High temperature damages of Ni-base-superalloy caused by the change of nanotexture due to strain-induced anisotropic diffusion

Yamato Sasaki, Hiroyuki Itoh, Naokazu Murata, Ken Suzuki, Hideo Miura

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

Abstract

In order to assure the reliability of advanced gas turbine systems, it is very important to evaluate the damage of high temperature materials such as Ni-base superalloys under creep and fatigue conditions quantitatively. Since the micro texture of the gamma-prime (γ') phase was found to vary during the creep damage process, it is possible, therefore, to evaluate the creep damage of this material quantitatively by measuring the change of the micro texture. The mechanism of the directional coarsening of γ' phases (rafting) of Ni-base superalloy under an uni-axial strain at high temperatures was analyzed by molecular dynamics (MD) analysis. The stress-induced anisotropic diffusion of Al atoms perpendicular to the initially finely dispersed γ/γ' interface in the superalloy crystal was observed clearly in a Ni(001)/Ni 3Al(001) interface structure. The stress-induced anisotropic diffusion was validated by experiment using the stacked thin films structures which consisted of the (001) face-centered cubic (FCC) interface. The reduction of the diffusion of Al atoms perpendicular to the interface is thus, effective for improving the creep and fatigue resistance of the alloy. It was also found by MD analysis that the dopant elements in the superalloy also affected the straininduced diffusion of Al atoms. Palladium was one of the most effective elements which restrain Al atoms from moving around the interface under the applied stress.

Original languageEnglish
Title of host publicationASME 2010 International Mechanical Engineering Congress and Exposition, IMECE 2010
Pages73-79
Number of pages7
DOIs
Publication statusPublished - 2010 Dec 1
EventASME 2010 International Mechanical Engineering Congress and Exposition, IMECE 2010 - Vancouver, BC, Canada
Duration: 2010 Nov 122010 Nov 18

Publication series

NameASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
Volume9

Other

OtherASME 2010 International Mechanical Engineering Congress and Exposition, IMECE 2010
CountryCanada
CityVancouver, BC
Period10/11/1210/11/18

ASJC Scopus subject areas

  • Mechanical Engineering

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