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A novel technique referred to as free bending in rotating rollers was employed to refine the initial structure and to produce gradient fine-grained microstructures in the Cu0.5Zr alloy and commercially pure titanium (CP Ti). A newly designed die allowing a continuous and repetitive movement of a workpiece through a set of rollers in a channel bent by 90 degrees was employed to produce a series of billets after different numbers of passes resulting in different strains imposed on the billet. Microstructure evolution with increasing number of passes was characterized by precise measurements of microhardness (HV) distribution along the cross section of individual billets. The heterogeneous distribution of HV observed after a single pass was transformed to almost a uniform one in the whole cross section of the billets after 8 passes. EBSD analysis and TEM observations revealed a significant microstructure refinement in both materials after the final stage of processing. A homogeneous microstructure with an average grain size of about 300 nm was observed in CP Ti, whereas the microstructure of the Cu0.5Zr alloy was not fully refined and exhibited a bimodal grain size distribution. The experimental results were compared with the theoretical modelling of strain distribution by FEM.

The paper gives short information about the results of monitoring the electrical properties of an earth-fill dam during the application of a nutrient aqueous solution used in the method BioSealing. Monitoring is carried out using a Z-meter device when applying the method of electrical impedance spectrometry and, in some cases, is part of a system of monitoring seepage through the earth-fill dam of the water reservoir by its administrator. Information about the changes that take place in the body of the dam during the movement of the water level in the reservoir or after the influence of weather changes or human activity are given through the monitored changes in the electrical parameters of the soil of the dam with time.

Processing of metastable titanium alloys by severe plastic deformation provides an opportunity to achieve exceptional grain refinement, to enhance the strength and to affect phase transformations occurring during thermal treatment. The main aim of this study is to investigate the microstructure of ultra-fine grained (UFG) material and effect of microstructural changes on phase transformations in metastable b-Ti alloy Ti-15Mo. Metastable b-Ti alloys are currently the most studied Ti-based materials with prospective use in medicine. Ti-15Mo alloy after solution treatment contains metastable b-phase. Metastable o-phase and stable a-phase particles are formed upon annealing,. Solution treated Ti-15Mo alloy was deformed by high pressure torsion (HPT) at room temperature. Severely deformed structure after HPT with grain size of ~200 nm was studied by transmission electron microscopy. In-situ electrical resistance measurements showed significant changes in undergoing phase transformations when compared to coarse-grained (CG) material. Scanning electron microscopy revealed heterogeneous precipitation of a-particles at grain boundaries (GB). Due to the high density of GBs in UFG structure, these precipitates are very fine and equiaxed. The study demonstrates that SPD is capable of enhancing mechanical properties due to grain refinement and via affecting precipitation processes in metastable b-Ti alloys.