scholarly journals Influence of Graphene Sheet on Microstructure and Properties of Ni-based Alloy Coatings Prepared by Laser Cladding

2019 ◽  
Vol 25 (3) ◽  
pp. 252-258
Author(s):  
Geng TIANYUAN ◽  
Cunshan WANG
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Graphene Sheet ◽  
Laser Cladding ◽  
Steel Substrate ◽  
Diffusion Reaction ◽  
Forming Quality ◽  
Volume Fractions ◽  
Microstructure And Properties ◽  
Cladding Layers

Ni-based alloy cladding layers with different graphene sheet additions were prepared by laser cladding on the 40CrNi2Si2MoV steel substrate. The influence of the graphene sheet on the microstructure and properties of the cladding layers was investigated. The results show that owing to the diffusion-reaction dissolution, the graphene sheet addition does not bring a corresponding change in the phase constitutions of the cladding layers, i. e., the cladding layers are still composed of γ-Ni, Ni3B, and M7C3 phases. But what has changed is that the solidified structure is refined, and the volume fractions of the eutectic and the carbide are increased with the increase of graphene sheet addition. As a result, the hardness and the wear resistance of the cladding layers gradually increase, whereas the friction coefficient firstly decreases and then increases, with the lowest friction coefficient obtained at 0.5 vol.% graphene sheet addition. Compared to the Ni-based alloy cladding layers with micro-size graphite additions, the studied cladding layers exhibit improved hardness and wear resistance, good forming quality, and increased friction coefficient. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19173

Study on Laser Cladding Coatings of Ni-Based Alloy/TiC/Nickel-Coated Graphite on Steel Substrate

2010 ◽  
Vol 450 ◽  
pp. 214-218 ◽  
Author(s):  
Li Xia Ying ◽  
Li Dong Jiang ◽  
Fan Kai Kong ◽  
En Xia Yang
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Laser Cladding ◽  
Metal Surfaces ◽  
Steel Substrate ◽  
Extreme Conditions ◽  
Cross Sectional ◽  
Graphite Composite ◽  
Forming Mechanism ◽  
Uniform Microstructure

In order to improve the antiwear and antifriction performances of tribological metal surfaces for the extreme conditions, the composite coating has been fabricated on metal surfaces by the technology of laser cladding. In the experiment, Ni-based alloy, TiC and Nickel-coated graphite are used as the main ingredients of composite. The cross-sectional macrographs, microstructure, compositions, microhardness, tribological properties and the forming mechanism of the coating was tested and analyzed. Results show that laser cladding Ni60A/TiC/Nickel-coated graphite composite can obtain excellent coating with fully compact and uniform microstructure, and good interface with the substrate. The microhardness of the clad coating is over HV1000, which is five times higher than that of the steel substrate. The friction coefficient is reduced to about 0.4-0.5 in comparison with that of the steel substrate (about 0.7-0.8). At the same time, the wear resistance of the clad coating is also improved greatly.

scholarly journals Wear Properties of TiC-Reinforced Co50 Composite Coatings from Room Temperature to High Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Nga Thi-Hong Pham ◽  
Van-Thuc Nguyen
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Laser Cladding ◽  
Wear Mechanism ◽  
Room Temperature ◽  
Steel Substrate ◽  
Composite Coatings ◽  
H13 Steel ◽  
Fatigue Wear ◽  
Wear Rates

In this paper, the laser cladding is created by using Co50 powder and TiC mixture, covering a H13 hot-working steel substrate. The samples are analyzed by the hardness test, XRD, SEM, and friction test to identify the forming phases, microhardness distribution, and wear-resistant characteristics. The results indicated that hardness reduces from the coating zone to the substrate, achieving the highest value at the coating zone. Increasing the content of TiC results in improving the coating hardness. The coatings with 10%–20% TiC show high-quality surface morphology and macrograph. With 30% TiC, the hardness obtains a higher hardness, but the surface appears to crack. The microstructures of the coatings present a well-mixed and well-distribution of the TiC particle on the Co matrix. The friction coefficient of H13 steel and Co50 coating reaches the maximum value when the load is 50 N and mostly decreases with the increase in the load. The wear rates of H13 steel and Co50 coatings mainly increase with the increase in the load. The temperature has a greater influence on the friction coefficient of the Co50 coating. However, the temperature has a small effect on the friction coefficient of the 20% TiC coating. The wear resistance of 20% TiC coating is higher than that of H13 steel, Co50 coating, and 10% TiC composite coating. At room temperature, the wear mechanism of the coating is mainly brittle spalling, adhesive wear, and ploughing. At 700°C, the wear mechanism is mostly oxidation wear and fatigue wear. After laser cladding, the service life of the coated surface could be greatly improved. The Co + 20% TiC coating has high hardness and wear resistance.

Fabrication of SiC Particulates Reinforced MoSi2 Composite Coating by Laser Cladding

2008 ◽  
Vol 373-374 ◽  
pp. 304-307
Author(s):  
Sen Yang ◽  
Ming Run Wang ◽  
Tao Gong ◽  
Wen Jin Liu
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Continuous Wave ◽  
Steel Substrate ◽  
Laser Output Power ◽  
Scanning Velocity ◽  
Sic Particulates ◽  
Metallurgical Bond ◽  
Improve Wear Resistance

In order to improve wear resistance of carbon steel, laser cladding experiments were carried out using a 3kW continuous wave CO2 laser. The diameter of the laser beam was 3-5mm, the scanning velocity was 3-10mm/s, and the laser output power was 1.0-1.3kW. The experimental results showed that MoSi2/SiCP composites coating could be in-situ synthesized from mixture powders of molybdenum, silicon and SiC by laser cladding. A good metallurgical bond between the coating and the substrate could be achieved. The microstructures of the coating were mainly composed of MoSi2, SiC and FeSiMo phases. The average microhardness of the coating was about HV0.21300, about 6.0 times larger than that of steel substrate.

scholarly journals Influence of nano-SiO2 on the bonding strength and wear resistance properties of polyurethane coating

2019 ◽  
Vol 26 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Fangfang Wang ◽  
Lajun Feng ◽  
Huini Ma ◽  
Zhe Zhai ◽  
Zheng Liu
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Composite Coating ◽  
Network Structure ◽  
Bonding Strength ◽  
Coating Layer ◽  
Steel Substrate ◽  
Polyurethane Coating ◽  
Nano Sio2

Abstract To improve the wear resistance of polyurethane (PU) coating and its adhesion to the steel substrate, a series of simple and practicable techniques were designed to mix nano-SiO2 with PU powder to cast a coating layer onto the steel. When the addition of nano-SiO2 was small, a network structure of PU-SiO2 was produced. It improved the wear resistance of the composite coating and its adhesion to the steel substrate. When the addition of nano-SiO2 was excessive, agglomerated nano-SiO2 particles not only affected the bond between the PU resin and the steel substrate but also became abrasive materials, intensifying the abrasion of the composite coating during friction. It resulted in lower bonding strength and poorer wear resistance of the composite coating. The wear rate and friction coefficient of 2 wt.% SiO2/PU composite coating were 1.52×10−6 cm3/min N and 0.31, respectively. Its wear resistance was about 10 times as high as that of the pure PU coating. Furthermore, a simple and practicable installation was designed to test the bonding strength between the coating and the steel substrate. The bonding strength between 2 wt.% SiO2/PU composite coating and the steel substrate was 7.33 MPa, which was 39% higher than that of the pure PU coating.

scholarly journals Effect of High−Speed Powder Feeding on Microstructure and Tribological Properties of Fe−Based Coatings by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Qiang Wang ◽  
Runling Qian ◽  
Ju Yang ◽  
Wenjuan Niu ◽  
Liucheng Zhou ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
High Speed ◽  
High Efficiency ◽  
Adhesive Wear ◽  
Steel Substrate ◽  
Powder Materials ◽  
Powder Feeding

In order to improve the wear resistance of 27SiMn steel substrate, Fe−based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high−speed powder feeding (HF) process was used to prepare Fe−based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X−ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe−based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high−speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high−efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.

scholarly journals Effect of Heat Treatment on Microstructure and Tribocorrosion Performance of Laser Cladding Ni-65 WC Coating

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ze Liu ◽  
Eryong Liu ◽  
Shuangming Du ◽  
Congwei Li ◽  
Huiling Du ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Laser Cladding ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Bonding Layer ◽  
Wear Performance ◽  
Comprehensive Comparison ◽  
Cladding Layers

The Ni-65wt%WC cladding layers were prepared on the surface of Q235 using laser cladding technology, in which the effect of heat treatment on microstructure and tribocorrosion performance was investigated. The results showed that the coating is mainly consisted of Ni, WC, and W2C, and a significant diffusion phenomenon is formed between the interfaces of WC/Ni matrix, benefited for the improvement of bonding layer between WC/Ni-based matrixes. Meanwhile, the crystallization of WC particles after heat treatment was more obvious than untreatment; the Ni matrix grain size was also grown remarkable, leading to the lower hardness and weaker plastic deformation resistance of Ni-65wt%WC coating. And the erosion results showed that the wear rate of coating gradually decreased with heat treatment temperature increasing, while brittle WC was not suitable for high impact wear conditions. Furthermore, with the increase of heat treatment temperature, the reciprocating wear performance showed that the friction coefficient and wear rate of Ni-65wt%WC coating decreased. And the friction coefficient and wear rate of the coating (700°C) in 3.5% NaCl solution were 0.15 and 4.82×10−8 mm3·N-1·m-1, respectively. Therefore, the comprehensive comparison showed that Ni-65WC coating had better performance in low impact reciprocating testing under corrosion environment, and heat treatment was helpful to further improve the tribocorrosion performance of laser cladding Ni-65wt%WC coating.

Wear Resistance of Laser Cladded NiCrFeSiB Self-Fluxing Composite Coatings

2016 ◽  
Vol 254 ◽  
pp. 290-295
Author(s):  
Iosif Hulka ◽  
Ion Dragoş Uţu ◽  
Viorel Aurel Şerban ◽  
Alexandru Pascu ◽  
Ionut Claudiu Roată
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Wear Behavior ◽  
Protective Coatings ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Base Material ◽  
Laser Cladding Process ◽  
Metallurgical Bond ◽  
Feedstock Material

Laser cladding process is used to obtain protective coatings using as heat source a laser. This melts the substrate and the feedstock material to create a protective coating and provides a strong metallurgical bond with minimal dilution of the base material and reduced heat affected zone. In the present study a commercial NiCrSiFeB composition was deposited by laser cladding process using different parameters onto the surface of a steel substrate. The obtained coatings were investigated in terms of microstructure, hardness and wear behavior. The experimental results revealed that the laser power had a considerable influence on the wear resistance of NiCrSiFeB coatings.

Microstructure and Properties of Laser Cladding Co-Based Alloy Layer

2013 ◽  
Vol 764 ◽  
pp. 47-53 ◽  
Author(s):  
X.R. Zhao ◽  
Dun Wen Zuo ◽  
H. Cheng ◽  
Q.T. Li ◽  
S. Dai ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Base Alloy ◽  
Steel Substrate ◽  
Alloy Layer ◽  
Crystal Layer ◽  
X Ray Diffraction ◽  
Continuous Laser ◽  
Columnar Crystal ◽  
Cladding Layer ◽  
Cladding Layers

The Co-base alloy laser cladding layer was coated on the 2738 mold steel surface by using the TJ-HL-5000 transverse-flow CO2 continuous laser. The morphology and hardness were investigated by metallography microscope, scanning electron microscopy (SEM), X-ray diffraction (XRD) and microhardness tester. The metallography microscope and SEM investigations show that from interface to surface along the cross section direction, the cladding layers consist of plane crystal layer, columnar crystal layer, dendrites layer and surface cellular crystal layer, respectively. XRD results indicate that the cladding layer is made of γ-Co, Cr23C6, MoC, FeCr and Co3Mo2Si phases. The micro-hardness of the laser cladding coating was about 900-1100HV1, 3 times or more of the steel substrate. And the mechanisms of microstructure formation and strengthening are investigated.

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