The high temperature oxidation behaviour of high and low alloyed TiAl-based intermetallics
The oxidation behaviour of the gamma-TiAl based Intermetallic alloys Ti-42AL-8.5Nb-0.2W-(Si, B, Y), Ti-46Al-8.5Nb-1Ta-(C, Si, B, Y), and Ti-47Al-2Cr-2Mo-(Si, B) (composition in at.%) in air at 700, 800 and 900°C was studied in comparison with Ti-48Al-2Nb-2Cr. Isothermal oxidation tests were performed in humidified synthetic air for 150 h. Cyclic oxidation experiments were executed in static laboratory air with each cycle corresponding with a period of 1 h at test and 12 min at ambient temperature. The results revealed for Ti-47Al-2Cr-2Mo- (Si, B a lower isothermal and cyclic oxidation resistance than for Ti-48Al-2Nb-2Cr. This was explained by a lower beneficial effect of molybdenum (compared with niobium) on the oxidation resistance of this type of gamma-TiAl based alloy. An improvement of the isothermal and cyclic oxidation resistance, when compared with that of Ti-48Al-2Nb-2Cr was obtained with both high niobium-containing alloys Ti-42AL-8.5Nb-0.2W-(Si, B, Y) and Ti-46Al-8.5Nb-1Ta-(C, Si, B, Y). Here, Ti-46Al-8.5Nb-1Ta-(C, Si, B,Y) showed the lowest isothermal oxidation rate and highest cyclic oxidation resistance.
Bibliographic Reference: An article published in: Intermetallics 10 (3), (2002), pp. 293-305
Record Number: 200214502 / Last updated on: 2002-03-28
Original language: en
Available languages: en