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1175 |
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Tuesday, June 03, 2008, Auditorium 2 12:30 PM Gasturbines 2 Coatings for mobile and stationary turbines, protection against wear, high temperature corrosion and thermal stresses, clearance control coatings for a better efficiency |
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Metal foam sandwich structure as a high temperature heat exchanger |
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Hamidreza Salimijazi* / Isfahan University of Technology, Iran Larry Pershin/ CACT, University of Toronto, Canada Javad Mostaghimi/ CACT, University of Toronto, Canada Tom Coyle/ CACT, University of Toronto, Canada Sanjeev Chandra/ CACT, University of Toronto, Canada |
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Nickel-based superalloys are commonly used for high temperature applications; up to 1050ºC in air. Superalloy metal foam sheets with plasma sprayed coatings on both sides could be used as high temperature heat exchangers provided that the two applied layers are dense and well adhered to the open cell foam. In this study two layers of coatings of Inconel 625 alloy were deposited on each side of a sheet of metal foam by APS. Two densities of open cell foams, 20 and 60 pores per inch (ppi), were used as substrates. The initial nickel foam structures were converted to a superalloy composition by depositing aluminum and chromium on the foam struts by APS, followed by a diffusion/solutionizing heat treatment. The adhesion strength between the coating and foam core of the sandwich structures was measured before and after heat treatment. Results of microstructural characterization and composition analysis of the foams and coatings at various stages of heat treatment are also presented. |