Strength and functional characteristics of hexa and pentagonal 2D materials. Hydrogen

An analysis of synthesized unique two-dimensional 2D materials with nanolayer hexagonal and pentagonal structures (based on carbon, silicon, tin, binary compounds CN2, BN2, PdSe2 and ternary compounds – BCN, CNP, PdSSe, Zn2C2P2) was carried out. The synthesis of these materials was performed by the chemical vapor deposition or metal epitaxy on pre-prepared substrates. The strength and functional characteristics (electronic, optical) of the created models were also analyzed using the DFT theory in the form of triple monolayers with double-sided deposition of hydrogen on the surface of the p-Si2C4 monolayer: hydrogen/p-Si2C4/hydrogen. It was found that the p-Si2C4-4H layer with its two-sided hydrogen adsorption and good properties was the most dynamically stable. This article also presents relatively recently obtained hexa- and pentagonal two-dimensional materials not only for the elements C, Si, Ge, B, but also for Cu1–xNix, Ti1–xNix alloys and Bi1–xSbx, CN2, BN2, PdSe2, etc. compounds. So, with the new unique materials created – the synthesis of superstrong, thermostable nanocomposites, superconducting layered composites (based on Bi, Hg and Sb), prospects are opening up for the development of nanoelectronics, spintronics, computer technology, as well as the creation of portable strain gauges, pressure sensors, gas sensors and dialysis catalysts for water dialysis with the release of hydrogen and oxygen

Alloying and strain hardening of high-entropy membrane storage nano and crystalline alloys

The article presents both molecular dynamics calculations of binary Fe–Ni alloys and experimental studies of Ti and Co alloyed nanocrystalline alloys with a B2–Ti(Fe, Co) matrix structure as well as bcc-(Nb, Ti) and B2– eutectic phases Ti(Fe, Co). The structures of membrane alloys based on Fe–Ni (arrangement of atoms in coordination polyhedra and interatomic distances between atoms), as well as the kinetics of hydrogen - diffusion and permeability have been studied. It is shown that in the membranes of alloyed alloys with the substitution of Ni for cobalt Fe35-XCoXTi35Nb30, with an excess of Fe than for cobalt, mechanical brittleness is manifested in the B2–TiFe phase, and the plasticity of the B2 phase also decreases. At the same time, the resistance to an increase in hydrogen absorption is also weakened, up to mechanical destruction of membranes, so that in high-entropy alloys Fe0,2Ni0,2Cr0,2Co0,2Mn0,2, Fe0,2Co0,2Cr0,2 Ti0,2Al0,2 Fe and Co in equal parts. Other intermetallic alloys are also promising, having more complex compositions with high or moderate entropy, for example, Zr0,2Ti0,2Nb0,2V0,2Co0,2 and Zr0,2Ti0,2Ta0,2V0,2Co0,2, in addition to hydrogen evolution, also have storage properties. Within the framework of molecular dynamics, the effect of strain hardening of membrane HEA alloys is experimentally presented - the mechanism of synergy with multiple deformation. As a result of such hardening, a partial transformation of the austenitic phase into a martensite phase occurs with the formation of twinning in their fcc/hcp grains and the formation of a two-phase matrix structure

Nanosized high-entropic materials based on HEA, design principles and synthesis methods

The principles of designing high-entropy alloys related to the selection of elements are analyzed. When selecting elements, a parametric approach is used, including chemical and topological parameters. The main chemical parameter is the enthalpy of mixing of elements, the main topological parameter is the atomic radius. It is emphasized that the use of modified atomic radii (which take into account the local electronic environment) better predicts the formation of either amorphous or crystalline high-entropy alloys. Four main effects that determine the properties of high-entropy alloys are considered: the high entropy effect, the lattice distortion effect, the delayed diffusion effect, and the «cocktail» effect. Obtaining nanosized high-entropy materials based on high-entropy alloys is a new promising direction that allows one to significantly expand their areas of application related to energy (catalysis, energy storage, etc.), nanoelectronics, etc. The article analyzes some methods for the synthesis of nanosized high-entropy alloys and materials based on them. basis, developed as catalysts. The improved performance over conventional catalysts is explained in terms of the effects and features specific to multicomponent systems

Laser surface hardening of Kh9VMF-Sh cluster mill work rolls

22.00; Translated from Russian (Stal' 1987 (2) p. 92-94)SIGLEAvailable from British Library Document Supply Centre- DSC:9022.06(BISI--25926)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Reduction of metal reject on 1150 slabbing mill through stabilization of length of slabs Report 2

Translated from Russian (Izv. Vyssh. Uchebn. Zaved., Chern. Metall. 1985 (7) p. 73-77)SIGLEAvailable from British Library Document Supply Centre- DSC:5828.4(M--36580)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo