Modern Physical Science Research Articles

Gradient of microhardness in the contact zone coating (HEA CoCrFeNiMn) – substrate (alloy 5083)

In this work, a coating of a high-entropy alloy CoCrFeNiMn of non-atomic composition is formed on a substrate made of alloy 5083 by the method of wire-arc additive manufacturing (WAAM). The authors investigated the change in microhardness in the contact zone of the coating – substrate system. Using the methods of modern physical materials science, the structural and phase state, defect structure and elemental composition of the coating – substrate system were analyzed. The discovered physical mechanisms contribute to an increase in hardness in the contact zone.

Complex Modification of the Surface Layer of a High-Entropy Al-Cr-Fe-Co-Ni Alloy by Electron-Ion-Plasma Treatment

Using the technology of wire-arc additive manufacturing (WAAM – wire arc additive manufacture), a high-entropy alloy (HEA) of non-equiatomic composition Al, Cr, Fe, Co, Ni was manufactured. Using the methods of modern physical materials science, an analysis of the elemental and phase composition, defective substructure, mechanical and tribological properties of the HEA surface layer, formed as a result of complex modification, combining the deposition of a film (B + Cr) and irradiation with a pulsed electron beam in an argon medium, was carried out. In the initial state, the alloy has a simple cubic lattice with a lattice parameter of 0.28795 nm; the average grain size of the HEA is 12.3 µm. Chemical elements (at. %) 33.4 Al; 8.3 Cr, 17.1 Fe, 5.4 Co, 35.7 Ni, which form HEA, are distributed quasi-periodically. The irradiation regime was revealed (energy density of the electron beam ES = 20 J/cm2, pulse duration 200 µs, number of pulses 3 pulses, frequency 0.3 s more than 5 times), allowing to increase microhardness (almost 2 times) and wear resistance (more than 5 times), reduce the coefficient of friction by 1.3 times. Regardless of the value of ES, HEA is a single-phase material and has a simple cubic crystal lattice. High-speed crystallization of the surface layer leads to the formation of a subgrain structure (150–200) nm. It is shown that an increase in the strength and tribological properties of HEA is due to a significant (4.5 times) decrease in the average grain size, the formation of particles of chromium and aluminum oxyborides, and the incorporation of boron atoms into the crystal lattice of HEA.

Investigate A New Tangent Bundle Space from A New Point and Two Curves using MATLAB

Our goal was to create a new tangent bundle space from a new point and two curves using the MATLAB program. We used the applied mathematical approach, and we arrived at an accurate model of the tangent bundle space by building an algorithm that implements the solution and displays the results and represents them graphically with ease and with high accuracy. This is what MATLAB makes a suitable working environment for dealing with tangent bundles. Given the importance of tangent bundles in modern engineering and physical sciences, this algorithm can be developed to include the most important areas of tangent bundles instead of the complex traditional method

Experimental sensing quantum atmosphere of a single spin

Understanding symmetry-breaking states of materials is a major challenge in the modern physical sciences. Quantum atmosphere proposed recently sheds light on the hidden world of these symmetry broken patterns. Yet, no experiment has been performed to demonstrate its potential. In our experiment, we prepare time-reversal-symmetry conserved and broken quantum atmosphere of a single nuclear spin and successfully observe their symmetry properties. Our work proves in principle that finding symmetry patterns from quantum atmosphere is conceptually viable. It also opens up entirely new possibilities in the potential application of quantum sensing in material diagnosis.

Biomimetic Materials in Pediatric Dentistry: From Past to Future.

“Biomimetics” is the field of science that uses the natural system of synthesizing materials through biomimicry. This method can be widely used in dentistry for regeneration of dental structures and replacement of lost dental tissues. This is a review paper that states its scope, history, different fields of biomimetic dentistry, and its future conditions in India. With Biomimetic dentistry, only the damage and decay are removed from the teeth, and the final restoration is bonded to the remaining healthy natural tooth structure. The scope of biomimetic dentistry in India is enormous in the near future. It is the designing of biomaterials that simulates physical and mechanical properties of the lost tissue, thus providing an opportunity to introduce and change treatment modalities for the disease. Biomimetic dentistry is an interdisciplinary approach and has potential for transforming everyday dental practice. It brings the power of modern biological, chemical, and physical science to solve real clinical problems. Biomimetics provides a new strategy that translates our knowledge of biological structures and functions and creates new synthetic pathways to mimic biological processes.

The Platonism of Modern Physical Science: Historical Roots and “Rational Reconstruction”

AbstractPerhaps the most influential historian of science of the last century, Alexandre Koyré, famously argued that the icon of modern science, Galileo Galilei, was a Platonist who had hardly performed experiments. Koyré has been followed by other historians and philosophers of science. In addition, it is not difficult to find examples of Platonists in contemporary science, in particular in the physical sciences. A famous example is the icon of twenty century physics, Albert Einstein. This paper addresses two questions related to the Platonism of modern physical science. The first is: How is Galileo’s Platonism compatible with the fact that he did perform experiments? The solution to this apparent paradox can be found in Plato’s late dialogue Timaeus. In the dialogue the world has been created by a divine craftsman according to an original plan. The task of the scientist is not primarily to describe the material world, but to reconstruct the original plan. This view has later been known as “God’s Eye View”. The second question is: If a God’s Eye View is unattainable, how is it possible to give a “rational reconstruction” of Galileo’s Platonism? The key-word is idealisation. It is further argued that idealisation is intimately related to technology. Technology is required to realize ideal experimental conditions, and the results are in its turn implemented in technology. The implication is that the quest for unity in science, based on physics as the basic science, should be replaced by the recognition of the diversity of the sciences.

Phase Diagram of High-Temperature Electron-Hole Quantum Droplet in Two-Dimensional Semiconductors.

Quantum liquids, systems exhibiting effects of quantum mechanics and quantum statistics at macroscopic levels, represent one of the most exciting research frontiers of modern physical science and engineering. Notable examples include Bose-Einstein condensation (BEC), superconductivity, quantum entanglement, and a quantum liquid. However, quantum liquids are usually only stable at cryogenic temperatures, significantly limiting fundamental studies and device development. Here we demonstrate the formation of stable electron-hole liquid (EHL) with the quantum statistic nature at temperatures as high as 700 K in monolayer MoS2 and elucidate that the high-temperature EHL exists as droplets in sizes of around 100-160 nm. We also develop a thermodynamic model of high-temperature EHL and, based on the model, compile an exciton phase diagram, revealing that the ionized photocarrier drives the gas-liquid transition, which is subsequently validated with experimental results. The high-temperature EHL provides a model system to enable opportunities for studies in the pursuit of other high-temperature quantum liquids. The results can also allow for the development of quantum liquid devices with practical applications in quantum information processing, optoelectronics, and optical interconnections.

Evolution of structural-phase state and properties of hypereutectoid steel rails at long-term operation

The methods of modern physical materials science were used to analyze the evolution of microhardness, tribological properties, dislocation substructure and phase composition of the rails with increased wear resistance and contact endurance of DT 400 IR category after missed tonnage of 187 million gross tons on the experimental ring of Russian Railways. It is shown that extremely long-term operation of the rails is accompanied by a decrease (3.1 times) in wear parameter of the rolling surface and an increase (1.4 times) in microhardness, scalar dislocation density (1.5 times) and Fe3C carbide content (1.24 times). Operation of the rails led to a decrease in the crystal lattice parameter, which correlates with an increase in the content of iron carbide. We made the assumptions about physical causes of the change in parameters.

The Stochastic Structural Modulations in Collapsing Maccari’s Model Solitons

The two-dimensional Maccari nonlinear system performs the energy and wave dynamical features in fiber communications and modern physical science as hydrodynamic and space plasma. Several new forms of solutions for the Maccari’s model are constructed by a unified solver method that mainly depends on He’s variations method. The obtained solutions identify new wave stochastic structures with important features in energy physics such as rational explosive, breather, dispersive, explosive dissipated, dark solitons and blow-up (shock structure). It was elucidated that the random effects amend the energy wave strength or the collapsing due to model medium turbulence. Finally, the produced stochastic structures may be vital in some of these relationships between dispersions, nonlinearity and dissipative effects. The predominant energy waves that are collapsing or being forced may be applied to electrostatic auroral Langmuir structures and energy-generating ocean waves.

Evolution of the Lamellar Pearlite Structure of Rail Steel under Tension

In this paper, the properties of rail steel subjected to fracture under uniaxial tension deformation are studied. Mechanical properties of rail steel, defective substructure of lamellar pearlite, and fracture surface of rail steel are investigated using methods of modern physical materials science.
 Tensile strength is found to vary from 1247 to 1335 MPa, and the fracture strain of the samples changes from 0.22 to 0.26. The deformation of the rail steel is accompanied by the process of breaking the ferrite plates into fragments by low angle boundaries along with the significant increase in the scalar dislocation density to 7.9-1010 cm-2 (the scalar dislocation density of the original rail steel is 3.2 -1010 cm-2). Also, there is a formation of internal stress fields appearing in the form of bend extinction contours. The sources of stress fields are identified. It is revealed that cementite plates are fractured by cutting and dissolution with subsequent transfer of carbon to ferrite plates by moving dislocations and formation of round-shaped nanodimensional (8.3 nm) round shaped particles of tertiary cementite. It is shown that the dissolution of cementite plates is accompanied by fragmentation (into coherent scattering regions with an average size of 9.3 nm).

Structure and Properties of the "Cantor HEA Coating (Mn-Fe-Cr-Co-Ni) / Substrate (Alloy 5083)" System

Using the technology of cold metal transfer (wire-arc additive manufacturing combined with welding surfacing), a coating is formed on a 5083 alloy substrate with a high-entropy Mn-Fe-Cr-Co-Ni alloy of nonequiatomic composition. Analysis of the structure, elemental composition, and microhardness of the coating-substrate system is carried out using the methods of modern physical materials science. A significant increase (up to 9.9 GPa) in the microhardness of the material is found in the zone of contact between the coating and the substrate. The formation of lamellar inclusions (Al13F4) enriched in coating atoms in the zone of contact between the coating and the substrate is revealed. The high entropy coating in the contact zone has a submicrocrystalline grain-subgrain structure with a crystallite size ranging from 0.5 ^m to 1.1 ^m along the boundaries where nanosized particles of the second phase (Al3Ni) are revealed. The volume of grains contains a dislocation substructure in the form of randomly distributed dislocations or dislocation clusters. The scalar density of the dislocations is (0.8-1.0)-1010 cm-2. An assumption is made about the physical mechanisms of hardening of the material in the "coating-substrate" contact zone. Key words: high-entropy alloy, coating / substrate system, aluminum alloy, elemental and phase composition, microhardness, hardening.

Transformation of fine structure of lamellar pearlite under deformation of rail steel

The defective substructure of polycrystalline bodies causes substructural hardening and mechanical properties. Perlite, which is the main structural component of rails, undergoes a significant transformation during deformation, which is accompanied by a number of processes. In this paper, the methods of modern physical materials science were used to study and analyze the defective substructure of perlite of lamellar morphology and the properties of rail steel subjected to destruction under deformation conditions by single-axis stretching of flat samples. It was established that the ultimate strength varies from 1247 to 1335 MPa, and the relative deformation to failure – from 0.69 to 0.75. The formation of three zones of the fracture surface was observed: fibrous, radial and shear zones. Their shape and sizes were analyzed. Deformation of rail steel is accompanied by destruction of cementite plates of perlite colonies and repeated release of nanoscale particles of tertiary cementite approximately 8.3 nm in size in the volume of ferrite plates. The main mechanisms of destruction of cementite plates are cutting and dissolution. The dislocation substructure is represented by a chaotic distribution of dislocations and their clusters. The scalar density of dislocations in ferrite increases from 3.2·1010 cm–2 in the initial state to 7.9·1010 cm–2 when it is destroyed. Deformation is accompanied by formation of internal stress fields, manifested in the form of bending extinction contours. The sources of stress fields are the interface of cementite and ferrite plates, as well as grain boundaries. Fragmentation of ferrite and cementite plates was revealed. The average size of cementite fragments is 9.3 nm. In fracture zone of the rail steel sample, rotation of perlite grains was noted, indicating the presence of a rotational mode of deformation. Electron microscopic images of cementite plates show a change in the contrast, which may be associated with the formation of Cottrell’s atmospheres.

Анализ механизмов упрочнения рельсовой стали при пластической деформации одноосным сжатием

Using the methods of scanning and transmission electron microscopy, an analysis was made of the evolution of the structure and defective substructure of rail steel under uniaxial compression up to a degree of 50%. It is revealed that the strain hardening has a multistage nature and is accompanied by a decrease in the scalar and excess dislocation density and fragmentation of pearlite grains, which increases with increasing strain. Fracture of cementite plates proceeding through the mechanisms of their dissolution and cutting by mobile dislocations is revealed. On the basis of data on the structural-phase states, the defective substructure of rail steel, obtained by the methods of modern physical materials science, a quantitative analysis of the mechanisms of hardening of rail steel at degrees of compression deformation of 15, 30, 50 % was carried out. It is shown that at the initial stage (ε = 15 %), the main strengthening factor of the steel under study is the presence of lamellar pearlite grains, and at high degrees of deformation (ε = 50 %), hardening by incoherent particles of the carbide phase. The overall yield strength of steel was estimated in the first approximation, based on the additivity principle, which assumes the independent action of each of the hardening mechanisms. A good qualitative agreement between the experimentally obtained and theoretically calculated values of steel strength has been revealed.

МЕТОДИЧНІ ОСОБЛИВОСТІ УЗАГАЛЬНЕННЯ ЗНАНЬ ШКОЛЯРІВ ПРО ФУНДАМЕНТАЛЬНІ ФІЗИЧНІ ПРИНЦИПИ

The article is devoted to solving the urgent, complex and multifaceted problem of increasing of the level and quality of fundamental training of schoolchildren in physics in modern educational conditions. The author notes that the solution of this problem requires the implementation of methodical approaches and learning technologies that will provide students with a purposeful and consistent mastery of a system of organically interconnected subject, worldview and methodological knowledge, followed by their generalization with the help of relevant physical principles at the level of modern physical pictures of the world. In this regard, the author determined the sequence of studying the material and highlighted the theoretical and methodological aspects of generalizing students' knowledge about the fundamental physical principles of relativity, conservation and atomism, which should be the focus of teachers' attention both during the educational process and at the final classes on the relevant topics. Schoolchildren's awareness of the physical essence of the principle of relativity contributes not only to the understanding of the general laws of mechanical motion and the interaction of bodies in different reference systems, but also expands and deepens knowledge of two basic scientific concepts (mass, energy) and forms an idea of a single four-dimensional space-time continuum that encompasses. Students' understanding of the fundamental importance of the principle of conservation is connected not only with the unity of space-time, but also with the symmetry of space, symmetry of interactions, and symmetry of laws. Elucidation by students of the physical essence of the fundamental principle of atomism involves a consistent awareness of the discrete structure of matter, electromagnetic radiation, the discreteness of the physical characteristics of micro-objects. It is noted that students' understanding of the physical essence and methodological significance of the latter will not only correspond to the development trends of modern physical science, but will also contribute to increasing the level of subject competence, the formation of a scientific worldview, and will be a guarantee of the success of further education and future professional growth. Key words: fundamental physical principles, systematization and generalization of schoolchildren's knowledge, scientific outlook, subject competence of students in physics.

The Origin of Modern Physical Science: Some Passages from A Theory of Wonder

The triumph of the Copernican revolution is commonly associated with the introduction of the scientific method, mainly by Galileo. The nature of science presumably depends on the way observation passes judgment on theory. This is how, according to empiricism, the practice of science improves our worldviews. Some historically inclined philosophers of science, most notably Kuhn and Feyerabend, have insisted on paying attention to what Galileo actually said and did. Shockingly, he drives a dagger through the heart of empiricism: observation does not have such priority over theory, because observation itself assumes theory. This is what he argues when dismantling Aristotle’s Tower Argument, according to which a stone dropped from a tower falls straight down to the base of the tower. If this is so, the Earth cannot rotate, for it would carry the tower with it, making our observation of the stone’s flight wildly different. According to Galileo, to conclude that the stone really falls vertically requires the assumption that the Earth does not move – the theoretical issue in question. Given Galileo’s proper understanding of the nature of science, I view Feyerabend’s principle of proliferation as the realization that a good strategy for the latter is to elaborate radical alternatives and, on their basis, reconsider what counts as evidence. Moreover, a science produced by human brains should be analyzed on the basis of evolutionary theory and neuroscience. From that perspective, we may be able to defend a sensible notion of relativism. These considerations have led me to the main arguments of my new book, A Theory of Wonder: Evolution, Brain, and the Radical Nature of Science (Philosophy of Science, Vernon Press, Wilmington — Malaga 2021). I hope to entice the reader into a discussion of some of the issues developed there.

Structure and properties of high-entropy FeCoCrNiAl alloy coating

The coating of a high-entropy alloy (HEA) of non-equiatomic composition was formed on a substrate of alloy 5083 using the technology of wire-arc additive manufacturing (WAAM) in an atmosphere of pure nitrogen. Analysis of the structure, elemental composition, micro-hardness, and wear resistance of the coating/substrate system was carried out using the methods of modern physical materials science.

INTENSIFICATION OF THE PROCESS OF PLASMA-INDUCTION GROWING OF LARGE PROFILED TUNGSTEN SINGLE CRYSTALS

The structure of a profiled tungsten single crystal obtained by plasma-induction layer-by-layer growth on a single crystal seed crystal at different deposition rates is investigated. Investigated – microhardness, size of the subgrain structure, angles of misorientation of subgrains, the nature of the distribution of dislocations, etc. A complex of experimental methods of modern physical materials science was used, including light, scanning and transmission microdiffraction electron microscopy. It was found that the ingot is a single crystal body with a crystallographic orientation given by the seed crystal. An increase in the growth rate to 70 mm/min leads to an insignificant decrease in microhardness, refinement of the substructure with a uniform distribution of the dislocation density, which makes it possible to obtain tungsten single crystals with a single crystal structure at disorientation angles not exceeding 3°.

Evolution of structure of AlCoCrFeNi high-entropy alloy on irradiation by pulsed electron beam

By the methods of modern physical materials science the change in structural-phase state of AlCoCrFeNi high-entropy alloy (HEA) of nonequiatomic composition obtained by the methods of wire arc additive technology (WAAM) after irradiation by electron beams with energy density of 10-30 J/cm2, durality of 50 μs, frequency 0.3 s-1 is studied. In the initial state the alloy had a dendritic structure indicating the inhomogeneous distribution of elements. It is shown that electron beam processing forms the structure of high-velocity cellular crystallization with cell size of 100-200 nm, along boundaries of which the nanodimensional (15-30 nm) inclusions of the second phase enriched in Cr and Fe atoms are located. Keywords: High-entropy alloy, electron beam processing, structure, phase composition.

Structural phase variations in high-entropy alloy at irradiation by pulsed electron beam

The high-entropy alloy (HEA) of Al - Co - Cr - Fe - Ni system of nonequiatomic composition is obtained by the technology of wire-arc additive manufacturing (WAAM) in atmosphere of pure nitrogen. By the methods of modern physical materials science it is shown that in the initial state the alloy has dendritic structure indicating nonhomogeneous distribution of alloying elements. It is a multiphase material whose main phases are Al3NCr3C2 , (Ni, Co)3Al4 . Nonadimensional particles (Ni, Co)3Al4 of cubic shape are located along interfaces of submicron phases Al3Ni and Cr3C2 . The HEA irradiation by pulsed electron beams with energy density Es = 10 + 30 J/cm2, pulse duration of 50 is, frequency of 3 Hz and pulse number of 3 leads to high-velocity melting and subsequent crystallization of surface layer. If Es = 10 J/cm2, no failure of dendritic crystallization structure happens. Interdendritic spaces are enriched in chemical elements Al, Ni and Fe, and dendrites themselves - in chromium atoms. The most liquating element of the alloy is Al, the least one is Co. If Es = 20 J/cm2, a nanocrystalline structure is formed in the layer 15 inn thick in bulk of grains. Size of crystallization cells amounts to 100 - 200 nm, size of inclusions in cell junctions is 20 - 25 nm, and along cell boundaries it is 10 - 15 nm. Cells of high-velocity crystallization are enriched in Al and Ni. The Co atoms are homogeneously distributed along the surface layer volume. The most liquating element is Cr, the least liquating one is Co. The increase in energy density of electron beam to 30 J/cm2 doesn't lead to substantial (as compared to Es = 20 J/cm2 ) variations in surface layer structure. The irradiation mode (Es = 20 J/cm2, 50 is, 3 pulses, 0.3 Hz) is detected that allows formation of the surface layer with the highest level of homogeneity of chemical element distribution in the alloy.

Retrospective Review of the Development of the Concepts of Consonance and Dissonance: On the Problem of Musical and Aesthetic as well as Physical and Mathematical Interpretation

"The research aimed at a comprehensive retrospective analysis of the development of “consonance and dissonance” as a musical and aesthetic category in physical and mathematical interpretation; defining the notion of consonance as a musical theoretical and aesthetic category, confirming the relevance of its use in physical and mathematical terminology to explain acoustic phenomena. Research methodology is based on the use of the retrospective method (or the retrospection method), which allowed identifying the theories of consonance and dissonance in the historical retrospective. The periodization method was used to find out individual stages in the development of science in order to discover the leading directions of scientific thought, identify new elements relating to various aspects of “consonance” and “dissonance”. The study of the retrospective review of the development of the notions of consonance and dissonance in the physical and mathematical interpretation involved an interdisciplinary method a way of organizing research work, providing for the interaction of music and mathematics in the study of consonance and dissonance. Scientific novelty. This study is the first to reflect the general tendency towards the mathematization of the humanities and the humanitarization of the physical and mathematical areas of modern culture. Some provisions of musical acoustics were clarified in the context of creating a harmonious conceptual structure. The article presents the author’s concept of clarifying the notion of phase in relation to the spectral structure of an audio signal based on the notion “slightly mistuned consonance”. Conclusions. A retrospective review of the development of the notions of consonance and dissonance in the physical and mathematical interpretation was carried out and presented as a comprehensive description and review of the formation of concepts in the temporal sequence of their creation. Retrospectiveness through a review of significant discoveries and achievements in music and natural science allowed tracing the formation of the theories of consonance and dissonance from the standpoint of the interdisciplinarity of modern knowledge in the humanities. The further process of the development of sound musical art technologies requires a significantly higher scientific level of their study, the creation of a coherent conceptual system based on modern physical and mathematical sciences as well as computer science to explain sound acoustic phenomena. Keywords: consonance, dissonance, mistuned consonance, overtone, harmonics, beats, phase, spectral component"