Molecular dynamics simulation of Cr-precipitate demixing in FeCr alloys

Panagiotis Grammatikopoulos*, Kai Nordlund

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


The mechanical properties of FeCr alloys rely heavily on atomic distribution and can be affected by phenomena such as Cr precipitation. While precipitation of FeCr alloys of various Cr concentrations has been studied before, dissolution of already existing Cr precipitates in FeCr alloys has not; this was the focus of this study. Our means of investigation was molecular dynamics computer simulation: we set up a number of configurations of FeCr alloys containing Cr precipitates of various sizes embedded in matrices of either pure Fe or with a 15% random Cr distribution, and examined their behaviour after thermal ageing at temperatures T ranging between 600 and 2000 K. The T range was selected so that it would include the (+)- transition in the standard FeCr phase diagram. High-T results provide insight into the mechanisms that govern the dissolution: Cr precipitates dissolve by vacancy exchange, leading to a random distribution of Cr atoms in an Fe matrix, as the short-range order parameter shifts from a positive value (clustering) to zero (random atomic arrangement). Precipitates at low T were found to be stable, as were those at intermediate T (∼1000 K), in agreement with previous experimental and simulation studies that challenge the standard phase diagram's reliability.

Original languageEnglish
Pages (from-to)646-654
Number of pages9
JournalRadiation Effects and Defects in Solids
Issue number7
StatePublished - 3 Jul 2014
Externally publishedYes


  • FeCr alloys
  • dissolution
  • miscibility gap
  • molecular dynamics


Dive into the research topics of 'Molecular dynamics simulation of Cr-precipitate demixing in FeCr alloys'. Together they form a unique fingerprint.

Cite this