ratio while maintaining all the other conditions the same. As expected, the analysis performed to estimate the dry friction coefficient based on the proposed equation and using NUCARS® simulation results shows that the coefficient of friction has a highly nonlinear dependence on its parameters.

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