bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma electrolytic polishing of nitrided steel under force convection condition
Authors: Belkin P N , Silkin S A , Dyakov I G , Tambovskiy I V , Korableva S S , Kusmanov S A 
Published: November 2019

Abstract
The effect of plasma electrolytic polishing in an ammonium chloride electrolyte under force convection condition on the characteristics of medium carbon steel after anodic plasma electrolytic nitriding was investigated. The morphology of the steel surface was studied using a metallographic microscope. The phase composition of the surface layers was studied using an X-ray diffractometer. Treatment specimens were tested under dry friction conditions with a counter body made of bearing steel. Corrosion studies were performed using potentiodynamic polarization curves in a 3.5 % sodium chloride solution. Nitriding increased the surface hardness up to 1130 HV due to the formation of a nitride-martensite layer with an outer oxide layer. After polishing of the nitrided surface, the loose outer part of the oxide layer containing microcracks and pores is removed, surface lightening has occurred. The reduction of the wear rate of 45-fold and the corrosion current density of 4.8-fold of nitrided steel by plasma polishing without changing the structure of the diffusion layers was shown.
Contribution of structural factors to the deformation behaviour of nanostructured Cu-Zn alloys
Authors: Chembarisova R G , Alexandrov I V , Zaynullina L I 
Published: November 2019

Abstract
The results of the analysis of the deformation behavior of nanostructured Cu-Zn alloys, obtained as a result of severe plastic deformation, implemented by the equal-channel angular pressing method, are presented. The role of structural factors responsible for increasing the strength characteristics and uniform elongation of the Cu-Zn alloys has been revealed.
Effects of grain refinement by HPT processing in carbon steel with various cementite morphology
Authors: Ganeev A V , Ivanisenko Y , Valiev R Z 
Published: November 2019

Abstract
This article reports on the effect of the initial phase composition (martensitic, patented, spheroidized) of the middle carbon steel C45 (0.45 wt.% C) on grain refinement during high-pressure torsion (HPT) at elevated temperature. It is established that the cementite dissolution and the final grain size after HPT strongly depend on the processing regime, as well as on the cementite morphology in the initial state of the steel. As result of this study, new approaches to obtain a very high-strength state in carbon steels have been proposed.
Effect of high-pressure torsion on the mechanical behavior of a Zr-based BMG
Authors: Gunderov D , Boltynjuk E , Churakova A , Batirshin E , Mullayanov A , Titov V , Ivanisenko J 
Published: November 2019

Abstract
The effect of high-pressure torsion (HPT) on the structure and mechanical properties of a Zr-based bulk metallic glass (BMG) was investigated. The structure of the BMG changes significantly after HPT processing. In tensile tests, the BMG samples before and after HPT processing are brittle under a stress of about 1700 MPa. For the first time, three-point bending tests of the HPT-processed BMG were performed. In the three-point bending tests of the initial BMG and that after HPT processing, the strength exceeds 3000 MPa and plastic flow is observed.
Combining methods of severe plastic deformation as an effective way to increase the strength of metallic materials
Authors: Ivanov A M 
Published: November 2019

Abstract
The article reviews the combined methods of severe plastic deformation (SPD) for hardening metallic materials. The combined deformation processing, extrusion with the equal-channel angular pressing (ECAP) is presented. The comparison is made of the mechanical characteristics and the fracture mode of the Fe360 low carbon steel strengthened by the combined methods of extrusion with ECAP and ECAP with extrusion.
Microstructure and mechanical properties of the Mg–Zn–Ca biodegradable alloy after severe plastic deformation
Authors: Khudododova G D , Kulyasova O B , Islamgaliev R K , Valiev R Z 
Published: November 2019

Abstract
Mg-Zn-Ca alloys are considered as promising biodegradable metals for implants because of their biocompatibility and proper physical properties. In this study, microstructure and strength of magnesium alloy Mg-1% Zn-0.2% Ca after a combination of the severe plastic deformation (SPD) methods have been investigated. It was shown that with an increase in the degree of deformation, an increase in the strength properties occurs. It was established that the ultimate tensile strength of the initial state was 125 MPa and after SPD a 2-fold increase in strength up to 283.3 MPa was achieved with sufficient ductility.
Relationship between the stress-strain state and the imperfection of the structure of metals with SPD shear
Authors: Raab G I , Raab A G , Aleshin G N , Kodirov I S 
Published: November 2019

Abstract
The paper presents the results of the computer simulation and physical experiment for the free and constrained transverse shear of round specimens of steel 10 with an accumulated strain of e> 1. The stress-strain state was investigated using computer simulation, and the degree of imperfection of the emerging structures was studied by metallographic methods. The laws governing the relationship between the parameters under study and the degree of imperfection of the structure during severe plastic deformation by shear are established.
Effect of point defects and functionalization on structural stability and electron properties of borophene as investigated by means of density functional theory
Authors: Khadiullin S Kh , Kistanov A A , Morkina A Y , Korznikova E A 
Published: November 2019

Abstract
The discovery of a new two dimensional material is a new trend emerged after the discovery of graphene in 2004. Hundreds of new materials have been predicted, designed and investigated during last decade. Many of them have outstanding properties for potential application in new technologies. One of those materials is so-called borophene, being isolated atomically thin boron. This material can show different electronic properties, including semiconducting, semi-metallic, and metallic states due to its unique structure. Borophene demonstrates unusually high in-plane elasticity and strength. The crucial point for application of borophene is its low structural stability at room temperature. A possible way to solve this problem is the functionalization of its surface by external atoms like hydrogen and fluorine. This work presents a study on the effect of O dopants and the presence of vacancy defects on electronic properties of borophene by using first-principles calculations. It was revealed that unlike other 2D materials, the band structure of borophene is stable by respect to the above-mentioned factors. However, the doping by O atoms is found as an effective way to increase the stability of the borophene sheet.
Evolution of the structure and mechanical properties of the Mg-1%Zn-0.2%Ca alloy during ECAP
Authors: Kulyasova O B , Evdokimova I A , Islamgaliev R K 
Published: November 2019

Abstract
Microstructure of the Mg-1%Zn-0.2%Ca magnesium alloy after equal-channel angular pressing (ECAP) has been investigated. It was shown that an increase of the shear strain leads to significant grain refinement, as well as to the improved uniformity of microhardness. As a result of grain refinement by ECAP processing, the microhardness was increased to a value of 45.5, which is 28% higher than the initial state. Tensile tests demonstrated the enhanced ultimate tensile strength of 248.1 MPa, yield stress of 153.2 MPa, ductility of 19.4 % whereas in the initial coarse-grained state these parameters were 124 MPa, 45.3 MPa and 8.7 %, accordingly.
Effect of friction-stir welding on the microstructure and mechanical properties of an Al-Mg-Si alloy
Authors: Vysotskiy I , Malopheyev S , Mironov S , Kaibyshev R 
Published: November 2019

Abstract
In this work, sheets of an Al-Mg-Si alloy were joined by double-side friction stir welding and tempered by standard post-weld artificial aging. The combination of relatively high FSW tool rotation and welding speed with subsequent post-weld artificial aging allowed obtaining welds with high joint efficiency. However, a high sensibility of joint efficiency from FSW tool rotation speed at constant welding speed was found. In turns, the joint efficiency of the friction-stir welds for ultimate tensile strength was found to be 72% at 800 rpm and 92% at 1100 rpm, respectively. The reasons of difference in the mechanical properties of the welds are studied.
Structure and strength of the 1570C aluminum alloy after complex SPD processing
Authors: Markushev M V , Avtokratova E V , Sitdikov O Sh , Linderov M L , Merson D L , Vinogradov A 
Published: November 2019

Abstract
The effect of severe plastic deformation (SPD), realized via multi-directional forging (MDF) at a constant temperature of 325 °C, as well as via a combination of MDF with subsequent room temperature rolling or high pressure torsion, on the microstructure, static and fatigue strength parameters of an ingot of non-age-hardenable commercial aluminum alloy 1570C (Al-5Mg-0.18Mn-0.2Sc-0.08Zr) was studied. It is found that the most effective treatment to enhance the balance of the alloy properties involves a sequence of hot MDF and cold rolling due to the development of a work hardened ultrafine-grain structure with uniformly distributed nanosized aluminides of transition metals. The role of precipitates in the alloy structure- and property-formation is discussed.
Effect of preliminary and post-SPD aging on nanostructuring and strengthening of the HPT processed 2024 aluminum alloy
Authors: Markushev M V , Krymskiy S V , Avtokratova E V , Sitdikov O Sh 
Published: November 2019

Abstract
Structural and mechanical behaviors of the 2024 commercial aluminum alloy, differed by heterogeneity of the initial structure, were examined after severe plastic deformation and further annealing. The superior strengthening of the pre-quenched alloy under high-pressure torsion (HPT) at room temperature was caused by the development of a more equiaxed nanostructure of the matrix with a lower fragment size than in pre-aged T6 condition. Post-HPT annealing at 100 °C led to extra strengthening of the pre-quenched alloy only due to the age hardening effect. The nature of the alloy behavior is discussed.
Abnormal grain growth in fine-grained aluminum produced by friction-stir welding
Authors: Mironov S , Kaibyshev R 
Published: November 2019

Abstract
In this work, fundamental aspects of abnormal grain growth, which typically occurs during annealing of friction-stir welded (FSW) aluminium, were studied. To this end, crystallographic orientations of abnormally-coarse grains were systematically examined. Statistical analysis showed that those were not random. Specifically, it was found that the abnormal grain growth resulted in ~30°<111> rotation of FSW-induced B/-B {112}<110> texture. Accordingly, the abnormal character of the grain growth was interpreted in terms of increased mobility of 30°<111> boundaries.
Mechanical behavior and impact toughness of the ultrafine-grained VT8M-1 alloy
Authors: Modina Iu M , Polyakova V V , Dyakonov G S , Polyakov A V , Semenova I P , Raab A G 
Published: November 2019

Abstract
This paper reports on a study of the relationship between the microstructure, mechanical behavior and impact toughness of the two-phase Ti alloy VT8M-1 (Ti-5.7Al-3.8Mo-1.2Zr-1.3Sn) in the ultrafine-grained (UFG) state, which was produced by two different techniques – equal-channel angular pressing (ECAP) and rotary swaging (RS). It is shown that both processing techniques enable forming a UFG structure and enhanced mechanical properties in the alloy. The UFG structures formed in the billets are characterized by different shapes and sizes of the α- and β-phases. The relationship between the structure, strength, ductility and impact toughness of the alloy processed by RS and ECAP is discussed.
Effect of ultrasonic pretreatment on the superplasticity of titanium alloy Ti-6Al-4V processed by ECAP
Authors: Mukhametgalina A A , Murzinova M A , Nazarov A A 
Published: November 2019

Abstract
Improving the superplasticity characteristics of alloys widely used in industry, such as titanium alloy Ti-6Al-4V, is an important practical problem. Processing by the methods of severe plastic deformation can reduce the temperature of superplasticity. However, the material exhibits high flow stresses. In this work we studied the effect of preliminary ultrasonic treatment with an amplitude of oscillating tension-compression stresses of 100 MPa on the characteristics of superplasticity of the Ti-6Al-4V alloy processed by equal channel angular pressing (ECAP). It is shown that high-frequency oscillating stresses resulted in the reduction of the flow stress, the increase in elongation and the strain rate sensitivity coefficient during tensile tests in the conditions of superplasticity.
The microstructure and properties of the alloy Ti-5Al-0.5V subjected to ECAP and ultrasonic treatment
Authors: Mukhametgalina A A , Murzinova M A , Nazarov A A 
Published: November 2019

Abstract
This work presents the results of a study of the mechanical properties of a titanium alloy Ti-5Al processed by equal channel angular pressing (ECAP) and ultrasonic treatment (UST). The UST was carried out at a frequency of 20 kHz with an amplitude of oscillating tension-compression stresses of 100 MPa. It was shown that the alloy subjected to UST exhibited low temperature superplastic properties. Its elongation exceeded a value of 300%, the coefficient m was 0.3 at a strain rate of 1.7×10−4 1/s.
Microstructure evolution of a Re-containing nickel-based superalloy by hot deformation and cold severe plastic deformation
Authors: Mukhtarov Sh , Shakhov R , Ganeev A 
Published: November 2019

Abstract
The microstructure evolutions of the cast rhenium containing nickel-based superalloy subjected to thermomechanical treatment and severe plastic deformation by high pressure torsion were investigated. Thermomechanical treatment led to the formation a fine-grained structure with γ grain size of about 7 μm and both large precipitates of the γ’ phase with a size of 1-5 μm and dispersed precipitates with a size of about 0.2 μm. Microstructure of the superalloy subjected to high pressure torsion up to 5 revolutions was nanocrystalline with partly dissolved of the dispersed γ′ precipitates. The effect of different kinds of deformation and subsequent annealing on the microstructure, grain boundaries and microhardness changes are also discussed.
Microstructure and microhardness studies of Inconel 718, manufactured by selective laser melting and subjected to severe plastic deformation and annealing
Authors: Mukhtarova K Sh , Shakhov R V , Smirnov V V , Mukhtarov Sh Kh 
Published: November 2019

Abstract
Microstructure investigations and microhardness measurements have been comparatively performed for the nickel-based superalloy Inconel 718 produced by selective laser melting (SLM) and conventional technology. The superalloy produced by SLM had a finer γ grain size and a developed dislocation substructure in contrast to a conventional wrought material. High pressure torsion of the superalloy led to a refinement in the microstructure and an increase in the microhardness in both superalloys. Annealing at 600 °C for 2 hours of the deformed superalloys caused an additional increase in microhardness. The microhardness of the SLM material was slightly higher than that of the conventional superalloy.
High strength and high conductive copper-based alloy produced by SPD for contact wires for high speed railway lines - A short review
Authors: Ravisankar B , Sivaprasad K , Ramesh Babu N , Raab G I , Valiev R Z 
Published: November 2019

Abstract
The development of high-speed railway lines, the requirements for contact wires of catenary becomes more essential. The contact wire should be strong, wear resistant and fatigue resistant, and also possess good thermal stability along with high electrical conductivity. At present, copper wires alloyed with cadmium are used. The replacement is more of a necessity since cadmium is a material hazardous to environment, and it is already banned by several countries. Over the last several decades, growing attention has been focused on the development of copper-based alloys with high strength and good electrical conductivity. Novel severe plastic deformation (SPD) procedure, namely equal-channel angular pressing (ECAP), has been applied for obtaining ultrafine-grained (UFG) materials with high strength and good electrical conductivity. This overview mainly focuses on the suitability of ECAPed copper and its alloys for contact wires in high-speed railway lines.
Computer simulation of the SPD process of a low-alloyed chromium bronze using a virtual full factorial experiment
Authors: Semenov V I , Tontchev N T , Shuster L Sh , Raab G I , Kamburov V V 
Published: November 2019

Abstract
Using computer simulation in the DEFORM-3D software package, we performed a virtual full factorial experiment for the ECAP-Conform processing of the low-alloyed chromium bronze Cu-0.14%Cr. In the course of the experiment we evaluated the effect of independent parameters (the rotation speed of the working wheel, the friction factor at the lateral surfaces of the working wheel and the friction factor between a billet and the die). As a result of the experiment, we obtained a regression equation and determined the most important individual factors and their combinations that influence the response parameter – the deformation force.
Evaluation of the tribological properties of a magnesium alloy of the Mg-Ca system depending on the structure of the material under study
Authors: Semenov V I , Lin H-C , Shuster L Sh , Chiu C 
Published: November 2019

Abstract
The paper presents the results of a study of the tribological characteristics of the contact of the tool steel of composition Fe-18W-4Cr-1.2V with a magnesium alloy of the Mg-Ca system, strengthened by SPD using the method of ECAP. It has been established that the SPD processing of a magnesium alloy, due to an increase in strength as a result of the grain structure refinement, makes it possible to significantly reduce the integral value of the friction coefficient in the moving friction contact. In addition, the SPD processing of the material under study leads to a decrease in the molecular component of the friction coefficient.
The effect of combined thermomechanical treatment on the structure, phases and hardness of a superelastic Ti-Zr-Nb bar stock
Authors: Sheremetyev V , Kudryashova A , Derkach M , Lukashevich K , Andreev V , Galkin S , Prokoshkin S , Brailovski V 
Published: November 2019

Abstract
The superelastic Ti-19Zr-14Nb (at.%) alloy was subjected to a novel sequence of thermomechanical treatment, including radial shear rolling, rotary forging and post-deformation annealing. The features of the grain structure, phase composition and hardness of a long-length bar stock for fabrication of bone implants were analyzed. It was shown that after the aforementioned combined thermomechanical treatment followed by annealing in the 550-750 °C temperature range, the produced bar stock demonstrates uniformly distributed grains of β-phase and uniform hardness across its section.
Microstructure and properties of permanent joints of ultrafine-grained titanium alloys produced by linear friction welding
Authors: Suleymanova G R , Medvedev A Y , Dyakonov G S , Yakovleva T V , Izmailova N F , Raab G I , Semenova I P 
Published: November 2019

Abstract
This paper presents the results of a study of the microstructure and mechanical properties of welded joints obtained by linear friction welding of samples from heat-resistant titanium alloys VT8M-1 (Ti-5.4Al-1Sn-1Zr-4Mo-0.15Si) and VT25U(Ti-6.5Al-1.8Sn-4Zr-4Mo-1W-0.2Si). In the VT8M-1 alloy, an ultrafine-grained (UFG) structure was formed prior to welding. The features of the phase and structural transformations in the areas of contact and thermomechanical effect of welding were shown, as well as the microhardness distribution across the width of the welded joints. The obtained values of strength characteristics of a welded joint during short-term and long-term tests at 400 °C indicate their correspondence to the level of the monolithic VT8M-1 alloy with a UFG structure.
Effect of precipitation under long-term aging at 650 °C on the tensile strength of advanced 10%Cr heat-resistant steel
Authors: Dudova N , Mishnev R , Tikhonova M , Kaibyshev R 
Published: November 2019

Abstract
The effect of long-term aging for 103 to 3.9·104 h at 650 °C on the microstructure, dispersion of secondary phases, and tensile strength properties was studied in a low-nitrogen 10%Cr martensitic steel with 3%Co and 0.008%B additives. Tensile tests of small specimens cut from grip portions of creep tested specimens were carried out at ambient and elevated (650 °C) temperatures. An increase in the yield stress and ultimate tensile strength after 10,000 h of aging was revealed to be associated with the precipitation of V-rich MX carbonitrides, which compensated for the coarsening of the boundary particles and depletion of W and Mo solutes from the ferritic matrix. The effect of changes of the microstructure and dispersion of secondary phases on strengthening of the steel is discussed.
Study of the dynamic strength of the ultrafine-grained titanium VT 1-0
Authors: Evstifeev A D , Valiev R R 
Published: November 2019

Abstract
We report the results from the testing of the strength properties of the ultrafine-grained Ti alloy VT 1-0 under dynamic and static loading. A comparative analysis was made of the ultimate static and dynamic strength of the small-sized samples of the material subjected to severe plastic deformation. The importance of studying the dynamic strength of Ti alloys is closely related to their practical application in structures and parts operating under high dynamic loads.
Corrosion resistance of ultrafine-grained pure titanium in simulated sea water
Authors: Li X , Dong Y , Alexandrov I V , Dan Z , Chang H 
Published: November 2019

Abstract
Corrosion resistance of ultrafine-grained Ti processed by equal channel angular pressing with 3 passes was investigated. Results indicated that corrosion rate of ultrafine-grained Ti significantly reduced in comparison with coarse grain Ti. Furthermore, corrosion resistance of 3 passes ECAP sample had an obvious distinguish for different extraction planes; normal plane has shown a best corrosion resistance than transversal and extrusion plane, which could be attributed to higher fraction of low angle grain boundary.
Microstructure and mechanical properties of workpieces of the ultrafine-grained two-phase Ti alloy produced by die forging
Authors: Yakovleva T V , Dyakonov G S , Stotskiy A G , Semenova I P 
Published: November 2019

Abstract
The paper presents the results of studies of the microstructure and mechanical properties of experimental workpieces of the ultrafine-grained (UFG) VT8M-1 (Ti–5.7Al– 3.8Mo–1.2Zr–1.3Sn in wt%) alloy produced by isothermal die forging (IDF). The UFG structure in the VT8M-1 alloy was formed by a high-performance method, namely rotary swaging (RS). The structural parameters (the shape and size of the α- and β-phases) and the homogeneity of the UFG structure were analyzed in different sections of forgings. It was shown that the fraction of the primary α- phase decreases, and the size of the secondary equiaxed grains of the α- and β-phases increases from 0.3 to 0.9 µm as a result of recrystallization during IDF. The relationship between the microstructure and mechanical properties of the forged workpieces of the UFG VT8M-1 alloy is discussed.