In this paper, aluminide coatings of various thicknesses and microstructural uniformity obtained using chemical vapor deposition (CVD) were studied in detail. The optimized CVD process parameters of 1040 °C for 12 h in a protective hydrogen atmosphere enabled the production of high density and porosity-free aluminide coatings. These coatings were characterized by beneficial mechanical features including thermal stability, wear resistance and good adhesion strength to MAR 247 nickel superalloy substrate. The microstructure of the coating was characterized through scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. Mechanical properties and wear resistance of aluminide coatings were examined using microhardness, scratch test and standardized wear tests, respectively. Intermetallic phases from the Ni-Al system at specific thicknesses (20-30 µm), and the chemical and phase composition were successfully evaluated at optimized CVD process parameters. The optimization of the CVD process was verified to offer high performance coating properties including improved heat, adhesion and abrasion resistance.
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http://dx.doi.org/10.3390/ma13173863 | DOI Listing |
Materials (Basel)
December 2024
School of Materials Science and Engineering, Zhejiang University, Hangzhou 310058, China.
In this work, the oxidation behavior of an aluminide coating at 900, 1000, and 1100 °C was investigated. The aluminide coating was prepared on a cobalt-based superalloy using a vapor phase aluminizing process, which is composed of a β-(Co,Ni)Al phase outer layer and a Cr-rich phase diffusion layer. The experimental results showed that the oxidation of the coating at 900-1100 °C all obey the parabolic law.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2024
Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Energy and Materials, Kemivägen 10, 412 96 Gothenburg, Sweden.
In this work, a slurry iron aluminide-coated ferritic steel SVM12 was subjected to a laboratory experiment mimicking superheater corrosion in a biomass-fired power boiler. The samples were exposed under model Cl-rich biomass conditions, in a KCl + O + HO environment at 600 °C for 168, 2000, and 8000 h. The morphology of corrosion and the composition of the oxide scale and the coating were investigated by a combination of advanced analytical techniques such as FESEM/EDS, SEM/EBSD, and XRD.
View Article and Find Full Text PDFMaterials (Basel)
March 2024
The Key Lab of Guangdong for Modern Surface Engineering Technology, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Institute of New Materials, Guangdong Academy of Sciences, Guangzhou 510651, China.
Platinum plays a crucial role in the superior high-temperature oxidation resistance of Pt-modified nickel aluminide (PtAl) coatings. However, PtAl coatings usually serve in thermo-mechanical coupling environments. To investigate whether Pt contributes to the high-temperature mechanical properties of PtAl coating, stress rupture tests under 1100 °C/100 MPa were performed on PtAl coatings with varying Pt contents.
View Article and Find Full Text PDFMetall Mater Trans A Phys Metall Mater Sci
June 2023
Department of Materials, Imperial College London, Exhibition Road, London, SW7 2AZ UK.
The current work presents a systematic study of two alloy compositions (RR3010 and CMSX-4) and two types of coatings: inward grown (pack) and outward grown (vapour) deposited aluminides, exposed to 98NaSO-2NaCl mixture. Grit blasting was used on some of the samples, prior to coating, to mimic in-service procedures and remove oxides from the surface prior to coating. Two-point bend tests were then performed on the coated samples, with and without applied salt at 550 °C for 100 hours.
View Article and Find Full Text PDFMaterials (Basel)
August 2022
Section IX-Materials Science and Engineering, Technical Sciences Academy of Romania, 030167 Bucharest, Romania.
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