Papers by Author: B. Efros

Abstract: Microstructures of Fe-Cr-Ni and Fe-Mn alloys subjected to severe plastic deformation under pressure have been studied by high pressure torsion and twist extrusion. This processes have similar deformation schemes, but very different pressure levels. The paper shows that this has a dramatic effect on the value of the residual high pressure e-phase in Fe-Mn alloys that underwent severe plastic deformation using these methods. Under roughly the same equivalent deformation of 5-6 units, the value of the residual e-phase in HPT with 20 GPa pressure reaches 100%. In TE with 1.5 GPa, it does not exceed 50%.

Abstract: It has been revealed that in Iridium influenced be severe plastic deformation (SPD) a ultrafine grained (UFG) structure is formed (the grain size of 20-30 nm), but in the bodies of grains there are practically no defects of structure, however, after irradiation a subgrain structure, (subgrain size of 3-5 nm) is formed, and in the bodies of subgrains there are defects. The subgrain structure was also revealed in UFG Nickel and Copper after SPD (subgrain size of 3-15 nm), but in the latter case the observed boundary region is broader and subgrain are highly disoriented.

Abstract: The analysis is made of effect and physical mechanisms of the influence of pressure on metal materials that are in the state of plastic flow, as well as on characteristics of materials undergone severe plastic deformation under pressure.