Premium
Protection of titanium aluminides by FeCrAlY Coatings
Author(s) -
Bennett M. J.,
Bull S. J.
Publication year - 1997
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.19970480109
Subject(s) - materials science , spallation , coating , metallurgy , titanium , oxide , diffusion , substrate (aquarium) , ceramic , ion plating , chemical engineering , composite material , oceanography , engineering , thermodynamics , geology , physics , quantum mechanics , neutron
The effectiveness of Fe+15%Cr+5%Al+0.3%Y coatings. produced by sputter ion plating, in improving the oxidation behaviour of γ‐2 Ti 3 Al at 800°C and γ‐TiAl at 900° and 1000°C. during cyclic exposures in air of up to 1000 hours duration, has been studied. The 45‐135 μm coatings were tested in both the as‐coated condition and following densification by peening. The kinetics of attack and of spallation were followed gravimetrically, while the reaction product compositions were examined by a range of surface analytical techniques. Oxidation protection was afforded by the formation on the coating surface of a γ‐Al 2 O 3 oxide scale but chemical reactions at the coating‐substrate interface with accompanying voidage development, eventually caused the coating to fail mechanically. To surmount this problem the potential of several ceramic interlayers produced by the same coating route, and interposed as diffusion barriers between the FeCrAlY overlayers and the Ti 3 Al substrate was examined in 1000 hour oxidation tests at 800°C.