High-Temperature Oxidation of Fe3Al and Fe3Al–Zr Intermetallics

Abstract

The oxidation behavior of Fe 3 Al and Fe 3 Al-Zr intermetallic compounds was tested in synthetic air in the temperature range 900-1200°C. The addition of Zr showed a significant effect on the high-temperature oxidation behavior. The total weight gain after 100 h oxidation of Fe 3 Al at 1200°C was around three times more than that for Fe 3 Al-Zr materials. Zr-containing intermetallics exhibited abnormal kinetics between 900 and 1100°C, due to the presence and transformation of transient alumina into stable a-Al 2 O 3 . Zr-doped Fe 3 Al oxidation behavior under cyclic tests at 1100°C was improved by delaying the breakaway oxidation to 80 cycles, in comparison to 5 cycles on the undoped Fe 3 Al alloys. The oxidation improvements could be related to the segregation of Zr at alumina grain boundaries and to the presence of Zr oxide second-phase particles at the metal-oxide interface and in the external part of the alumina scale. The change of oxidation mechanisms, observed using oxygen-isotope experiments followed by secondary-ion mass spectrometry, was ascribed to Zr segregation at alumina grain boundaries.

Effect of Coatings on a Commercial Stainless Steel for SOEC Interconnect Application in Anode Atmosphere

“…In order to obtain the required H 2 O fraction (5%), the O 2 gas was passed through boiling distilled water and then through a vertical tube cooled at a well-determined temperature (15°C). The H 2 O fraction was checked using a hygrometer (16). For isothermal ageing tests, the samples were placed in a horizontal furnace for 100h.…”

High-Temperature Oxidation of Fe3Al Intermetallic Alloy Prepared by Additive Manufacturing LENS

“…Thermal contraction associated with cooling causes exfoliation. Other authors confirm very good oxidation resistance of Fe-Al compounds [14,15,16], especially those alloyed with Zr [17,18,19], Nb [20], Ce [21], and Y 2 O 3 [22]. …”

Preparation technique and alloying effect of aluminide coatings as tritium permeation barriers: A review

“…Experimentally, the formation temperature of a-Al 2 O 3 can be lowered down by doping alloying elements. It is found that the transformation temperature of a-Al 2 O 3 from g-Al 2 O 3 decreased from 950 C to 900 C after the addition of 0.05 at.% Zr in Fe 3 Al [103]; the transformation temperature could be further decreased to 750 C when co-doped by Zr, Nb, C and B elements [93]. It is obvious that the alloying effect in aluminide coatings composed of a FeAl transition layer and an Al 2 O 3 film is closely dependent on the temperature.…”