The Effect of an Oxide Dispersion on the Critical Al Content in Fe-Al Alloys

Oxide-dispersed iron aluminides with Al contentsranging from 10 to 28 at.% were oxidized in air attemperatures between 600 and 1300°C in order todetermine the critical Al content necessary to form a protective, external alumina scale. AY2O3-Al2O3dispersion, performed similarly to anAl2O3 dispersion, indicated littleeffect of Y on the critical Al content. Compared toingot-processed iron aluminides, the addition of an oxide dispersion reduced thecritical Al content at 900°C. This reduction isattributed to the finer grain size in theoxide-dispersed Fe-Al.