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

Laser Sintering of Nano-Al2O3 Powders on Plasma Sprayed Ceramic Based Coatings

2007 ◽  
Author(s):  
Lida Shen ◽  
Yinhui Huang ◽  
Zongjun Tian ◽  
Guoran Hua
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Bond Coat ◽  
Continuous Wave ◽  
Ceramic Coatings ◽  
Laser Sintering ◽  
Al2o3 Ceramic ◽  
Plasma Sprayed ◽  
Steel Substrates

This paper describes an investigation of nano-Al2O3 powders reinforced ceramic coatings, which has included NiCrAl and Al2O3+13%wt.TiO2 coats pre-produced by atmosphere plasma spraying, implemented by laser sintering. Commercial NiCrAl powders were plasma sprayed onto 45 Steel substrates to give a bond coat with thickness of ∼100μm. The 600μm thick Al2O3+13%wt.TiO2 based coating was also plasma sprayed on top of the NiCrAl bond coat. With 2.5kw continuous wave CO2 laser, nano-Al2O3 ceramic powders were laser sintered on the based Coatings. The micro structure and chemical composition of the modified Al2O3+13%wt.TiO2 coatings were analyzed by such detection devices as scanning electronic microscope (SEM) and x-ray diffraction (XRD). Microhardness, wear resistance and corrosion resistance of the modified coatings were also tested and compared with that of the unmodified. The results show that the crystal grain size of Al2O3 had no obvious growth. In addition, due to the nanostructured Al2O3 ceramic phases, the coatings exhibited higher microhardness, better wear resistance and corrosion resistance than those unmodified counterparts. The complex process of plasma spraying with laser sintering as a potential effective way of the application of ceramic nano materials was also simply discussed and summarized in the end.

Tungsten Carbide Dispersed High Cr-Ni Cast Iron Produced by Plasma Spraying

2017 ◽  
Vol 891 ◽  
pp. 565-568
Author(s):  
Yasuhiro Hoshiyama ◽  
Kyouhei Yamaguchi ◽  
Hidekazu Miyake
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Alloy Powder ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Ni Alloy ◽  
Low Pressure Plasma ◽  
Plasma Sprayed ◽  
Carbide Particles

Fe-C-W-Cr-Ni alloy powder in diameter of 32-53 μm made by argon atomization was low-pressure plasma sprayed to produce high Cr-Ni cast iron base deposits with finely dispersed tungsten carbide particles. The as-sprayed deposit produced on a non-cooled substrate was composed of γFe, αFe and carbide. The fine precipitates in the as-sprayed deposit were carbide. With increasing heat treatment temperature up to 1273 K, the carbide particles coarsened. The as-sprayed deposit produced on a non-cooled substrate had higher hardness than the heat-treated deposits. The wear resistance of the as-sprayed deposit produced on a non-cooled substrate was lower than that of heat-treated deposits. The as-sprayed deposit produced on a non-cooled substrate and heat-treated deposits had higher wear resistance than commercial stainless steel.

Compared Study on Laser Cladding and Plasma Spraying of Nuclear Valve Clacks

2007 ◽  
Vol 353-358 ◽  
pp. 890-893
Author(s):  
Chun Liang Zhang ◽  
Li Ping Chen ◽  
Bin He
Keyword(s):  
High Temperature ◽  
Plasma Spraying ◽  
Laser Cladding ◽  
Base Alloy ◽  
Experimental Results ◽  
Temperature Impact ◽  
Electron Microscopes ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Scanning Electron Microscopes

Laser cladding of Co-base alloy on the sealing surfaces of nuclear valve clacks has been performed with a 5KW CO2 transverse flowing laser. The laser cladding was compared with plasma spraying. Both laser cladded and plasma sprayed zones were characterized by optical and scanning electron microscopes. The high temperature impact-slide wear resistance of laser cladded and plasma sprayed coatings were studied. The experimental results showed that compared with that of plasma sprayed coating, the laser cladded coating has higher microhardness, more uniform microstructure, smaller grain size, lower dilution rate, and fewer pores and impurities. The experimental results also showed that the weight loss of plasma sprayed coating during the high temperature impact-slide wear is two times larger than that of laser cladded coating.

Preparation and Properties Study of Laser Cladding of Ni-Based Alloy on Copper

2010 ◽  
Vol 455 ◽  
pp. 216-219
Author(s):  
Y.S. Wang ◽  
F.D. Zhu ◽  
N.W. Liu
Keyword(s):  
Plasma Spraying ◽  
Laser Cladding ◽  
Alloy Coating ◽  
Alloy Layer ◽  
Laser Remelting ◽  
Yag Laser ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
Organization Analysis ◽  
Surface Performance

In order to improve the surface Performance of thick copperplate, A Ni- Cr alloy coating metallurgically bonded onto thick copperplate is performed by YAG laser remelting plasma spraying coating process. In laser cladding processing, it is difficult to get good metallurgical bonding between the layer and copperplate. Plasma spraying technology is developed to get a alloy layer on the surface of thick copperplate, and then using YAG laser cladding method to make a coating. The results of Micro organization analysis indicate that the cladding layer and substrate form favorable metallurgical bonding, as a narrow metallurgical bonding zone, about 3m in thickness. The structure is more compact compared with witch of plasma spraying coating, and the crystal grains are refined grain.

Wear Performance of the Plasma Sprayed Fine WC-Co Composite Powders Coatings

2012 ◽  
Vol 454 ◽  
pp. 144-147
Author(s):  
Lian Wei Yang ◽  
Jin Hui Li ◽  
Yun Dong ◽  
Xiao Ping Lin
Keyword(s):  
Wear Resistance ◽  
Brittle Fracture ◽  
Composite Coating ◽  
Plasma Spraying ◽  
Composite Coatings ◽  
Composite Powders ◽  
Wear Performance ◽  
Wear And Friction ◽  
Plasma Sprayed ◽  
Increasing Load

WC/Co; Composite coating; Plasma spraying; Friction and wear Abstract: WC- Co composite powders were synthesized by direct mechanical grinding in a rotary-vibration mill under 8h, and then analyzed by SEM and XRD. WC and WC/Co composite coatings were prepared by supersonic plasma spraying fine WC-Co composite powders. The wear and friction properties of both coatings were evaluated. The results showed that the wear resistance of the WC/Co composite coating was superior to that of the WC coating. The improvement in wear resistance of the WC/Co composite coating was attributed to its higher fracture toughness and adhesion strength as well as better thermal diffusivity. As for the WC/Co composite coating, the mechanism was mainly adhesion with micro-abrasion and fatigued-induced brittle fracture within splats, and the delamination along splat boundaries only occurred at high load. However, the failure of the WC coating was predominantly detachment of transferred film and brittle fracture within the splats and delamination along splat boundaries, which were enhanced with the increasing load.

Research on Laser Remelting of Plasma Sprayed Ceramic Nanometer Coatings on the Inner Wall of the Cylinder Liner

2014 ◽  
Vol 912-914 ◽  
pp. 301-304
Author(s):  
Jun Yuan Mao ◽  
Wei Gang Zheng
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Composite Ceramic ◽  
Working Environment ◽  
Laser Remelting ◽  
Pressure Shock ◽  
Coating Technology ◽  
Plasma Sprayed

The Cylinder liner is one of the working environment of the worst parts in internal combustion engine ,it is required to have good wear resistance, corrosion resistance, resistance to high temperature and high pressure shock, etc. After tests showed, better comprehensive mechanical properties of cylinder liner is got by using Plasma Spray composite ceramic nanometer coating technology, and after laser remelting treatment.

Preparation and Characterization of Plasma-Sprayed and Laser-Remelted Ni60/Ni-WC Coatings

2014 ◽  
Vol 540 ◽  
pp. 17-20
Author(s):  
Dong Sheng Wang
Keyword(s):  
Laser Power ◽  
Composite Coatings ◽  
Microstructural Characterization ◽  
Matrix Alloy ◽  
Laser Remelting ◽  
Base Matrix ◽  
High Microhardness ◽  
Sprayed Coating ◽  
Plasma Sprayed

In this study, Ni60/Ni-WC composite coatings were first prepared by plasma spraying. Then, the coatings were remelted successively with a CO2 laser. The influences of laser power on the microstructural characterization and microhardness of the coatings were investigated. The results show that the defects of as-sprayed coating like lamellar stacking microstructure and pores were eliminated by laser remelting, and the remelted coating possessed a denser microstructure. With the increase of the laser power, the burning loss and dissolve of the WC particles is increased, while the dilution rate of the coating becomes large. The laser-remelted samples had higher hardness than the as-sprayed one. Laser power has a great impact on the coating and an optimized process parameter is helpful to achieve appropriate melting of WC particles, which leads to retain a high proportion of hard phase in the coating, good combination between the WC particles and Ni-base matrix alloy, and high microhardness.

Effect on Reverse Transferred Arc Treating on Bonding Strength in Low Pressure Plasma Spraying

1996 ◽  
Author(s):  
K. Honda ◽  
I. Chida ◽  
T. Fuse ◽  
T. Murakami ◽  
K.F. Kobayashi
Keyword(s):  
Plasma Spraying ◽  
Bonding Strength ◽  
Low Pressure ◽  
Test Method ◽  
Pressure Plasma ◽  
Low Pressure Plasma ◽  
Transferred Arc ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Low Pressure Plasma Spraying

Abstract Both bonding strength of coating to substrate in low pressure plasma spraying and the effect of reverse transferred arc treating before spraying are studied in this paper. It is difficult to obtain the bonding strength precisely in low pressure plasma spraying by standard testing methods, such as, ASTM Standard C633-79 and JIS H8666-80. Therefore, for the bonding strength test rather than using a conventional adhesive, we believe a vacuum brazing process using Ag-Cu-In-Ti active filler metal at 1023 K should be used. We have also confirmed the practicality of this step. By the above test method, it has been proven that the bonding strength of low pressure plasma sprayed coating is over 100 MPa. Also, that reverse transferred arc treating after blasting enhances the bonding strength of low pressure plasma sprayed coating. It is also believed that the projections formed on the substrate surface by reverse transferred arc treating are buried into the coating and perform the pile effect.

Preparation and Solid Particle Erosion Behaviors of Plasma-Sprayed and Laser-Remelted ZrO2-7wt.%Y2O3 Thermal Barrier Coatings

2012 ◽  
Vol 159 ◽  
pp. 191-197 ◽  
Author(s):  
Dong Sheng Wang ◽  
Zong Jun Tian ◽  
Bin Yang ◽  
Li Da Shen
Keyword(s):  
Solid Particle ◽  
Thermal Barrier Coatings ◽  
Thermal Barrier ◽  
Solid Particle Erosion ◽  
Laser Remelting ◽  
Particle Erosion ◽  
Barrier Coatings ◽  
Erosion Damage ◽  
Sprayed Coating ◽  
Plasma Sprayed

In this study, ZrO2-7wt.%Y2O3 thermal barrier coatings (TBCs) were prepared on TiAl base intermetallic alloy substrates by plasma spraying process. After that, the plasma-sprayed TBCs were laser remelted using a CO2 laser. Influences of laser remelting on the microstructure and solid particle erosion characterization of the coatings were researched. Meanwhile, the erosion damage modes of the two types of TBCs were discussed. The results show that the as-sprayed TBC has a typical lamellar stacking characteristic. The lamellar defect of the plasma-sprayed coating is erased, and the compactness of the coating is improved significantly after laser remelting. The laser-remelted coating consists of column-like crystals along the direction of the heat current. The laser-remelted coating had better erosion resistance than the as-sprayed coating. Owing to the limited bonding at the interfaces between lamellar, the spalling of the sprayed splats from the lamellar interface is mainly attributed to the erosion failure of the as-sprayed coating. In addition, crushing of brittle ceramic coating is also responsible for the erosion damage of the plasma-sprayed TBC. In contrast, cracking occurs within region near the surface of the laser-remelted layer and that erosion occurs mainly by removal of these small blocks. Moreover, the laser-remelted has evident mciro-cutting marks and shows some ductile erosion characteristic.

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