SERS AuNP EF dimer/EF monomer vs. gap, nm (y = e^−x) on Au, Ag, Al, Si, 1220+ nanoantennae.

An overview of the prospects for the development of nuclear technologies and the conclusion of the relevant requirements for advanced structural materials, their classification and features were performed. In order to obtain a bar with a modified radiation-resistant outer layer, an experiment of radial-shear rolling under the most stringent conditions was carried out. For the same conditions, a FEM-simulation of sequential rolling in eight passes with a total compression of 70.7% (from a diameter of 37 mm to 20 mm) was conducted. For adequate simulation results a new material database for Zr-1%Nb alloy using plastometry investigations was generated. An experimental obtaining of a gradient-modified structure with an ultrafine-grained (UFG) periphery and an elongated rolling texture in the center of the bar was performed.

Improving the quality of metal products by crushing of the microstructure of material is one of the promising areas of modern metallurgy. The basic idea consists in refinement the grain structure of the material to sizes less than a micron, i.e. the obtaining of ultrafine-grained (UFG) materials, offering higher strength properties of the material under preservation or a small loss of ductility. Stainless austenitic steel AISI 321 is widely used in all the above areas as well as in chemical, vacuum and nuclear technology. For the obtaining of UFG structure in this material the method of radial-shear rolling is used. For the purpose of identifying the influence of radial-shear rolling on microstructure and mechanical properties of stainless austenitic steel AISI-321, the experiment was conducted where at the radial-shear rolling mill SVP-08 at 800 °C in several passes of the workpieces with a diameter of 30 mm rolled till a diameter of 13 mm with following cooling in water. The analysis of the microstructure of deformed samples showed the presence of equiaxed ultrafine-grained structure in the peripheral areas of the workpiece and the presence of elongated fibrous texture in the axial zone. The strength characteristics of the workpiece has increased more than 2 times, with a slight decrease of plasticity.

In this article, we present research results on the closing conditions of internal metallurgical discontinuities during the hot elongation operation of a Zr-1%Nb alloy ingot using physical and numerical modeling. Research on the influence of thermal and deformation parameters of elongation operations on the rheological behavior of a Zr-1% Nb alloy was conducted using the Gleeble 3800 metallurgical process simulator. Modeling of the influence of thermal–mechanical parameters of hot elongation operations in combinations of rhombic and flat anvils on the closure of metallurgical discontinuities was performed with the help of the FORGE^®NxT 2.1 program. Based on the results of the research, recommendations were made regarding forging elongation technology and the geometry of working tools in order to ensure the closure of metallurgical discontinuities during hot elongation operations of Zr-1% Nb alloy ingots.

In advancing special materials, seamless integration into existing production chains is paramount. Beyond creating improved alloy compositions, precision in processing methods is crucial to preserve desired properties without drawbacks. The synergy between alloy formulation and processing techniques is pivotal for maximizing the benefits of innovative materials. By focusing on advanced deep processing technology for small ingots of modified 12% Cr stainless steel, this paper delves into the transformation of cast ingot steel structures using radial shear rolling (RSR) processing. Through a series of nine passes, rolling ingots from a 32 mm to a 13 mm diameter with a total elongation factor of 6.02, a notable shift occurred. This single-operation process effectuated a substantial change in sample structure, transitioning from a coarse-grained cast structure (0.5–1.5 mm) to an equiaxed fine-grained structure with peripheral grain sizes of 1–4 μm and an elongated rolling texture in the axial part of the bar. The complete transformation of the initial cast dendritic structure validates the implementation of the RSR method for the deep processing of ingots.

In this work a simulation of the innovation process "helical rolling – pressing" in the software package Simufact.Formingwas performed. The result is several models of this process. To analyze the feasibility of the process various key parameters that have a significant impact on the implementation processwere carried out. As a result, the optimal values of friction coefficients in the rolls and in the matrix, the angle of intersection of channels in the matrix and the distance of matrix from the deformation zone of the rollswere obtained.