The superplasticity behavior of Fe-28Al, Fe-28Al-2Ti, Fe-28Al-4Ti (all composition reported are in atomic percent) alloys has been investigated by tensile testing, optical microscopy and transmission electron microscopy. Tensile test were performed at 700 to 900°C under a strain rate range of about 10-5/s to 10-2/s. Maximum strain rate sensitivity index m was found to be 0.5 and the largest elongation reached 620%. The flow activation energy was measured to be 263kJ/mol for Fe-28Al and 191 kJ/mol for Fe-28Al-2Ti, which are much lower than the creep activation energy generally observed in Fe3Al alloys. After deformation grain size became much finer from about 100 μm to 20-30 μm. As combined with TEM observations, it is suggested that a continuous recrystallization process took place and superplasticity may arise from this process.
|Number of pages||11|
|Journal||Acta Metallurgica Sinica Series A, Physical Metallurgy & Materials Science|
|Publication status||Published - 1995 Jun 1|
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