Influence of copper content on wear behavior of composites “steel ShKh15/copper” at sliding against copper under electric current of contact density higher than 100 A/cm2

2019 ◽  
pp. 88-95
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin
Keyword(s):  
Current Density ◽  
Wear Behavior ◽  
Pore Space ◽  
Bearing Steel ◽  
Powder Steel ◽  
High Wear Resistance ◽  
Steel Shkh15 ◽  
Contact Density ◽  
Sliding Electric Contact ◽  
Powder Composites

Powder composites “steel ShKh15/copper” in alumina ceramics and graphite powders surrounding were sintered in the air. Powder steel was restored from grinding slime of bearings production. It is shown that the steel framework has low level of mechanical properties, but high pore space percolation. Copper concentration increases isolated pores concentration impeding oil impregnation. This effect did not allow making the long and steady sliding electric contact with contact current density higher than 150 A/cm2. The sintered composites based on recycled bearing steel and containing near 15%Cu show high wear resistance at sliding with a contact current density 150–200 A/cm2 under boundary lubrication.

Effects of structural inhomogeneities on the steel balls resistance to loading

2020 ◽  
pp. 29-38
Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
L. A. Krivina ◽  
S. V. Kirikov ◽  
S. I. Gerasimov ◽  
...  
Keyword(s):  
Brittle Fracture ◽  
Bearing Steel ◽  
Metallographic Analysis ◽  
Structural Factors ◽  
Steel Shkh15 ◽  
Maximum Hardness ◽  
High Shock ◽  
Steel Balls ◽  
Plasticity Coefficient ◽  
Microstructure Of The Material

When conducting impact tests of protective glasses, nonunique cases of destruction of balls made of bearing steel ShKh15 were recorded. The causes of their destruction were determined. The state of the material was studied by fractographic and metallographic analysis, hardness and microhardness measurement. In the structure of the metal of all the balls, no critical defects were found such as flockens, shells and microcracks, but adverse factors were detected in the microstructure of the material, namely, the presence of fineneedle martensite with excessive carbides. It is established that the detected structural factors lead to liability to brittle fracture, an increase in the hardness of the material, a decrease in plasticity. To prevent brittle fracture of the balls and provide a reserve of plasticity of steel ShKh15 at high shock loads assessment calculations of ductility coefficient were made; and it was recommended to limit the maximum hardness of the material critical value HV=5.70 HPa (54 HRC), with the corresponding plasticity coefficient equal to 0.8.

THE WEAR BEHAVIOR OF BRUSH-PLATED Ni-W-Co/SiC COMPOSITE LAYER WITH OIL LUBRICATION

2005 ◽  
Vol 12 (04) ◽  
pp. 573-578
Author(s):  
JIANG XU ◽  
WENJIN LIU
Keyword(s):  
Wear Behavior ◽  
Profile Analysis ◽  
Composite Layer ◽  
High Wear Resistance ◽  
Oil Lubrication ◽  
Average Size ◽  
1045 Steel ◽  
Worn Surface ◽  
Xrd And Tem ◽  
Laser Profile

The wear behavior of brush-plating a Ni-W-Co/SiC composite layer on 1045 steel with oil lubrication is investigated. The composite layer is determined by OM, XRD and TEM. The worn surface of the plated layer is observed with SEM and laser profile analysis. The composition and average size of worn debris are analyzed by means of ferrograph and fluid spectrum. The results show that the brush-plated composite layer with added SiC particles reveals high wear resistance compared to the Ni-W-Co brush-plated layer.

Investigation of friction and wear behavior of hydroxyl-functionalized graphene nanoplatelets filled elastomer nanocomposites

2021 ◽  
pp. 146442072110616
Author(s):  
Hasan Kasim ◽  
Adem Onat ◽  
Barış Engin ◽  
İsmail Saraç
Keyword(s):  
Wear Rate ◽  
Tribological Properties ◽  
Wear Behavior ◽  
Normal Load ◽  
Graphene Nanoplatelets ◽  
Rubber Matrix ◽  
High Wear Resistance ◽  
Homogeneous Distribution ◽  
Functionalized Graphene ◽  
Sealing Elements

The use of unfilled pure elastomer parts is limited in friction wheels, roller tires, sealing elements, and dynamic friction air suspension applications requiring high wear resistance. This study investigates the mechanical and tribological properties of new nanocomposites obtained by adding hydroxyl-functionalized graphene nanoplatelets at 1, 4, and 8 phr (parts per hundred rubber) ratios to the carbon black filled main rubber compound of sealing elements designed for axle hubs. The synergistic effect of nanofiller materials on the wear behavior of nanocomposites was tested with a block-on-ring wear tester under dry sliding conditions at 1000 rpm and 15 N normal load conditions. The worn surfaces were examined with scanning electron microscopy and circularly polarized light–differential interference contrast topology microscopy to reveal the wear mechanism. The addition of functionalized graphene nanoplatelets to the nanocomposite compound caused significant changes in tensile strength and elongation values by changing the cross-link density. The wear rate of nanocomposites prepared with graphene nanoplatelets at 1, 4, and 8 phr ratios was 11.15%, 25.24%, and 36.54% lower than the main rubber mixture used, respectively. While the hysteresis loss decreased by 14.83% at 1 phr, this value increased in other filler ratios. Significant differences in temperature change occurred as the amount of filler increased. After the test, the temperature values of nanocomposites with 1 and 4 phr filler ratios were between about 85–89°C, while it was measured as 99°C in nanocomposites with 8 phr filler ratios. It has been observed that the homogeneous distribution of two-dimensional carbon allotropes such as graphene nanoplatelet added to the rubber matrix at the optimum rate will improve tribological properties such as better surface lubrication, low wear rate, and low friction coefficient.

Effect of Repeated Quenching on the Rotating Bending Strength of SAE52100 Bearing Steel

2012 ◽  
Vol 457-458 ◽  
pp. 1025-1031 ◽  
Author(s):  
Koshiro Mizobe ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
Katsuyuki Kida ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Bending Strength ◽  
High Strength ◽  
Bearing Steel ◽  
Rolling Contact ◽  
High Wear Resistance ◽  
High Carbon ◽  
Austenite Grain ◽  
High Fatigue ◽  
Rotating Bending

Martensitic high carbon high strength SAE 52100 bearing steel is one of the main alloys used for rolling contact applications where high wear resistance are required. Due to its high fatigue strength, SAE 52100 is recently being used not only for the production of bearings but also shafts. Refining of prior austenite grain through repeated quenching is a procedure that can be used to enhance the material’s strength. In this work, the microstructure of repeatedly quenched SAE 52100 steel and its fatigue strength under rotating bending were investigated. It was found that repeated furnace heating and quenching effectively refined the martensitic structure and increased the retained austenite content. Repeated quenching was found to improve the fatigue strength of SAE 52100.

The effect of electroplating current density on microstructure, corrosion, and wear behavior of Ni–P–W–TiO2 coating

2021 ◽  
Vol 112 (6) ◽  
pp. 474-485
Author(s):  
Sajjad Sadeghi ◽  
Hadi Ebrahimifar
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Micro Hardness ◽  
Aisi 304L

Abstract The use of ceramic particles in the matrix of alloy coatings during the electroplating process has received considerable attention. These particles can create properties such as high corrosion resistance, insolubility, high-temperature stability, strong hardness, and self-lubrication capability. Herein, an Ni–P–W–TiO2 coating was deposited on an AISI 304L steel substrate using the electroplating method. Electroplating was performed at current densities of 10, 15, 20, and 25 mA · cm–2, and the effect of current density on microstructure, corrosion behavior, and wear behavior was investigated. The coatings were characterized by means of scanning electron microscopy. To investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed in a 3.5% NaCl aqueous solution. A pin-on-disk test was conducted to test the wear resistance of uncoated and coated samples. Sample micro-hardness was also measured by Vickers hardness testing. Examination of the microstructure revealed that the best coating was produced at a current density of 20 mA · cm–2. The results of potentiodynamic polarization and electrochemical impedance spectroscopy tests were consistent with microscopic images. The coating created at the current density of 20 mA · cm–2 had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the wear test showed that increasing the current density of the electroplating path up to 20 mA · cm–2 enhances micro-hardness and wear resistance.

Phase, microstructure, and wear behavior of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites

2019 ◽  
Vol 234 (3) ◽  
pp. 467-480
Author(s):  
Akash Saxena ◽  
Neera Singh ◽  
Bhupendra Singh ◽  
Devendra Kumar ◽  
Kishor Kumar Sadasivuni ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Metal Matrix ◽  
Alloy Composition ◽  
Wear Behavior ◽  
High Hardness ◽  
Industrial Applications ◽  
High Wear Resistance ◽  
Wear Properties ◽  
Metal Matrix Nanocomposites ◽  
Matrix Nanocomposites

In the present work, phase, microstructure, and wear properties of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites have been studied. Composites using 2 wt.% and 5 wt.% of Si and rest Fe powder mix were synthesized via powder metallurgy and sintered at different temperature schedules. Iron–silicon alloy specimens were found to have high hardness and high wear resistance in comparison to pure iron specimens. Addition of 5 wt.% and 10 wt.% alumina reinforcement in Fe–Si alloy composition helped in developing iron aluminate (FeAl2O4) phase in composites which further improved the mechanical properties i.e. high hardness and wear resistance. Formation of iron aluminate phase occurs due to reactive sintering between Fe and Al2O3 particles. It is expected that the improved behavior of prepared nanocomposites as compared to conventional metals will be helpful in finding their use for wide industrial applications.

Dry Sliding Wear Behavior of the Reinforced by Graphite Particle and Heat Treated of Recycled Aluminum AA6061 Based MMC Fabricated by Powder Metallurgy Method

2017 ◽  
Vol 740 ◽  
pp. 9-16
Author(s):  
Ahmed Sahib Mahdi ◽  
Mohammad Sukri Mustapa ◽  
Mahmod Abd Hakim Mohamad ◽  
Abdul Latif M. Tobi ◽  
Muhammad Irfan Ab Kadir ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Powder Metallurgy ◽  
Compression Strength ◽  
Sliding Wear ◽  
Wear Behavior ◽  
High Wear Resistance ◽  
Dry Sliding Wear ◽  
Powder Metallurgy Method ◽  
Heat Treated ◽  
Improvement Ratio

The micro-hardness and compression of recycling aluminum alloy AA6061 were investigated as a function of the different microstructure and constituent powder metallurgy method. Five specimens were selected to investigate the compression strength and microhardness. The first, as fabricated specimen (as compacted), the second was as heat treated by quenching and aging process. Three specimens were mixed with Graphite particles as a reinforcement material. Compression strength values were tested for the specimens as fabricated and heat treated which were 195 and 300 MPa, respectively. The improvement ratio was 52% for the specimen as heat treated. On the other hand, high wear resistance was given by the specimen as heat treated, whereas, the lower wear strength was at the specimen mixed with 4.5% Graphite. These results were attributed to that the wear resistance related to the microhardness value.

scholarly journals Laser alloying of bearing steel with boron and self-lubricating addition

2016 ◽  
Vol 36 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Mateusz Kotkowiak ◽  
Adam Piasecki ◽  
Michał Kulka
Keyword(s):  
Wear Resistance ◽  
Calcium Fluoride ◽  
High Hardness ◽  
Bearing Steel ◽  
Operating Conditions ◽  
High Wear Resistance ◽  
Laser Alloying ◽  
Amorphous Boron ◽  
Rolling Bearings ◽  
Borided Layer

Abstract 100CrMnSi6-4 bearing steel has been widely used for many applications, e.g. rolling bearings which work in difficult operating conditions. Therefore, this steel has to be characterized by special properties such as high wear resistance and high hardness. In this study laser-boriding was applied to improve these properties. Laser alloying was conducted as the two step process with two different types of alloying material: amorphous boron only and amorphous boron with addition of calcium fluoride CaF2. At first, the surface was coated with paste including alloying material. Second step of the process consisted in laser re-melting. The surface of sample, coated with the paste, was irradiated by the laser beam. In this study, TRUMPF TLF 2600 Turbo CO2 laser was used. The microstructure, microhardness and wear resistance of both laser-borided layer and laser-borided layer with the addition of calcium fluoride were investigated. The layer, alloyed with boron and CaF2, was characterized by higher wear resistance than the layer after laser boriding only.

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