Investigation of the relationship between wear resistance in dry friction and mechanical properties of sintered composites of the Al-Sn system

2020 ◽  
Vol 5 ◽  
pp. 55-65
Author(s):  
N.M. Rusin ◽  
◽  
A.L. Skorentsev ◽  
M.G. Krinitsyn ◽  
◽  
...  
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Grain Boundaries ◽  
Dry Friction ◽  
Aluminum Matrix ◽  
Treatment Method ◽  
Mechanical And Tribological Properties ◽  
Angular Pressing ◽  
Silicon Doped ◽  
The Relationship

Effect of tin-insoluble alloying elements (Zn, Si) on the mechanical and tribological properties of the Al-40Sn sintered composite has been studied. Powder mixtures with alloying additions were sintered at a temperature above the melting point of tin (232°C). Sintered specimens had residual porosity, which negatively affected the strength, ductility, and wear resistance of the composite under dry friction. Compression in a closed die and equal channel angular pressing (ECAP) at a temperature of 250°C reduced the porosity of the material and significantly increased its strength and ductility. Regardless of the pressure treatment method, the compacted specimens showed good wear resistance. The main mechanism of composite wear is the exfoliation of matrix grains in the surface layer due to their shift along the tin interlayers in the direction of friction. The shear and peeling of grains were preceded by a strong deformation of the surface layer, in which the grain boundaries with tin interlayers were stretched in the direction of friction, that is, a layered structure was formed. Composites in which most of the grain boundaries of the aluminum matrix are oriented perpendicular to the sliding direction have the maximum wear resistance. A similar structure is formed in the plane of the material flow during ECAP processing. It was found that the wear resistance of a composite with a zinc-doped matrix is higher than with a silicon-doped matrix.

Tribological Characteristics of Nano Structured Nickel Coatings for Renivating of Extruding Shafts

2012 ◽  
Vol 217-219 ◽  
pp. 221-225 ◽  
Author(s):  
Dimitar Karastoyanov ◽  
Todor Penchev ◽  
Mara Kandeva
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Contact Interaction ◽  
Dry Friction ◽  
Experimental Results ◽  
Tribological Characteristics ◽  
Resistance Testing ◽  
Temperature Changes ◽  
Wear Process ◽  
Nickel Coatings

The methods for wear resistance testing is described and the experimental results for the dependence of the massive wear, wear speed, intensity of wear and wear resistance on the friction road and the time of a contact interaction are obtained. A testing micromanipulator with piezo actuators for measuring the roughness of the surface layer is developed. A methodology for thermographic testing and experimental results for wear and temperature changes in the contact by the wear process of the coatings under dry friction and abrasion is obtained

scholarly journals Strengthening of the Restored Surface Layer of Steel Parts 45 by Laser Boring

2018 ◽  
Vol 7 (4.3) ◽  
pp. 71
Author(s):  
Oleg Cherneta ◽  
Vadim Kubich ◽  
Roman Voloshchuk ◽  
Vladimir Averyanov ◽  
Dmytro Shmatko ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Laser Treatment ◽  
Complex Structure ◽  
Pulsed Laser ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Processing Zone ◽  
The Relationship

By means of the proposed technologies, the relationship and strengthening of the optimal modes of recovery of the restoring layer and the optimal laser treatment modes with bat-retaining straps are chosen. The microstructural, X-ray diffraction studies of the restored surfaces of the cams of the distributing shaft of the car were determined, the wear resistance and microhardness of the working surfaces were determined. By means of the proposed technologies of restoration and strengthening, optimum modes of applying the restoring layer and optimal modes of laser treatment (pumping energy of 20 kJ without melting of the surface) with bat-retaining coatings (thickness 2 mm) were chosen. The unevenness of the pulsed laser treatment with the restriction of the diameter of the laser spot and the treatment of a boron-rich surface layer with overlapping of the corresponding zones leads not only to the quenching but also to the release of individual local microparticles. New phases such as boron carbide, carbides - borides, iron borides, and others are formed. The strengthened surface layer has a complex structure and generally contains a martensite base with thin layers of borides, сarbides. The microhardness of the processing zone rises 3-4 times (Нμ 6500-7000 MPa).  

Effect of borating on resistance to abrasive wear of chromium-bearing iron-carbon alloys

2020 ◽  
pp. 457-460
Author(s):  
P.G. Ovcharenko ◽  
S.A. Tereshkina ◽  
A.Yu. Leshchev ◽  
V.V. Tarasov
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Cast Iron ◽  
Thermal Treatment ◽  
Abrasive Wear ◽  
Dry Friction ◽  
Comparative Tests ◽  
Fixed Abrasive

The effect of chemical-thermal treatment (borating) on the structure, composition, depth and hardness of the surface layer of samples from chromium-bearing iron-carbon alloys: 95Kh18 steel and ChKh12 and ChKh32 cast iron is shown. The results of comparative tests of the studied materials on the wear resistance in the conditions of dry friction on fixed abrasive are presented.

scholarly journals Tribotechnical Properties of Sintered Antifriction Aluminum-Based Composite under Dry Friction against Steel

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 180
Author(s):  
Nikolay M. Rusin ◽  
Alexander L. Skorentsev ◽  
Maksim G. Krinitcyn ◽  
Andrey I. Dmitriev
Keyword(s):  
Wear Resistance ◽  
Dry Friction ◽  
Aluminum Matrix ◽  
Press Mold ◽  
Vacuum Furnace ◽  
Two Phase ◽  
Friction Process ◽  
Tribotechnical Properties ◽  
Pin On Disk ◽  
Tin Content

The disadvantage of antifriction Al–Sn alloys with high tin content is their low bearing capacity. To improve this property, the aluminum matrix of the alloys was alloyed with zinc. The powder of Al–10Zn alloy was blended with the powder of pure tin in the proportion of 40/60 (wt.%). The resulting mixture of the powders was compacted in briquettes and sintered in a vacuum furnace. The sintered briquettes were subjected to subsequent pressing in the closed press mold at an elevated temperature. After this processing, the yield strength of the sintered (Al–10Zn)–40Sn composite was 1.6 times higher than that of the two-phase Al–40Sn one. The tribological tests of the composites were carried out according to the pin-on-disk scheme without lubrication at pressures of 1–5 MPa. It was established that the (Al–10Zn)–40Sn composite has higher wear resistance compared with the Al–40Sn one. However, this advantage becomes insignificant with an increase in the pressure. It was found that the main wear mechanism of the investigated composites under the dry friction process is a delamination of their highly deformed matrix grains.

Dry Friction and Wear Properties of Aluminum Matrix Composites Reinforced with 3D Network Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 1701-1704
Author(s):  
Jun Ping Yao ◽  
Wei Wang ◽  
Leping Chen ◽  
Bing Kun Chen ◽  
Lei Zhang
Keyword(s):  
Wear Resistance ◽  
Dry Friction ◽  
Friction And Wear ◽  
Volume Fraction ◽  
Normal Load ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Friction Coefficients ◽  
3D Network ◽  
The Matrix

A new 3D network ceramics (skeleton) reinforced aluminum alloy composites was designed and fabricated. Dry friction and wear behaviors of the new composites were investigated. The friction coefficients and wear rates of the matrix and the composites were measured at various temperatures and loads. The worn surfaces of the samples were examined with a scanning electron microscope, and the effect of the 3D network ceramics on the wear mechanisms was discussed accordingly. The composites had much better wear resistance than the matrix. The improvement in the wear resistance of the composites became more prominent at higher ceramics volume fraction, higher temperature, and larger normal load. Moreover, the friction coefficients of the composites remained stable with increasing normal load, especially at elevated temperature. It is suggested that the 3D network ceramics support the load applied onto the sliding surface, which not only restricts the plastic deformation and high temperature softening of the alloy, but also protects the oxide film(Al2O3) on the surface.

Improving the wear resistance of hoe blades by modifying of restoration coatings

2019 ◽  
Vol 24 (94/4) ◽  
pp. 27-32
Author(s):  
T.S. Skoblo ◽  
I.N. Rybalko ◽  
A.V. Tihonov ◽  
T.V. Maltsev
Keyword(s):  
Wear Resistance ◽  
Transition Layer ◽  
Surface Coating ◽  
Dry Friction ◽  
Raw Materials ◽  
Bentonite Clay ◽  
Magnetic Fraction ◽  
Cutting Surface ◽  
Agricultural Machines ◽  
Modifying Additive

The possibility of using a non-magnetic fraction of a detonation charge with a diamond fraction from the disposal of ammunition to modify the restoration coatings of a natural product – clay and secondary raw materials — was studied. Four different coating variants were investigated. For this, a T-620 electrode was used with its additional modification by coating with bentonite clay, as well as with a non-magnetic fraction of the detonation charge and applying it in the form of a slip coating on the cutting surface of the cultivator. It is shown that the use of such additives allows to increase the resistance of the working tool of agricultural machines, reduces its tendency to damage due to the minimum penetration of the thin-walled product of the hoe blade and a decrease in the cross section of the transition layer and the level of stress. Each modifier makes changes to increase the microhardness to varying degrees. An increase in microhardness is observed on the surface of the coating and its gradual decrease to the transition layer. The surface coating with the additional introduction of bentonite clay in a liquid bath has the highest microhardness. Its microhardness varies from HV-50-1009.7 to HV-50-615.2. Similarly, the effect of the modifying additive of the detonation charge, the microhardness varies from HV-50-969.6 to HV-50-633.26. When clay or a mixture is introduced into the restoration coating, the wear resistance increases by 1.3 - 2 times with respect to the deposited surfacing only by the electrode and by 2 - 3 times to the initial material of the cultivator. It was found that the lowest coefficient is characteristic for dry friction, as well as for hydroabrasive, for samples with additional modification with clay or a detonation charge

scholarly journals Effect of Boron Carbide Addition on Wear Resistance of Aluminum Matrix Composites Fabricated by Stir Casting and Hot Rolling Processes

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 989
Author(s):  
Donghyun Lee ◽  
Junghwan Kim ◽  
Sang-Kwan Lee ◽  
Yangdo Kim ◽  
Sang-Bok Lee ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Boron Carbide ◽  
Hot Rolling ◽  
Rolling Direction ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Aluminum Matrix Composites ◽  
Wear Depth ◽  
Wear Properties ◽  
B4c Particles

In this study, to evaluate the effect of boron carbide (B4C) addition on the wear performance of aluminum (Al), Al6061 and 5, 10, and 20 vol.% B4C/Al6061 composites were manufactured using the stir casting and hot rolling processes. B4C particles were randomly dispersed during the stir casting process; then, B4C particles were arranged in the rolling direction using a hot rolling process to further improve the B4C dispersion and wear resistance of the composites. Furthermore, a continuous interfacial layer between B4C and the Al6061 matrix was generated by diffusion of titanium (Ti) and chromium (Cr) atoms contained in the Al6061 alloy. Wear depth and width of the composites decreased with increasing B4C content. Furthermore, with B4C addition, coefficient of friction (COF) improved as compared with that of Al6061. The results indicate that interface-controlled, well-aligned B4C particles in the friction direction can effectively increase the wear properties of Al alloys and improve their hardness.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

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