Phase Separation from L2<SUB>1</SUB> to (B2+L2<SUB>1</SUB>) in Fe-24.6Al-7.5Ti Alloy

Abstract

As-quenched microstructure of the Fe-24.6 at% Al-7.5 at% Ti alloy was a mixture of (A2+L2 1 ) phases. When the as-quenched alloy was aged at 1173 K for moderate times, the L2 1 domains grew considerably and B2 phase was formed at a/2h100i anti-phase boundaries (APBs) as well as phase separation from well-grown L2 1 to (B2+L2 1 Ã ) occurred basically contiguous to the APBs, where L2 1 Ã is also a L2 1 -type phase. With continued aging at 1173 K, the phase separation would proceed toward the whole well-grown L2 1 domains. This microstructural evolution has not been reported in the Fe-Al-Ti alloy systems before.