Effect of thermal history on microstructural changes in aluminized nickel-based single-crystal superalloy

Kazuki Kasai, Hideyuki Murakami, Kazuhiko Noda

Research output: Contribution to journalReview article

Abstract

The effect of thermal history on microstructural changes in the aluminized and Pt-aluminized Ni-based single-crystal superalloy was investigated. The substrate superalloys were firstly electro-polished in order to get rid of the surface residual strain. Then the electrodeposition of Pt followed by vacuum annealing was conducted for some of the substrates, and the aluminized and Pt-aluminized specimens were prepared by the conventional aluminizing process. It was found that in the case of the aluminized specimens, voids were formed in the vicinity of substrate/coating interfaces, by thermal cyclic heating, whereas secondary diffusion zones (SDZ) were formed by isothermal heating. These differences in microstructural changes of the aluminized specimens can be explained by the diffusion kinetics between the coating layer and the substrate during heating/cooling processes. In the case of the Pt-aluminized specimen, on the other hand, secondary reaction zone (SRZ) formation was observed by both the thermal cyclic and isothermal treatments. These results can be explained by the poly-crystallization of the substrate surface by the annealing process that could promote the interdiffusion, resulting in the formation of SRZ.

Original languageEnglish
Pages (from-to)402-406
Number of pages5
JournalNippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
Volume76
Issue number6
DOIs
Publication statusPublished - 2012 Jan 1
Externally publishedYes

Fingerprint

heat resistant alloys
Nickel
Superalloys
histories
Single crystals
nickel
single crystals
Substrates
Heating
heating
Annealing
aluminum coatings
coatings
Coatings
annealing
Crystallization
Electrodeposition
electrodeposition
voids
Hot Temperature

Keywords

  • Aluminize
  • Nickel-based superalloy
  • Platinum-aluminize
  • Secondary diffusion zone
  • Secondary reaction zone

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry

Cite this

Effect of thermal history on microstructural changes in aluminized nickel-based single-crystal superalloy. / Kasai, Kazuki; Murakami, Hideyuki; Noda, Kazuhiko.

In: Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, Vol. 76, No. 6, 01.01.2012, p. 402-406.

Research output: Contribution to journalReview article

@article{1459f5ecc2b44d168043391c283db444,
title = "Effect of thermal history on microstructural changes in aluminized nickel-based single-crystal superalloy",
abstract = "The effect of thermal history on microstructural changes in the aluminized and Pt-aluminized Ni-based single-crystal superalloy was investigated. The substrate superalloys were firstly electro-polished in order to get rid of the surface residual strain. Then the electrodeposition of Pt followed by vacuum annealing was conducted for some of the substrates, and the aluminized and Pt-aluminized specimens were prepared by the conventional aluminizing process. It was found that in the case of the aluminized specimens, voids were formed in the vicinity of substrate/coating interfaces, by thermal cyclic heating, whereas secondary diffusion zones (SDZ) were formed by isothermal heating. These differences in microstructural changes of the aluminized specimens can be explained by the diffusion kinetics between the coating layer and the substrate during heating/cooling processes. In the case of the Pt-aluminized specimen, on the other hand, secondary reaction zone (SRZ) formation was observed by both the thermal cyclic and isothermal treatments. These results can be explained by the poly-crystallization of the substrate surface by the annealing process that could promote the interdiffusion, resulting in the formation of SRZ.",
keywords = "Aluminize, Nickel-based superalloy, Platinum-aluminize, Secondary diffusion zone, Secondary reaction zone",
author = "Kazuki Kasai and Hideyuki Murakami and Kazuhiko Noda",
year = "2012",
month = "1",
day = "1",
doi = "10.2320/jinstmet.76.402",
language = "English",
volume = "76",
pages = "402--406",
journal = "Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals",
issn = "0021-4876",
publisher = "Japan Institute of Metals (JIM)",
number = "6",

}

TY - JOUR

T1 - Effect of thermal history on microstructural changes in aluminized nickel-based single-crystal superalloy

AU - Kasai, Kazuki

AU - Murakami, Hideyuki

AU - Noda, Kazuhiko

PY - 2012/1/1

Y1 - 2012/1/1

N2 - The effect of thermal history on microstructural changes in the aluminized and Pt-aluminized Ni-based single-crystal superalloy was investigated. The substrate superalloys were firstly electro-polished in order to get rid of the surface residual strain. Then the electrodeposition of Pt followed by vacuum annealing was conducted for some of the substrates, and the aluminized and Pt-aluminized specimens were prepared by the conventional aluminizing process. It was found that in the case of the aluminized specimens, voids were formed in the vicinity of substrate/coating interfaces, by thermal cyclic heating, whereas secondary diffusion zones (SDZ) were formed by isothermal heating. These differences in microstructural changes of the aluminized specimens can be explained by the diffusion kinetics between the coating layer and the substrate during heating/cooling processes. In the case of the Pt-aluminized specimen, on the other hand, secondary reaction zone (SRZ) formation was observed by both the thermal cyclic and isothermal treatments. These results can be explained by the poly-crystallization of the substrate surface by the annealing process that could promote the interdiffusion, resulting in the formation of SRZ.

AB - The effect of thermal history on microstructural changes in the aluminized and Pt-aluminized Ni-based single-crystal superalloy was investigated. The substrate superalloys were firstly electro-polished in order to get rid of the surface residual strain. Then the electrodeposition of Pt followed by vacuum annealing was conducted for some of the substrates, and the aluminized and Pt-aluminized specimens were prepared by the conventional aluminizing process. It was found that in the case of the aluminized specimens, voids were formed in the vicinity of substrate/coating interfaces, by thermal cyclic heating, whereas secondary diffusion zones (SDZ) were formed by isothermal heating. These differences in microstructural changes of the aluminized specimens can be explained by the diffusion kinetics between the coating layer and the substrate during heating/cooling processes. In the case of the Pt-aluminized specimen, on the other hand, secondary reaction zone (SRZ) formation was observed by both the thermal cyclic and isothermal treatments. These results can be explained by the poly-crystallization of the substrate surface by the annealing process that could promote the interdiffusion, resulting in the formation of SRZ.

KW - Aluminize

KW - Nickel-based superalloy

KW - Platinum-aluminize

KW - Secondary diffusion zone

KW - Secondary reaction zone

UR - http://www.scopus.com/inward/record.url?scp=84864724414&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84864724414&partnerID=8YFLogxK

U2 - 10.2320/jinstmet.76.402

DO - 10.2320/jinstmet.76.402

M3 - Review article

VL - 76

SP - 402

EP - 406

JO - Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals

JF - Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals

SN - 0021-4876

IS - 6

ER -