Serration of grain boundary in Ni-30Fe alloy through high temperature deformation

Grain boundary serration that evolved during high temperature deformation was investigated under various deformation conditions in a Ni-30Fe alloy. The maximum amplitudes of the serration at compressive strains of 0.13 and 0.34 were about 7 mum and 9 mum, respectively, at 1 123 K. The amplitude decreased at lower deformation temperature and no serration was observed at 823 K. The amplitude of the serration increased linearly with an increase of strain in the first stage and became saturated above the strain of 0.2. TEM analysis showed that the grain boundary serration was closely related to the evolution of the subboundaries. The correlation between the development of the grain boundary serration and the size of the recovered equiaxed grain is discussed.