Modification of the B2-type matrix of aluminide diffusion coatings on nickel-base superalloys -- Bulk aluminide analogues
- Auburn Univ., AL (United States). Materials Engineering Program
- Univ. of Cambridge (United Kingdom). Dept. of Materials Science and Metallurgy
Pack aluminide coating is a useful method for conferring oxidation resistance on nickel-base superalloys. Nominally, these coatings have a matrix composed of a Ni-Al based B2-type phase (commonly denoted as {beta}). However, following high-temperature exposure in oxidative environments, aluminum is depleted from the coating. Aluminum depletion in turn, leads to destabilization of the {beta} phase, resulting in the formation of a characteristic lath like {beta}-derivative microstructure. This article presents a transmission electron microscopy study of the formation of the lath like {beta}-derivative microstructure using bulk nickel aluminides as model alloys. In the bulk nickel aluminides, the lath like microstructure has been found to correspond to two distinct components: L1{sub 0}-type martensite and a new {beta} derivative. The new {beta} derivative is characterized and the conditions associated with the presence of this feature are identified and compare those leading to the formation of the L1{sub 0} martensitic phase.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 42867
- Journal Information:
- Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 4 Vol. 26; ISSN 0360-2133; ISSN MTTABN
- Country of Publication:
- United States
- Language:
- English
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