Ultra-Fine Grained Fe-32%Ni Alloy Processed by Multi-Axial Forging
The Fe-32%Ni alloy was multi-axially forged at the temperature of 873K and strain rate of 10-2s-1, then the microstructure evolution in Fe-32%Ni alloy during deformation was investigated by the transmission electron microscopy (TEM). The results show that the grain size decreases with strain. The severe plastic deformed microstructure is characterized by the ultra-fine equiaxed grains and high internal stresses. The microstructure evolution mechanism is presented as the following: firstly, the dislocations accumulate as deformation bands in some directions with the progress of deformation; then the cellular structured subgrains are formed by continuous intersecting of deformation bands for the changing of strain path; eventually, the ultra-fine structured grains are formed by the subgrains rotation and the dislocations rearrangement.
Zhengyi Jiang and Chunliang Zhang
B. J. Han "Ultra-Fine Grained Fe-32%Ni Alloy Processed by Multi-Axial Forging", Advanced Materials Research, Vols. 97-101, pp. 187-190, 2010