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
EditorsMark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis, Cathie Rae, Venkat Seetharaman, Sammy Tin
PublisherMinerals, Metals and Materials Society
Pages719-726
Number of pages8
ISBN (Electronic)9781118996669
DOIs
Publication statusPublished - 2016
Externally publishedYes
Event13th International Symposium on Superalloys, SUPERALLOYS 2016 - Seven Springs, United States
Duration: 2016 Sept 112016 Sept 15

Publication series

NameProceedings of the International Symposium on Superalloys
Volume2016-January

Other

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

Keywords

  • Aluminize
  • Orientation
  • Recrystallization
  • Thermal history

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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