Microstructure Characteristic of Laser Cladding Ceramic Layer on High Cr Cast Steel Surface

2010 ◽  
Vol 97-101 ◽  
pp. 1542-1545
Author(s):  
Yuan Shan He ◽  
Yi Shan Li ◽  
Wei Ling Huang ◽  
Yong Wang
Keyword(s):  
Phase Composition ◽  
Intermetallic Compound ◽  
Laser Cladding ◽  
Steel Surface ◽  
Cast Steel ◽  
Crystal Form ◽  
Cladding Layer ◽  
Equiaxed Grain ◽  
Microstructure Characteristic ◽  
Grain Characteristic

In this experiment Al2O3 gradient ceramics coating is cladded on the high Cr cast steel by 5kW crosscurrent CO2 laser with Ni-based alloy which is used as transitive metal. The microstructure is analyzed with optics microstructure analyzer and the crystal grain characteristic is studied. The microstructure of the laser cladding layer have the plane crystal zone, the butcher crystal zone, the dendrite zone and the surface equiaxed grain zone that grow along the substrate. The microstructure of the coating compared with the substrate is extremely tiny, and the microstructure of the multi-layer cladding presents stratification. The phase composition of the clad coating is composed primarily of NiAl intermetallic compound, but also includes γ-FeNi and a little Ni3Al compound. In the coating the Al2O3 pellet that some present the unit crystal form, and some little accumulate in together, plays the dissemination strengthening role in the coating material. The massive twin crystals and the dislocation staffing are presented in the clad coating.

Microstructure Characteristic of Laser Cladding Ceramic Layer on High Cr Cast Steel Surface

2013 ◽  
Vol 652-654 ◽  
pp. 1866-1870
Author(s):  
Yi Shan Li ◽  
Bin Han ◽  
Cai Gao
Keyword(s):  
Phase Composition ◽  
Laser Cladding ◽  
Steel Surface ◽  
Cast Steel ◽  
Crystal Form ◽  
Dispersion Strengthening ◽  
Dendritic Crystal ◽  
Cladding Layer ◽  
Microstructure Characteristic ◽  
Grain Characteristic

The Al2O3 gradient ceramics coating was cladded on the high Cr cast steel by 5KW crosscurrent CO2 laser with Ni-based alloy which was used as transition metal in this experiment. The microstructure is analyzed with optics microstructure analyzer and the crystal grain characteristic is studied. The results show that the microstructure of laser cladding layer contains the plane crystal zone which grows along the substrate, the cellular crystal zone, the dendritic crystal zone and the surface equiaxed cryatal zone. The microstructure of the coating compared with the substrate is extremely fine, and the microstructure of multi-layer cladding presents stratification. The phase composition of the cladding layer is composed primarily of NiAl intermetallic compound, also includes γ-FeNi and a little Ni3Al compound. The Al2O3 particles that some present the single crystal form and some accumulate in together, play the dispersion strengthening role in the coating material. The massive twin crystals and the dislocation pile-ups are found to exist in the cladding layer.

The Microstructure and Wear-Resistant Properties of Laser Cladding Ni-Based WC Alloy on Q345 Steel Surface

2014 ◽  
Vol 556-562 ◽  
pp. 189-192 ◽  
Author(s):  
Shun Min Zhu ◽  
Ya Dong Zhang
Keyword(s):  
Wear Resistance ◽  
Grain Refinement ◽  
Laser Cladding ◽  
Steel Surface ◽  
Surface Hardness ◽  
Wear Resistant ◽  
Cladding Layer

With the laser cladding technology, 70%Ni60A+30%WC cladding layer was cladded on the surface of Q345 steel. And the phase, microstructure and wear resistance of cladding layer were analyzed. Experiments show that the Ni-based WC alloy laser cladding treatment on Q345 steel surface have a great upgrade on grain refinement, surface hardness and wear-resistance of Q345 steel surface.

Preparation of Ni-Base Alloy Coatings on Monel Alloy by Laser Cladding

2012 ◽  
Vol 472-475 ◽  
pp. 313-316 ◽  
Author(s):  
Chun Hua Zhang ◽  
Yu Xi Hao ◽  
Lin Qi ◽  
Fang Hu ◽  
Song Zhang ◽  
...  
Keyword(s):  
Phase Composition ◽  
Laser Cladding ◽  
Surface Hardening ◽  
Alloy Powder ◽  
Base Alloy ◽  
Dendritic Structure ◽  
Eutectic Phase ◽  
Inconel 625 ◽  
Cladding Layer ◽  
The Matrix

Abstract. The paper presents the results of a study concerned with the surface hardening of Inconel 625 alloys and Ni-base alloy powder on Monel alloy by electro spark deposition and laser cladding processes. The microstructure, the phase composition and the microhardness of samples are investigated by SEM, EDS, XRD and microhardness instrument. It is shown that, the matrix phase is mainly made up of dendritic structure (γ-Ni), interdendritic eutectic phase (Ni3(B,Fe,Si)) and some precipitates (Cr7C3, Cr23C6). Additional, the microhardness of laser cladding layer can be substantially increased, duo to formation of precipitates.

scholarly journals Microstructure and Corrosion Properties of Laser Cladding Fe-Based Alloy Coating on 27SiMn Steel Surface

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 552
Author(s):  
Changyao Ouyang ◽  
Qiaofeng Bai ◽  
Xianguo Yan ◽  
Zhi Chen ◽  
Binhui Han ◽  
...  
Keyword(s):  
Weight Loss ◽  
Corrosion Resistance ◽  
Laser Cladding ◽  
Steel Surface ◽  
Layer Structure ◽  
Salt Spray ◽  
Morphological Characteristics ◽  
Alloy Coating ◽  
Salt Spray Corrosion ◽  
Cladding Layer

In this paper, the corrosion performance of a laser cladding Fe-based alloy coating on the surface of 27SiMn steel was studied. The Fe-based alloy coating was prepared on a 27SiMn steel surface by high-speed laser cladding. The microstructure, morphological characteristics, element content, and phase composition of the cladding layer were analyzed by an optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and X-ray diffractometer (XRD), respectively. The corrosion resistance of the 27SiMn substrate and Fe-based coating in different corrosive environments was tested through an electrochemical experimental station, a salt spray corrosion test box, and an immersion experiment. The Fe-based alloy cladding layer is mainly composed of a-Fe, M7C3, M2B, and Cr3Si. The cladding layer structure forms planar, cellular, dendrite, and equiaxed dendrite during rapid solidification. The corrosion potential of the cladding layer is higher than that of the substrate, and the arc radius of the cladding layer is larger than that of the substrate. After salt spray corrosion, a large number of red and black corrosion products appeared on the surface of the substrate; the surface of the cladding layer sample was still smooth, and the morphology was almost unchanged. The weight loss results of the cladding layer and 27SiMn matrix after 120 h of immersion are 0.0688 and 0.0993 g·cm−2, respectively. The weight loss of the cladding layer is 30.7% less than that of the matrix. Conclusion: Laser cladding an Fe-based alloy coating on the surface of 27SiMn has better corrosion resistance than the substrate, which improves the corrosion resistance of hydraulic supports.

Research Status of Subsequent Machining of Laser Cladding Layers

2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Laser Cladding ◽  
Wear Surface ◽  
Chip Formation ◽  
Cutting Temperature ◽  
Dimensional Accuracy ◽  
Cutting Parameters ◽  
Cladding Layer ◽  
Cladding Layers

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.

Modeling and Experiments of Laser Cladding With Droplet Injection

2005 ◽  
Vol 127 (9) ◽  
pp. 978-986 ◽  
Author(s):  
J. Choi ◽  
L. Han ◽  
Y. Hua
Keyword(s):  
Fluid Flow ◽  
Laser Cladding ◽  
Dynamic Motion ◽  
Cladding Layer ◽  
Melt Pool ◽  
Material Deposition ◽  
Modeling And Experiments ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Impact

Laser aided Directed Material Deposition (DMD) is an additive manufacturing process based on laser cladding. A full understanding of laser cladding is essential in order to achieve a steady state and robust DMD process. A two dimensional mathematical model of laser cladding with droplet injection was developed to understand the influence of fluid flow on the mixing, dilution depth, and deposition dimension, while incorporating melting, solidification, and evaporation phenomena. The fluid flow in the melt pool that is driven by thermal capillary convection and an energy balance at the liquid–vapor and the solid–liquid interface was investigated and the impact of the droplets on the melt pool shape and ripple was also studied. Dynamic motion, development of melt pool and the formation of cladding layer were simulated. The simulated results for average surface roughness were compared with the experimental data and showed a comparable trend.

scholarly journals Study on the Effect of Ni Addition on the Microstructure and Properties of NiTi Alloy Coating on AISI 316 L Prepared by Laser Cladding

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4373
Author(s):  
Yuqiang Feng ◽  
Zexu Du ◽  
Zhengfei Hu
Keyword(s):  
Laser Cladding ◽  
Niti Alloy ◽  
Second Phase ◽  
Content Increase ◽  
Strengthening Effect ◽  
Mixed Powder ◽  
Microstructure And Properties ◽  
Cladding Layer ◽  
Ni Addition ◽  
Aisi 316 L

This paper investigated 55 NiTi commercial alloy powder and 55 NiTi with 5% pure Ni mixed powder (55 NiTi + 5 Ni) coatings fabricated by laser cladding to study the effect of extra Ni addition on the microstructure and properties of the coating. The XRD and EDS results show that the major phases in the coatings were NiTi and Ni3Ti. Besides that, a second phase like Ni4Ti3, Fe2Ti, and NiTi2 was also detected, among which, NiTi2 was only found in 55 NiTi coating. The proportion of the phase composition in the coating was calculated via the software Image-Pro Plus. The hardness of the cladding layer reaches 770–830 HV, which was almost four times harder than the substrate, and the hardness of 55 NiTi + 5 Ni coating was around 8% higher than that of 55 NiTi coating. The wear resistance of the 55 NiTi + 5 Ni coating was also better; the wear mass loss decreased by about 13% and with a smaller friction coefficient compared with the 55 NiTi coating. These results are attributed to the solid solution strengthening effect caused by Ni addition and the second phase strengthening effect caused by the content increase of the Ni3Ti phase in the cladding layer.

scholarly journals Effect of Cooling Method on Formability of Laser Cladding IN718 Alloy

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3734
Author(s):  
Jianyu Yang ◽  
Xudong Li ◽  
Fei Li ◽  
Wenxiao Wang ◽  
Zhijie Li ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Primary Dendrite ◽  
Solidification Rate ◽  
Processing Condition ◽  
Layer By Layer ◽  
Water Cooling ◽  
Cooling Device ◽  
K Value ◽  
Cladding Layer ◽  
Thin Walled

The finite element model (FE) of temperature field of straight thin-walled samples in laser cladding IN718 was established, and the growth of microstructure was simulated by cellular automata (CA) method through macro-micro coupling (CA-FE). The effects of different cooling conditions on microstructure, hardness, and properties of laser-cladding layer were studied by designing cooling device. The results show that the simulation results are in good agreement with the microstructure of the cladding layer observed by the experiment. With the scanning strategy of reducing laser power layer-by-layer, the addition of water cooling device and the processing condition of 0.7 mm Z-axis lift, excellent thin-walled parts can be obtained. With the increase of cladding layers, the pool volume increases, the temperature value increases, the temperature gradient, cooling rate, solidification rate, K value gradually decrease, and eventually tend to be stable, in addition, the hardness shows a fluctuating downward trend. Under the processing conditions of layer-by-layer power reduction and water cooling device, the primary dendrite arm spacing reduced to about 8.3 μm, and the average hardness at the bottom of cladding layer increased from 260 HV to 288 HV. The yield strength and tensile strength of the tensile parts prepared under forced water cooling increased to a certain extent, while the elongation slightly decreased.

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