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Low carbon steel AISI 10 was subjected to a severe plastic deformation technique called Equal Angular Channel Pressing (ECAP) at different increased temperatures. The steel was subjected to ECAP with channel’s angle j = 90°, at different temperature in range of 150 - 300 °C. The number of passes at each temperature was N = 3. Light, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of thin foils were used to study the formation of substructure and ultrafine grains in deformed specimens. The size of newly born polygonized grains (subgrains and/or submicrocrystalline grains) is in range of 300 - 500 mm. The formation of such of predominant submicrocrystalline structure resulted in significant increase of yield stress [Re] and tensile strength of the steel [Rm].

The possibility of producing alloys, which are characterized by high degradation rate and used for manufacturing biodegradable implants, is studied on Fe–Mn–C alloys subjected to equal-channel angular pressing (ECAP). In particular, the attention is paid to the preparation of alloys, which have an ultrafine-grained structure and a high density of boundaries of structural elements and are in completely austenitic state. The effect of a structure on the corrosion rate, the mechanical properties, and in vitro biocompatibility has been revealed. An analysis of X-ray diffraction and transmission electron microscopy data for the alloys subjected to ECAP shows the formation of an austenitic partially or completely twin structure. The formed structure determines a high level of the strength characteristics while maintaining an adequate plasticity. As the uniformity of the twin structure and density of twin packets increases and the twin size decreases, the corrosion rate is shown to decrease. Based on results of in vitro studies of the hemolytic efficiency and cytotoxicity, the biocompatibility of the alloys subjected to ECAP is retained. The treatment conditions of samples are found not to affect their biocompatibility and to ensure a similar level of the adherence of mesenchymal cells with an osteogenic potential on the surface of the alloy samples subjected to ECAP. [ABSTRACT FROM AUTHOR]

Properties of Cu-Cr-Zr alloy with ultrafine-grained (UFG) structure produced by equal-channel angular pressing (ECAP) via different routes have been investigated. Special attention was paid to the optimization of multi-functional structural, thermal, electrical and mechanical properties of the alloy by aging of UFG one. Multi-pass ECAP via different routes gives rise to the formation of a deformation-induced submicrocrystalline structure with the grain (subgrain) sizes in the range of 200-300 nm depending on applied routes which leads to high hardness and strength in the Cu-Cr-Zr alloy with reduced ductility. Amongst the applied routes, route-Bc was found to be the best processing path for achieving the lowest grain size, the highest hardness and strength. Aging of 8Bc-processed UFG samples increases the hardness and strength of Cu-Cr-Zr alloy while retaining an electrical conductivity comparable to that of aged coarse-grained (CG) one. A satisfactory electrical conductivity of 71%IACS without considerable loss of peak hardness was achieved after aging of 8Bc-processed UFG alloy at 425 °C for 240 min. The precipitation strengthened UFG alloy remains its stable behavior at elevated temperatures up to 450 °C. [ABSTRACT FROM AUTHOR]