Formation of Aluminide Coatings on Fe-Based Alloys by Chemical Vapor Deposition

Journal Article · Tue Jan 01 00:00:00 EST 2008 · Surface and Coatings Technology

DOI:https://doi.org/10.1016/j.surfcoat.2008.01.023· OSTI ID:931010

Zhang, Ying ^[1]; Pint, Bruce A ^[2]; Cooley, Kevin M ^[2]; Haynes, James A ^[2]

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1. Tennessee Technological University
2. ORNL

Aluminide and Al-containing coatings were synthesized on commercial ferritic (P91) and austenitic (304L) alloys via a laboratory chemical vapor deposition (CVD) procedure for rigorous control over coating composition, purity and microstructure. The effect of the CVD aluminizing parameters such as temperature, Al activity, and post-aluminizing anneal on coating growth was investigated. Two procedures involving different Al activities were employed with and without including Cr-Al pellets in the CVD reactor to produce coatings with suitable thickness and composition for coating performance evaluation. The phase constitution of the as-synthesized coatings was assessed with the aid of a combination of X-ray diffraction, electron probe microanalysis, and existing phase diagrams. The mechanisms of formation of these CVD coatings on the Fe-based alloys are discussed, and compared with nickel aluminide coatings on Ni-base superalloys. In addition, Cr-Al pellets were replaced with Fe-Al metals in some aluminizing process runs and similar coatings were achieved.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: FE USDOE - Office of Fossil Energy (FE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 931010
• Journal Information: Surface and Coatings Technology, Vol. 202, Issue 16; ISSN 0257-8972
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
CHEMICAL VAPOR DEPOSITION
COATINGS
ELECTRON PROBES
HEAT RESISTING ALLOYS
PHASE DIAGRAMS
X-RAY DIFFRACTION
Fe-base alloys
coatings
CVD
corrosion
microstructure