Thermodynamic study of single crystal, Ni-based superalloys in the γ+γ’ two-phase region using Knudsen effusion mass spectrometry, DSC and SEM

Research output: Contribution to journalArticlepeer-review


  • Dmitry Sergeev
  • Dietmar Kobertz
  • Michael Michael Müller
  • Duncan Putman

Colleges, School and Institutes

External organisations

  • Institute of Energy and Climate Research IEK-PBZ


Second and third generation single crystal (SX) Ni-based superalloys are considered to be sensitive to microsegragation, incipient melting and microstructural instability. Thus, their thermodynamic properties and stability at high temperatures are of key importance. Vapour composition consisting of four species has been detected in the temperature range 1453-1573 K. This was found after studies of three single crystal Ni-based superalloys CMSX-4, CMSX-10K and CMSX-10N using the method of Knudsen Effusion Mass Spectrometry (KEMS). The activities of Ni, Co, Cr, and Al have been determined in the γ+γ', two-phase region. A series of Differential Scanning Calorimetry (DSC) measurements were carried out at various ramping up rates to determine phase transition temperatures; the γ' solvus, the solidus and the liquidus temperature were obtained. Back-scattered Electron Imaging (BEI) and Energy Dispersive Spectroscopy (EDS) measurements were performed and depicted the effect post KEMS for such complex multicomponent systems.


Original languageEnglish
Article number159295
JournalJournal of Alloys and Compounds
Early online date24 Feb 2021
Publication statusPublished - 21 Jul 2021


  • activity, sublimation, vaporisation, Knudsen effusion mass spectrometry, high-temperature alloys, gas-solid reactions