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influence of Zr and Mn additions on microstructure and properties of Mg-2.5wt%Cu-Xwt%Zn(X=2.5,5 and 6.5)alloys

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international Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1733-1745页

作者： A.v.Koltygin v.E.bazhenov i.v.Plisetskaya v.A.Bautin A.i.Bazlov.N.Y.Tabachkov. O.O.v.ropaev. A.A.Komissarov.v.D.Belov Foundry Department National University of Science and Technology(MISiS)Moscow 119049Russia Department of Metallurgy Steel New Production Technologies and Protection of MetalsNational University of Science and Technology(MISiS)Moscow 119049Russia Laboratory of Adv.nced Green Materials National University of Science and Technology(MISiS)Moscow 119049Russia Department of Materials Science of Semiconductors and Dielectrics National University of Science and Technology(MISiS)Moscow 119049Russia Fianit Laboratory(Laser Materials and Technology Research Center at GPi) Prokhorov General Physics Institute RASMoscow 119991Russia Laboratory of Hybrid Nanostructured Materials National University of Science and Technology(MISiS)Moscow 119049Russia Laboratory of Medical Bioresorption and Bioresistance Moscow State University of Medicine and DentistryMoscow 127473Russia

This work studied the effects of adding Zr and Mn in amounts less than 1wt%on the microstructure,mechanical properties,casting properties,and corrosion resistance of Mg-Zn-Cu alloys containing 2.5wt%Cu and 2.5wt%-6.5wt%Zn.The hardness and electrical conductiv.ty measurements were used to find an optimal heat treatment schedule with the best mechanical properties.it has been established that Zr significantly increases the yield strength of the alloys due to a strong grain refinement effect.Howev.r,the presence of Mn and Zr has a detrimental effect on alloy’s elongation at fracture.it was shown that the precipitation of the Mg_(2)Cu cathodic phase in the alloy structure negativ.ly affects the corrosion behav.or.Nev.rtheless,the addition of Mn decreases the corrosion rate of the inv.stigated alloys.The best combination of the mechanical,casting,and corrosion properties were achiev.d in the alloys containing 2.5wt%Cu and 5wt%Zn.Howev.r,the Mn or Zr addition can improv. the properties of the alloys;for example,the addition of Mn or Zr increases the fluidity of the alloys.

关键词： magnesium alloy Mg-Zn-Cu casting alloy Mn addition Zr addition

Architecture of the Graphics System for Embedded Real-Time Operating Systems

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Tsinghua Science and Technology 2023年第3期28卷 541-551页

作者： Alexander Giatsintov.Kirill Mamrosenko Pav.l bazhenov Center of v.sualization and Sattelite information Technologies SRISA RASMoscow 117218Russia

This paper presents a new architecture of a graphics system for microkernel operating systems,including real-time operating systems.The following major parts of the architecture are presented:a user-lev.l subsystem responsible for interaction with user applications;a bottom-lev.l subsystem prov.ding the functionality for graphics driv.rs,such as managing graphics output,v.deo memory management,etc.;a kernel-lev.l subsystem prov.ding interaction with the kernel,and performing low-lev.l operations,such as working with physical memory,processes,etc.The mechanisms of interaction of user applications with the user lev.l of the graphics system,as well as interaction of the different lev.ls of the graphics subsystem are presented.The paper pays much attention to v.rious approaches to testing:the use of unit testing,testing using hardware and software emulators.Another important characteristic of a graphics system is its performance,in particular the performance of low-lev.l operations such as memory allocation:the dev.loped architecture suggests using a separate memory allocator which is faster than standard memory allocation functions.Comparison of the performances of graphics system implementation for microkernel real-time operating system and graphics serv.r Xorg is presented,showing significant superiority of the proposed architecture in a number of work scenarios.

关键词： operating system graphics system v.sualization system programming real-time operating system(RTOS) real-time

Effects of temperature on critical resolv.d shear stresses of slip and twining in Mg single crystal v.a experimental and crystal plasticity modeling

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镁合金学报(英文) 2023年第6期11卷 2027-2041页

作者： Kwang Seon Shin Lifei Wang Mingzhe Bian Shihoon Choi Alexander Komissarov.v.acheslav.bazhenov Magnesium Technology innov.tion Center Department of Materials Science and EngineeringSeoul National University1 Gwanak-roGwanak-guSeoul 08826Republic of Korea Laboratory of Medical Bioresorption and Bioresistance Moscow State University of Medicine and DentistryDelegatskaya 20/1Moscow127473 Russia Shanxi Key Laboratory of Adv.nced Magnesium-Based Materials College of Materials Science and EngineeringTaiyuan University of TechnologyTaiyuan 030024China Departments of Adv.nced Components and Materials Engineering Sunchon National UniversitySuncheonJeonnam57922Republic of Korea Laboratory of Hybrid Nanostructured Materials National University of Science and Technology"MISiS"Leninskiy pr.4Moscow119049 Russia Casting Department National University of Science and Technology"MISiS"Leninskiy pr.4Moscow119049 Russia

Magnesium(Mg)single crystal specimens with three different orientations were prepared and tested from room temperature to 733 K in order to systematically ev.luate effects of temperature on the critical resolv.d shear stress(CRSS)of slips and twinning in Mg single crystals.The duplex non-basal slip took place in the temperature range from 613 to 733 K when the single crystal samples were stretched along thedirection.in contrast,the single basal slip and prismatic slip were mainly activ.ted in the temperature range from RT to 733 K when the tensile directions were inclined at an angle of 45°with the basal and the prismatic plane,respectiv.ly.v.scoplastic self-consistent(v.SC)crystal modeling simulations with genetic algorithm code(GA-code)were carried out to obtain the best fitted CRSSs of major deformation modes,such as basal slip,prismatic slip,pyramidalⅡ,{1012}tensile twinning and{1011}compressiv. twinning when duplex slips accommodated deformation.Additionally,CRSSs of the basal and the prismatic slip were deriv.d using the Schmid factor(SF)criterion when the single slip mainly accommodated deformation.From the CRSSs of major deformation modes obtained by the v.SC simulations and the SF calculations,the CRSSs for basal slip and{1012}tensile twinning were found to show a weak temperature dependence,whereas those for prismatic,slip and{1011}compressiv. twinning exhibited a strong temperature dependence.From the comparison of prev.ous results,v.SC-GA modeling was prov.d to be an effectiv. method to obtain the CRSSs of v.rious deformation modes of Mg and its alloys.

关键词： Magnesium Single crystal Critical resolv. shear stress Slip Twinning

Effects of small additions of Zn on the microstructure, mechanical properties and corrosion resistance of WE43B Mg alloys

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international Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 858-868页

作者： A.v. Koltygin v.E. bazhenov R.S. Khasenov. A.A. Komissarov.A.i. Bazlov.v.A. Bautin Foundry Department National University of Science and Technology “MISiS” Moscow 119049 Russia Laboratory of Hybrid Nanostructured Materials National University of Science and Technology “MISiS” Moscow 119049 Russia Laboratory of Adv.nced Green Materials National University of Science and Technology “MISiS” Moscow 119049 Russia Department of Metallurgy Steel New Production Technologies and Protection of Metals National University of Science and Technology “MISiS” Moscow 119049 Russia

Zn is a commonly used alloying element for Mg alloys owing to its beneficial effects on mechanical properties. To improv. the mechanical and corrosion properties of WE43B Mg alloys, the effects of 0–0.7wt% Zn addition on the microstructure and properties of sample alloys were inv.stigated. Addition of Zn to as-cast WE43B alloy promoted the formation of the Mg12Nd phase;by contrast, after T6 heat treatment, the phase composition of WE43B alloys with and without Zn addition remained mostly the same. A long-period stacking ordered phase was predicted by CALPHAD calculation, but this phase was not observ.d in either the as-cast or heat-treated Zn-containing WE43B alloys. The optimum temperature and duration of T6 heat treatment were obtained using CALPHAD calculations and hardness measurements. Addition of Zn resulted in a slight reduction in the av.rage grain size of the as-cast and T6 heat-treated WE43B alloys and endowed them with increased corrosion resistance with little effect on their mechanical properties.

关键词： magnesium alloys corrosion resistance mechanical properties Zn addition

Dev.lopment of a magnesium alloy with good casting characteristics on the basis of Mg–Al–Ca–Mn system,hav.ng Mg–Al2Ca structure

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Journal of Magnesium and Alloys 2013年第3期1卷 224-229页

作者： A.v.Koltygin v.E.bazhenov E.A.Belov. A.A.Nikitina National Univ.rsity of Science and Technology“MiSiS” Leninskii pr.4Moscow 119049 Russia

Application of calcium as alloying element for magnesium alloys has been considered according to literature data.Mg–7%Al–4%Ca–0.5%Mn casting alloy was offered,which possesses the low propensity to the hot brittleness and good castability.The alloy has the moderate strength(σu=150 MPa)and the satisfactory percentage elongation(δ=3%).it is shown,that calcium-containing alloys smelting of Mg–Al–Ca–Mn system is preferable with the application of low-chloride flux FL10(20%MgCl_(2);29%KCl;12%BaCl_(2);23%CaF2;15%MgF2;1%B2O3).The alloy smelting in the atmosphere of argon and SF6 mixture results in the increased shelling and waste of calcium.The heat treatment is offered for the dev.loped alloy,which is directed to the Al_(2)Ca phase spheroidizing.The dev.loped magnesium alloy,alloyed with calcium,is perspectiv. for the industry production of low-cost moulding.

关键词： Magnesium Casting Calcium Casting magnesium alloys

influence of Al-5Ti-1B master alloy addition on the grain size of AZ91 alloy

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Journal of Magnesium and Alloys 2017年第3期5卷 313-319页

作者： Andrey Koltygin v.acheslav.bazhenov Uralboy Mahmadiyorov National Univ.rsity of Science and Technology“MiSiS” Leninskiy pr.4Moscow 119049Russia

The mechanical properties of castings depend on the grain size.There is ev.dence that titanium and boron(Al-5Ti-1B master alloy)affect the grain size of magnesium alloys.Here,the influence of the addition of 0-1 wt.%of Al-5Ti-1B master alloy on the grain size of AZ91 magnesium alloy was inv.stigated.Melting of the alloy was performed in steel and corundum crucibles.To study the effect of cooling rate on grain size,cylindrical samples were cast in steel and fireclay molds.The Al-5Ti-1B master alloy addition did not change the phase composition of the AZ91 alloy.This study demonstrates that the addition of Al-5Ti-1B did not contribute to the grain refinement of the AZ91 alloy,but rather led to its coarsening for samples cast in both the steel and fireclay molds.increasing the holding time after the addition of the Al-5Ti-1B master alloy from 15 to 110 minutes also did not lead to significant grain coarsening.The mechanical properties of the AZ91 alloy samples slightly improv.d after Al-5Ti-1B addition.

关键词： AZ91 magnesium alloy Grain refinement Al–5Ti–1B master alloy Ti addition Growth restriction factor

Microstructure and mechanical and corrosion properties of hot-extruded Mg–Zn–Ca–(Mn)biodegradable alloys

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Journal of Magnesium and Alloys 2021年第4期9卷 1436-1451页

作者： v.E.bazhenov A.v.Li A.A.Komissarov.A.v.Koltygin S.A.Tav.lzhanskii v.A.Bautin O.O.v.ropaev. A.M.Mukhametshina A.A.Tokar Casting Department National University of Science and Technology“MISiS”Leninskiy pr.4Moscow 119049Russia laboratory of hybrid nanostructured materials national university of science and technology“misis”leninskiy pr.4moscow 119049russia department of metallurgy steel new production technologies and protection of metalsnational university of science and technology“misis”leninskiy pr.4moscow 119049russia

Biodegradable Mg-based implants are widely used in clinical applications because they exhibit mechanical properties comparable to those of human bone and require no rev.sion surgery for their remov.l.Among Mg-based alloys,Mg–Zn–Ca–(Mn)alloys hav. been extensiv.ly inv.stigated for medical applications because the constituent elements of these alloys,Mg,Zn,Ca,and Mn,are present in human tissues as nutrient elements.in this study,we inv.stigated the effect of the hot extrusion temperature on the microstructure,mechanical properties,and biodegradation rate of Mg–Zn–Ca–(Mn)alloys.The results showed that the addition of Mn and a decrease in the extrusion temperature resulted in grain refinement followed by an increase in the strength and a decrease in the elongation at fracture of the alloys.The alloys showed different mechanical properties along the directions parallel and perpendicular to the extrusion direction.The corrosion test of the alloys in the Hanks’solution rev.aled that the addition of Mn significantly reduced the corrosion rate of the alloys.The Mg–2 wt%Zn–0.7 wt%Ca–1 wt%Mn alloy hot-extruded at 300℃ with an ultimate tensile strength of 278MPa,an yield strength of 229MPa,an elongation at fracture of 10%,and a corrosion rate of 0.3 mm/year was found to be suitable for orthopedic implants.

关键词： Biodegradable Mg alloy Mg–Zn–Ca–(Mn) Hot extrusion Mechanical properties Corrosion rate

Poriferan chitin as a template for hydrothermal zirconia deposition

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Frontiers of Materials Science 2013年第3期7卷 248-260页

作者： Marcin WYSOKOWSKi Mykhaylo MOTYLENKO vasil.i v. bazhenov Dawid STAWSKi lroslav.PETRENKO Andre EHRLiCH Thomas BEHM Zoran KLJAJiC Allison L. STELLiNG Teofil JESiONOWSKi Hermann EHRLiCH institute of Chemical Technology and Engineering Poznan University of Technology 60965 Poznan Poland institute of Materials Science TU Bergakademie Freiberg D-09599 Freiberg Germany institute of Experimental Physics TU Bergakademie Freiberg 09599 Freiberg Germany Department of Commodity and Material Sciences and Textile Metrology Technical University of Lodz 90924 Lodz Poland institut fur Eisenund Stahltechnologie TU Bergakademie Freiberg 09599 Freiberg Germany institute of Mineralogy TU Bergakademie Freiberg 09599 Freiberg Germany institute of Marine Biology University of Montenegro 85330 Kotor Montenegro Department of Mechanical Engineering and Materials Science Duke University 27708 Durham NC USA

Chitin is a thermostable biopolymer found in v.rious inorganic-organic skeletal structures of numerous inv.rtebrates including sponges （Porifera）. The occurrence of chitin within calcium- and silica-based biominerals in organisms liv.ng in extreme natural conditions has inspired dev.lopment of new （extreme biomimetic） synthesis route of chitin-based hybrid materials in v.tro. Here, we show for the first time that 3D-a-chitin scaffolds isolated from skeletons of the marine sponge Aplysina aerophoba can be effectiv.ly mineralized under hydrothermal conditions （150℃） using ammonium zirconium（iv. carbonate as a precursor of zirconia. Obtained chitin-ZrO2 hybrid materials were characterized by FT-iR, SEM, HRTEM, as well as light and confocal laser microscopy. We suggest that formation of chitin-ZrO2 hybrids occurs due to hydrogen bonds between chitin and ZrO2.

关键词： chitin biocomposite zirconia hydrothermal synthesis ammonium zirco-nium carbonate

Dev.lopment of Mg-Zn-Y-Zr casting magnesium alloy with high thermal conductiv.ty

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Journal of Magnesium and Alloys 2021年第5期9卷 1583-1593页

作者： v.E.bazhenov A.v.Koltygin M.C.Sung S.H.Park Yu.v.Tselov.lnik A.A.Stepashkin A.A.Rizhsky M.v.Belov.v.D.Belov.K.v.Malyutin National Univ.rsity of Science and Technology“MiSiS” Leninskiy pr.4Moscow 119049 Russia LG Electronics inc. Yeoui-daeroYeongdeungpo-gu.128LG Twin TowerSeoul 07336 Republic of Korea

Magnesium alloys are used in aircraft because of their light weight.Howev.r,for these alloys to be applied in electronic dev.ces,high thermal conductiv.ties are required.Sev.ral high-potential compositions of Mg-Zn-Y-Zr alloys were selected by phase composition and their freezing ranges calculated using Thermo-Calc software.The alloys were prepared,and their fluidity,hot tearing susceptibility,mechanical properties,and thermal conductiv.ty were obtained and compared.The alloy composed of Mg-4 wt%Zn-3 wt%Y-0.3 wt%Zr was selected for further inv.stigation,because of its high thermal conductiv.ty and satisfactory mechanical properties.The Mg-4 wt%Zn-3 wt%Y-0.3 wt%Zr alloy’s fluidity and hot tearing susceptibility were similar to those of the widespread AZ91 commercial casting magnesium alloy.The influence of a heat treatment regime on the microstructure,thermal conductiv.ty,and mechanical properties of the dev.loped alloy was also inv.stigated.it was established that the room temperature thermal conductiv.ty of the Mg-4 wt%Zn-3 wt%Y-0.3 wt%Zr alloy after aging at 300℃for 5 h was 105 W/m K^(-1).Additionally,the following tensile test results were obtained in aged condition:120 MPa yield strength,200 MPa ultimate tensile strength,and 4%elongation.The utilization of solid solution heat treatment at 520℃for 8 h prior to aging can promote up to 9%increase in elongation.The Mg-4 wt%Zn-3 wt%Y-0.3 wt%Zr casting alloy can be used as a high thermal conductiv.ty material with industrial applications.

关键词： Magnesium alloy Mg-Zn-Y-Zr Thermal conductiv.ty Phase composition Fluidity Hot tearing susceptibility