Thermodynamics of Modifying Effect and Experiment Research of Rare Earth in Plasma Jet Surface Metallurgy

2011 ◽  
Vol 214 ◽  
pp. 89-92
Author(s):  
Hao Chen ◽  
Jian Gao Yang ◽  
Mi Song Chen

The Fe-based composite coatings with RE oxides were prepared on low-carbon steel substrate by use of the plasma jet surface metallurgy, and the effect of RE on microstructure of coating was investigated. The result shows that the microstructure and properties with a proper amount of RE oxides are better than these of the coatings without RE oxides. In addition, the modifying effect of RE oxide on inclusions in metallurgical coating was studied by means of thermodynamics. The thermodynamics analysis shows that RE oxide (Ce2O3) can be reduced to RE by carbon, then the RE element can react with oxygen and sulfur to form the RE oxide-sulfide in metallurgical pool. As a result, the coating is purified and the solidification crack of coating can be restrained by deoxidization and desulphurization.

2011 ◽  
Vol 179-180 ◽  
pp. 253-256
Author(s):  
Hao Chen ◽  
Jian Gao Yang ◽  
Mi Song Chen

The Fe-based composite coatings were formed by plasma jet surface metallurgy using Fe, C, W, Cr and Al alloy powders on the low carbon steel. The morphology, microstructure, interface structure and the distribution of the in situ particles in the coatings were observed with optical microscope, scanning electron microscope and x-ray diffraction analysis. The results show that metallurgical bonding is obtained between coating and substrate, and the microstructure of coatings is mainly composed of γ-Fe, (Fe,Cr,W,Nb)7C3 and AlFe particles which are synthesized in stiu, are dispersivly distributed in the coatings. The micro-hardness gradually increased from bottom to the top of the coating, the maximum is 986 Hv0.1, about 4 times larger than that of the steel substrate.


2016 ◽  
Vol 849 ◽  
pp. 677-682
Author(s):  
Hao Chen ◽  
Yang Rong Zhang ◽  
Zhu Huang

By plasma jet surface metallurgy, the thick composite coatings reinforced by in-situ TiC were produced on low carbon steel. Composition, microstructures and performance were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), micro-hardness tester and wear tester. The results showed that the excellent bonding between the coating and the carbon steel substrate was achieved by strong metallurgical interface. The microstructure of the coating is mainly composed of γ-(Fe, Ni) dendrite, M23C6, CrB and in-situ synthesized TiC ceramic particle. Because of the particulate reinforcement, the dispersion strengthening, refinement strengthening, micro-hardness and wear resistant of Fe-based coating can be enhanced.


2015 ◽  
Vol 228 ◽  
pp. 108-115
Author(s):  
B. Łosiewicz ◽  
Magdalena Popczyk

Co-deposition process of amorphous nickel and PTFE particles in the presence of Ni (OH)2carrier suspended in the bath by magnetic stirring, was investigated. Composite Ni-P+Ni (OH)2+PTFE coatings and comparative Ni-P deposits, were electrodeposited on low carbon steel substrate under galvanostatic conditions at room temperature. The physical and chemical characterization of the coatings was carried out using X-Ray diffraction analysis and microanalysis, stereometric quantitative microscopy and atomic absorption spectroscopy. The optimum production conditions of the composite coatings based on the Ni-P matrix into which PTFE and Ni (OH)2components can be embedded uniformly, were found.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5583
Author(s):  
Iosif Hulka ◽  
Ion D. Uțu ◽  
Diana Avram ◽  
Mircea L. Dan ◽  
Alexandru Pascu ◽  
...  

To enhance the sliding wear and corrosion behavior of steels with low carbon content, cermet composite coatings are usually deposited on their surface by various deposition processes. Laser cladding, compared to other deposition techniques such as electroplating, arc welding, and thermal spraying, has numerous advantages to produce such protective coatings. The paper presents the optimization of laser cladding deposition speed versus energy density in order to obtain WC-Co/NiCrBSi coatings with Ni-Al addition free of defects and reduced porosity deposited on low carbon steel substrate. The microstructure and chemical composition were investigated by SEM combined with EDX analysis while XRD was performed in order to examinate the phases within the coatings. In order to investigate the cladding speed influence on the coatings, hardness measurements, POD (pin on disk) wear tests and corrosion tests in 3.5% NaCl solution were carried out. The results showed that an optimal cladding speed has a crucial impact on the microstructure, composition, and hardness. It was found out that optimizing the cladding deposition speed proved to be effective in enhancing the sliding wear resistance and corrosion behavior by controlling the iron content within the coatings.


2011 ◽  
Vol 686 ◽  
pp. 569-573 ◽  
Author(s):  
Ming Feng Tan ◽  
Wan Chang Sun ◽  
Lei Zhang ◽  
Quan Zhou ◽  
Jin Ding

Electroless Ni-P coating containing ZrO2particles was successfully co-deposited on low carbon steel substrate. The surface and cross-sectional micrographs of the composite coatings were observed with scanning electron microscopy (SEM). And the chemical composition of the coating was analyzed with energy dispersive spectroscopy (EDS). The oxidation resistance was evaluated by weight gains during high temperature oxidation test. The results showed that the embedded ZrO2particles with irregular shape uniformly distributed in the entire Ni-P matrix, and the coating showed a good adhesion to the substrate. The weight gain curves of Ni-P-ZrO2composite coatings and Ni-P coating at 923K oxidation experiments were in accordance with . The ZrO2particles in Ni-P matrix could significantly enhance the high temperature oxidation resistance of the carbon steel substrate as compared to pure Ni-P coating.


2013 ◽  
Vol 734-737 ◽  
pp. 2269-2272
Author(s):  
Hong Mei Zhu ◽  
Shu Mei Lei ◽  
Tong Chun Kuang

In this paper, a low carbon steel was used as the substrate to prepare the carbon nanostructural materials by the oxygen-acetylene flame method. The experimental results show that the composite products including nodular carbon nanoparticles and amorphous carbon were obtained on the substrate after a mechanical polishing pretreatment. Comparatively, the short tubular carbon nanofibers with the diameter of around 100 nm were deposited on the substrate pretreated by dipping in the concentrated nitric acid solution. The possible mechanism for the growth of such carbon nanofibers was discussed.


2021 ◽  
Vol 886 ◽  
pp. 168-174
Author(s):  
Mohanad N. Al-Shroofy ◽  
Hanna A. Al-Kaisy ◽  
Rabab Chalaby

Powder spray coating was used for many applications such as paint decoration and protection against corrosive environments. The electrostatic spray method is used to lower the manufacturing cost and the environmental effect during the production process. It is done by electrostatic device and spray gun to create a layer on the substrate to play a protective role. Different dry powders were mixed to form a composite mixture consisted of Al2O3 and SiC or ZrSiO4 with Al powder as a binder. The powders mixture was deposited by electrostatic spray technique with a high voltage of 15 kV on a low carbon steel substrate of (40 x 10 x 4) mm in dimensions. Two groups of mixtures were used to form the coating layers. Powders of Al2O3 with (20 and 40) weight percent (wt%) of SiC as the first group and (20 and 40) wt% of ZrSiO4 as the second group were used. 5 wt% of Al powder was added as a binder, and the samples were heat treated at 900 C° for 2 hours. A detailed characterization of the composite coating layers was performed using XRD, SEM, and EDX, as well as, micro-hardness measurements. The obtained surface composite layers were smooth and having good particle distribution which leads to enhance roughness values (Ra). Furthermore, the hardness increased with increasing the amount of carbide and zirconia, and the obtained layers show no presence of defects or cracks.


2012 ◽  
Vol 57 (2) ◽  
pp. 517 ◽  
Author(s):  
M. Żelechower ◽  
J. Kliś ◽  
E. Augustyn ◽  
J. Grzonka ◽  
D. Stróż ◽  
...  

The Microstructure of AnnealedGalfanCoating on Steel SubstrateThe commercially availableGalfancoating containing 5-7wt.% of Al deposited on the low carbon steel substrate by hot dipping has been examined with respect to the microstructure of the coating/substrate interface area. The application of several experimental techniques (SEM/EDS, XRD, TEM/AEM/EDS/ED) allowed demonstrating the two-phase structure of the alloy coating in non-treated, commercially availableGalfansamples: Zn-rich pre-eutectoidηphase grains are surrounded by lamellar eutectics ofβ-Al andη-Zn. The transition layer between the alloy coating and steel substrate with the considerably higher Al content (SEM/EDS, TEM/EDS) has been found in both non-treated and annealed samples (600°C/5 minutes). Only the monoclinic FeAl3Znxphase however was revealed in the annealed sample (TEM/electron diffraction) remaining uncertain the presence of the orthorhombic Fe2Al5Znxphase, reported by several authors.


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