scholarly journals Microstructure and Wear Resistance of TIG Remelted NiCrBSi Thick Coatings

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Guo-lu Li ◽  
Ya-long Li ◽  
Tian-shun Dong ◽  
Hai-dou Wang ◽  
Xiao-dong Zheng ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Plasma Spraying ◽  
Steel Substrate ◽  
The Self ◽  
Thick Coating ◽  
Sprayed Coating ◽  
Thick Coatings ◽  
Aisi1045 Steel ◽  
Nicrbsi Coatings

The self-fluxing NiCrBSi coatings with 800 μm thickness were prepared on the surface of AISI1045 steel substrate by plasma spraying. And the remelted coating was obtained using by the tungsten inert gas (TIG) arc process. The microstructure, surface roughness, hardness, phase composition, and wear resistance of the sprayed coating and remelted coating were systematically investigated. The results demonstrate that TIG remelted treatment can significantly eliminate the microscopic defects in thick coating and improve its density. The surface roughness (Ra) of the remelted coating is only 18.9% of the sprayed coating. The hardness of the remelted coating is 26.8% higher than that of the sprayed coating. The main phases in the sprayed coating are changed from γ-Ni, Cr7C3, and Cr2B to γ-Ni, Cr23C6, CrB, Ni3B, and Fe3C. The wear mass loss of the remelted coating is only 17.1% of the sprayed coating. Therefore, a Ni-based thick coating with good wear resistance can be obtained by plasma spraying and remelted technique.

Wear properties of WC–Co and WC–CoCr coatings applied by HVOF technique on different steel substrates

2020 ◽  
Vol 62 (12) ◽  
pp. 1235-1242
Author(s):  
Hatice Varol Ozkavak ◽  
Serife Sahin ◽  
Mehmet Fahri Sarac ◽  
Zehra Alkan
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Steel Substrate ◽  
Wear Properties ◽  
Sem Images ◽  
Steel Alloys ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Aisi 4340

Abstract Low alloy and stainless steel are the most used types of iron-based materials world wide. Their use against in machine element work, reclamation, corrosion and wear resistance are still challenging. To overcome this problem, many steel alloys are coated with cermet coatings to protect the parts from wear and corrosion. In the present study, WC-Co and WC-CoCr coatings were applied by means of a high velocity oxy-fuel (HVOF) technique on AISI 304, AISI 1040, and AISI 4340 steel alloys used as substrates. The aim was to investigate surface properties and wear resistance of the coatings and to determine their relationship with the type of coating and substrate. In accordance with this purpose, hardness and thickness of the coatings were measured, sliding wear tests were performed, scanning electron microscope (SEM) images and X-ray diffractions (XRD) were taken, surface roughness and friction coefficients were determined. The results showed that the WC-CoCr coatings had higher hardness and lower thickness than the WC-Co coatings. Maximum hardness was obtained in the WC-CoCr coating applied to AISI 4340 steel, which was also the hardest alloy among those studied. After wear resistance tests, it was revealed that the wear resistance of the WC-CoCr coatings was better than that of the WC-Co coatings for each steel substrate. During the coating, the new phases resulting from the decomposition of the WC phase in the WC-CoCr coatings contributed more to wear resistance than those of the WC-Co coatings. A lower friction coefficient and lower surface roughness of the WC-CoCr coatings during wear were obtained, resulting in higher wear resistance. A WC-CoCr coating on AISI 4340 alloy which has the highest hardness, lowest surface roughness and lowest friction coefficient resulted in the highest wear resistance among all types studied.

Abrasive Wear Resistance of Recycled Hardmetal Reinforced Thick Coating

2012 ◽  
Vol 527 ◽  
pp. 185-190 ◽  
Author(s):  
Priit Kulu ◽  
Riho Tarbe ◽  
Arkadi Žikin ◽  
Heikki Sarjas ◽  
Andrei Surženkov
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Metal Matrix ◽  
Abrasive Wear Resistance ◽  
Low Velocity ◽  
Wheel Wear ◽  
Hvof Spraying ◽  
Thick Coating ◽  
The Cost ◽  
Thick Coatings

The aim of the current study was to elaborate and compare abrasive wear resistance of thick coatings deposited with different hardfacing technologies. To produce metal matrix composite (MMC) coatings commercial iron and nickel based powders with recycled hardmetal content of 40 vol. % were studied. For deposition technologies plasma transferred arc (PTA) hardfacing, high-velocity oxy-fuel (HVOF) spraying were used. The microstructure of produced thick coatings was examined, including the distribution of hard phase and homogeneity of metal matrix. Micromechanical properties, including hardness and elastic modulus of features were measured by universal hardness measurements. Furthermore, behavior of coatings subjected to abrasive rubber-wheel wear (ARWW) and impact wear (AIW) tests were studied. Wear resistance of experimental PTA hardfacings at low velocity ARWW and AIW tests notably exceeds that of HVOF sprayed coatings. Wear mechanism dominating at abrasive wear in most cases is the removal of metal matrix due to lower hardness. Assignment of hardmetal waste as initial material can significantly decrease the cost of production, improve the mechanical characteristics of coatings and consequently increase their wear resistance. Results indicate, that the choice of matrix for the same reinforcements can also be as an important factor for combating abrasive wear. Fe-based thick coating, produced by PTA is more wear resistant compared to the Ni-based ones.

Study on Wear Resistance of Plasma Sprayed Coating Remelted by Laser

2008 ◽  
Vol 373-374 ◽  
pp. 392-395
Author(s):  
Y.J. Liu ◽  
Y.S. Wang ◽  
Xi Chen Yang
Keyword(s):  
Wear Resistance ◽  
Plasma Spraying ◽  
Alloy Powder ◽  
Laser Remelting ◽  
Large Area ◽  
Surface Appearance ◽  
Organization Analysis ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Spraying Method

In order to improve the wear resistance of the surface of thick copperplate, a coating of alloy powder is produced on the surface of the thick copperplate with the method of laser remelting plasma sprayed coating. The value simulation of temperature and the experimental results show that, it is difficult to produce ferronickel coating with large area and crackfree on thick copperplate for laser cladding technique. Using transsonic plasma heat spraying method to fix the alloy powder on the surface of thick copperplate, a sprayed coating can be produced, which has certain adhesion strength to the copperplate. In order to prevent crack produced in large area laser remelting coating, a method with band-like and point-like remilting area at intervals of same distance has been taken. The surface appearance and roughness of the coating produced by plasma spraying are compared with that of the coating produced by plasma spraying and remelted by laser, micro organization analysis and wear resistance comparison experiments are taken to the specimen. The microstructure photos show that the coating of the plasma heat sprayed is mainly made up by grains, with a great deal of pores existing. After laser remelting, microstructure of the coating is more compact, and the most of pores disappeared, so the strength of the boundary between the remelted coating and the copperplate is build up and the coating with large area and crackfree on thick copperplate is performed by the method of laser remelting plasma spraying coating in large amount of point-like remilting areas The experiment result shows that the wear resistance of laser remelting plasma heat sprayed coating enhances 3 times more than That of the unremelt coating, and about 14 times compared with the copperplate, and the wear resistance of the surface with point-like laser remelting area is between that of plasma heat sprayed coating and that of the laser remelting coating, it depends on the ratio of the remelted part to the whole in area, however, the wear resistance increases with the value of the ratio

Microstructure Control of Zirconia Thermal Barrier Coatings by Using YAG Laser Combined Plasma Spraying Technique

1997 ◽  
Author(s):  
Z. Zhou ◽  
N. Eguch ◽  
A. Ohmori
Keyword(s):  
Laser Irradiation ◽  
Plasma Spraying ◽  
Steel Substrate ◽  
Thermal Barrier ◽  
Zirconia Coating ◽  
Yag Laser ◽  
Barrier Coating ◽  
Irradiation Treatment ◽  
Coating Microstructure ◽  
Sprayed Coating

Abstract As an ideal zirconia thermal barrier coating, the coating microstructure with the strong bonding among coating particles and with certain amount porosities in the coating without connected porosity is desirable. However, it is difficult for usual plasma-spraying to create a zirconia coating with these characters. In order to obtain an excellent zirconia coating with these characters, we prepared zirconia coating on steel substrate under coated with NiCrAlY alloys by means of a hybrid spraying (that is, YAG laser combined plasma spraying) and studied the effect of this hybrid spraying process and plasma and laser conditions on the microstructure of coating, and further compared the microstructure of the coating in this hybrid spraying with that in post-laser irradiation of as-sprayed zirconia coating. It is known that the microstructure with densification is formed by the post-laser irradiation of as-sprayed coating and that microcracks are newly produced in the process of rapid cooling. However, by using this newly-developed hybrid spraying, the microstructure with partial densification in the coating without connected porosities was formed and cracks which is generally produced in the post-laser irradiation treatment were inhibited completely. In addition, this hybrid spraying can be done without the post-treatment of coating. Furthermore, the coating properties, such as hardness and wear resistance associated with bonding state among the coating particles in the zirconia coating created by this hybrid spraying were improved.

scholarly journals EFFECTS OF ALUMINUM PHOSPHATE CONTAINING Al2O3 NANOPARTICLES ON THE MECHANICAL PROPERTIES OF THE Al2O3-TiO2 PLASMA SPRAYED COATING

2017 ◽  
Vol 55 (6) ◽  
pp. 698
Author(s):  
Pham Thi Ha ◽  
Pham Thi Ly ◽  
Nguyen Van Tuan ◽  
Vo An Quan ◽  
Le Thu Quy
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Aluminum Phosphate ◽  
Phosphate Solution ◽  
Al2o3 Nanoparticles ◽  
Study Results ◽  
Composition Structure ◽  
Sprayed Coating

In the present study, Al2O3-40% TiO2 composite coatings were fabricated on CT3 steel substrate by plasma spraying technique. The coatings were sealed with aluminum phosphate solution contained 5 wt.% Al2O3 nanoparticles and then heat treated at 400oC. The permeability of aluminum phosphate solution, phase composition, structure morphology, microhardness and wear resistance of the coating were studied. The study results phase composition of the coatings showed that the coatings were composed γ-Al2O3 and Al2TiO5 phase. The compounds AlPO4 and Al(PO3)3 were found in the coating sealed with aluminum phosphate. The presence of Al2O3 nanoparticles was increased the permeability of the aluminum phosphate solution into the coating. The coatings sealed  with aluminum phosphate contained Al2O3 nanoparticles have lower density, higher hardness and wear resistance higher than the coating sealed with aluminum phosphate uncontain Al2O3 nanoparticles and the unsealed coating.

scholarly journals Increase of wear resistance of crankshafts of timber transport machines

2021 ◽  
Vol 875 (1) ◽  
pp. 012062
Author(s):  
K A Yakovlev ◽  
A V Latynin
Keyword(s):  
Wear Resistance ◽  
Plasma Spraying ◽  
Technological Process ◽  
Regression Equations ◽  
Application Process ◽  
Properties Of Coatings ◽  
Sprayed Coating ◽  
Two Parameters ◽  
Sprayed Coatings ◽  
Separate Regression

Abstract The paper considers the technological process of restoration of crankshaft necks by plasma spraying with wear-resistant thermoreacting powder PG-NA80. Wear of the crankshaft necks during operation requires repair, restoration or replacement of this part. As a result of the literature analysis, plasma spraying was found to be the most optimal and relatively inexpensive method of crankshaft recovery. The purpose of our work is to investigate the wear resistance properties of the sprayed coating and the search for op-optimal parameters of its application process. The sprayed coatings were studied according to two parameters: joint strength and wear resistance. For the study, experimental equipment of the plasma spraying laboratory of the department was used. As a result of the experimental study, separate regression equations of the effect of the main factors of plasma spraying on relative wear resistance were obtained. A comparison of physical, mechanical and tribotechnical characteristics showed an improvement in the properties of coatings by 8-12% obtained from thermoreacting powder in comparison with traditional PGSR-4 and PN55T45. Analysis of the obtained research results showed that this technological process can be effectively used to restore worn out crankshafts of forestry vehicles.

scholarly journals Investigation of Multiparameter Laser Stripping of AlTiN and DLC C Coatings

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 951
Author(s):  
Tomáš Primus ◽  
Josef Hlavinka ◽  
Pavel Zeman ◽  
Jan Brajer ◽  
Martin Šorm ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Efficiency ◽  
Steel Substrate ◽  
Cutting Tools ◽  
High Hardness ◽  
Working Time ◽  
Nanosecond Laser ◽  
Altin Coating ◽  
Successful Removal ◽  
Frequency Laser

The lifetime and properties of cutting tools and forming moulds can be prolonged and enhanced by the deposition of hard, thin coatings. After a certain period of usage, the coating will deteriorate. Any remaining coating must be removed prior to successful recoating. Laser stripping is a fast and environmentally friendly coating removal method. In this paper, we present laser removal of two types of coatings deposited on a 1.2379 tool steel substrate, namely, an AlTiN coating with high hardness and a DLC C coating with a small coefficient of friction (COF). A powerful nanosecond laser was employed to remove the coating from the substrate with high efficiency, along with suitable residual surface roughness. Measurements were taken of surface roughness, removed depth, and working time on a stripped area of 1 cm2. The samples were evaluated under a microscope, with a 3D profilometer, and by EDS chemical analysis. Successful removal of the coating was confirmed by optical analysis, but detailed chemical characterisation showed that about 30% of the coating element may remain on the surface. Moreover, a working time of less than 7.5 s per cm2 was obtained in this study. In addition, it was shown that the application of a second low energy, high frequency laser beam pass leads to remelting of the peaks of the material and reduced surface roughness.

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