ISSN:
1573-4889
Keywords:
TiAl
;
oxidation
;
high temperature
;
additive
;
Hf
;
alumina layer
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The isothermal oxidation behavior of TiAl coupons containing 0.24 wt.% Hf has been studied in the temperature range 1100 to 1400 K in a flow of purified oxygen at atmospheric pressure. The addition of Hf is very effective in decreasing the overall oxidation rate at temperatures up to 1300 K, although the oxidation rate was slightly increased during the initial period of about 10 ks, after which a very low oxidation rate was maintained. However, at 1350 K the effect becomes small, and at 1400 K it is inverted. The excellent oxidation resistance obtained is attributable to the formation of two alumina-rich layers in the scale; one is beneath the outer rutile layer and the other at the scale/substrate interface. In addition, no internal oxides were formed in the substrate up to 1300 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01052023
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