Microsegregation and secondary phase formation during directional solidification of the single-crystal Ni-based superalloy LEK94

Research output: Contribution to journalArticlepeer-review

Authors

  • Inmaculada Lopez-Galilea
  • Stephan Huth
  • Suzana G. Fries
  • Ingo Steinbach
  • Werner Theisen

Colleges, School and Institutes

External organisations

  • Universitat Bochum
  • Ruhr-Universität Bochum
  • Lehrstuhl Werkstofftechnik
  • Research Department IS3/HTM
  • STKS, Scale Bridging Thermodynamic and Kinetic Simulation

Abstract

A multicomponent phase-field method coupled to thermodynamic calculations according to the CALPHAD method was used to simulate microstructural evolution during directional solidification of the LEK94 commercial single-crystal Ni-based superalloy using a two-dimensional unit cell approximation. We demonstrate quantitative agreement of calculated microsegregation profiles and profiles determined from casting experiments as well as calculated fraction solid curves with those determined in differential thermal analysis (DTA) measurements. Finally, the role of solidification rate on dendrite morphology and precipitation of the secondary phases is investigated and a new measure of the dendrite morphology is presented to quantify the effect of back diffusion on the amount of secondary phases.

Details

Original languageEnglish
Pages (from-to)5153-5164
Number of pages12
JournalMetallurgical and Materials Transactions A
Volume43
Issue number13
Publication statusPublished - Dec 2012