TY  - JOUR
AU  - Terberger, Philipp
AU  - Sebold, Doris
AU  - Webler, Ralf
AU  - Ziener, Marco
AU  - Neumeier, Steffen
AU  - Klein, Leonhard
AU  - Virtanen, Sannakaisa
AU  - Göken, Mathias
AU  - Vassen, Robert
TI  - Isothermal aging of a γ′-strengthened Co–Al–W alloy coated with vacuum plasma-sprayed MCrAlY bond coats
JO  - Surface and coatings technology
VL  - 276
SN  - 0257-8972
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2015-05706
SP  - 360 - 367
PY  - 2015
AB  - Cobalt-based superalloys with a γ/γ′ microstructure were discovered in 2006 and are currently being investigated as an alternative to nickel-based superalloys for high-temperature, high-load applications in gas turbine blades. They promise a better castability combined with a similar creep strength. Superalloy turbine blades are commonly coated with oxidation resistant bond coats. For this reason their compatibility needs to be studied. Co–9Al–9W specimens with a γ/γ′ microstructure were coated with either a nickel-based or cobalt-based MCrAlY bond coat using vacuum plasma spraying. After aging at 900 °C in air for up to 500 h no decomposition of the γ′ phase was found in the bulk superalloy. The interdiffusion zone shows several different W-rich topologically close-packed phases arising from the dissolution of the γ′ phase in this region. The W-rich phases are identified to be μ phase for both bond coats and R phase for the nickel-based bond coat only. Their total volume is higher for the nickel-based bond coat. Therefore the cobalt-based bond coat is better suited for the Co-based superalloy substrate. Room temperature hardness and Young's modulus were measured using nanoindentation in the initial state and after heat treatment. A significantly higher Young's modulus was found for the cobalt-based bond coat.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000360594600045
DO  - DOI:10.1016/j.surfcoat.2015.06.048
UR  - https://juser.fz-juelich.de/record/255546
ER  -