Microstructural degradation of polycrystalline superalloys from oxidized carbides and implications on crack initiation

Paraskevas Kontis; David M. Collins; Angus J. Wilkinson; Roger C. Reed; Dierk Raabe; Baptiste Gault

doi:10.1016/j.scriptamat.2017.12.028

Microstructural degradation of polycrystalline superalloys from oxidized carbides and implications on crack initiation

Paraskevas Kontis^*, David M. Collins, Angus J. Wilkinson, Roger C. Reed, Dierk Raabe, Baptiste Gault

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

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Abstract

Surface connected carbides in a polycrystalline superalloy oxidized at 750 °C in air were studied as potential crack initiation sites. Lattice rotations measured in the γ/γ′ grains using high-resolution electron backscatter diffraction enabled investigation of the plastic deformation induced solely by the oxidation of carbides. Dislocations were found to enhance γ′ precipitate dissolution kinetics, resulting in soft recrystallized regions in the vicinity of the oxidized carbide with substantial compositional variation compared to the original γ/γ′ microstructure. Ramifications of such deleterious oxidized carbides alongside soft recrystallized regions on the crack initiation life in superalloys are discussed.

Original language	English
Pages (from-to)	59-63
Number of pages	5
Journal	Scripta Materialia
Volume	147
Early online date	8 Jan 2018
DOIs	https://doi.org/10.1016/j.scriptamat.2017.12.028
Publication status	Published - 1 Apr 2018

Keywords

Atom probe tomography
Oxidized carbides
Partial dislocation
Recrystallization
γ′ Dissolution

ASJC Scopus subject areas

General Materials Science
Condensed Matter Physics

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10.1016/j.scriptamat.2017.12.028Licence: None: All rights reserved

Kontis_et_al_Microstructual_degradation_Scripta_Materialia_2018
DOI: 10.1016/j.scriptamat.2017.12.028
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title = "Microstructural degradation of polycrystalline superalloys from oxidized carbides and implications on crack initiation",

abstract = "Surface connected carbides in a polycrystalline superalloy oxidized at 750 °C in air were studied as potential crack initiation sites. Lattice rotations measured in the γ/γ′ grains using high-resolution electron backscatter diffraction enabled investigation of the plastic deformation induced solely by the oxidation of carbides. Dislocations were found to enhance γ′ precipitate dissolution kinetics, resulting in soft recrystallized regions in the vicinity of the oxidized carbide with substantial compositional variation compared to the original γ/γ′ microstructure. Ramifications of such deleterious oxidized carbides alongside soft recrystallized regions on the crack initiation life in superalloys are discussed.",

keywords = "Atom probe tomography, Oxidized carbides, Partial dislocation, Recrystallization, γ′ Dissolution",

author = "Paraskevas Kontis and Collins, {David M.} and Wilkinson, {Angus J.} and Reed, {Roger C.} and Dierk Raabe and Baptiste Gault",

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T1 - Microstructural degradation of polycrystalline superalloys from oxidized carbides and implications on crack initiation

AU - Kontis, Paraskevas

AU - Collins, David M.

AU - Wilkinson, Angus J.

AU - Reed, Roger C.

AU - Raabe, Dierk

AU - Gault, Baptiste

PY - 2018/4/1

Y1 - 2018/4/1

N2 - Surface connected carbides in a polycrystalline superalloy oxidized at 750 °C in air were studied as potential crack initiation sites. Lattice rotations measured in the γ/γ′ grains using high-resolution electron backscatter diffraction enabled investigation of the plastic deformation induced solely by the oxidation of carbides. Dislocations were found to enhance γ′ precipitate dissolution kinetics, resulting in soft recrystallized regions in the vicinity of the oxidized carbide with substantial compositional variation compared to the original γ/γ′ microstructure. Ramifications of such deleterious oxidized carbides alongside soft recrystallized regions on the crack initiation life in superalloys are discussed.

AB - Surface connected carbides in a polycrystalline superalloy oxidized at 750 °C in air were studied as potential crack initiation sites. Lattice rotations measured in the γ/γ′ grains using high-resolution electron backscatter diffraction enabled investigation of the plastic deformation induced solely by the oxidation of carbides. Dislocations were found to enhance γ′ precipitate dissolution kinetics, resulting in soft recrystallized regions in the vicinity of the oxidized carbide with substantial compositional variation compared to the original γ/γ′ microstructure. Ramifications of such deleterious oxidized carbides alongside soft recrystallized regions on the crack initiation life in superalloys are discussed.

KW - Atom probe tomography

KW - Oxidized carbides

KW - Partial dislocation

KW - Recrystallization

KW - γ′ Dissolution

U2 - 10.1016/j.scriptamat.2017.12.028

DO - 10.1016/j.scriptamat.2017.12.028

M3 - Article

AN - SCOPUS:85040350675

SN - 1359-6462

VL - 147

SP - 59

EP - 63

JO - Scripta Materialia

JF - Scripta Materialia

ER -

Microstructural degradation of polycrystalline superalloys from oxidized carbides and implications on crack initiation

Abstract

Keywords

ASJC Scopus subject areas

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