Diffusion Study of Al-8%Si Alloy Double-Coating on Steel

2011 ◽  
Vol 189-193 ◽  
pp. 1080-1084
Author(s):  
Yu Heng Lu ◽  
Cai Min Huang ◽  
Jian Min Zeng

Al-8%Si alloy double-coating on Q235 steel were produced, Then the samples were executed diffusion at high temperatures protecting with flowing argon gas. Scanning electron microscope (SEM), optical microscope (OM), and energy dispersive X-ray spectroscope (EDS) were employed for microstructure observation of cross-sectional, surface and compositional analysis of coating. The diffusion mathematical model was established with the finite element method. The results show that good quality Al-8%Si coating is made; after heat-diffusion treatment, the new phases FeAl and Fe3Al presents; Silicon atoms in Al-8%Si alloy can hinder the diffusion of aluminum atoms into steel substrate at high temperature; Al-8%Si alloy double-coating sample’s high-temperature oxidation resistance is higher than Q235 steel. This material is hopefully used in the engine exhaust manifold.

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.


2021 ◽  
Vol 40 (1) ◽  
pp. 397-409
Author(s):  
Ziliu Xiong ◽  
Zhangguo Lin ◽  
Jianjun Qi ◽  
Li Sun ◽  
Guangxin Wu ◽  
...  

Abstract High-temperature oxidation resistance, hot formability, element distribution, and microstructure of Al-10% Si-(0.5–3.0%)Cu coating were investigated by means of glow discharge spectroscopy, optical microscope, scanning electron microscope, and energy-dispersive spectroscopy. Results show that the addition of Cu can increase high-temperature oxidation resistance above 950°C and improve hot formability so that no crack spreads into substrate steel as hot forming at 33.3% strain. Oxidation film structure is continual and compacting, and Si highly concentrates in the surface layer. The distribution of Cu has skin effect with peaking content 8.2% in the surface layer. After hot stamping, Al and Si diffuse into substrate steel, and Cu diffuses from inner to outer coating. Al–Si–Cu coating has smoother surface, straighter diffusion layer, and finer metal compound than Al–Si coating. Surface and diffusion layers are identified as aluminum oxide, Si-rich, and Cu phase and Al7SiFe2, Al3Fe, and CuAl3, respectively. Al-rich phase and the metal compound are composed of α-Al dissolving Fe, Si, and Cu and Al–Si matrix, Cu3Al, respectively.


2011 ◽  
Vol 189-193 ◽  
pp. 441-446
Author(s):  
Xiao Xia Tan ◽  
Zong De Liu

NiAl and Ni3Al intermetallic compound claddings are prepared by argon arc cladding technology on the 16Mn steel substrate. These claddings were oxidized for 100 hours at 850 and the oxide quality of each sample was recorded every 10 hours. The results show that the NiAl and Ni3Al claddings have homogeneous structure and few defects, and form excellent metallurgical bonding with the matrix. The oxidation kinetics results show that, the oxidation weight gain rate of NiAl was more stable than Ni3Al and tended to zero earlier. Oxide layer spallation of Ni3Al cladding was more serious than that of NiAl cladding. Thus, NiAl argon arc cladding has the more excellent high temperature oxidation properties than Ni3Al argon arc cladding.


2006 ◽  
Vol 510-511 ◽  
pp. 410-413
Author(s):  
Y.A. Shapovalov ◽  
Dong Bok Lee

The high temperature oxidation behavior of the TiAl(La)N coating, which was deposited on a steel substrate by the arc-ion plating method, was investigated at 700, 800 and 900oC in atmospheric air. The oxidation kinetics of the coating were mainly governed by the inward diffusion of oxygen and outward transport of nitrogen. The oxide scale was porous, nonadherent, and prone to cracking, indicating the oxidation resistance above 700oC is poor.


Author(s):  
Xin Zhang ◽  
Zehua Wang ◽  
Jinran Lin

AbstractFeCrBAlMo coating was deposited on an AISI 20 steel substrate by high velocity arc spraying (HVAS). Compared with FeCrBSiMo coating and pristine AISI 20 steel, the microstructure and high temperature oxidation behavior of FeCrBAlMo coating were investigated by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Meanwhile, the bonding strength of the coatings was also measured. The results indicated that both coatings were composed of α(Fe,Cr) and Fe


2013 ◽  
Vol 690-693 ◽  
pp. 2039-2045
Author(s):  
Zhong Li Zhang ◽  
Qi Shen Wang ◽  
Peng Rao Wei ◽  
Xue Gong

An arc-spraying composite coating system for high-temperature oxidation protection is composed of an inner Fe-Cr-Al alloy layer and an Al-Si alloy outer layer. The high-temperature oxidation behavior of the composite coatings on steel substrate was studied during isothermal exposures in air at 900°C. Experiments show that the coatings on steel substrate are not deteriorated and the substrate is protected well, being exposed to high temperatures up to 900°C. Inter diffusion of alloying elements within the protective coatings occur, while the elements, Cr and Al, are also diffusing to the core of the base metal. As test time proceeds, a large number of chromium oxides are generated in situ within the protective coatings, especially close to the coating/substrate interface. The oxides generated increase the bond strength of the coating to the steel substrate, and together with the surface alumina they provide a long-term effective anti-oxidant protection to steel substrate. The results on titanium sponge production site show that the protective coatings on the reactor have provided an effective protection and prolong the lifetime at least forty percent for the reactors.


2019 ◽  
Vol 38 (2019) ◽  
pp. 639-646
Author(s):  
Jinheng Luo ◽  
Na Shi ◽  
Ya-Zhe Xing ◽  
Chaoping Jiang ◽  
Yongnan Chen

AbstractAtmospheric plasma spraying (APS) technique is employed to prepare Fe-based amorphous coatings on T91 steel substrate under various arc powers of 30 kW, 35 kW and 40kW. The morphology and microstructure of both Fe-based powders and amorphous coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the wear resistance and high-temperature oxidation resistance of the plasma-sprayed coatings at various arc powers are studied. It is found that with increasing the arc power, the content of the porosity and the amorphous phase in the coatings declines. Specifically, under 30 kW, 35 kW and 40 kW arc power, the porosity of the coatings is 7.96%, 6.13% and 5.75%. Correspondingly, the relative content of amorphous phase from the coatings is measured to be 96.07% (mass fraction), 73.89% and 65.54%. Moreover, under 40 kW arc power, it gives the coating the highest micro-hardness having more compact microstructure and more dispersive α-Fe grains. Besides, the coatings fabricated at high arc power exhibit less wear induced weight loss and less weight gain from high-temperature oxidation comparing with those fabricated at lower arc power.


2016 ◽  
Vol 63 (3) ◽  
pp. 171-176 ◽  
Author(s):  
Xiaodong Zhang ◽  
Xiaohua Jie ◽  
Liuyan Zhang ◽  
Song Luo ◽  
Qiongbin Zheng

Purpose This paper aims to discuss that a WC/Co-Cr alloy coating was applied to the surface of H13 steel by laser cladding. Design/methodology/approach The oxidation behavior of the WC/Co-Cr alloy coating at 600°C was investigated by comparing it with the performance of the steel substrate to better understand the thermal stability of H13 steel. Findings The results showed that the WC/Co-Cr alloy coating exhibited better high-temperature oxidation resistance and thermal stability than did uncoated H13 steel. The coated H13 steel had a lower mass gain rate and higher microhardness than did the substrate after different oxidation times. Originality/value The WC/Co-Cr alloy coating was composed of e-Co, CW3, Co6W6C, Cr23C6 and Cr7C3; this mixture offered good thermal stability and better high-temperature oxidation resistance.


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