TY  - JOUR
AU  - Volz, N.
AU  - Zenk, C. H.
AU  - Cherukuri, R.
AU  - Kalfhaus, T.
AU  - Weiser, M.
AU  - Makineni, S. K.
AU  - Betzing, C.
AU  - Lenz, M.
AU  - Gault, B.
AU  - Fries, S. G.
AU  - Schreuer, J.
AU  - Vaßen, R.
AU  - Virtanen, S.
AU  - Raabe, D.
AU  - Spiecker, E.
AU  - Neumeier, S.
AU  - Göken, M.
TI  - Thermophysical and Mechanical Properties of Advanced Single Crystalline Co-base Superalloys
JO  - Metallurgical and materials transactions / A
VL  - 49A
IS  - 9
SN  - 1543-1940
CY  - Boston
PB  - Springer
M1  - FZJ-2018-03299
SP  - 4099-4109
PY  - 2018
AB  - A set of advanced single crystalline γ′ strengthened Co-base superalloys with at least nine alloying elements (Co, Ni, Al, W, Ti, Ta, Cr, Si, Hf, Re) has been developed and investigated. The objective was to generate multinary Co-base superalloys with significantly improved properties compared to the original Co-Al-W-based alloys. All alloys show the typical γ/γ′ two-phase microstructure. A γ′ solvus temperature up to 1174 °C and γ′ volume fractions between 40 and 60 pct at 1050 °C could be achieved, which is significantly higher compared to most other Co-Al-W-based superalloys. However, higher contents of Ti, Ta, and the addition of Re decrease the long-term stability. Atom probe tomography revealed that Re does not partition to the γ phase as strongly as in Ni-base superalloys. Compression creep properties were investigated at 1050 °C and 125 MPa in 〈001〉 direction. The creep resistance is close to that of first generation Ni-base superalloys. The creep mechanisms of the Re-containing alloy was further investigated and it was found that the deformation is located preferentially in the γ channels although some precipitates are sheared during early stages of creep. The addition of Re did not improve the mechanical properties and is therefore not considered as a crucial element in the design of future Co-base superalloys for high temperature applications. Thermodynamic calculations describe well how the alloying elements influence the transformation temperatures although there is still an offset in the actual values. Furthermore, a full set of elastic constants of one of the multinary alloys is presented, showing increased elastic stiffness leading to a higher Young’s modulus for the investigated alloy, compared to conventional Ni-base superalloys. The oxidation resistance is significantly improved compared to the ternary Co-Al-W compound. A complete thermal barrier coating system was applied successfully
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000440714700028
DO  - DOI:10.1007/s11661-018-4705-1
UR  - https://juser.fz-juelich.de/record/847991
ER  -