@misc{FellahHezilSamadetal., author = {Fellah, Mamoun and Hezil, Naouel and Samad, Mohammed Abdul and Djellabi, Ridha and Montagne, Alex and Mejias, Alberto and Kossman, Stephania and Iost, Alain and Purnama, Agung and Obrosov, Aleksei and Weiß, Sabine}, title = {Effect of Molybdenum Content on Structural, Mechanical, and Tribological Properties of Hot Isostatically Pressed β-Type Titanium Alloys for Orthopedic Applications}, series = {Journal of Materials Engineering and Performance}, volume = {28}, journal = {Journal of Materials Engineering and Performance}, number = {10}, issn = {1059-9495}, doi = {10.1007/s11665-019-04348-w}, pages = {5988 -- 5999}, abstract = {Aiming to develop alloys with better properties for orthopedic applications, the focus of the present research was to evaluate the effect of Mo at.\% content on structural, mechanical, and tribological properties of hot isostatically pressed Ti-xMo (x = 4, 8, 12, 15, and 20 at.\%) alloys. The structural evolution, mechanical properties, and tribological behavior of the nanostructured Ti-xMo alloys were evaluated using x-ray diffraction, scanning electron microscope, and ball-on-disk tribometer. Wear tests were conducted under different applied loads of 2, 8, and 16 N. Experimental results indicated that the structural evolution and morphological changes of the milled alloys were sensitive to their molybdenum (Mo) content. The morphological characterization showed that the crystallite size and the particle size decreased with increasing Mo content (at.\%) reaching the lowest values of 27 and 26 nm in the case of Ti-15Mo and Ti-20Mo, respectively. On the other hand, the coefficient of friction and wear rates were found to be decreasing with increasing Mo content.}, language = {en} } @misc{ObrosovKashkarovSharmaetal., author = {Obrosov, Aleksei and Kashkarov, Egor B. and Sharma, A. and Weiß, Sabine}, title = {Microstructure and defect structure of Zr-1Nb alloy deep surface modified by high Intensity Ti Ion implantation}, series = {MC Microscopy Conference, 01-05 September 2019, Berlin, Abstracts}, journal = {MC Microscopy Conference, 01-05 September 2019, Berlin, Abstracts}, address = {Berlin}, pages = {86}, abstract = {A deep surface modified TiZr layer was fabricated by high-intensity low-energy titanium ion implantation into zirconium alloy Zr-1Nb alloy with the various dose in the range of (5.4-9.56) × 1020 ion/cm2. The gradient distribution of titanium as well as vacancy type defects were analysed. The effects of ion implantation on microstructure, phase composition and elemental distribution of TiZr layer were analysed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and glow-discharge optical emission spectroscopy, respectively. The results show the appearance of Zr-Ti intermetallic phases of different stoichiometry after Ti implantation. The intermetallic phases are transformed from both Zr0.7Ti0.3 and Zr0.5Ti0.5 to single Zr0.6Ti0.4 phase with the increase in the implantation dose. The depth of Ti penetration into the bulk of Zr increases from 6 to 13 μm with the implantation dose. The higher current density (170 mA/cm2) leads to the increase in the grain size and surface roughness. It was revealed that TiZr layer (~10 μm thickness) is represented by α′ + α(TiZr) lamellar microstructure with gradient distribution of Ti through the layer depth. Transmission electron microscopy was used for investigation of the physical basis of Ti diffusion and its influence on the evolution of the defect structure after surface modification. Furthermore, it was found that on the surface between substrate and implanted layer was found an amorphous layer, which occur as a result of further stress accumulations from the higher implantation doses.}, language = {en} } @misc{ShevelevKashkarovRyabchikovetal., author = {Shevelev, Alexey and Kashkarov, Egor B. and Ryabchikov, Alexander I. and Syrtanov, Maxim S. and Obrosov, Aleksei}, title = {Surface Modification of E110 Alloy by High-Intensity Low Ion Energy Cr Implantation}, series = {The 21st International Conference on Surface Modification of Materials by Ion Beams, 25-30 August 2019}, journal = {The 21st International Conference on Surface Modification of Materials by Ion Beams, 25-30 August 2019}, address = {Tomsk}, pages = {109 -- 109}, abstract = {The Fukushima disaster has strongly effected on nuclear energetics and their progress [1]. It pointed to a crucial oxidation and subsequent destruction of nuclear fuel claddings in light-water reactors in the case of loss of coolant accident conditions. Surface modification is one of the promising approaches to protect Zr alloys in normal operation and accident conditions of nuclear reactors [2]. Surface modified layers or coatings forming chromia during oxidation is of greatest interest since it meets the basic requirements for accident tolerant fuel materials [3]. The aim of this research is to study the possibility of deep surface modification of zirconium alloy E110 by high intensity ion implantation using low energy metal ion beam. The formation of the metal ion beams is provided by the application of negatively pulsed bias (1.5 kV) to the system immersed in the chromium vacuum arc plasma. The structure and composition of Cr-implanted zirconium alloy were studied by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The mechanical properties and wear resistance were measured by nanoindentation and «ball on disk» testing, respectively. The influence of implantation temperature on the phase composition, microstructure, and mechanical properties as well as on the corrosion behavior of Cr-implanted zirconium alloy under high-temperature oxidation (up to 1100÷1200 °C) have been described.}, language = {en} } @misc{FellahHezilDekhiletal., author = {Fellah, Mamoun and Hezil, Naouel and Dekhil, Leila and Samad, Mohammed Abdul and Djellabi, Ridha and Kosman, Stephania and Montagne, Alex and Iost, Alain and Obrosov, Aleksei and Weiß, Sabine}, title = {Effect of sintering temperature on structure and tribological properties of nanostructured Ti-15Mo alloy for biomedical applications}, series = {Transactions of Nonferrous Metals Society of China}, volume = {29}, journal = {Transactions of Nonferrous Metals Society of China}, number = {11}, issn = {1003-6326}, doi = {10.1016/S1003-6326(19)65137-X}, pages = {2310 -- 2320}, abstract = {The effect of sintering temperature (1073-1373 K) on the structural and tribological properties of nanostructured ball-milled β-type Ti-15Mo samples was investigated. The prepared samples were characterized using various apperatus such as X-ray diffractometer, scanning electron microscope (SEM) and ball-on-plate type oscillating tribometer. Wear tests were conducted under different applied loads (2, 8 and 16 N). Structural results showed that the mean pore and crystallite size continuously decreased with increasing sintering temperature to reach the lowest values of 4 nm and 29 nm at 1373 K, respectively. The relative density of the sintered sample at 1373 K was as high as 97.0\%. Moreover, a higher sintering temperature resulted in higher relative density, greater hardness and elastic modulus of the sample. It was observed that both the friction coefficient and wear rate were lower in the sample sintered at 1373 K which was attributed to the closed porosity.}, language = {en} } @misc{KashkarovRyabchikovSyrtanovetal., author = {Kashkarov, Egor B. and Ryabchikov, Alexander I. and Syrtanov, Maxim S. and Obrosov, Aleksei and Zacharchenko, S.}, title = {ФОРМИРОВАНИЕ ГЛУБОКИХ МОДИФИЦИРОВАННЫХ СЛОЕВ TIZR НА ПОВЕРХНОСТИ ЦИРКОНИЕВОГО СПЛАВА Э110 МЕТОДОМ ВЫСОКОИНТЕНСИВНОЙ ИОННОЙ ИМПЛАНТАЦИИ}, series = {24rd International Conference on Ion-Surface Interactions}, journal = {24rd International Conference on Ion-Surface Interactions}, address = {Moscow}, pages = {190 -- 193}, abstract = {This work describes the effect of high-intensity low ion energy implantation on the structure and properties of the surface modified layer forming on zirconium alloy. The influence of irradiation dose on the microstructure, phase composition, thickness and mechanical properties of surface modified zirconium alloy were investigated.}, language = {ru} } @misc{NaumovMorozovaRylkovetal., author = {Naumov, Anton and Morozova, Iuliia and Rylkov, Evgenii and Obrosov, Aleksei and Isupov, Fedor and Michailov, Vesselin and Rudskoy, Andrey I.}, title = {Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy}, series = {Materials}, volume = {12}, journal = {Materials}, number = {24}, issn = {1996-1944}, doi = {10.3390/ma12244211}, pages = {16}, abstract = {The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations.}, language = {en} } @misc{FellahHezilDekhiletal., author = {Fellah, Mamoun and Hezil, Naouel and Dekhil, Leila and Samad, Mohammed Abdul and Montagne, Alex and Mejias, Alberto and Iost, Alain and Obrosov, Aleksei and Weiß, Sabine}, title = {Structural characterization of developed near β-Type Titanium Alloys (Ti-25NbxZr) for biomedical Applications}, series = {3rd International Conference on Mechanics and Materials : ICMM'2019 11-12 November 2019. Setif, Algeria, Abstracts book}, journal = {3rd International Conference on Mechanics and Materials : ICMM'2019 11-12 November 2019. Setif, Algeria, Abstracts book}, address = {Setif, Algeria}, pages = {224 -- 225}, abstract = {The osteoarthritis and degenerative diseases osteoporosis as well as trauma lead to the bone mechanical properties degradation due to absence of normal biological self healing processes or excessive loading [1-5]. These problems solution are artificial biomaterials, as surgical implantation of appropriate shapes helps restore function for the otherwise functionally compromised structures [1-5]. Biocompatibility is considered to be optimal once tissue neoformation and later function occurs around implantable devices [6]. The efficacy of biomaterials implants is determined mostly by their surface characteristics such as microstructure, surface morphology, composition and biological properties [2]. Aiming to develop alloys with better properties for orthopedic applications, the focus of the present research was to evaluate the effect of Zr at. \% content on structural, mechanical and tribological properties of hot isostatically pressed Ti-25Nb-xZr (x = 5, 10, 15, 20 and 25 at. \%) alloys. The structural evolution, and mechanical properties of the nanostructured Ti-Nb-xZr alloys were evaluated using X-Ray diffraction, scanning electron microscope. The mechanical properties were performed using Vickers hardness and berkovich nanoindentation. Experimental results indicated that the structural evolution and morphological changes of the milled alloys were sensitive to their Zirconium (at. \%) content. The morphological characterization showed that the crystallite size and the particle size decreased with increasing Zr content (at. \%). As well, as the Zr was added to the Ti-25NbXZr system, there was a clear decrease in the Vickers hardness and young's modulus. On the other hand, the coefficient of friction and wear rates were found to be decreasing with increasing Zr content.}, language = {en} } @misc{KhalilFellahHeziletal., author = {Khalil, S. and Fellah, Mamoun and Hezil, Naouel and Smata, L. and Montagne, Alex and Mejias, Alberto and Kossman, Stephania and Iost, Alain and Obrosov, Aleksei and Weiß, Sabine}, title = {Synth{\`e}se et caract{\´e}risation structurale d'un compos{\´e} nanostructur{\´e} de Ti, Mo et Zr pour applications biom{\´e}dicales}, series = {3rd International Conference on Mechanics and Materials : ICMM'2019 11-12 November 2019. Setif, Algeria, Abstracts book}, journal = {3rd International Conference on Mechanics and Materials : ICMM'2019 11-12 November 2019. Setif, Algeria, Abstracts book}, address = {Setif, Algeria}, pages = {243 -- 244}, abstract = {Le milieu m{\´e}dical est un perp{\´e}tuel demandeur de biomat{\´e}riaux compatibles surtout en orthop{\´e}die. Effectivement le nombre important d'arthroplasties effectu{\´e}es chaque ann{\´e}e ne cesse d'augmenter dans le monde, non seulement du fait vieillissement de la population ({\`a} partir de 65 ans), mais aussi de demandes de patients plus jeunes entre 45 ans et 55 ans. Actuellement, les compos{\´e}s {\`a} base de titane Ti sont largement utilis{\´e}s comme des biomat{\´e}riaux pour leur biocompatibilit{\´e}, leur r{\´e}sistance {\`a} la corrosion et leur faible module d'{\´e}lasticit{\´e}. Le molybd{\`e}ne et le zirconium sont parmi les meilleurs {\´e}l{\´e}ments alli{\´e}s parce qu'ils sont non toxiques et non allergiques et offrent d'excellentes propri{\´e}t{\´e}s. De plus,Le Zr peut augmenter la trempabilit{\´e} et la r{\´e}sistance {\`a} la corrosion de l'alliage . Mo est un {\´e}l{\´e}ment fort stabilisant pour la phase des alliages de titane et les alliages {\`a} base de Ti-Mo pr{\´e}sentent des propri{\´e}t{\´e}s m{\´e}caniques ad{\´e}quates compatibilit{\´e} et bonne cyto-compatibilit{\´e} . Par cons{\´e}quent, le syst{\`e}me Ti-Mo-Zr, qui a montr{\´e} une bonnes performances et de magnifiques perspectives dans l'application de biomat{\´e}riaux, a {\´e}t{\´e} intensivement{\´e}tudi{\´e} [1,2,3]. Cependant, les alliages de Ti largement utilis{\´e}s, tels que les interstitiels extra-low (ELI) Ti-6Al-4V (wt.\% en poids ), Ti- 5Al-2,5 Fe et Ti-6Al-7Nb, ont le risque de lib{\´e}rer de l'aluminium toxique (Al) et les Ions de vanadium (V) in vivo, ce qui peut causer des probl{\`e}mes de sant{\´e}, comme la maladie d'Alzheimer et la neuropathie[4].La m{\´e}tallurgie des poudres (MP), y compris la m{\´e}thode de mixture des composants en poudre, qui consiste {\`a} fritter titane en poudre ou ses m{\´e}langes avec d'autres composants en poudre, est un proc{\´e}d{\´e} {\´e}conomique {\`a} moindre cout. La nanotechnologie est intervenue dans la structuration des biomat{\´e}riaux {\`a} l'{\´e}chelle nanom{\´e}trique (entre1nmet 100 nm) par soucis d'am{\´e}lioration des propri{\´e}t{\´e}s m{\´e}canique surtout le module de Young.}, language = {fr} } @misc{MarchenkoYasenchukGuntheretal., author = {Marchenko, Ekaterina and Yasenchuk, Yuri and Gunther, Sergey and Baigonakova, Gulsharat and Gunther, Victor and Chekalkin, Timofey and Weiß, Sabine and Obrosov, Aleksei and Dubovikov, Kirill}, title = {Structural-phase surface composition of porous TiNi produced by SHS}, series = {Materials Research Express}, volume = {6}, journal = {Materials Research Express}, number = {11}, issn = {2053-1591}, doi = {10.1088/2053-1591/ab4e32}, pages = {12}, abstract = {The study aimed to characterize the structural-phase composition of the porous SHS TiNi surface explored by the GIXRD method. The surface layers at a depth of up to 100 nm mainly consist of amorphous nanocrystalline intermetallic oxycarbonitrides Ti₄Ni₂(O,N,C) with nonmetallic inclusions of different structural variants and routes of origin. Fine-porous alloys were synthesized at ignition temperatures of 450-480 °C. A distinct feature of the surface of crystalline phases therein was shown to be a low degree of crystallinity (up to 40\%) and presence of multifarious glass and cermet phases evident as NiSi₂, NaAlSiO (SO₄), SiO₂, MgSi₂, and CaCO₃. Conversely, large-pore alloys ignited at temperatures of 280-330 °C have a higher degree of crystallinity (up to 70\%). An individually selected GIXRD technique and precision structural phase analysis are capable to determine a set of other superficial nonmetallic and cermet phases reported as CaTiO₃, Si (P2O₇), CaSiO₃, MgAl₂O₄, TiNiAl, as well as the Ti₃SiC₂MAX phase.}, language = {en} } @misc{HezilFellahDjellabietal., author = {Hezil, Naouel and Fellah, Mamoun and Djellabi, Ridha and Touhami, Mohamed Zine and Montagne, Alex and Bouaksa, Fethia and Iost, Alain and Mejias, Alberto and Obrosov, Aleksei}, title = {Assessment of the Hydrophilic-Hydrophobic Balance of Alumina Oxidized at Different Temperatures via H₂O and C₄H₁₀ Vapor Adsorption}, series = {Defect and Diffusion Forum}, volume = {397}, journal = {Defect and Diffusion Forum}, issn = {1662-9507}, doi = {10.4028/www.scientific.net/DDF.397.161}, pages = {161 -- 168}, abstract = {The hydrophilic-hydrophobic surface area of alumina powder (Al₂O₃) oxidized at different temperatures was determined on the base of adsorption of water and butane vapor at 25°C. In the order to study the influence of thermal oxidation upon hydrophilic/hydrophobic character of the surface, samples of Al₂O₃ were characterized using granulometry, SEM and BET surface area measurement. SEM results showed that the thermal treatment does not affect the morphology of the Alunima. However, the increase of treatment temperature from 250 to 900°C results in changing of the hydrophilic-hydrophobic balance of Al₂O₃ surface.}, language = {en} } @misc{ObrosovSidelev, author = {Obrosov, Aleksei and Sidelev, Dmitry}, title = {Magnetron Sputtering System for High-rate Deposition of Al Thin Films}, abstract = {The study reports on technological possibilities of magnetron sputtering systems to high-rate deposition of aluminum films and its structure. There is shown the comparison of deposition rates of magnetron sputtering systems with direct current (DC), middle-frequency (MF) and high power pulsed (HiPIMS) supplies. This article presents the using of the combination of middle-frequency (MF) and high impulse power (HiPIMS) supply is a way to significant increase of deposition rates of Al films. The composition of discharge plasma in dependence of parameters of pulse is considered by optical emission spectroscopy. XRD survey shows the role of deposition mode on crystal structure and grain size of Al films. It can be interested to thermal-control and radio-technical coatings.}, language = {en} } @misc{FellahHezilSamadetal., author = {Fellah, Mamoun and Hezil, Naouel and Samad, Mohammed Abdul and Touhami, Mohamed Zine and Montagne, Alex and Iost, Alain and Obrosov, Aleksei and Weiß, Sabine}, title = {Preliminary investigation on the bio-tribocorrosion behavior of porous nanostructured β-type titanium based biomedical alloys}, series = {Materials Letters}, volume = {257}, journal = {Materials Letters}, issn = {0167-577X}, doi = {10.1016/j.matlet.2019.126755}, pages = {4}, abstract = {The bio-tribocorrosion behavior of newly developed near β-types Ti-15Nb and Ti-15Mo alloys was investigated in Phosphate-Buffered Saline (PBS) under different loads. Open-Circuit Potential (OCP), friction coefficient, wear volume and wear rate were evaluated. The results revealed that Ti-15Nb alloy exhibited lower wear rate, lower friction coefficient and better corrosion resistance during tribocorrosion than the Ti-15Mo alloy. This can be attributed to the diffusion of Nb which increases the repassivation rate (formation of a protective layer) in the Ti-15Nb alloy. In contrast Ti-15Mo shows a significantly higher rate of chemical reaction.}, language = {en} } @misc{GoncharovMasayloOrlovetal., author = {Goncharov, I. S. and Masaylo, Dmitriy V. and Orlov, Alexey and Razumov, Nikolay G. and Obrosov, Aleksei}, title = {The Effect of Laser Power on the Microstructure of the Nb-Si Based In Situ Composite, Fabricated by Laser Metal Deposition}, series = {Key Engineering Materials}, volume = {822}, journal = {Key Engineering Materials}, issn = {1662-9795}, doi = {10.4028/www.scientific.net/KEM.822.556}, pages = {556 -- 562}, abstract = {The Nb-Si in-situ composite samples were fabricated by laser metal deposition additive manufacturing technology from mechanically alloyed powders in vario-planetary ball mill. A laser metal of samples was carried out at various laser powers: 500 W, 1000 W, 1400 W. The microstructure of a sample grown at a laser power of 500 W consists of a solid solution of Nb, Nb3Si, and dendritic chains of Ti. When the laser power is increased to 1000 W, the volume fraction of silicides increases, the structural heterogeneity decreases. With further increase in laser power to 1400 W, Ti dissolves in Nb, dendritic chains disappear, Nb5Si3 silicide stabilizes.}, language = {en} } @misc{FellahHezilTouhamietal., author = {Fellah, Mamoun and Hezil, Naouel and Touhami, Mohamed Zine and Obrosov, Aleksei and Weiß, Sabine and Kashkarov, Egor B. and Lider, Andrey M. and Montagne, Alex and Iost, Alain}, title = {Enhanced Structural and Tribological Performance of Nanostructured Ti-15Nb Alloy for Biomedical Applications}, series = {Results in Physics}, volume = {15}, journal = {Results in Physics}, issn = {2211-3797}, doi = {10.1016/j.rinp.2019.102767}, pages = {7}, abstract = {Low modulus β-type Ti-15Nb alloys were prepared by subjecting them to different sintering temperatures (800, 900, 1000 and 1100 °C) and their morphological and structural properties were evaluated. X-ray diffraction analysis was used for the morphological characterization which indicated that the mean pore and crystallite size continuously decreased with increasing sintering temperature to reach the lowest values of 41 nm and 27.5 nm at 1100 °C, respectively. Moreover, the higher sintering temperature resulted in higher relative density, greater hardness and young's modulus of the Ti-15Nb alloys. Wear tests were conducted using a ball-on-plate type Oscillating tribometer, under different applied loads (2, 8 and 16 N) to evaluate their tribological characterization. The wear rate and friction coefficient were lower at higher sintering temperature. This enhancement in tribological properties was attributed to a grain refinement. The Ti-15Nb alloys sintered at 1100 °C showed the best tribological performance.}, language = {en} } @incollection{FellahHezilAbderrahimetal., author = {Fellah, Mamoun and Hezil, Naouel and Abderrahim, Karima and Samad, Mohammed Abdul and Montagne, Alex and Mejias, Alberto and Iost, Alain and Kossman, Stephania and Chekalkin, Timofey and Obrosov, Aleksei and Weiß, Sabine}, title = {Investigating the Effect of Sintering Temperature on Structural and Tribological Properties of a Nanostructured Ti-20Nb-13Zr Alloy for Biomedical Applications}, series = {Characterization of Minerals, Metals, and Materials}, booktitle = {Characterization of Minerals, Metals, and Materials}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-36628-5}, issn = {2367-1181}, doi = {10.1007/978-3-030-36628-5_61}, pages = {619 -- 629}, abstract = {β-type Ti-20Nb-13Zr alloys with low Young's modulus were prepared at different sintering temperatures (950, 1050, 1150, and 1250 °C). The morphological and structural characteristics of as-prepared samples were investigated by several methods. Wear tests were conducted using a ball-on-plate type oscillating tribometer under different applied loads (2, 10, and 20 N). The morphological characterization indicated that the mean pore and crystallite size continuously decreased with increasing sintering temperature to reach lowest values of 40 nm and 38 nm at 1250 °C, respectively. The relative density of the 1250 °C sintered sample was as high as 98.7\%. Moreover, the higher sintering temperature resulted in higher relative density and closed porosity of the sample. Both the friction coefficient and wear rate were lower in the sample sintered at 1250 °C as compared to other samples. This enhancement in tribological properties was attributed to a closed porosity.}, language = {en} } @misc{FellahHezilTouhamietal., author = {Fellah, Mamoun and Hezil, Naouel and Touhami, Mohamed Zine and Hussien, Mohammed A. and Montagne, Alex and Mejias, Alberto and Iost, Alain and Kossman, Stephania and Chekalkin, Timofey and Obrosov, Aleksei and Weiß, Sabine}, title = {Effect of Sintering Temperature on Mechanical and Tribological Behavior of Ti-Ni Alloy for Biomedical Applications}, series = {TMS 2020 149th Annual Meeting \& Exhibition Supplemental Proceedings}, journal = {TMS 2020 149th Annual Meeting \& Exhibition Supplemental Proceedings}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-36295-9}, issn = {2367-1181}, doi = {10.1007/978-3-030-36296-6_157}, pages = {1701 -- 1710}, abstract = {Ti-Ni powder compacts were prepared by mechanical alloying (MA), followed by hot isostatic pressing (HIP). Afterwards, the samples were sintered at different temperatures (950, 1050, 1150 and 1250 °C). Microhardness, density, crystallite size as well as microstrain of the sintered samples were measured and analyzed. Wear characteristics in phosphate-buffered saline (PBS) solution was tested under different applied loads of 2 N, 10 N, and 20 N, respectively. The results indicated that the crystallite size continuously decreases with increasing sintering temperature and reaches the lowest value of 31.3 nm at 1250 °C. The relative density of the sample sintered at 1250 °C is 98.0\%. Moreover, the higher sintering temperatures lead to the higher relative density and the increase in hardness and young's modulus of the sample. At the same time the friction coefficient and wear rate were lower for the samples sintered at 1250 °C. This improvement in friction and wear resistance is attributed to the grain size refinement. Ti-Ni sintered at 1250 °C showed good tribological performance under all test conditions.}, language = {en} } @misc{HezilFellahMontagneetal., author = {Hezil, Naouel and Fellah, Mamoun and Montagne, Alex and Iost, Alain and Obrosov, Aleksei and Weiß, Sabine}, title = {Removal of Chromium (VI) from Water onto Activated Carbon by Adsorption in Dynamic Mode}, series = {TMS 2020 149th Annual Meeting \& Exhibition Supplemental Proceedings}, journal = {TMS 2020 149th Annual Meeting \& Exhibition Supplemental Proceedings}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-36295-9}, issn = {2367-1181}, doi = {https://doi.org/10.1007/978-3-030-36296-6_80}, pages = {855 -- 863}, abstract = {Hexavalent chromium pollution from industrial waste water is a serious problem as it can cause adverse effects on the environment. Several methods are used to reduce the harmful effects of this pollutant, especially physico-chemical methods, such as adsorption technology. The present study aims to remove Cr (VI) from industrial sources in a fixed-bed column of activated carbon. The experiments were carried out at natural pH and temperature with a flow rate (5, 10, and 20 mL/min) and bed height (3.5 cm). Breakthrough curves for feed concentrations (0.01, 0.03, and 0.05 mol/L) were investigated. The results indicated a marked decrease up to 99\%. The value of the flow constant for the Thomas model decreased with the increase in the concentration of the incoming substance, but increased with the increase in the flow rate.}, language = {en} } @misc{EvdokimovDoynovOssenbrinketal., author = {Evdokimov, Anton and Doynov, Nikolay and Ossenbrink, Ralf and Obrosov, Aleksei and Weiß, Sabine and Michailov, Vesselin}, title = {Thermomechanical laser welding simulation of dissimilar steel-aluminum overlap joints}, series = {International Journal of Mechanical Sciences}, volume = {190}, journal = {International Journal of Mechanical Sciences}, issn = {1879-2162}, doi = {10.1016/j.ijmecsci.2020.106019}, pages = {18}, abstract = {Mixing of steel and aluminum within the weld pool during keyhole laser welding results in a complex dissimilar microstructure, which in turn, initiates a shift in weld metal mechanical properties. In this study, a numerical model for computation of distortions in laser-welded dissimilar overlap joints (austenitic stainless steel 304 - 6082-T6 aluminum alloy), which considers properties of the mixed steel-aluminum weld metal was developed. The required yield strength, Young's modulus, and strain hardening exponent of the weld metal were experimentally determined using the indentation technique coupled with energy-dispersive X-ray spectroscopy. The designed material model calculates the weld elastic-plastic properties as a function of the aluminum concentration. The softening of the alloys in the heat-affected zone was determined by physical simulations and considered as a function of maximum temperature. Computed and measured distortions showed good agreement for various welding regimes with an average deviation of 18.4\%. The sensitivity analyses indicated that the application of the developed weld material model significantly improves the accuracy of the thermomechanical simulations.}, language = {en} } @misc{FellahHezilTouhamietal., author = {Fellah, Mamoun and Hezil, Naouel and Touhami, Mohamed Zine and Samad, Mohammed Abdul and Obrosov, Aleksei and Bokov, Dmitry O. and Marchenko, Ekaterina and Montagne, Alex and Iost, Alain and Alhussein, Akram}, title = {Structural, tribological and antibacterial properties of (α + β) based ti-alloys for biomedical applications}, series = {Journal of Materials Research and Technology}, volume = {9}, journal = {Journal of Materials Research and Technology}, number = {6}, issn = {2238-7854}, doi = {10.1016/j.jmrt.2020.09.118}, pages = {14061 -- 14074}, abstract = {Implant-related follow up complications resulting from poor implant integration, delamination, chipping, mechanical instability, inflammation or graft-vs-host reaction may lead to low patient tolerance, prolonged care and sometimes leading to a second surgery. Hence, there is an urgent need for developing biomaterials which will help to overcome the above compatibility problems. Ti based alloys have been widely used for biomedical applications, due to their excellent properties, such as low modulus, high biocompatibility and high corrosion resistance. In order to further improve the physical, mechanical and tribological properties of these alloys, microstructural modification is often required. Hence, this study aims to develop and evaluate the structural and tribological behavior of Hot Isostatic Pressed (HIPed) and sintered Ti-6Al-7Nb samples containing niobium, which is less toxic and less expensive as compared to the usual alloying element, vanadium (Ti-6Al-4 V). The Ti-6Al-7Nb alloys were fabricated by using nanoparticle powders milled for different durations (2, 6, 12 and 18 h) to evaluate the effect of milling time on the morphological and structural properties. Friction and wear tests were carried out on the (HIPed) and finally sintered Ti-6Al-7Nb alloy samples, to evaluate their tribological properties under different applied loads (2, 8 and 16 N), with an alumina α-Al2O3 ball as a counter face using an oscillating tribometer. The physical characterization of the nanopowders formed using different milling times indicated that the particle and crystallite size continually decreased with increasing milling time, while the microstrain increased. It is observed that the friction coefficient and wear rate for the samples prepared by powders milled for 18 h and tested under 2 N were lowest with values of 0.25 and 1.51 × 10-2 μm3∙N-1 μm-1, respectively compared to other milled samples. This improvement in tribological properties is attributed to the grain refinement at high milling times. The antibacterial evaluation of the fabricated alloys showed an improvement in antibacterial performance of the samples milled at 18 h compared to the other milling times.}, language = {en} } @misc{BaigonakovaMarchenkoChekalkinetal., author = {Baigonakova, Gulsharat and Marchenko, Ekaterina and Chekalkin, Timofey and Kang, Ji-hoon and Weiß, Sabine and Obrosov, Aleksei}, title = {Influence of Silver Addition on Structure, Martensite Transformations and Mechanical Properties of TiNi-Ag Alloy Wires for Biomedical Application}, series = {Materials}, volume = {13}, journal = {Materials}, number = {21}, issn = {1996-1944}, doi = {10.3390/ma13214721}, pages = {11}, abstract = {The microstructural and functional behavior of TiNi-based wires with a silver content of 0-1.5 at.\% was evaluated. The concentration range for Ag doping determined for the TiNi wires with potential for the medical industry was 0-0.2 at.\%. Microstructure analysis of TiNi wires with different silver contents at room temperature indicated a multiphase structural state. Various internal structures with tangled grain boundaries were formed by intense plastic deformation. The nanocrystalline structure and phase state of wire with the minimum silver content (0.1 at.\% Ag) provide full shape recovery, the greatest reversible strain, and optimal strength and ductility. TiNi ingots with a high Ag content (0.5-1.5 at.\%) cracked under minimum load due to excess silver that crystallized along the grain boundaries and broke cohesion bonds between the TiNi grains.}, language = {en} } @misc{SaoudiFellahHeziletal., author = {Saoudi, Adel and Fellah, Mamoun and Hezil, Naouel and Lerari, Djahida and Khamouli, Farida and Atoui, L'hadi and Bachari, Khaldoun and Morozova, Iuliia and Obrosov, Aleksei and Samad, Mohammed Abdul}, title = {Prediction of mechanical properties of welded steel X70 pipeline using neural network modelling}, series = {International Journal of Pressure Vessels and Piping}, volume = {186}, journal = {International Journal of Pressure Vessels and Piping}, issn = {0308-0161}, doi = {10.1016/j.ijpvp.2020.104153}, pages = {8}, abstract = {An artificial neural network (ANN) model was developed to predict tensile and impact properties of a submerged arc helical welded (SAHW) pipeline steel API X70 based upon its chemical composition. Weight percent of the elements was considered as the input, while the tensile and Charpy impact properties were considered as the outputs. Scatter diagrams and two statistical parameters (absolute fraction of variance and relative error) were used to evaluate the prediction performance of the developed artificial neural network model. The predicted values were found to be in excellent agreement with the experimental data and the current model has a good learning precision and generalization (for training, validation and testing data sets). The results revealed that the developed model is very accurate and has a strong potential for capturing the interaction between the mechanical properties and chemical composition of welded high strength low alloy (HSLA) steels.}, language = {en} } @misc{FellahHezilGuerfietal., author = {Fellah, Mamoun and Hezil, Naouel and Guerfi, Kamel and Djellabi, Ridha and Montagne, Alex and Iost, Alain and Borodin, Kirill and Obrosov, Aleksei}, title = {Mechanistic pathways of cationic and anionic surfactants sorption by kaolinite in water}, series = {Environmental Science and Pollution Research}, volume = {28}, journal = {Environmental Science and Pollution Research}, number = {6}, issn = {1614-7499}, doi = {10.1007/s11356-020-11083-6}, pages = {7307 -- 7321}, abstract = {Surfactants are widely used in many chemical industries and as primary components of cleaning detergents due to their specific characteristics, which in turn results in high pollution of domestic and industrial wastewaters by such substances. In this study, the mechanistic pathways of the adsorption of cationic benzyl-dimethyl-dodecyl ammonium bromide (BDDAB) and anionic sodium dodecyl sulfate (SDS) surfactants on kaolinite clay in water were investigated. The results showed that the adsorption of anionic surfactant (SDS) on kaolinite is better compared with cationic surfactant (BDDAB), wherein the ♦maximum adsorption capacity was found 161.4 μmol g-1 and 234 μmol g-1 for BDDAB and SDS, respectively. Adsorption kinetics were the best suited to pseudo-second-order model for both BDDAB and SDS with an adsorption rate constant of 0.028 g μmol-1 min-1 and 0.023 g μmol-1 min-1, respectively. Meanwhile, the adsorption of BDDAB by kaolinite showed that the isotherm adsorption tended to follow the Langmuir-Freundlich and Freundlich isotherm models. However, the SDS adsorption isotherm obeyed only the Langmuir-Freundlich model.}, language = {en} } @misc{KokorevChekalkinMarchenkoetal., author = {Kokorev, Oleg and Chekalkin, Timofey and Marchenko, Ekaterina and Yasenchuk, Yuri and Gunther, Sergey and Serebrov, Vladimir and Chernyshova, Alena and Obrosov, Aleksei and Kang, Ji-hoon}, title = {Exploring the role of surface modifications of TiNi-based alloys in evaluating in vitro cytocompatibility: a comparative study}, series = {Surface Topography: Metrology and Properties}, volume = {8}, journal = {Surface Topography: Metrology and Properties}, number = {4}, issn = {2051-672X}, doi = {10.1088/2051-672X/abc0f9}, pages = {14}, abstract = {The aim of this study was the comparative analysis of in vitro bio-testing of solid and porous TiNi samples with modified surfaces (intact, oxidated, and etched). Tests for cytocompatibility, hemolysis, and cytotoxicity (MTT) as well as visualization by confocal and scanning electron microscopy have shown that the chemically modified samples are the most cytocompatible. The intact and etched samples did not induce hemolysis greater than 2\%, and thus they comply with the ISO 10993-4:2018 standard for hemolysis by blood-contacting biomaterials. Direct culture of etched samples with MCF-7 cells and human leukocytes showed low cytotoxicity. At the same time, the cytotoxicity of samples oxidated at 500 °C was significantly greater than that of the etched samples. Confocal and electron microscopy also confirmed the abovementioned quantitative data. The cells attached to the etched surface in numbers sufficient for them to be able to grow and proliferate on this substrate in vitro. These findings indicate that solid and porous TiNi alloy with surface modifications achieved by a cost-effective method is biotolerable and promising for clinical use and for tissue engineering.}, language = {en} } @misc{YasenchukMarchenkoBaigonakovaetal., author = {Yasenchuk, Yuri and Marchenko, Ekaterina and Baigonakova, Gulsharat and Gunther, Sergey and Kokorev, Oleg and Gunther, Victor and Chekalkin, Timofey and Topolnitskiy, Evgeniy and Obrosov, Aleksei and Kang, Ji-hoon}, title = {Study on tensile, bending, fatigue, and in-vivo behavior of porous SHS-TiNi alloy used as a bone substitute}, series = {Biomedical Materials}, volume = {16}, journal = {Biomedical Materials}, number = {2}, issn = {1748-605X}, doi = {10.1088/1748-605X/aba327}, pages = {14}, abstract = {Intermetallic porous SHS-TiNi alloys exhibit tangled and specific stress-strain characteristics. The article aims to evaluate the findings emanated from experiments using standard and proprietary instruments. Fatigue testing under repeated complex loading was used to measure the total number of load cycles to failure of SHS-TiNi samples. 70\% of the tested samples, passed through 106 cycles without failure due to the reversible martensite transformation in the TiNi phase, one of the prevailing constituents of a multiphase matrix. The fractured surfaces were analyzed using SEM and confocal laser scanning instruments. Microscopic studies showed that the entire surface of the sample is concealed with the miscellaneous strata resulted from the SHS process, which effectively protect the porous alloy in a corrosive environment. Numerous non-metallic inclusions, which are also attributed to the SHS reaction, do not have a significant impact on the deformation behavior and fatigue performance. In this context, the successful in vivo functioning of porous grafts assessed in a canine rib-plasty model allows the bone substitute to be congruentially deformed in the body without rejection and degradation, having a long operational life, often greater than 17 million cycles. It acknowledges the potential benefits of SHS-TiNi as a superior osteoplastic material and its high resistance to corrosion fatigue.}, language = {en} }