Microstructural formation and effects on the performance of platinum modified aluminide coatings
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Authors
Boone, Donald H.
Deb, Prabir
Subjects
Platinum-aluminide and chromium modified platinum-aluminide coatings
inward and outward types
hot corrosion
cyclic oxidation
mechanical properties, structure and formation mechanisms of coatings.
inward and outward types
hot corrosion
cyclic oxidation
mechanical properties, structure and formation mechanisms of coatings.
Advisors
Date of Issue
1985-11
Date
1985-11
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The use of noble metal modified aluminide coatings has gained renewed interest as the requirements of improved protectivity for gas turbine engine components has increased. Increasing temperature, severity of operating environment and required lifetime extension are cited as reasons for their selection. While the literature documents examples of significant improvements in hot corrosion resistance at low (800 C) and high (800 C) temperatures and in cyclic oxidation with Pt additions, there are also examples of limited improvements and even detrimental effects. These controversies have been preliminarily ascribed to the considerable differences in microstructural features possible in these systems and to the variation in test procedures between laboratories, and between rigs and engines. A systematic study was therefore initiated to identify the microstructural variations obtained for platinum-modified aluminide coatings on IN738 and to develop a fundamental understanding of their mechanism of formation. In this final report, the several classical structural types are defined together with the beginnings of their formation understanding. These microstructures were then subjects to a series of tests under conditions including hot corrosion at 700 and 900 C, and cyclic oxidation. In addition, measurements of mechanical properties such as DBTT were performed. It was found tha platinum addition to a standard aluminate is beneficial at 900 C, so far as hot corrosion attack is concerned
Type
Technical Report
Description
Series/Report No
Department
Identifiers
NPS Report Number
NPS69-85-008
Sponsors
supported by the Office of Naval Research
Funder
N0001425WR24098
Format
Citation
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.