Effect of Deposition Parameters on the Microstructure and Growth Rate of CVD Mullite Environmental Barrier Coatings

2005 ◽  
Vol 890 ◽  
Author(s):  
Soumendra Basu ◽  
Tushar Kulkarni ◽  
Vinod Sarin
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Metal Chloride ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings ◽  
Environmental Barrier ◽  
Deposition Parameters ◽  
Mullite Coatings ◽  
Coating Microstructure ◽  
Reactor Pressure

ABSTRACTSi-based ceramics such as SiC require environmental barrier coatings to protect against hot-corrosion and recession in gas turbine applications. Dense, crystalline mullite coatings of uniform thickness have been deposited by hot-wall chemical vapor deposition (CVD) on SiC substrates, using the AlCl3-SiCl4-CO2-H2 system. The effects of the CVD deposition parameters such as temperature, total reactor pressure, and metal-chloride partial pressure on the coating microstructure and growth kinetics have been investigated, and are discussed in this paper.

Advanced Environmental Barrier Coatings (EBC’s)

2007 ◽  
Vol 333 ◽  
pp. 59-70 ◽  
Author(s):  
T. Kulkarni ◽  
S.N. Basu ◽  
V.K. Sarin
Keyword(s):  
Crystal Structure ◽  
Growth Rate ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Vapor Deposition ◽  
Surface Composition ◽  
Narrow Range ◽  
Chemical Vapor ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings

Dense, uniform and crack-free mullite (3Al2O3·2SiO2) coatings were deposited on Sibased substrates by chemical vapor deposition using the AlCl3–SiCl4–H2–CO2 system. The coatings were compositionally graded, with the Al/Si ratio increasing towards the outer surface of the coatings for improved corrosion resistance. Mullite grains nucleated when the surface composition of the growing coating was in a narrow range close to that of stoichiometric mullite. The growth rate and crystal structure of mullite were dependent upon temperature, pressure, reactant concentration, and reactant ratios. The phase transformations occurring in these coatings during high-temperature anneals in the range 1100–1400 °C were studied.

Polymer Derived SiAlCN for Environmental Barrier Coatings

2005 ◽  
Author(s):  
Yiguang Wang ◽  
Linan An
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Elevated Temperatures ◽  
Chemical Vapor ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings ◽  
Environmental Barrier ◽  
Alkali Salt ◽  
Near Term ◽  
Silicon Based

Silicon-based ceramics and composites are one of the most promising candidates for high temperature structural components in next generation gas turbines due to their excellent thermo-mechanical properties. However, these materials severely degraded when used in high temperature oxidizing environments, particularly, in the presence of corrosive species such as alkali elements or water vapor. Currently, the most promising approach with near-term benefits is to employ environmental barrier coatings (EBCs) that prevent direct contact between silicon-based materials and aggressive environments exist in turbine engines. Previous work on EBCs has primarily focused on using oxide coatings because oxides are in general more resistant to corrosive environments than Silicon-based ceramics. In this study, we propose to develop polymer-derived SiAlCN amorphous ceramics for EBC applications. Our research revealed that the oxidation rate of the SiAlCN ceramics is about 10 times lower than the lowest values observed on chemical vapor deposition (CVD) silicon carbide/nitride. Furthermore, the SiAlCN also exhibited good corrosion resistance to alkali salt at elevated temperatures.

scholarly journals Study of deposition parameters and growth kinetics of ZnO deposited by aerosol assisted chemical vapor deposition

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18493-18499
Author(s):  
Sergio Sánchez-Martín ◽  
S. M. Olaizola ◽  
E. Castaño ◽  
E. Urionabarrenetxea ◽  
G. G. Mandayo ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Growth Kinetics ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Kinetics Analysis ◽  
Deposition Parameters ◽  
Kinetics Of

Impact of deposition parameters, microstructure and growth kinetics analysis of ZnO grown by Aerosol-assisted Chemical Vapor Deposition (AACVD).

Study of the Role of Small Additions of Zr in the CVD- FBR Aluminization Process

2009 ◽  
Vol 289-292 ◽  
pp. 293-300
Author(s):  
L. Sánchez ◽  
F.J. Bolívar ◽  
M.P. Hierro ◽  
F.J. Pérez
Keyword(s):  
Fluidized Bed ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Fluidized Bed Reactor ◽  
Iron Aluminide ◽  
Martensitic Steels ◽  
Aluminide Coatings ◽  
Deposition Parameters ◽  
Zirconium Powder

In this work, iron aluminide coatings were developed by Chemical Vapor Deposition in Fluidized Bed Reactor (CVD-FBR) on ferritic-martensitic steels. Small additions of zirconium powder were introduced in the fluidized bed; as a consequence, the obtained coatings are thicker than that without zirconium additions. When Zr powders are added in the fluidized bed, the deposition atmosphere drastically changes, leading to increase the deposition rate. Thermodynamic calculations were carried out to simulate the modifications in the CVD atmosphere in the Al/Zr deposition system in comparison to the single aluminization. In order to optimize the conditions of the deposition, parameters such as temperature and concentration of zirconium introduced into the bed were evaluated and compared with the results obtained for the single aluminum deposition.

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