Microstructural formation and effects on the performance of platinum modified aluminide coatings
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
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.NPS Report Number
NPS69-85-008Related items
Showing items related by title, author, creator and subject.
-
Geometric formation with uniform distribution and movement in formation of distributed mobile robots
Alptekin, Gokhan (Monterey, California. Naval Postgraduate School, 1996-06);The formation problem of distributed mobile robots was studied in the literature for idealized robots. Idealized robots are able to instantaneously move in any direction, and are equipped with perfect range sensors. In ... -
Understanding Swift Trust to Improve Interagency Collaboration in New York City
Fahy, Michael J. (Monterey, California. Naval Postgraduate School, 2012-09);For over a decade, homeland security leaders have urged emergency response agencies to improve their collaborative capacity. Collaboration and coordination is critical to homeland security effectiveness. The homeland ... -
Western North Pacific Typhoons with Concentric Eyewalls
Kuo, H.-C.; Chang, C.-P.; Yang, Y.-T.; Jiang, H.-J. (2009);This study examines the intensity change and moat dynamics of typhoons with concentric eyewalls using passive microwave data and best track data in the western North Pacific between 1997 and 2006. Of the 225 typhoons ...