Formation Of Cellular Structure Research Articles

Effects of 1:5H-type Cu-rich phase around grain boundary on cell boundary phase and squareness of the demagnetization curve in sintered Sm2Co17-type magnets

The unique cellular structure of Sm2Co17-type magnets is responsible for their outstanding magnetic properties. However, the cell boundary phase around grain boundaries is few, and cannot form a complete cellular structure. This study explores the microstructure and microchemistry of the grain interiors and grain boundary regions in both the solid solution precursor and the final magnet. The Cu-rich phase precipitates around grain boundaries in the solid solution precursor, and it remains present in the final magnet. The Cu-rich phase is not present as a standalone grain boundary phase, rather, it possesses a hexagonal CaCu5-type crystal structure and demonstrates a coherent orientation relationship with the surrounding matrix. The Cu-rich phase inhibits cellular structure formation nearby, while boosting Cu content in the cell boundary phase at the grain boundary regions in the final magnet. The formation of a Cu-rich phase around the grain boundary increases the heterogeneity of the domain wall pinning field in the final magnet, becoming an unfavorable factor for the improvement of the squareness of the demagnetization curve. These discoveries enhance our comprehension of the precipitated phase surrounding the grain boundary and its impact on the cellular structure and magnetic characteristics of the magnet.

PIK3R1 fusion drives chemoresistance in ovarian cancer by activating ERK1/2 and inducing rod and ring-like structures

Gene fusions are common in high-grade serous ovarian cancer (HGSC). Such genetic lesions may promote tumorigenesis, but the pathogenic mechanisms are currently poorly understood. Here, we investigated the role of a PIK3R1-CCDC178 fusion identified from a patient with advanced HGSC. We show that the fusion induces HGSC cell migration by regulating ERK1/2 and increases resistance to platinum treatment. Platinum resistance was associated with rod and ring-like cellular structure formation. These structures contained, in addition to the fusion protein, CIN85, a key regulator of PI3K-AKT-mTOR signaling. Our data suggest that the fusion-driven structure formation induces a previously unrecognized cell survival and resistance mechanism, which depends on ERK1/2-activation.

Experimental study on the explosion characteristics of ammonia-hydrogen-air mixtures

Ammonia-hydrogen blended fuel has drawn substantial attention as an environmentally friendly, carbon-free fuel because it effectively overcomes the inherent disadvantages of pure ammonia in combustion performance, such as a high ignition energy, slow combustion rate, and low combustion efficiency. While recent research on the combustion performance of hydrogen-ammonia blends has advanced, there remains a scarcity of studies addressing the explosion characteristics of these fuels. In this paper, a series of experiments conducted within a standard 20-L spherical combustion chamber to investigate the explosion characteristics of ammonia-hydrogen-air premixed gases under diverse conditions, spanning from low to high pressures (0.02–0.3 MPa) and from fuel-lean to fuel-rich scenarios (0.7–1.5), are discussed. The results reveal that the explosion characteristics are pronouncedly enhanced by hydrogen addition. The maximum explosion pressure (Pmax) and maximum pressure rise rate ((dP/dt)max) increase, while the explosion time (texp) decreases with increasing hydrogen concentration. Pmax and (dP/dt)max exhibit linear increases as the initial pressure rises and reach their peaks at an equivalence ratio of 1.1; texp displays nonmonotonic variations with increasing initial pressure and equivalence ratio. Hydrogen addition remarkably increases the hydrodynamic instability and thermal-diffusion instability of the reactive mixture, enhances the thermal-mass diffusion on the flame front, and promotes flame deformation and cellular structure formation, resulting in an improvement of the flame propagation and compression effect on the unburnt reactant before the flame. Research into the explosion characteristics provides valuable insights for the safe storage and transportation of ammonia-hydrogen blended fuels. These results indicate avenues for further enhancing the detonation characteristics and explosion performance of ammonia-hydrogen blended fuels.

Investigation of cellular instabilities and local extinction for two-phase flames under microgravity conditions

The initial mechanism of cellular instabilities on the flame surface was investigated experimentally. Firstly, mono-dispersed ethanol droplets were created via the Wilson cloud principle in a spherical combustion chamber, and aerosol ethanol/air flame propagation was tracked under microgravity conditions. Schlieren images revealed that at the beginning of the cellular structure formation, dark spots formed linking to the signal loss in a density gradient. This phenomenon is assumed to be local extinction and quenching on the flame front due to either liquid droplets’ presence or evaporation. To further investigate the observed phenomenon, stagnation flame experiments were performed for rich propane/air gaseous flames with isolated ethanol droplet injection. The evidence for the local extinction on the flame surface due to droplet passage was found via the Chemiluminescence method. The intrinsic instabilities were found to be triggered by the droplets in cases where the flame cannot recover its initial state.

Role of scanning speed on the microstructure and mechanical properties of additively manufactured Al2O3‒ZrO2

AbstractMelt‐grown Al2O3–ZrO2 eutectic (AZ eutectic) ceramics have attracted extensive attention for harsh environment applications. In this work, AZ eutectic ceramic is additively manufactured via one‐step laser powder bed fusion (LPBF). The role of scanning speed on phase formation, crystallographic characteristics, microstructure evolution, and mechanical properties were systematically investigated. The as‐fabricated specimens are mainly composed of α‐Al2O3 and t‐ZrO2. Lower scanning speeds induced the formation of cellular structures consisting of randomly oriented ZrO2. In contrast, nanometer eutectic lamellar structure with well‐defined multiple crystallographic orientation relationships, for example, {100} Al2O3 || {100} ZrO2 and {0001} Al2O3 || {001} ZrO2, occurred at higher scanning speeds. Both the cell size and lamellar spacing decreased with increasing scanning speed. With the microstructure refinement, the crack propagation mode changes from intergranular to transgranular fracture, leading to progressively enhanced fracture toughness with a maximum value of 7.76 MPa·m1/2. The present work could shed light on tailoring the microstructure of LPBF AZ eutectic ceramic via varying processing parameters.

Understanding cellular structure formation in rapidly solidified Al–Ni alloys by constructing solidification microstructure selection maps

Understanding cellular structure formation in rapidly solidified Al–Ni alloys by constructing solidification microstructure selection maps

Experimental investigation of cell generation in an expanding spherical hydrogen-air flame front

This paper reports on the cellular structure formation on the front of a spherically expanding hydrogen-air flame. The hydrogen-air mixture was considered with hydrogen concentration in experiments from 10 to 50 vol%. This paper aims to analyze cell cascade formation, which occurs due to diffusional-thermal and hydrodynamics instabilities. Using experimentally obtained schlieren images, the flame front radius as the function of an angle was obtained. The cell amplitude dependencies on the normalized time were also analyzed. The values corresponding to cell splitting were obtained by the discrete Fourier transform method. The cell split criterion, which allows taking into account the known instability mechanisms, was formulated.

Numerical Modeling of the Cellular Structure Formation Process in SiC Solution Growth for Suppression of Solvent Inclusions

Numerical Modeling of the Cellular Structure Formation Process in SiC Solution Growth for Suppression of Solvent Inclusions

Alterations in The Functional and Structural Properties of Erythrocytes Due to Alcohol Intoxication; Correction of Disorders

Alcohol abuse is among the leading reasons for disability and accounts for at least 5% of the global health burden. This study aims to define changes in the functional and structural properties of erythrocytes in chronic ethanol intoxication and to design methods for correction of the identified disorders. The experiments has been conducted on 93 healthy sexually mature and newborn Wistar rats. Acute and chronic alcohol intoxication has been designed by forced intragastric administration of 20% ethanol solution at a dose of 3 ml/kg (2.92 g/kg) on a daily basis for 5, 30 and 60 days. From the newborn animals we obtained allogeneic hepatocytes and their cultural fluid, from which proteins were isolated. The proteins of allogeneic hepatocyte and the combined administration of immunomodulatory, hepatoprotective and antioxidant agents were used to correct disorders in chronic intoxication. The membranes of circulating erythrocytes were obtained by the method of Dodge; electrophoretic separation of membrane proteins was carried out according to the method of Laemli. The lipid content in the erythrocyte membrane was determined by liquid thin-layer chromatography. It has been elucidated that in presence of chronic alcohol intoxication there is a change in the content of the membrane proteins in circulating erythrocytes, which are responsible for flexibility and shaping, intrinsic cellular metabolism, stabilization and structure formation, and a disruption in the lipids representativeness and ratio that form the basis for the lipid framework of the plasmalemma and play the major role in arrangement of protein macromolecules and the normal metabolism of red blood cells as well. When analyzing the corrective activity of the proteins of allogeneic hepatocytes and the combination Glutoxim + Mexidol + Heptral, we have established their high efficiency towards the disorders in the functional and structural properties of circulating erythrocytes caused by chronic alcohol intoxication.

General principles and criteria of failure of solids on different scale-structural levels under static and alternating loading

Experimental and theoretical studies of the fracture regularities under monotonic and alternating loadings, including stress-corrosion fracture, revealed the main scale-structural levels of the brittle fracture (formation of a strip structure, nucleation of microcracks, microstructurally short non-propagating cracks and short propagating cracks, merging of short cracks with a macrocrack nucleation) and viscous fracture (an evolution of dislocation in slip bands, cellular structure formation, nucleation of a pit relief with micropores, merging of pores with a formation of meso-shear bands and initiation of a viscous crack, growing of a viscous crack under inelastic deformation) of crystal bodies. A transition from one level to another is determined by changes in the fracture mechanisms and occurs with varying degrees of probability. The necessity of considering the destruction as a hierarchical random step-by-step process on all scale-structural levels is substantiated. The fracture of plastic materials is considered as the sum of independent or dependent events, namely the initiation and growing of brittle cracks and evolution of pores through various mechanisms. Attaining of the limit states is determined by the statistics of the distribution of inhomogeneities throughout the entire body volume. The results of physical studies (using electron microscopy, X-ray structural analysis, etc.) provide determination of the geometry and density of defects, dislocations, pores, cracks at different levels. Macrocharacteristics of static, long-term and fatigue strength are determined using methods of mechanical tests. The regularities of the fracture evolution of engineering structures are determined using methods of non-destructive testing (ultrasonic analysis, acoustic emission analysis, magnetic flaw detection, etc.). A brief analytical review of the main known physical approaches — dislocation and energy structural theories, dislocation continuous theories, dilaton-frustron models, stochastic physical theories, and phenomenological approaches, including continuum damage theory and fracture mechanics — is presented. The analysis of gained data leads to the necessity of describing fracture in the framework of stochastic multilevel models. We consider the approach according to which the probability of reaching limit sates at each level under arbitrary multiaxial loading is determined by linear functionals of the loading process, kernels of the functionals being random functions of time. For simple proportional loading, the theory of brittle fatigue scale-structural failure is presented.

Hierarchical architecture and mechanical behavior of K418 Ni-based superalloys manufactured by laser powder bed fusion

Laser powder bed fusion (LPBF) has great potential in the manufacturing of difficult-to-cut Ni-based superalloys with complex geometries. The approach endows the alloys with multi-scale microstructure hierarchy, while its formation mechanism and contribution to mechanical properties are poorly understood. In this work, the hierarchical architecture in LPBF-fabricated K418 Ni-based superalloys, in terms of 3D interlocked grains, low-angle grain boundaries (LAGBs), cellular structure, inter-cellular segregation, and nano-sized γ′ precipitates and carbides, is comprehensively investigated. The formation of cellular structure is governed by the rapid solidification condition, and the 3D interlocked grain structure is associated with the cell growth behavior regulated by locally varied temperature gradient in the melt pool. The LPBF K418 alloys show a higher tensile strength but a slightly lower ductility at both room temperature and 600 °C than their conventional cast counterparts. The superior strength of LPBF alloys is dominantly attributed to the strengthening effect of interlocked grain boundaries and cellular microstructure. This work demonstrates the capability of LPBF to manufacture Ni-based superalloys with hierarchical microstructures and high performance for the application of hot-section gas turbine components.

Inorganic phosphate transporter in Giardia duodenalis and its possible role in ATP synthesis

Giardia duodenalis is a flagellated protozoan that inhabits vertebrate host intestines, causing the disease known as giardiasis. Similar to other parasites, G. duodenalis must take advantage of environmental resources to survive, such as inorganic phosphate (Pi) availability. Pi is an anionic molecule and an essential nutrient for all organisms because it participates in the biosynthesis of biomolecules, energy storage, and cellular structure formation. The first step in Pi metabolism is its uptake through specific transporters on the plasma membrane. We identified a symporter H+:Pi-type ORF sequence in the G. duodenalis genome (GenBank ID: GL50803_5164), named GdPho84, which is homologous to Saccharomyces cerevisiae PHO84. In trophozoites, Pi transport was linear for up to 15 min, and the cell density was 3 × 107 cells/ml. Physiological variations in pH (6.4–8.0) did not influence Pi uptake. This Pi transporter had a high affinity, with K0.5 = 67.7 ± 7.1 µM Pi. SCH28080 (inhibitor of H+, K+-ATPase), bafilomycin A1 (inhibitor of vacuolar H+-ATPase), and FCCP (H+ ionophore) were able to inhibit Pi transport, indicating that an H+ gradient in the cell powered uphill Pi movement. PAA, an H+-dependent Pi transport inhibitor, reduced cell proliferation, Pi transport activity, and GdPHO48 mRNA levels. Pi starvation stimulated membrane potential-sensitive Pi uptake coupled to H+ fluxes, increased GdPho84 expression, and reduced intracellular ATP levels. These events indicate that these cells had an increased capacity to internalize Pi as a compensatory mechanism compared to cells maintained in control medium conditions. Internalized Pi can be used in glycolytic metabolism once iodoacetamide (GAPDH inhibitor) inhibits Pi influx. Together, these results reinforce the hypothesis that Pi is a crucial nutrient for G. duodenalis energy metabolism.

RNA sequencing analysis of hepatocellular carcinoma identified oxidative phosphorylation as a major pathologic feature.

Dysregulation of expression of functional genes and pathways plays critical roles in the etiology and progression of hepatocellular carcinoma (HCC). Next generation‐based RNA sequencing (RNA‐seq) offers unparalleled power to comprehensively characterize HCC at the whole transcriptome level. In this study, 17 fresh‐frozen HCC samples with paired non‐neoplastic liver tissue from Caucasian patients undergoing liver resection or transplantation were used for RNA‐seq analysis. Pairwise differential expression analysis of the RNA‐seq data was performed to identify genes, pathways, and functional terms differentially regulated in HCC versus normal tissues. At a false discovery rate (FDR) of 0.10, 13% (n = 4335) of transcripts were up‐regulated and 19% (n = 6454) of transcripts were down‐regulated in HCC versus non‐neoplastic tissue. Eighty‐five Kyoto Encyclopedia of Genes and Genomes pathways were differentially regulated (FDR, <0.10), with almost all pathways (n = 83) being up‐regulated in HCC versus non‐neoplastic tissue. Among the top up‐regulated pathways was oxidative phosphorylation (hsa00190; FDR, 1.12E‐15), which was confirmed by Database for Annotation, Visualization, and Integrated Discovery (DAVID) gene set enrichment analysis. Consistent with potential oxidative stress due to activated oxidative phosphorylation, DNA damage‐related signals (e.g., the up‐regulated hsa03420 nucleotide excision repair [FDR, 1.14E‐04] and hsa03410 base excision repair [FDR, 2.71E‐04] pathways) were observed. Among down‐regulated genes (FDR, <0.10), functional terms related to cellular structures (e.g., cell membrane [FDR, 3.05E‐21] and cell junction [FDR, 2.41E‐07], were highly enriched, suggesting compromised formation of cellular structure in HCC at the transcriptome level. Interestingly, the olfactory transduction (hsa04740; FDR, 1.53E‐07) pathway was observed to be down‐regulated in HCC versus non‐neoplastic tissue, suggesting impaired liver chemosensory functions in HCC. Our findings suggest oxidative phosphorylation and the associated DNA damage may be the major driving pathologic feature in HCC.

High performance laminated FEP/PTFE piezoelectret films for air-borne sound transducers

Piezoelectret (also known as ferroelectret) is a kind of cellular electret material with strong piezoelectric effect. Such a material exhibits flexibility, low density and small acoustic impedance. Therefore, piezoelectret is an ideal material for air-borne flexible sound transducers. Aiming at high-sensitivity and thermal-stability sound transducers, in this work, laminated fluorinated polyethylene propylene (FEP) and polytetrafluoroethylene (PTFE) piezoelectret film with a regular cellular microstructure is prepared by a procedure involving template-based cellular structure formation and polarization. The results show that the characteristic acoustic impedance of such a laminated FEP/PTFE film is 0.02 MRayl. The quasi-static piezoelectric charge coefficient &lt;i&gt;d&lt;/i&gt;&lt;sub&gt;33&lt;/sub&gt; up to 800 pC/N is achieved in a small applied pressure range. The maximum value of sensitivity of the microphones based on laminated FEP/PTFE piezoelectrets film can reach to 6.4 mV/Pa at 1 kHz. Besides, the frequency response curve of the device is flat in the whole audio range. For an ultrasonic transmitter with a diameter of 20 mm, driven by a voltage of 600 V (&lt;i&gt;V&lt;/i&gt;&lt;sub&gt;p&lt;/sub&gt;), the sound pressure level (SPL) generated by it increases from 80 to 90 dB (Ref. 20 µPA) as frequency increases from 40 to 80 kHz. The thermal stability of the sensitivity for the transducers made of such a laminated FEP/PTFE piezoelectret film is much superior to that of polypropylene (PP) piezoelectret based device. The sensitivity of the present device remains 26% of the initial value after being annealed at 125 ℃ for 211 h. The improvement of thermal stability is attributed to the excellent space charge storage stability of FEP and PTFE.

Collaborative enhancement of luminous efficacy and fracture toughness based on interface design of Al2O3/YAG:Ce3+ eutectic phosphor ceramic grown by laser floating zone melting

A solid-state light source of directionally solidified Al2O3/Y3Al5O12:Ce3+ (YAG:Ce3+) eutectic phosphor ceramic with superior luminous efficacy (∼116.48 lm/W) and high fracture toughness (∼4.0 MPa·m1/2) is fabricated by laser floating zone melting (LFZM) for white light emitting diodes (WLEDs). The CeO2-doped Al2O3/YAG eutectic ceramic presents improved fracture toughness and prevents from the pore formation as compared to the undoped eutectic ceramic. Impressively, the doping of Ce element and the diffusion coefficient play dominant roles in accelerating the formation of cellular structure and causing the enlargement of the eutectic lamella spacing, respectively. Moreover, the optimal phase interface design act as scattering center and enhance the light conversion efficiency. The maximum luminous efficacy is achieved under the comprehensive investigation of the eutectic structure, phase interface as well as Ce3+ dopant. Moreover, the eutectic phosphor ceramic also exhibits excellent capability of thermal self-managing. The as-designed Al2O3/Y3Al5O12:Ce3+ eutectic phosphor ceramics have great potential as structural and functional materials in the high-brightness application of WLEDs.

STUDY ON EVOLUTION MODEL OF GASEOUS DETONATION WAVE IN PERIODIC INHOMOGENEOUS MEDIUM

The initiation, steady propagation and failure mechanism of gaseous detonation wave in periodic inhomogeneous media are very complex, and many physical mechanisms are still unclear, which is an active topic in detonation physics. Numerical simulation of propagation of gaseous detonations in the inhomogeneous medium is studied by using the reactive Euler equations coupled with a two-step chemical reaction model. The inhomogeneity is generated by placing artificial temperature perturbations with different wavelengths and amplitudes. The influence of temperature disturbance with different wavelength and amplitude on the structure of wave front is analyzed. The results show that, the transition of ZND detonation to cellular detonation under artificial temperature disturbance is mainly controlled by two competitive factors: one is the intrinsic instability of detonation wave, the other is the wavelength and amplitude of artificial disturbance, the former is the internal factor, the latter is the external factor. The existence of artificial temperature disturbance delays the evolution of ZND detonation to cellular detonation by suppressing the development of shear wave, and the increase of internal instability can slow down this delay phenomenon. This shows that the artificial temperature disturbance can restrain the development of cell instability in a certain range, but it cannot stop the process. The discontinuity of temperature makes the detonation wave front more distorted, which leads to the existence of a weak triple-wave structure near the shear wave, which is, the artificial disturbance increases the inherent instability of detonation wave and changes the propagation mechanism of detonation wave front. The propagation of detonation and the instability of detonation are restrained by the artificial temperature disturbance with large amplitude. The formation of detonation front cellular structure depends on the artificial temperature disturbance and its own instability.

NUMERICAL INVESTIGATION ON THE SPACE-TIME CORRELATION BETWEEN OBLIQUE DETONATION AND NORMAL DETONATION PROPAGATION

The propagation theory of one-dimensional detonation is complete and accurate, while prediction of two-dimensional oblique detonation propagation with large scale and high accuracy is still difficult primarily due to the treatment of wedge wall during the calculation and the modelling of viscosity. In this paper, the space-time correlation between two-dimensional steady oblique detonation induced by finite wedge and one-dimensional unsteady detonation supported by piston is investigated by numerical simulations of multi-species Euler equations with H2-Air detailed chemical kinetics. The initiation and propagation process of detonation wave, together with its interaction with rarefaction waves are numerically analyzed from the perspective of both space and time. The results show that under the same overdriven degree, the wave structure, wall parameters and profile variation calculated from one-dimensional case fit well both qualitatively and quantitatively with two-dimensional case after a certain space-time transformation, which validates the space-time correlation between one- and two-dimensional detonation waves. The difference mainly lies in the transition process between different stages of detonation development, such as the transition from over-driven oblique detonation wave to near Chapman-Jouguet (CJ) oblique detonation wave under the effect of rarefaction waves. Since most features of oblique detonation waves over finite wedge can be obtained efficiently by one-dimensional numerical calculation of piston-driven detonation and space-time transformation, the present work provides a feasible way to understand the spatial structure of oblique detonations waves, including detonation initiation, formation of over-driven oblique detonation and cellular structure downstream. Besides, this paper also provides a novel method to distinguish the effect of wall compression and boundary layer by comparing one- and two-dimensional numerical results. Moreover, the results imply that two-dimensional flow field over wedges of different shapes can be obtained with satisfying accuracy by altering the velocity of piston, which greatly reduces the time, cost and complexity of numerical simulation during the design of combustion chamber in an oblique detonation wave engine.

Self-assembly of polyethylene oxide and its composite nanofibrous membranes with cellular network structure

Cellular network structured nanofibrous membranes (NFMs) hold great promise in a broad range of applications; however, constructing the cellular network structured NFMs by electrospinning has proved to be extremely challenging. Herein, we present a facile method to controllably fabricate polyethylene oxide (PEO) and PEO/ZIF-8 NFMs with cellular network structure via electrospinning. We systematically study the effects of the properties of electrospinning solution and electrospinning conditions on the self-assembly formation of cellular nanofibrous network structure. The results show that the self-assembly of the charged electrospun nanofibers could be ascribed to the competitive action of surface tension and electrostatic repulsion on the nanofibers. In addition, we successfully obtain the optimal electrospinning parameters and solution composition ratio for the preparation of regular network structure. This work opens pathways for designing and developing the electrospun composite NFMs with cellular network structure.

Study of the Convective Stratification of Airflows in a Mine Shaft

The experimental study of heat and mass transfer in the atmosphere of a skip shaft of a Gypsum mine was carried out during the summer and winter seasons. The air flow overturning was observed in the winter season due to the ingress of cold heavy air from the surface into the shaft space. To analyze this phenomenon, a computational fluid dynamics (CFD) model of heat and mass transfer processes in a mine shaft was developed, considering the vertical temperature gradient, roughness of the shaft walls, heat exchange with the shaft lining. Based on numerical simulation, it was found that at relatively low air velocities in the shaft and with a relatively large difference between warm air in the shaft and cold air on the surface, the latter begins to penetrate the shaft and descend down it, gradually filling its space. The interaction of cold air from the surface with the warm air rising up the shaft, as well as with warm walls of the shaft leads to the formation of an unsteady convective vortex cellular structure along the shaft. The depth of the vortex depends on the velocity of the air in the shaft, as well as the difference between the temperatures of the warm and cold air. Based on the obtained numerical simulation data, it was possible to calculate the minimum allowable air velocity at which partial return air flows appear in the shaft cross-section.

Regularities of structure and properties modification of the steel surface layer as a result of high-cycle high-speed melting of the “film (Si + Nb) / (steel) substrate” system by an intense pulsed electron beam

Surface alloying is a promising method for improving the service characteristics of machine parts and mechanisms. The aim of this work is to analyze the patterns of evolution of the elemental and phase composition, the state of the defect substructure of the surface layer of carbon steel subjected to multi-cycle treatment (the number of cycles was varied from 1 to 5), which combines the formation of a film / substrate system and irradiation with an intense pulsed electron beam. Silicon and niobium are used as alloying elements. It has been established that irradiation of the system “film (Si + Nb) / (steel 5135) substrate” at an electron beam energy density of 20 J / cm2 leads to the formation of a multiphase high-speed cellular crystallization structure in the surface layer. The size of the crystallization cells varies from 180 nm to 520 nm, reaching the maximum size after 3 cycles of deposition-irradiation. The surface layer of steel is quenched during processing to form a martensitic structure. It was found that the Nb5Si3 is the hardening phase of the modified layer, the maximum amount of what (up to 9 wt%) was revealed after three processing cycles. It is shown that the maximum hardness of the surface layer of modified steel 5135, equal to 9300 MPa (3.2 times higher than the hardness of steel 5135 in the initial state), is achieved after 3 cycles of deposition / irradiation. The wear resistance of steel at this processing mode increases more than 90 times. It has been suggested that the hardening of steel surface layer is due to the formation of a quenched structure and the release of niobium silicide particles.