bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of an early stage of the abnormal grain growth in the friction-stir welded 6061-T6 aluminum alloy
Authors: Vysotskiy I , Malopheyev S , Mironov S 
Published: January 2021

Abstract
In this work, quasi in-situ electron backscatter diffraction (EBSD) was applied to study an early stage of the abnormal grain growth occurring in the friction-stir welded 6061 aluminium alloy during post-weld solution heat treatment. It was found that the catastrophic grain growth completed during the heating stage of the annealing treatment, and further static storage at the solutionsizing temperature provided almost no microstructural changes.
On the local variation of mechanical properties in friction-stir welded 6061 aluminum alloy
Authors: Kalinenko A , Kim K , Vysotskiy I , Malopheyev S , Mironov S 
Published: January 2021

Abstract
In this work, digital image correlation technique was applied to investigate local variations of mechanical properties in friction-stir welded 6061 aluminium alloy. A pronounced strain concentration in the bottom section of stir zone was revealed during transverse tensile tests. This effect was suggested to be associated with residual stress generated in this microstructural region during friction-stir welding.
Effect of tempering temperature on the microstructure and creep resistance of a 10%Cr martensitic steel
Authors: Mishnev R V , Dudova N R , Kaibyshev R O 
Published: January 2021

Abstract
The tempered martensite lath structure of a 10% Cr martensitic steel after normalizing and tempering at 750 °C was studied. The effect of reducing the tempering temperature from 770 by 20 °C on the microstructural parameters in steel was shown. Tempering at a lower temperature of 750 °C provides thinner laths and finer M23C6 particles (55 nm) than tempering at 770 °C. Such structural changes do not affect the creep rupture time at 650 °C and applied stresses of 180 and 160 MPa, whereas the positive effect occurs at 140 MPa, the time to rupture increases by more than two times from 1426 to 3909 hours.
Microstructure of a low alloyed Cu-Cr-Zr alloy after ECAP-Conform
Authors: Morozova A , Lugovskaya A , Pilipenko A , Tkachev M , Raab G , Belyakov A , Kaibyshev R 
Published: January 2021

Abstract
The microstructure of a Cu-0.1%Cr-0.1%Zr alloy after annealing or aging and equal channel angular pressing with conform (ECAP-C) process was investigated. ECAP-C led to formation of strain induced low-angle boundaries (LAB) which transformed in high-angle boundaries (HAB) during deformation. Deformation microbands developed after 1 ECAP-C pass, leading to new ultrafine grain formation in the microbands upon further processing. Average grain size gradually decreased with strain while dislocation density increased. After 8 ECAP-C passes average grain size achieved 1 μm. Maximum of LAB density occurred after 4 ECAP passes and then LAB density decreased with strain while HAB density gradually increased during ECAP-C. Relationships between dislocation density, grain size, and density of crystallite boundaries were discussed.
Effect of the deformation temperature on the deformation behavior of a Cu-Cr-Zr alloy
Authors: Morozova A , Tkachev M , Pilipenko A , Lugovskaya A , Belyakov A , Kaibyshev R 
Published: January 2021

Abstract
The mechanical properties and deformation behavior of a Cu-Cr-Zr alloy after solution treatment (ST) or aging (ST+AT) and equal channel angular pressing (ECAP) at elevated temperature were investigated. ECAP at elevated temperature led to strengthening and degradation of plasticity compared with the initial state. The deformation behavior of the alloy after 1 and 2 ECAP passes at 200 °C was almost the same. An increase in ECAP temperature promoted uniform strain and plasticity. An increase in the number of ECAP led to a gradual increase in strength. YS and UTS in ST+AT condition were higher than in ST samples regardless of the ECAP temperature and the number of passes. The maximum values of YS and UTS were obtained after 4 ECAP passes at 400 °C and achieved 525 MPa and 600 MPa in ST and 570 MPa and 650 MPa in ST+AT condition, respectively. The effect of deformation strain and ECAP temperature on work hardening rate and recovery were discussed in terms of the Voce equitation.
Studying the Impact of Blast Treatment on the Structure and Mechanical Properties of Carbon Steel
Authors: Nagicheva G S , Nokhrin A V , Berendeev N N , Melekhin N V , Piskunov A V , Sysoev A N , Gryaznov M Y 
Published: January 2021

Abstract
The study has covered the effects of blast treatment on the microstructure parameters and mechanical performance of carbon steel. The calculation results of examining the structure and properties of carbon steel in its initial state and after explosive hardening in various sections of cylindrical carbon steel workpieces have been verified with the finite-element analysis using the ANSYS Workbench software environment. Blast treatment has been demonstrated to lead to a perceptible change in the structural state of carbon (cementite) in steel.
Cracking of Ti2AlNb-based alloy after laser beam welding
Authors: Panov D O , Naumov S V , Sokolovsky V S , Volokitina E I , Kashaev N , Ventzke V , Dinse R , Riekehr S , Povolyaeva E A , Alekseev E B , Nochovnaya N A , Zherebtsov S V , Salishchev G A 
Published: January 2021

Abstract
Crack formation process in the Ti-23Al-23Nb-1.4V-0.8Zr-0.4Mo-0.4Si (at.%) alloy based on orthorhombic titanium aluminide (Ti2AlNb), especially in the weld zone (WZ), heat-affected zone (HAZ), and base metal (BM), during laser beam welding (LBW) at room temperature was considered. It was determined that the crack spread in the WZ throughout the crystallites of β-phase. In the HAZ, cracks spread throughout the globular β-phase crystals body and along the edges of globular α2- and O-phases. The cracking stopped in BM due to a mechanism similar to shear ligament toughening. Cracking can be effectively suppressed by increasing the LBW temperature.
Studying Corrosion Resistance of Weld Joints of Ultrafine-Grained Titanium Alloys
Authors: Nokhrin A V , Andreev P V , Likhnitskii C V , Vostokov M M , Kopylov V I , Chuvil’deev V N , Gudz’ D A , Chegurov M K , Murashov A A 
Published: January 2021

Abstract
Ultrafine-grained (UFG) samples of PT-3V near-α titanium alloy were subjected to diffusion welding using the Spark Plasma Sintering system. It has been shown that the destruction of welded UFG samples under hot salt corrosion (HSC) is two-staged – first, intercrystalline corrosion is manifested, which then graduates to pitting corrosion. It has been established that the corrosion resistance of weld joints is determined by vanadium concentration at the grain boundaries, the size and volume ratio of β-phase particles and the presence of pores in the weld joints. It has been shown that welded UFG samples possess higher hardness and corrosion resistance than coarse-grained samples.
Effect of carbon on microstructure and mechanical properties of titanium
Authors: Ozerov M S , Klimenko D N , Rtishcheva L P , Kopylov V N , Stepanov N D , Zherebtsov S V 
Published: January 2021

Abstract
The microstructure and mechanical properties of cold rolled titanium with 0.0, 0.1 and 0.2 wt.% of carbon were studied after annealing in a temperature range of 500-800 °C. The addition of carbon resulted in slower grain growth kinetics and less intensive softening during annealing of the cold rolled alloys in the temperature range 500-800 °C. Besides, the alloys with carbon are considerably stronger in comparison with pure titanium; cold rolling resulted in an increase in the yield stress from 540 MPa for titanium to 630 and 605 MPa for Ti-0.1C and Ti-0.2C, respectively. However, ductility of the carbon doped titanium was also found to be decreased to ∼32% in comparison with 40% for pure titanium.
The effect additives of magnesium, titanium and zirconium oxides additives on the densification kinetics and structure of alumina during spark plasma sintering
Authors: Popov A A , Boldin M S , Nokhrin A V , Chuvil’deev V N 
Published: January 2021

Abstract
The results of an experimental study of the effect of metal oxide additives on the sintering kinetics of systems based on alumina by the method of spark plasma sintering (SPS) are presented. The influence of additives at the stage of intensive compaction of powder pressing and at the stage of intensive growth of ceramic grains is analyzed. A qualitative explanation of the mechanism of the effect of magnesium oxide additives on the stabilization of the grain structure of aluminum oxide is given.
Effect of solid-solution treatment on the microstructure and mechanical properties of high-nitrogen FeMnCrNiCo high entropy alloys
Authors: Reunova K A , Astafurova E G , Melnikov E V , Astafurov S V , Panchenko M Yu , Moskvina V A 
Published: January 2021

Abstract
The effect of solid-solution treatment on the microstructure and tensile properties of high-nitrogen and nitrogen-free high entropy alloys (FeMnCrNiCo and FeMnCrNiCoN, N=0.36 mass.% and N=0.44 mass.%) has been investigated. It has been established that all materials under study possess an fcc crystal lattice, the lattice parameter of which increases with increasing nitrogen content. In comparison with the cast state, which is characterized by a coarse-grained dendritic microstructure, the alloys after solid-solution treatment show a more homogeneous microstructure. Solid-solution treatment does not significantly affect the mechanical characteristics of the alloys and their fracture micromechanisms.
Studying Thermal Stability of Cast and Microcrystalline Alloys Al-(2.5, 4)%Mg-Sc-Zr
Authors: Shadrina I S , Nokhrin A V , Kopylov V I , Chuvil’deev V N , Bobrov A A , Likhnitskii C V 
Published: January 2021

Abstract
The article presents the results of experimental studies of the structure and mechanical properties of cast and microcrystalline (MC) aluminum alloys Al-(2.5, 4)%Mg-Sc-Zr with a total content of Sc+Zr = 0.32%. The Sc content was varied from 0.10% to 0.22% at an interval of 0.02%, with the Zr concentration in the alloy being changed proportionally. In their initial state, cast alloys are characterized by a homogeneous coarse-grained macrostructure. The structure of the alloy structure presents single submicron particles Al3 (Sc,Zr) that are formed during crystallization of the alloys. It has been demonstrated that the recrystallization onset temperature in MC alloys depends on the scandium-to-zirconium ratio.
Structural-phase features of WC-based ceramics obtained by the spark plasma sintering method
Authors: Smetanina K E , Andreev P V , Lantsev E A , Vostokov M M , Malekhonova N V , Murashov A A 
Published: January 2021

Abstract
Ceramics obtained by spark plasma sintering of tungsten carbide powder were studied by X-ray diffraction layer-by-layer analysis. The surface of the ceramic samples was mechanical grinded and polished in several stages. The distribution of crystal phases by the depth of ceramics was investigated.
Effect of microstructure on the oxidation behavior of a β-solidified γ-TiAl based alloy after nitrogen ion implantation
Authors: Panov D O , Sokolovsky V S , Stepanov N D , Zherebtsov S V , Novikov V Y , Nochovnaya N A , Panin P V , Salishchev G A 
Published: January 2021

Abstract
The microstructure of the oxide layer of a β-solidifying γ-TiAl alloy (Ti-43.2Al-1.9V-1.1Nb-1.0Zr-0.2Gd-0.2B) after nitrogen ion implantation was studied after cyclic oxidation tests at 800 °C. Oxidation resulted in the formation of the continuous oxide scale, consisting of thin inner and outer TiO2, dense Al2O3 and mixed Al2O3 + TiO2 layers. It was revealed that the nitrogen ion implantation considerably inhibited the growth of the oxide scale, internal oxidation and Al-depleted zones. Thick Al-depleted zones and a mixture of Al2O3 and TiO2 were formed along the colony boundaries. Tooth-shaped Al-depleted zones propagated along the lamella boundaries. In addition, the presence of Gd-rich particles in the oxide scale promoted the formation of Al2O3 particles in surrounding areas and increased the depth of the oxide scale around.
The new indicator coating to detect the place of barely visible impacts on aircraft composite structures
Authors: Buslaeva O S , Sapozhnikov S B , Bezmelnitsyn A V , Ignatova A V , Kudryavtsev A 
Published: January 2021

Abstract
There was developed indicator coating made of epoxy resin filled with hollow glass spheres of the volume fraction up to 50% on GFRP substrates. This coating has a high sensitivity to local impacts changing light reflection by the failure of epoxy and glass spheres in the contact area. Mechanical behaviours of the coating are close to the pure epoxy resin but the density is twice less. We also provided experimental data concerning the contact traces under barely visible impact and the numerical model to predict residual traces onto indicator coating with GFRP substrate.
Solvent-free process for the synthesis of highly stretchable piezoresistive sensors based on polydimethylsiloxane filled with graphene nanoplatelets and carbon nanotubes
Authors: Piscitelli F. , Lo Gatto M. L. , Rollo G. , Filippone G. , Lavorgna M. 
Published: January 2021

Abstract
This work reports on the design, the development, and a preliminary characterization of highly stretchable polydimethylsiloxane (PDMS) elastomers as matrices for piezoresistive composites with graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) applicable to aircrafts with morphing shape changes. The strategy adopted for the formulation of the polymeric matrices was to use precursors at low molecular weights, in order to avoid the use of solvents, and functionalized with lateral phenyl groups, to improve the filler dispersion and the filler-polymer interactions. The nanocomposites show high deformability (90%), high conductivity (0.85-0.9S/m), and piezoresistive behavior (Gauge Factor equal to 0.75). Additionally, CNT and GNP show a synergistic effect in the electrical conductivity, since the percolative threshold of hybrid nanocomposites is lower than those observed with CNT or GNP separately.
Multilayer and high-entropy alloy-based protective coatings for solving the issue of critical raw materials in the aerospace industry
Authors: Postolnyi Bogdan , Buranich Vladimir , Smyrnova Kateryna , Araújo João Pedro , Rebouta Luís , Pogrebnjak Alexander , Rogoz Vladyslav 
Published: January 2021

Abstract
Aerospace is an actively developing industry that continuously requires the implementation of modern technologies. The rapid growth in new vehicle production demands much support. Hence, the problem of resources with complicated supply and distribution is always of current interest. These critical raw materials (CRMs) are involved in almost all areas of aerospace manufacturing and service. An efficient and profitable solution to the problem of critical materials can be found in protective coatings, especially in such advanced concepts as multilayer and high-entropy alloy (HEA)-based coatings. In this paper, we study both ways of manufacturing effective coatings. We have shown that multilayer CrN/MoN coatings with exceptional toughness and hardness could find promising applications in the aerospace industry. The developed strategy for the novel materials screening based on the prediction of their properties has been demonstrated on the example of the refractory HEA-based coatings. A brief state of the art of the EU critical raw materials and their place in the aerospace/defence industry has been given.
Numerical procedure for electro-thermal anti-icing system simulation coupling internal thermal analysis and external multi-physic code
Authors: Carozza A. , Petrosino F. , Mingione G. 
Published: January 2021

Abstract
The present work has the aim of coupling two codes, one able to perform icing simulations and another one capable to simulate the performance of an electro-thermal anti-icing system in an integrated fashion. In fact, the classical tool chain of icing simulation (aerodynamics, water catch and impact, mass and energy surface balance) is coupled to the thermal analysis through the surface substrate and the ice thickness. In general, the substrate consists of a multi-layered composite with different properties for each layer and embedded heaters (resistors) at interfaces between layers. In the present approach, the ice protection simulation is not decoupled from the ice accretion simulation, but a single computational workflow is considered. Validation results obtained on benchmark test cases from NASA database will be detailed as well as comparison with numerical results from other authors.
Comparison of lightning strike damage in bolted and bonded CFRP joints using a coupled electro-thermal FE model
Authors: Alexandros Sofianos , Konstantinos Tserpes 
Published: January 2021

Abstract
Carbon Fiber Reinforced Plastics (CFRPs) composite structures are widely used in aeronautical structures. Due to the semiconducting nature of CFRPs, lightning strikes can cause significant damages in aircraft components made from such materials. In CFRP laminates joined by mechanical fasteners or adhesive bonding, the damage induced by lightning strikes is a complex multiphysics coupling process. In the present work, in order to study the effects of the different lightning current components on CFRP joints due to the Joule heat flux phenomenon, a coupled electro-thermal FE model has been developed using the ANSYS commercial FE code. Two case studies are considered, i.e. a bolted single-lap joint and an adhesively bonded single-lap joint of CFRP laminates. The model is based on the SOLID5 coupled field solid element and applies a non-linear, time-transient analysis. The main input to the model are the thermal-electrical properties of the CFRP material which vary with temperature. Three electrical lightning strikes of low, medium, and high peak intensity have been applied according to the SAE ARP 5412 standard. The numerical results reveal the detrimental effect of the lightning strike on the bolted joint of the riveted case as the electro-thermal conditions on the bolt facilitated the through-the-thickness degradation of the CFRP material, as opposed to the adhesively bonded joint where the increase of the peak intensity has led to an escalation of the area and penetration of matrix thermal damage (pyrolysis) as well as to the increase of fiber damage (deterioration and ablation). Through static mechanical analysis, the residual joint stiffness has been also predicted.
Finite Element Analysis of Composite Matrix Material with Micro-damage Healing Ability
Authors: Smojver I. , Ivanćevič D. , Brezetič D. 
Published: January 2021

Abstract
A novel constitutive model for modelling of polymer composite matrix material is proposed. Investigated material is an advanced ethylene/methacrylic acid (E/MAA) copolymer, DuPont™ Surlyn® 8940 thermoplastic resin, which exhibits intrinsic self-healing ability. The model incorporates damage evolution and healing model, and the von Mises linear isotropic hardening plasticity model and is validated with static tensile and two-cycle tensile tests on pure Surlyn® 8940 specimens. The concept of nominal and healing configurations is used in the development and numerical implementation of the model, which is additionally streamlined by the application of the strain equivalence hypothesis. Developed constitutive model enables accurate prediction of Surlyn® 8940 behaviour under tensile loading and precise prediction of accumulated plastic strain.
Investigation on Electrically-Assisted Rolling Process of Surface Texture for Drag Reduction
Authors: Xu Zhenhai , Xue Shaoxi , Wang Chunju , Liu Baosheng , Shan Debin , Guo Bin 
Published: January 2021

Abstract
Surface texture is employed for drag reduction in the aviation and aerospace, since it has a positive effect on boundary layers of flow. In this paper, the triangular surface texture was formed via the rolling process. The effects of the roll gap, sheet thickness, the space and size of the triangular shape on the forming quality of the surface texture were studied. The simulation indicates that a small roll gap is benefit for forming full profile. With the decrease of sheet thickness, the forming height is greater, but the sheet flatness is poorer. The size and space of riblet have significant effects on the stress and strain distribution and forming height. When the electric current is introduced into the rolling process, the formed surface texture shows greater forming profile and better flatness. It is concluded that the electrically-assisted rolling process is a promising way of forming surface texture on metal sheets.
TOD – Thermoplastics on Doors: Development of full scale innovative composites doors, surrounds and sub-structure for Regional Aircraft Fuselage barrel on-ground demonstrators. Innovative overall manufacturing and assembly approach and preliminary results obtained at the early stage of the project
Authors: Miraglia A , Felline F , Rocco C , Ceresa A , Raganato Umberto , Zavala-Arredondo M , Flipo B , Liaptsis G , Riise J , Cui X , Wu M , Sampethai S 
Published: January 2021

Abstract
Thermoplastic composites can reduce cost and save weight in airplane structures. Currently on the market there is no thermoplastic door available for commercial aircraft. The overall goal of TOD project is to demonstrate and validate the manufacturing process of thermoplastic door components, induction welding assembly process, additive manufacturing and metallic parts of door mechanism, metallic and thermoset parts of surrounding structure of the passenger and service door of an aircraft. The activities of TOD project have received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement number 821192.
Experimental investigation of damage detection on structures with friction stir welding (FSW) junctions
Authors: Sorrentino A , Chiariello A , Di Palma L , De Fenza A 
Published: January 2021

Abstract
A Structural Health Monitoring system for damage detection is proposed in this paper. The Probability Ellipses method (PE) is a non-destructive method based on Guided waves. This method estimates a global index called Damage Index (DI), that represents a way to measure how much critical is the related sensing-path (actuator-sensor). The DI is high when the damage is closer to the sensing-path and it increases again when the damage severity grows. The work is being developed in the framework of the Clean Sky 2 specifically for More Affordable Small Aircraft Manufacturing (SAT-AM) project, whose main goal is the development of new technologies to be employed in the development of next generation of small aircrafts category responding to CS/FAR-23 certification specification Rules. The Friction Stir Welding (FSW) is one of key technologies to reduce cost, time and manufacturing costs. Conversely, the low historical data on structural degradation of FSW joints require a conservative approach during design stage. A possible answer to the lack of structural knowledge behavior could be overpassed by using structural health monitoring system that periodically evaluates the born of any criticalities of the FSW structures. Preliminary experimental investigations of the ET method, applied to structures with Friction Stir Welding (FSW) junctions, are illustrated. Aluminum panels were joined with FSW technique and damage was produced in the junctions. The structures were instrumented with piezoelectric actuators and sensors. The Guided waves were acquired on both undamaged and damaged configurations and the PE method was applied to identify the damage position.
The dependence of the speed of sound in the Earth’s atmosphere on its density and the correction of Mach’s number
Authors: Kirtskhalia V. 
Published: January 2021

Abstract
According to the modern theory of sound, its speed in the Earth’s atmosphere depends only on temperature and does not depend on its density (height). The report shows a significant dependence of the speed of sound on the density of the atmosphere and, consequently, the requirement to adjust the Mach number, which plays an important role in determining the aerodynamic parameters of an aircraft.