The effect of chromium and cobalt segregation at dislocations on nickel-based superalloys

Research output: Contribution to journalArticlepeer-review

Authors

  • Paraskevas Kontis
  • Zhuangming Li
  • Jonathan Cormier
  • Dierk Raabe
  • Baptiste Gault

Colleges, School and Institutes

External organisations

  • Max-Planck-Institut für Eisenforschung
  • UPR CNRS 3346

Abstract

The segregation of solutes at dislocations in a polycrystalline and a single crystal nickel-based superalloy is studied. Our observations confirm the often assumed but yet unproven diffusion along dislocations via pipe diffusion. Direct observation and quantitative, near-atomic scale segregation of chromium and cobalt at dislocations within γ' precipitates and at interfacial dislocations leading to the partial or complete dissolution of γ' precipitates at elevated temperatures is presented. Our results allow us to elucidate the physical mechanism by which pipe diffusion initiates the undesirable dissolution of γ' precipitates.

Details

Original languageEnglish
Pages (from-to)76-80
Number of pages5
JournalScripta Materialia
Volume145
Early online date18 Oct 2017
Publication statusPublished - 1 Mar 2018

Keywords

  • Atom probe tomography, Dissolution, Pipe diffusion, Rafting, Recrystallisation