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Microstructural examination of TGO formed during pre‐oxidation on Pt‐aluminized Ni‐based superalloy
Author(s) -
Swadźba R.,
Wiedermann J.,
Hetmańczyk M.,
Swadźba L.,
Witala B.,
Moskal G.,
Mendala B.,
Komendera Ł.
Publication year - 2014
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201307231
Subject(s) - materials science , yttria stabilized zirconia , superalloy , aluminide , metallurgy , thermal barrier coating , electron beam physical vapor deposition , coating , grain boundary , oxide , focused ion beam , chemical engineering , cubic zirconia , composite material , chemical vapor deposition , microstructure , ceramic , intermetallic , alloy , nanotechnology , ion , physics , quantum mechanics , engineering
The study concerns electron beam physical deposition (EB‐PVD) of yttria stabilized zirconia (YSZ) deposited on pre‐oxidized Pt‐modified aluminide bond coating. The coating was prepared by the means of Pt galvanizing followed by vapor phase aluminizing at 1050 °C. During annealing at 1100 °C in air atmosphere for 4 h a 1 µm thick layer of thermally grown oxide (TGO) consisting of equiaxed α‐alumina grains was formed. Focused ion beam and scanning/transmission electron microscopy analysis revealed the presence of nanoscale Cr‐rich precipitates distributed in the TGO as well as Cr precipitation in the grain boundaries of the β phase at the interface between the TGO and bond coat. Deposition of the YSZ on a pre‐oxidized substrate provided mechanical keying with the TGO. Void formation was observed at the TGO and bondcoat interface presumably due to initial transient alumina formation.