Grain boundary and intragranular deformations during high temperature creep of a PM nickel-based superalloy

A. Soula, Y. Renollet, D. Boivin, J. L. Pouchou, D. Locq, P. Caron, Y. Bréchet

Research output: Contribution to conferencePaper

14 Citations (Scopus)

Abstract

Grain boundary and intragranular deformations have been analysed during high temperature creep of a PM nickel-based superalloy. Local deformation has been quantified using an original microextensometry technique. This technique consists in calculating deformation of ceramic square grids deposited on flat specimens thanks to an electron lithography technique. Grain boundary sliding (GBS) was quantified by measuring microgrid offsets at grain boundaries. Strain maps and GBS maps have been computed. Superimposition with electron back scattered diffraction (EBSD) maps allowed studying the influence of grain boundary character on their deformation behaviour. The effectiveness of this technique was demonstrated through creep test performed at 700, 750 and 800°C under an applied stress of 700 MPa. The results showed that grain boundary and intragranular mechanisms of deformation accommodate one's each other to preserve the continuity of deformation in the material. Modification of deformation mechanisms within grains was related to coarsening of tertiary γ′ precipitates with increase of temperature. Simultaneously, decrease of GBS contribution was observed when temperature increases.

Original languageEnglish
Pages387-394
Number of pages8
DOIs
Publication statusPublished - 2008
Externally publishedYes
EventInternational Symposium on Superalloys 2008 - Champion, United States of America
Duration: 14 Sep 200818 Sep 2008
Conference number: 11th

Conference

ConferenceInternational Symposium on Superalloys 2008
Abbreviated titleSuperalloys 2008
CountryUnited States of America
CityChampion
Period14/09/0818/09/08

Keywords

  • Disk superalloy
  • Mechanical properties
  • Microstructure
  • Powder metallurgy

Cite this