The microstructural evolution during superplastic deformation in FeAl intermetallic compound

• Published in: Scripta materialia 1996-04, Vol.34 (7), p.1095-1100
• Main Authors: Liu, Yi, Li, Dingqiang, Lin(T.L. Lin), Dongliang, Chen, Shipu
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Deformation, plasticity, and creep; Exact sciences and technology; Materials science; Metals. Metallurgy; Physics; Treatment of materials and its effects on microstructure and properties
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/1359-6462(95)00634-6

The intermetallic compound FeAl has received a great deal of attention during the past few years because of its excellent oxidation resistance, retention of good strength to intermediate temperatures and its low density compared with most iron or nickel-based alloys. Superplasticity has been discovered in some intermetallics with fine grain size, such as Ni sub 3 Al and Ni sub 3 Si Ti sub 3 Al and TiAl. Recently, some work on the phenomenon of superplasticity in Fe sub 3 Al and FeAl-based alloys has been reported. A FeAl based-alloy with a grain size of > 350 mu m exhibited an elongation of > 150% at 900approx1000 deg C in air. The maximum elongation of 208% was obtained at 1000 deg C under a strain rate of 1.39x10 exp -2 /s. The index of strain rate sensitivity, the m value, was in a range from 0.25-0.42. In this paper, the dislocation features in an FeAl-based alloy after superplastic deformation, which have been investigated by transmission electron microscopy (TEM), are presented and the microstructural evolution during superplastic deformation is discussed.