Thermal annealing action on plastic deformation of submicrocrystalline alpha-iron

The unique physical and chemical, mechanical properties of nano- and submicrocrystalline materials are due to such factors as the small size of grains, defective structure of the grains boundaries, high level of the internal stresses, microstrainings of crystal lattice, and high density of grain-boundary dislocations. This paper considers the structure, mechanical characteristics and the peculiarities of plastic flow of SMC Armco-iron subjected to thermal annealing at different temperatures. Structural investigations were performed by the methods of translucent electron microscopy (TEM). Investigation of straining relief showed that regardless of the mode and the quantity of passages in even-channel angular pressing the samples of SMC alpha-Fe have high tendency to the straining localization. Mechanical properties of the investigated samples are determined by the mode of ECAP. Thermal annealing of the samples of SMC alpha-Fe allows one to change their mechanical characteristics within wide ranges.