Deformation-induced interfacial-twin-boundary ω-phase in an Fe_(48)Mn_(37)Al_(15) body-centered cubic metastable alloy

摘要

Omega(ω)phase has a trigonal or hexagonal crystal structure and was first discovered inβ-type Ti-Cr alloys[1].Since then,theω-phase has been widely reported in numerous group IV transition metal(Ti,Ta,Hf,and Zr)based alloys[2–9].The morphologies ofω-phase could be particle-like(athermalω-phase)[10],ellipsoidal or cuboidal after aging(isothermalω-phase)[11],and plate-like after deformation(stress-relatedω-phase)[12].Amongst,the stressrelatedω-phase is usually located at the twinning boundary,thus also called interfacial-twin-boundary-ω(ITB-ω)phase.The formation of the ITB-ωphase is considered to be related to the formation of{112}bccmechanical twin(i.e.,{112}bcc twin)in bodycentered cubic(BCC)metals and alloys[13].