Laboratory of functional materials for nuclear/thermonuclear energy Research Group
1. Research Team
Prof. Serhii Malykhin
Department of Physics of metals and semiconductors
Mr. Valerii Kondratenko
Department of Physics of metals and semiconductors
Mr. Serhii Surovytskyi
Department of Physics of metals and semiconductors
Mr. Ihor Kopylets
Department of Physics of metals and semiconductors
Mr. Leonid Konotopsky
Department of Physics of metals and semiconductors
2. Research Focus
Within the framework of this area, an important task of the world level is solved within the framework of priority directions of development of science of Ukraine, namely the development and research of new functional-active SMART structures for the needs of nuclear and thermonuclear energy, in order to increase the level of safety and duration of use of elements of power units. Laboratory and practical testing of quasi -cycrystalline film systems is carried out in radiation and thermal conditions of imitation of the transient processes of ITERa thermonuclear reactor and radiation of nuclear reactor. Patterns of change in structural-phase state, residual stresses and physical properties of layered systems with W and Ti-Zr-Ni quasicrystal on the surface of the Eurofer steel
3. Key Projects
Various in the alternation and number of layers of the tungsten system and Titan-quirkonium-nickel-quasicristals or their approximents, which are considered as new perspective materials with high hardness and durability, with low heat conductivity. They can be used on the surface of the steel as the protective barriers of the first wall steel, the elements of the diverter, or for the turbine. Complex experimental studies of physical phenomena and parameters of kinetic processes, structural-reversed changes in film systems under the action of hydrogen plasma of the transient processes of the ІТЕРа and radiation are planned.
The novelty of this project is based on the fact that the authors for the first time established the features of phase composition and structure, the thermal stability of thin coatings of Ti-Zr-Ni quasicristals was studied. Laboratory technology for the formation of coatings of the controlled composition and structure has been developed, which allows to obtain single -phase structurally perfect quasi -cycrystalline coatings, which was obtained by a utility model. For the first time in the world, data on the existence in the Ti-Zr-Ni phase of the crystalline approximetant 2/1 was obtained.
The research samples of multilayer nanocompositions based on Mg2Si/Si, W/Mg2Si, WC/Si, W/Si, Sc/Si, Sc/C/Si, Sc/W/Si, Zr/Mg. Experimental measurements of the structure, chemical and phase composition of the studied materials, depending on the parameters of their synthesis, and structural changes under the influence of temperature factors are analyzed. Samples of quasicrystalline coatings with nano -size thickness were created. The description of new X -ray methods of phase composition analysis and morphology of fine materials was made. The real structural characteristics of layers and mixing zones in multilayered nanocompositions, in particular chemical and phase composition, morphology, inter -layer roughness, tense state, density of nanosters and transition zones are determined. The link between the structure and thickness of the coatings is investigated.
Electrophysical characteristics of contacts between quasi -crystals and metals, as well as between quasicristals and dielectrics were obtained. Experimental samples of ultra -thin film compositions with optimized parameters for use in X -ray optics, durable coatings, electronic devices and infrared sensors were created.
Methods of formation and made thin films of quasicrystalline and related phases on the basis of titanium and zirconium and composites and layered systems are produced. Experimental stands for the generation of nano -secrete electric and world pulses for the study of high -frequency properties of semiconductor and quasicrystalline materials have been developed and tested.
New, unknown knowledge of the patterns of change of structure, substructure, stress, surface morphology and physical properties of promising functional metal materials used or can be used in conditions of intense cyclic radiation and thermal loads, which are characteristic of the international thermalcordial reactor ITER, is obtained. Physical bases for the creation of stable metal materials for nuclear and thermonuclear energy have been developed.
It is established that the mechanism of cracks in tungsten diverters when irradiated by hydrogen plasma by ELMS transitional modes on QSPA Kh-50 is that the relaxation of temporary thermal stress by deformation by the mechanism of twin and coalescence of vacancy complexes. The crack occurs as a result of the interaction of the double with the micropora filled.
It has been found that quasicrystalline thin Ti-Zr-Ni films in radiation loads are less prone to cracks, and the pores are not characteristic at all, so we propose the concept of protection of the first wall and tungsten divergent of the thermonuclear reactor with the use of йuasicrystallic coatings Ti-Zr-Ni. Thin films with a quasi -krystalic structure have always been practiced for metal systems based on aluminum. The use of fine coatings on metal substrates solves the problem of fragility of QCs in a massive and tape state. For Ti-Zr-Ni quasicristals, the ability to accumulate in the form of a solid solution is a large (till 2 n/at.) The amount of hydrogen. In addition, it is known that a target-saturated film can be used as an important device of a neutron generator based on a D-T reaction. But a few work with Ti-Zr-Ni films did not allow to get films with a qualitative perfect structure. The films remained amorphous, or lost the necessary composition. We have developed and used a different method and kept films with high -quality diffraction paintings over a wide range of diffraction angles. Initial study of radiation and thermal effects on quasi-cycricists was conducted. Plasma interaction with the first ITER wall and the components of the divergence is one of the most important tasks for determining the productivity and safety of future thermonuclear reactors. The high flow of heat and particles in both the stationary and transitional period leads to significant surface erosion and cracks on the surface and under the surface. Understanding the mechanisms of cracking would allow you to develop counter -measures and significantly extend the life of thermonuclear devices to meet the requirements for ITER and DEMO. The studies of this work have established a mechanism for the formation of quasicrystal samples when irradiated with stationary and pulsed ionic bundles. For the first time, data on the dominant mechanisms of change of structure, substructure, stressful state and morphology of the surface of solids and coatings with extreme radiation and thermal loads that model working conditions and those that are characteristic of the international thermonuclear experimental reactor ITER.
The project is aimed at the study of radiation-thermally stimulated processes of change of structural-phase and stressful state of film compositional nano- and microsystems of refractory metals and quasicristals on the surface of steels are suitable for long-term use in conditions nuclear power. Systems consisting of W/Ti-Zr-Ni Qasocristal (QC) are offered to study diffusion and between layer mixing, phase transformations, the development of internal macro and micro-comparisons, changes in structure and microstructure characteristics, x-ray parameters and physical properties. The possibility of forming a physical and material foundations for solving the problem of radiation and thermal stability of materials will be considered.
4. Contact Information
Principal Investigator Contact: Prof. Serhii Malykhin
Email: serhii.malykhin@khpi.edu.ua