Relationship Between the Texture and Young’s modulus over the Section of Cold-rolled Rods of Low-modulus Biocompatible Alloy

The influence of the texture type on the Young’s modulus value in the different sections of cold-deformed rods of Zr-31Ti-18Nb alloy (IMP BAZALM) was studied. It was found, an increase in the compression deformation degree from 63 to 84 % of Zr-31Ti-18Nb alloy during cold rolling contributed to the improvement of {001} <110> deformation cube texture. This contributed to the preferential orientation of the directions <001> and <110> parallel to ND and RD (TD) directions, accordingly. The minimum values of the Young’s modulus were typical for areas where low-module <001> orientation prevailed, and the maximum values of the Young’s modulus were characteristic for areas with high-modules <110> orientations. So, in the alloy deformed by 84 %, the lowest values of the Young’s modulus were obtain in the rolling plane up to 53 GPa, and the highest values in plane perpendicular to the rolling direction up to 70 GPa.     Keywords: Zr-Ti-Nb system, biocompatible alloy, Young’s modulus, texture

Structural and Phase Transformation in a Cold-Deformed Titanium Alloy During Aging

The change of structure, phase composition and properties during aging of VT22 (Ti-5Al-5Mo-5V-1Fe-1Cr) titanium alloy rods, pre-quenched fro

Osteointegration Characterization of Additive Manufactured Porous Titanium Scaffold Based on Microhardness and Ca/P Ratio

Additive technologies are getting widely used in orthopedics due to the opportunity of full modelling of complex cellular structures and producing personalized implants. Titanium and its alloys are still the main material used for metallic implants manufacturing. In this study microhardness and Ca/P ratio of bone tissue surrounding the implant were investigated. By means of ABAQUS software titanium porous structure implants were designed. Their biomechanical properties were close to biomechanical properties of trabecular bone tissue. Direct metal laser sintering (DMLS) was used to manufacture implants from Ti-6Al-4V titanium alloy. They were augmented in trabecular bone defects of Chinchilla rabbits for 6, 12 and 25 weeks. The samples were examined by scanning electron microscopy (SEM) in a FEG SEM ZEISS CrossBeam AURIGA and the Ca/P ratio was calculated using the accompanying Oxford Inca software. Vickers hardness test method was performed for microhardness. It was shown that there was a significant increase in both mineral and mechanical properties of bone samples with an increase of observation period. The results found in this study illustrate a distinct relationship between the mineralization parameter of bone tissue and its microhardness (r = 0.808, r2 = 0.65).     Keywords: Scaffold, Microhardness, Titanium, Ca/P ratio, Bone defect, Osteointegration, Additive manufacturin

Structural and Textural State of a Corrosion-Resistant Super Alloys Ni–Cr–Mo System after Deformation

The structural and textural state of the nickel-based alloy (Ni–Cr–Mo) after cold rolling with degree of strain ∼ 0.7 was investigated by means of electron backscatter diffraction (EBSD). It is shown that a multicomponent texture is formed during the deformation, including orientations: strong {110} < 112 >, and weaker {110} < 001 > and {110} < 111 >. The structure contains band elements of the mesostructure, which can be interpreted as deformation twins and shear bands. The orientation of the crystal lattice in all bands formed in grains with the main component of the texture ∼ {110} < 112 > is close to {110} < 001 >. This orientation is connected to the matrix, by turning at an angle of 70 ∘ around the transverse direction. It corresponds to the twin disorientation or the coincidence site lattice special (CLS) Σ3 (60∘ , оcь < 111 >). It is shown that all band elements of the mesostructure in the alloy are formed by the mechanism of deformation twinning. Moreover, the special disorientation formed at the beginning of the process (the special boundary Σ3), is preserved in the deformation process as an energy stable object.     Keywords: FCC-metal, cold rolling, twinning, shear bands, texture

The interior and the fusion crust in Sariçiçek howardite: Study using X-ray diffraction, magnetization measurements and Mössbauer spectroscopy

PubMed: 318064802-s2.0-85076566142The meteorite Sariçiçek, a 2015 howardite fall in Turkey, was analyzed using various physical techniques. Both the interior and the fusion crust were studied by optical and scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy. The main and minor iron-bearing phases such as orthopyroxene, Ca-poor and Ca-rich clinopyroxene, chromite with hercynite, Fe2+ and Fe3+ ilmenite, troilite, ?-Fe(Ni, Co), ?2-Fe(Ni, Co) and ?-Fe(Ni, Co) phases were identified. The ratios of Fe2+ occupancies in the M1 and M2 sites in the silicate phases as well as the equilibrium Fe2+ and Mg2+ cations distribution temperatures (Teq) for orthopyroxene were estimated using X-ray diffraction and Mössbauer spectroscopy, which appeared to be in a good agreement: for example, Teq were 886 and 878 K, respectively. The glass-like fusion crust of Sariçiçek consists of orthopyroxene with ferrous and ferric compounds that are likely products of combustion and melting. © 2019 Elsevier B.V.Ministry of Education and Science of the Russian Federation, Minobrnauka Government Council on Grants, Russian Federation: ? 02. Ural Federal University, UrFU Ministry of Science and Higher Education of the Russian Federation: 3.1959.2017/4.6The authors wish to thank Dr. E.I. Denisov (Institute of Physics and Technology, Ural Federal University) for his kind help with chemical analysis using X-ray fluorescence spectroscopy. This work was supported by the Ministry of Science and Higher Education of the Russian Federation (the Project ? 3.1959.2017/4.6 ) and Act 211 of the Government of the Russian Federation , contract ? 02.A03.21.0006 .The authors wish to thank Dr. E.I. Denisov (Institute of Physics and Technology, Ural Federal University) for his kind help with chemical analysis using X-ray fluorescence spectroscopy. This work was supported by the Ministry of Science and Higher Education of the Russian Federation (the Project ? 3.1959.2017/4.6) and Act 211 of the Government of the Russian Federation, contract ? 02.A03.21.0006

ТЕХНИЧЕСКИЕ НАУКИ ИЗУЧЕНИЕ СТРУКТУРЫ НЕМЕТАЛЛИЧЕСКИХ ВКЛЮЧЕНИЙ В СТАЛИ МАРКИ 13ХФА И ИХ ВЛИЯНИЯ НА ИНИЦИИРОВАНИЕ ПРОЦЕССОВ ПИТТИНГООБРАЗОВАНИЯ STUDY OF NONMETALLIC INCLUSIONS STRUCTURE IN 13CRV STEEL AND THEIR EFFECTS ON INITIATION THE PROCESSES OF PI

Основной идеей работы являлось определение неметаллических включений в стали 13ХФА, влияющих на питтинговую коррозию в газонефтепроводных трубах. В процессе исследования показаны преимущества автоматического определения местоположения включений различных классов на поверхности отдельно взя-того образца с помощью растровой электронной микроскопии перед методикой травления. Впервые была применена резка включений ионным пучком на растровом электронном микроскопе AURIGA, что позволи-ло установить структуру отдельных включений. Определено, что включения в исследуемой стали являются двухфазными и состоят из магнезиальной шпинели и сульфида кальция и марганца, плотно прилегающих друг к другу. Установлено, что растворение сульфидной части двухфазного включения в хлорсодержащих водных средах является первой ступенью к уменьшению коррозионной устойчивости посредством образо-вания питтинга. Ural Federal University named after First President of Russia B.N. Yeltsin, Ekaterinburg, e-mail: [email protected] It is known that some kind of inclusions account for pitting formation in steel tube. Therefore the identifi cation of this sort of nonmetallic inclusions in 13CrV steel was the main idea of this work. The new method for estimation dirty steel was introduced. It involves using scanning electron microscopy and software for detecting dimensions, chemical composition and location every inclusion on the investigated surface. Microstructure of certain inclusions was investigated on nonmetallic inclusion cross-section made cutting ion beam of scanning electron microscope AURIGA. It was found that in nonmetallic inclusions of this steel were two-phase. The fi rst phase is MgO·Al 2 O 3 spinel inclusion, the second phase is calcium and manganese sulphide. These two parts of one inclusion bear against. This sort of inclusions infl uences on corrosion processes in steel. It was established that sulphide part of inclusion was thermodynamically unstable in environment with chlorine ion. Therefore calcium and manganese sulphide dissolves and forms pitting. Keywords: low-alloy steel, nonmetallic inclusions, corrosion, pitting Наиболее частой и наиболее опасной причиной выхода трубопровода из строя в последнее время является питтинговая коррозия. Питтинговая коррозия относится к локальному виду коррозии пассивных ме-таллов и приводит к развитию углублений небольшого размера (питтингов). Этот вид коррозии очень опасен даже в том случае, когда общая убыль массы металла мала [14]. Давно известно [5], что в качестве цен-тров питтингообразования в нержавеющих сталях могут выступать неметаллические включения различной природы. Относи-тельно низколегированных сталей авторами [9, 10] установлено, что основной причиной аномально высоких скоростей коррозии не-фтепромысловых трубопроводов является загрязненность стали неметаллическими включениями особого типа, вносимыми в сталь в процессе ковшевой обработки при неоптимальных технологических параме-трах. Такие включения получили название коррозионно-активных неметаллических включений (КАНВ). Однако существует мнение Так как результаты исследований, про-веденных различными авторами, противо-речивы, вопрос о влиянии неметаллических включений (в том числе идентифицируемых в соответствии с [10] как КАНВ) на процес-сы локальной коррозии остается открытым

The Sariçiçek howardite fall in Turkey: Source crater of HED meteorites on Vesta and impact risk of Vestoids

The Sari\c{c}i\c{c}ek howardite meteorite shower consisting of 343 documented stones occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sari\c{c}i\c{c}ek experienced a complex cosmic ray exposure history, exposed during ~12-14 Ma in a regolith near the surface of a parent asteroid, and that an ca.1 m sized meteoroid was launched by an impact 22 +/- 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 +/- 2.5 Ma and 4553 +/- 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 +/- 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 +/- 0.7 and 2.6 +/- 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Ti- isotopic studies confirm that Sari\c{c}i\c{c}ek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sari\c{c}i\c{c}ek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 +/- 0.8 kms-1 from NW, fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sari\c{c}i\c{c}ek with the Vesta asteroid family spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the disruption of a ca.1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids <4 m in size to account for the influx of meteorites from this HED clan

The Sariçiçek howardite fall in Turkey: Source crater of HED meteorites on Vesta and impact risk of Vestoids

###EgeUn###The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on September 2, 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic-ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one-third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic; geochemical; and O-, Cr-, and Ti-isotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 km s -1 from NW; fragmentations at 37, 33, 31, and 27 km altitude; and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ?4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antionia impact crater on Vesta was formed on terrain of the same age as given by the 4 He retention age of Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was formed ~22 Ma ago. © The Meteoritical Society, 2019.58261, 40339 nccr – on the move NNX14AM62G MFAG/113F035 Simons Foundation: 302497 NNX14-AR92G, NNX16AD34G Academy of Finland: 299543 Government Council on Grants, Russian Federation: ? 02., A03.21.0006 Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung: PZ00P2_154874 Ministry of Education and Science of the Russian Federation: 3.1959.2017/4.6 National Natural Science Foundation of China: 41403055Acknowledgments—We thank N. Ergu€n and family in the village of Sari©ci©cek for donating the meteorites studied here and collecting meteorite fall coordinates. We thank E. Atalan and S. Ozdemir€ at Bingo€l University, and E. Necip Yardım and M. C© i©cek at Mu©s Alparslan University, for facilitating our research at the campuses, and S. Pamuk at the Bingo€l police headquarters. We thank A. and T. Ozdum€ an, police officers in Bingo€l, for assisting with the field study. For technical assistance, we further acknowledge support from M. Fehr, Y.-J. Lai, and L. Hoffland (NASA Ames Research Center); David Mittlefehldt (NASA JSC); K. Wimmer (Ries Crater Museum); J. Sanchez (Planetary Science Institute); A. Neesemann (Free University Berlin); S. Atanasova-Vladimirova and I. Piroeva (Institute of Physical Chemistry, BAS); and B. Georgieva and V. Strijkova (Institute of Optical Materials and Technologies, BAS). This work was supported by Istanbul University (Project No. 40339 and 58261), the Scientific and Technological Research Council of Turkey (MFAG/113F035), the Swiss National Science foundation (PZ00P2_154874 and NCCR PlanetS), the Ministry of Science and Higher Education of the Russian Federation (Project # 3.1959.2017/4.6), Act 211 of the Government of the Russian Federation, contract ? 02.A03.21.0006, the National Natural Science Foundation of China (41403055), the Simons Foundation (302497), the Academy of Finland (299543), the NASA Cosmochemistry Program (NNX14AM62G), the NASA Emerging Worlds Program (NNX16AD34G), and the NASA NEOO program (NNX14-AR92G). -