The EBSD Investigation on Microstructure Evolution in Fe-32%Ni Alloy during Multi-Axial Forging
The microstructure evolution taking place in Fe-32%Ni alloy during multi-axial forging was investigated by electron backscattered diffraction (EBSD). The samples were compressed with loading direction changed through 90º from pass to pass at temperature of 650°C and a strain rate of 10-1/s. The results show the microstructure evolution is characterized by continuous grain subdivision process, i.e. the multi-axial forging promotes the development of deformation bands in various direction followed by their frequent intersection in grain interiors with changing of strain path, which results in continuous fragmentation of coarse grains into subgrains. Concurrently the misorientations of subgrain boundaries rise gradually with repetitive deformation followed by their progressive transformation into high angle boundaries. The ultra-fine grains are concluded to evolve by continuous dynamic recrystallization (CDRX).
Zhenyu Du and Bin Liu
B. J. Han "The EBSD Investigation on Microstructure Evolution in Fe-32%Ni Alloy during Multi-Axial Forging", Applied Mechanics and Materials, Vols. 26-28, pp. 260-264, 2010