Strain-induced abnormal grain growth of Fe foils

Highlights: • Polycrystalline Fe foils were converted to close to single crystal by abnormal grain growth. • Abnormal grain growth is driven by pre-strain in the foils. • Abnormal grain growth behavior is affected by the stored energy in the foils. • Intragranular orientation spread can be used as an indicator to estimate the stored energy in the foils. -- Abstract: Abnormal grain growth of polycrystalline iron (Fe) foil up to grains of 1 cm × 2.2 cm in size, is reported. Pre-strain generated by plastic deformation promoted the abnormal grain growth during post-strain annealing, resulting in large area regions close to single crystal within the foil. The number of nucleus/nuclei and maximum grain size for the abnormal grain growth were highly affected by the plastic deformation conditions as they cause different stored energies in the foils. These stored energies were estimated from the intragranular orientation spread using electron back scatter diffraction, and the relationship between this spread and the abnormal grain growth was investigated.