Polymorphism of FeNi and FeMn nanostructured alloys subjected to pressure shear

Abstract

The phase transformations [BCC]-[HCP], [BCC]-[FCC], [FCC]-[HCP] caused by deformation and high pressure in stable iron-based alloys: iron, FeNi alloys N6, N23, N27, and Fe Mn alloy G40 were studied. The nuclear gamma resonance [NGR] technique was used to examine samples subjected to high pressure and deformation shear in situ. The phase transformations studied on pressure shear in situ are accompanied by a large decrease in grain dimensions and a rise of local stresses, which are responsible for the observed changes in the polymorphism of FeNi and FeMn alloys and formation of new structural states: a ε{lunate}* sextet with a broad distribution of [NGR,1 parameters in iron (or intercrystalline structure), a ε{lunate}* singlet in the [FCC] Gadfield steel ([SF] clusters), etc. © 1995.