Microstructure changes and oxidation resistance of aluminized Ni-based single crystal superalloys

Hideyuki Murakami, Kazuki Kasai

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Microstructural changes and oxidation resistance of simply aluminized Ni-based single-crystal superalloys were systematically investigated. There are several kinds of microstructural changes observed in the as-aluminized Ni-based single crystal superalloys. For instance, in the case of a gritblasted specimen, secondary reaction zone (SRZ) was formed in the vicinity of substrate/coating interfaces. On the other hand, in the polished specimens, voids were formed by thermal cyclic heating. It is also found that grit-blasted specimens with SRZ formation exhibited accelerated oxidation. Microstructural changes are slightly accelerated along 〈110〉 direction rather than 〈100〉 direction. These experimental results can be explained by the recrystallization of substrate surfaces and subsequent interdiffusion between the coated layer and the substrate. Cyclic oxidation tests were also performed to assess the oxidation resistance of specimens with different microstructure and it is found that specimens with SRZ formation demonstrated worse oxidation resistance than those with voids formation, probably due to the difference in interdiffusion of solute elements between aluminized coatings and substrates.

Original languageEnglish
Title of host publicationSUPERALLOYS 2016 - Proceedings of the 13th International Symposium on Superalloys
PublisherMinerals, Metals and Materials Society
Pages719-726
Number of pages8
Volume2016-January
ISBN (Electronic)9781118996669
Publication statusPublished - 2016 Jan 1
Externally publishedYes
Event13th International Symposium on Superalloys, SUPERALLOYS 2016 - Seven Springs, United States
Duration: 2016 Sep 112016 Sep 15

Other

Other13th International Symposium on Superalloys, SUPERALLOYS 2016
CountryUnited States
CitySeven Springs
Period16/9/1116/9/15

Keywords

  • Aluminize
  • Orientation
  • Recrystallization
  • Thermal history

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Microstructure changes and oxidation resistance of aluminized Ni-based single crystal superalloys'. Together they form a unique fingerprint.

  • Cite this

    Murakami, H., & Kasai, K. (2016). Microstructure changes and oxidation resistance of aluminized Ni-based single crystal superalloys. In SUPERALLOYS 2016 - Proceedings of the 13th International Symposium on Superalloys (Vol. 2016-January, pp. 719-726). Minerals, Metals and Materials Society.