ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
In the present study, high temperature properties of Ir-modified and Ir-Hf-modifiedaluminide coatings on Ni-based single crystal superalloy TMS-82+ were discussed. They wereprepared by depositing pure Ir and Ir-Hf alloys on TMS-82+ using magnetron sputtering andEB-PVD, followed by a conventional Al-pack cementation process. The effects of Hf addition on theoxidation resistance and top-coat spallation resistance were investigated. Cyclic oxidation test at1423K for 1h as one heating cycle revealed that while there is a small difference in oxidation kineticsand spallation lives between Ir and Ir-Hf coatings, drastic difference in surface morphology wasobserved. After 50 oxidation cycles the Ir-modified aluminide coating showed surface rumplingwhereas the Ir-Hf modified aluminide coatings kept the flat surface. It was also revealed thatexcessive addition of Hf promoted the internal oxidation, resulting in the deterioration of substrates.These results agree with the conventional Pt-modified aluminide coatings and Ni-Al-Hf alloys
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.546-549.1689.pdf
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