scholarly journals STRUCTURE AND PROPERTIES OF THE АК12М2МгН (AlSi12Cu2MgNi) PISTON ALLOY FORMED UNDER THE INFLUENCE OF A COMPLEX MODIFYING ADDITIVE OF FULLERENE-CONTAINING SOOT AND COPPER

2021 ◽  
Vol 2 (55) ◽  
pp. 73-80
Author(s):  
A.I. Komarov ◽  
◽  
D.V. Orda ◽  
D.O. Iskandarova ◽  
◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Relative Elongation ◽  
High Wear Resistance ◽  
Simultaneous Increase ◽  
Structure And Properties ◽  
Carbon Particles ◽  
Study Results ◽  
The Coefficient Of Friction ◽  
Tribotechnical Characteristics ◽  
Modifying Additive

The article presents the study results of the complex modification of eutectic silumin АК12М2МгН (AlSi12Cu2MgNi) with additives of fullerene-containing soot (FCS) and copper. It is shown that the effect on the alloy structure is caused by the introduction of carbon nanoparticles into the melt and is manifested in the dispersion of the structural phases and their uniform distribution in the casting volume. At the same time, the use of dispersed copper powder provides wetting of aluminum carbon particles with the melt and additional alloying of the melt. The formation of a dispersed structure leads to an increase in the mechanical and tribotechnical characteristics of the alloy: an increase in the ultimate strength (by 1.3–1.6 times) with a simultaneous increase in the relative elongation by up to 3 times, a significant decrease in the coefficient of friction (by 1.1–1.7 times) and the intensity of wear. The lowest coefficient of friction and high wear resistance are achieved at small fractions of FCS (0.05–0.1 wt.%) and the copper content in the modifier is not more than 0.5 wt.%.

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.

Mechanical Properties of Aluminium Matrix Composites Reinforced with Glassy Carbon Particles

2011 ◽  
Vol 176 ◽  
pp. 39-48 ◽  
Author(s):  
Jerzy Myalski ◽  
Józef Śleziona
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Coefficient Of Friction ◽  
Glassy Carbon ◽  
Friction And Wear ◽  
Matrix Composites ◽  
Carbon Particles ◽  
Small Influence ◽  
The Coefficient Of Friction ◽  
Reinforcement Value

The mechanical properties of composite materials with glassy carbon (GC) have been presented. The effect of size and reinforcement value on tensile strength, impact and tribological characteristics (coefficient of friction and wear) were estimated. It has been found that the reinforcement value decide on mechanical properties. Enlargement of particles value leads to decreasing of tensile strength and impact strength. It has been shown that particle size has small influence on studied properties. Destruction energy for the composites with particles exceeding 100 µm is similar. The measurement of coefficient of friction proved, that increase of reinforcement value leads to decreasing of coefficient of friction from 0.4 for 5% value to about 0.12 for 20% of particle value. The coefficient of friction is comparable for the composites containing particles of 200 µm size and is less dependent on reinforcement value. However size of the particles decide on the character of coefficient of friction changes.

scholarly journals The tribological properties of lubricating greases produced on vegetable base and modified of polytetrafluoroethylene

2020 ◽  
Vol 37 (1−2) ◽  
Author(s):  
Rafal Kozdrach
Keyword(s):  
Correlation Function ◽  
Fatigue Life ◽  
Rheological Properties ◽  
Coefficient Of Friction ◽  
Sunflower Oil ◽  
Test Results ◽  
Wear Protection ◽  
The Coefficient Of Friction ◽  
Load Conditions ◽  
Modifying Additive

The article presents the results of research on the influence of polytetrafluoroethylene additive on the tribological and rheological properties of selected lubricant compositions. Based on the obtained test results, it was found that the introduction of a modifying additive to the lubricant structure allows a significant reduction of the coefficient of friction, thus increasing the efficiency of tribological protection of the tribosystem. All lubricating compositions modified with at least 1% polytetrafluoroethylene guarantee effective anti-wear protection under load conditions of the tribosystem. Modification of the tested lubricating compositions with the applied additive affects the increase of indicators characterizing the fatigue life of the examined lubricating greases based on sunflower oil. The introduction of the polytetrafluoroethylene into the structure of the tested lubricants changed the values of the MSD correlation function and the G’ and G’’ modules, which significantly influenced the internal structure of the tested lubricant compositions.

Electroless Plating of Ni-P-CNTs Composite Coating

2007 ◽  
Vol 280-283 ◽  
pp. 1445-1448 ◽  
Author(s):  
Guo Gang Zhao ◽  
Fu Ming Deng
Keyword(s):  
Carbon Nanotubes ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Surface Morphology ◽  
Composite Coating ◽  
Coefficient Of Friction ◽  
Electroless Plating ◽  
Structure And Properties ◽  
Plating Bath ◽  
The Coefficient Of Friction

Ni-P-CNTs composite coating were deposited by electroless plating. The factors which influenced the content of carbon nanotubes in deposits, such as the types of agitation, surfactants and carbon nanotubes concentration in the plating bath, were examined. The surface morphology, structure and properties, such as microhardness, wear resistance and friction coefficient of the -CNTs coating, were investigated. The results showed that the Ni-P-CNTs composite coating greatly increased the hardness and wear resistance and decreased the coefficient of friction with the increase of the content of carbon nanotubes in deposits, and the introduced carbon nanotubes did not change the structure of the Ni-P marix of the composite coating.

scholarly journals Research of tribotechnical characteristics of materials used in the development of compositions of lubricants for casting under pressure of aluminum alloys and polymeric products

2020 ◽  
pp. 110-115
Author(s):  
A. M. Mikhaltsov ◽  
A. A. Skaskevich ◽  
Ya. I. Tsishkova
Keyword(s):  
Aluminum Alloys ◽  
Injection Molding ◽  
Coefficient Of Friction ◽  
Soap Stock ◽  
Polymeric Materials ◽  
Petroleum Jelly ◽  
Steel Disk ◽  
The Coefficient Of Friction ◽  
Materials Used ◽  
Tribotechnical Characteristics

The article describes the requirements for lubricants (release coatings) used in injection molding of aluminum alloys and polymeric materials. A methodology for conducting research to determine the tribotechnical characteristics of materials used in the development of the composition of a lubricant for injection molding aluminum alloys and polymer products, as well as the results of a study of tribotechnical characteristics (friction coefficient) are presented. It has been established that as materials used in the development of a multifunctional lubricant composition for casting aluminum alloys and polymer products, it is advisable to use a fraction of soap stock and fus after their preliminary sedimentation (at least 3 months). It is shown that the smallest value of the coefficient of friction at the time of indenter breaking on the surface of the steel disk was obtained using a fus. Moreover, the value of the coefficient of friction is 14–33% lower than the same indicator for other studied lubricants (petroleum jelly, PMS-100 and soap stock). It was found that in the mode of reciprocal movement of the indenter on the surface of the steel disk, the coefficient of friction when using a fus is 1,7–3,3 times lower than when using Vaseline, PMS-100 and soap stock as lubricant.

Experimental Investigation of aluminum doping crumb rubber/epoxy composite in reciprocating motion

2015 ◽  
Vol 3 ◽  
pp. 1
Author(s):  
Goutam Chandra Karar ◽  
Nipu Modak
Keyword(s):  
Experimental Investigation ◽  
Coefficient Of Friction ◽  
Epoxy Composite ◽  
Normal Load ◽  
Crumb Rubber ◽  
The Other ◽  
Reciprocating Motion ◽  
Molding Process ◽  
Friction Tester ◽  
The Coefficient Of Friction

The experimental investigation of reciprocating motion between the aluminum doped crumb rubber /epoxy composite and the steel ball has been carried out under Reciprocating Friction Tester, TR-282 to study the wear and coefficient of frictions using different normal loads (0.4Kg, 0.7Kgand1Kg), differentfrequencies (10Hz, 25Hz and 40Hz).The wear is a function of normal load, reciprocating frequency, reciprocating duration and the composition of the material. The percentage of aluminum presents in the composite changesbut the other components remain the same.The four types of composites are fabricated by compression molding process having 0%, 10%, 20% and 30% Al. The effect of different parameters such as normal load, reciprocating frequency and percentage of aluminum has been studied. It is observed that the wear and coefficient of friction is influenced by the parameters. The tendency of wear goes on decreasing with the increase of normal load and it is minimum for a composite having 10%aluminum at a normal load of 0.7Kg and then goes on increasing at higher loads for all types of composite due to the adhesive nature of the composite. The coefficient of friction goes on decreasing with increasing normal loads due to the formation of thin film as an effect of heat generation with normal load.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

scholarly journals Influence of Beam Power on Young’s Modulus and Friction Coefficient of Ti–Ta Alloys Formed by Electron-Beam Surface Alloying

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1246
Author(s):  
Stefan Valkov ◽  
Dimitar Dechev ◽  
Nikolay Ivanov ◽  
Ruslan Bezdushnyi ◽  
Maria Ormanova ◽  
...  
Keyword(s):  
Electron Beam ◽  
Young’S Modulus ◽  
Coefficient Of Friction ◽  
Young's Modulus ◽  
Beam Power ◽  
Surface Alloying ◽  
Surface Alloys ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Beam Surface

In this study, we present the results of Young’s modulus and coefficient of friction (COF) of Ti–Ta surface alloys formed by electron-beam surface alloying by a scanning electron beam. Ta films were deposited on the top of Ti substrates, and the specimens were then electron-beam surface alloyed, where the beam power was varied from 750 to 1750 W. The structure of the samples was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Young’s modulus was studied by a nanoindentation test. The coefficient of friction was studied by a micromechanical wear experiment. It was found that at 750 W, the Ta film remained undissolved on the top of the Ti, and no alloyed zone was observed. By an increase in the beam power to 1250 and 1750 W, a distinguished alloyed zone is formed, where it is much thicker in the case of 1750 W. The structure of the obtained surface alloys is in the form of double-phase α’and β. In both surface alloys formed by a beam power of 1250 and 1750 W, respectively, Young’s modulus decreases about two times due to different reasons: in the case of alloying by 1250 W, the observed drop is attributed to the larger amount of the β phase, while at 1750 W is it due to the weaker binding forces between the atoms. The results obtained for the COF show that the formation of the Ti–Ta surface alloy on the top of Ti substrate leads to a decrease in the coefficient of friction, where the effect is more pronounced in the case of the formation of Ti–Ta surface alloys by a beam power of 1250 W.

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