Nowadays, there is a great demand for increasing the strength and corrosion resistance of magnesium alloys for their wider use in machine engineering, oil industry, and medicine. This paper is devoted to a study on the effects of the combined process of reduction and equal channel angular pressing, as well as the subsequent ultrasonic irradiation on the structure, strength, and corrosion properties of the Mg-Al-Zn alloy. Deformation processing results in an increase of the strength up to 280 ± 10 MPa. A fine-grained structure is formed with a grain size of 10–20 µm and small recrystallized grains 1–2 µm in size. The corrosion resistance in the HCl medium falls down significantly. Action of ultrasound on the deformed specimen leads to an increased fraction of high-angle boundaries, in particular, the fractions of special, fully overlapping Σ13a boundaries and twin boundaries of Σ15b and Σ17a systems. Due to the ultrasonic treatment, the strength of the Mg-Al-Zn alloy increases up to 310 ± 5 MPa, while the corrosion resistance in HCl almost doubles.

The quantitative concentration of alloying elements in low-alloyed copper alloys is an important factor in forming electrical and mechanical characteristics. It is known that severe plastic deformation is accompanied by both a substantial refinement of the structure and changes in the kinetics of phase transformations during the deformation and the post-deformation thermal treatment. This paper presents the results of a comparative analysis of the Cu–0.2Cr and Cu–1.1Cr alloys subjected to equal-channel angular pressing at room temperature. The analysis was performed for the grain structure, solid solution, and second-phase particles using transmission electron microscopy, scanning electron microscopy, X-ray crystal analysis, and the small-angle diffraction method. It was found that the level of structure refinement and mechanical characteristics after equal-channel angular pressing was almost the same for both studied alloys. Post-deformation aging of the Cu–0.2Cr alloy leads to the development of polygonization and re-crystallization within it. The aging of the Cu–1.1Cr alloy shows a better thermal stability than that of the Cu–0.2Cr alloy. In the Cu–1.1Cr alloy, after aging, in comparison with Cu–0.2Cr, a denser-packed ensemble of fine particles with an average size of 54 ± 2 nm is formed. In this case, the average size of fragments is 270 ± 15 nm and the ultimate tensile strength reaches 485 MPa.

An increase in the service life of electrical products from copper and its alloys is directly related to an increase in the wear resistance of materials. Structural refinement and alloying with cadmium are known to have a positive effect on the strength characteristics and wear resistance of copper, which makes it possible, with a Cd content of 1% by weight, to increase the wear resistance of copper several times, but cadmium is considered an environmentally unsafe element. In this regard, the paper presents the results of studies of a widely used Cu-Cr-Zr alloy system in the ultrafine-grained (UFG) state, micro-alloyed with cadmium (0.2%, weight), in order to improve physical, mechanical, and operational properties, as well as environmental safety. Severe plastic deformation, providing structure refinement to ~150 nm, and microalloying with cadmium of a Cu-Cr-Zr system alloy, after a complete processing cycle, provides a tensile strength of 570±10 MPa and 67% electrical conductivity. At the same time, the abrasion resistance increases by 12 and 35% relative to the industrial systems Cu-Cd and Cu-Cr-Zr, respectively. The obtained characteristics are very promising for improving the operational properties of continuous welding tips, collector plates, and contact wires operating under conditions of intense wear.

The effect of the structure and size of grains on changes in the microrelief and optical characteristics of specimens of mirrors made of copper alloys with substantially differing grain size upon...

This work considers the development and the application of combined severe plastic deformation (SPD) techniques to produce contact wire with an enhanced complex of physical, mechanical, and service properties used for high-speed railway lines. This type of processing can be used as an alternative to most conventional production methods, including rolling and drawing. The proposed technique is based on the combination of radial swaging and equal-channel angular pressing, bundled with the wire-forming process. Laboratory contact wire samples with an enhanced complex of physical, mechanical, and service properties were produced during physical experiments. The composition of processed alloy samples meets modern requirements for contact wires for high-speed railways. Ultimate tensile strength of 560 ± 20 MPa, electrical conductivity of 76 ± 2% IACS, and relative tensile elongation of 20 ± 2% are achieved through the formation of a band structure. Fragments of 300 ± 20 nm were formed inside strips with the precipitation of secondary phase particles of 20–100 nm along the fragment boundaries, mainly during the aging process.

The authors analyze the effect of the accumulated strain during severe plastic deformation as well as the temperature and aging time on the physico-mechanical properties of low-alloyed chromium-zirconium bronze Cu-1Cr-0.08Zr. The following SPD processing techniques were employed in the work: high-pressure torsion (HPT) and equal-channel angular pressing (ECAP). As a result of the investigation there have been revealed the most reasonable regimes of thermomechanical treatment, leading to the maximum increment in mechanical properties, while preserving a high level of electrical conductivity.