TY - JOUR
T1 - Thermodynamic study of single crystal, Ni-based superalloys in the γ+γ’ two-phase region using Knudsen effusion mass spectrometry, DSC and SEM
AU - Spathara, Dimitra
AU - Sergeev, Dmitry
AU - Kobertz, Dietmar
AU - Michael Müller, Michael
AU - Putman, Duncan
AU - Warnken, Nils
PY - 2021/7/21
Y1 - 2021/7/21
N2 - 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.
AB - 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.
KW - activity
KW - sublimation
KW - vaporisation
KW - Knudsen effusion mass spectrometry
KW - high-temperature alloys
KW - gas-solid reactions
U2 - 10.1016/j.jallcom.2021.159295
DO - 10.1016/j.jallcom.2021.159295
M3 - Article
SN - 0925-8388
VL - 870
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
M1 - 159295
ER -