@misc{AissaniFellahChadlietal., author = {Aissani, Linda and Fellah, Mamoun and Chadli, Abdel Hakim and Samad, Mohammed Abdul and Cheriet, Abderrahmane and Salhi, Faiza and Nouveau, Corinne and Weiß, Sabine and Obrosov, Aleksei and Alhussein, Akram}, title = {Investigating the effect of nitrogen on the structural and tribo-mechanical behavior of vanadium nitride thin films deposited using R.F. magnetron sputtering}, series = {Journal of Materials Science}, volume = {56}, journal = {Journal of Materials Science}, number = {30}, issn = {1573-4803}, doi = {10.1007/s10853-021-06393-0}, pages = {17319 -- 17336}, abstract = {Magnetron sputtering is one of the most commonly used deposition techniques, which has received considerable attention in industrial applications. In particular, owing to its compatibility with conventional fabrication processes, it can produce and fabricate high-quality dense thin films of a wide range of materials. In the present study, nitrogen (N) was combined with pure vanadium in order to form binary nitride to improve its mechanical and tribological performance. To evaluate the influence of nitrogen on the structure of the as-deposited vanadium nitride (VN) coatings, the following techniques were used: XPS, XRD, SEM, AFM and optical profilometry. The residual stresses were determined by the curvature method using Stoney's formula. The hardness and Young's modulus were obtained by nanoindentation measurements. The friction behavior and wear characteristics of the films were evaluated by using a ball-on-disk tribometer. The obtained results showed that the N/V ratio increased with increasing the N2 flow rate while the deposition rate decreased. The preferred orientation was changed from (200) to (111) as the N2 flow rate increased with the presence of V-N and V-O binding energies as confirmed by XPS analysis. The nitrogen addition resulted in a columnar morphology and a fine structure with fine surface roughness. The VN thin film containing 49.5 at.\% of nitrogen showed the best performance: highest mechanical properties (hardness = 25 GPa), lowest friction coefficient (μ = 0.37) and lowest wear rate (Ws = 2.72 × 10-5 mm3N-1 m-1). A good correlation between the film microstructure, crystallite size, residual stress and mechanical and tribological properties was observed.}, language = {en} } @misc{AissaniFellahBelgrouneetal., author = {Aissani, Linda and Fellah, Mamoun and Belgroune, Ahlam and Obrosov, Aleksei and Samad, Mohammed Abdul and Alhussein, Akram}, title = {Effect of O2 flow rate on the structure, wettability and tribo-mechanical behaviour of Zr-O-N thin films}, series = {Surfaces and Interfaces}, volume = {26}, journal = {Surfaces and Interfaces}, issn = {2468-0230}, doi = {10.1016/j.surfin.2021.101441}, pages = {33}, abstract = {Structural and tribo-mechanical properties of Zr-O-N films deposited by reactive magnetron sputtering in a mixture of Ar (flow rate = 80 sccm), N2 (flow rate = 20 sccm) and O2 with a varying flow rate of 0 to 12 sccm were investigated. The films were characterized using scanning electron microscopy, energy dispersive x-ray analysis, atomic force microscopy, nanoindentation and wear tests. Oxygen content have a significant effect on the microstructure, wettability, tribo-mechanical properties of Zr-O-N films. The Zr-O-N films showed a dense structure with a mixture of zirconium oxides and nitrides and the preferred orientation changed from (111) ZrN to (200) ZrN with increasing O2 flow rate. The ZrON film, deposited at an oxygen flow rate of 10 sccm exhibited the highest contact angle (147°), the highest hardness (27.1 GPa), the lowest friction coefficient (0.36) and the lowest wear rate (5.8 × 10-7 mm3.Nm-1). The improvement in the tribological performance of the ZrON film deposited at 10 sccm is attributed to the improved hardness and increased H/E and H3/E2 ratios, due to the formation of a hard solid solution by the diffusion of oxygen.}, language = {en} } @misc{TopolnitskiyChekalkinMarchenkoetal., author = {Topolnitskiy, Evgeniy and Chekalkin, Timofey and Marchenko, Ekaterina and Yasenchuk, Yuri and Kang, Seung-Baik and Kang, Ji-Hoon and Obrosov, Aleksei}, title = {Evaluation of Clinical Performance of TiNi-Based Implants Used in Chest Wall Repair after Resection for Malignant Tumors}, series = {Journal of Functional Biomaterials}, volume = {12}, journal = {Journal of Functional Biomaterials}, number = {4}, issn = {2079-4983}, doi = {10.3390/jfb12040060}, pages = {11}, abstract = {In this study, we assessed the outcomes after surgical treatment of thoracic post-excision defects in 15 patients, using TiNi knitted surgical meshes and customized artificial TiNi-based ribs. Methods: Eight patients were diagnosed with advanced non-small cell lung cancer (NSCLC) invading the chest wall, of which five patients were T3N0M0, two were T3N1M0, and one was T3N2M0. Squamous cell carcinoma was identified in three of these patients and adenocarcinoma in five. In two cases, chest wall resection and repair were performed for metastases of kidney cancer after radical nephrectomy. Three-dimensional CT reconstruction and X-ray scans were used to plan the surgery and customize the reinforcing TiNi-based implants. All patients received TiNi-based devices and were prospectively followed for a few years. Results: So far, there have been no lethal outcomes, and all implanted devices were consistent in follow-up examinations. Immediate complications were noted in three cases (ejection of air through the pleural drains, paroxysm of atrial fibrillation, and pleuritis), which were conservatively managed. In the long term, no complications, aftereffects, or instability of the thoracic cage were observed. Conclusion: TiNi-based devices used for extensive thoracic lesion repair in this context are promising and reliable biomaterials that demonstrate good functional, clinical, and cosmetic outcomes.}, language = {en} } @misc{SalhiAissaniFellahetal., author = {Salhi, Faiza and Aissani, Linda and Fellah, Mamoun and Chadli, Abdel Hakim and Cheriet, Abderrahmane and Belgroune, Ahlam and Nouveau, Corinne and Obrosov, Aleksei and Samad, Mohammed Abdul and Alhussein, Akram}, title = {Experimental investigation of structural, wetting, mechanical and Tribological properties of TiZrN thin films deposited by magnetron sputtering}, series = {Surfaces and Interfaces}, volume = {27}, journal = {Surfaces and Interfaces}, issn = {2468-0230}, doi = {10.1016/j.surfin.2021.101519}, abstract = {TiZrN thin films were deposited on Si (100) wafers and XC100 steel substrates by reactive R.f. magnetron sputtering using titanium and zirconium targets in an Ar-N2 mixture atmosphere to evaluate the effect of varying Zr content (0 to 22.2 at.\%), on the film structure, surface wettability, hardness and wear resistance. The presence of different phases such as TiN, ZrN, and ZrO2 were confirmed by XRD analysis. Results showed that, the lattice parameter and film thickness increased while the crystallite size and average roughness decreased with increasing Zr content. Total surface energy between the film surface and testing liquids decreased with the addition of Zr. TiZrN film containing 18.3 at.\% of Zr showed the lowest surface energy of 38.7 mN/m, indicating its hydrophobicity. The nanoindentation measurements, friction and wear tests showed that the TiZrN thin film containing 18.3 at.\% of Zr had the best tribo-mechanical performance. The TiZrN (18.3 at.\% Zr) film exhibited the lowest friction coefficient (0.31), and the lowest wear rate (6.65 × 10-5 mm3/Nm), which corresponds to the highest H/E ∼ 0.139, and H3/E2 ∼ 0.49 GPa ratios. The improvement in the tribo-mechanical properties is attributed to the solid solution strengthening due to the incorporation of Zr atoms in TiN system, which results in the highest hardness of 25 GPa for TiZrN (18.3 at.\% Zr) film.}, language = {en} } @misc{ObrosovRylkovMorozovaetal., author = {Obrosov, Aleksei and Rylkov, Evgenii and Morozova, Iuliia and Naumov, Anton}, title = {НАНЕСЕНИЕ ИЗНОСОСТОЙСКИХ ПОКРЫТИЙ НА ИНСТРУМЕНТЫ ДЛЯ СВАРКИ ТРЕНИЕМ С ПЕРЕМЕШИВАНИЕМ МЕТОДОМ МАГНЕТРОННОГО РАСПЫЛЕНИЯ}, series = {International Scientific Conference Modern materials and advanced manufacturing technology (MMAMT-2021)}, journal = {International Scientific Conference Modern materials and advanced manufacturing technology (MMAMT-2021)}, pages = {169 -- 170}, language = {ru} } @misc{BelgrouneAlhusseinAissanietal., author = {Belgroune, Ahlam and Alhussein, Akram and Aissani, Linda and Zaabat, Mourad and Obrosov, Aleksei and Verdy, Christophe and Langlade, C{\´e}cile}, title = {Effect of He and N2 gas on the mechanical and tribological assessment of SS316L coating deposited by cold spraying process}, series = {Journal of Materials Science}, volume = {57}, journal = {Journal of Materials Science}, number = {8}, issn = {1573-4803}, doi = {10.1007/s10853-022-06950-1}, pages = {5258 -- 5274}, abstract = {In this study, simulation and experimental methods were used to investigate the influence of cold spray conditions on AISI 316L stainless steel coatings. The effect of both helium and nitrogen gases used was investigated. The temperature, particle sizes of spraying powder, and distance from the nozzle throat to the impinging point were estimated by using the Kinetics Spray Solutions GmbH software. The 316L stainless steel (SS) coatings were examined by X-ray diffraction, Scanning Electron Microscopy and Energy Dispersive X-Ray Microanalysis. The tribological behavior was evaluated under different loads (2 N and 5 N) in dry conditions. It was found that the nitrogen and helium propellant gas with high speed and fine particles led to produce good coatings with dense microstructures. From the nanoindentation experiments, the Young's modulus and hardness of the SS 316L samples were enhanced of about 8\% with helium due to the high particle velocity. It was shown that the wear resistance of SS 316L produced with helium was higher than that of the standard SS 316L coatings. The coatings produced with helium revealed lower friction coefficient (0.65) and wear rate (6.9 × 10-4 mm3/Nm) under 2 N applied load than that obtained nitrogen. It was also found that the SS 316L cold sprayed by helium with dense structure presents high hardness and good tribological performance that can be suggested for several applications.}, language = {en} } @misc{BourasFellahMecifetal., author = {Bouras, Dikra and Fellah, Mamoun and Mecif, Abla and Barill{\´e}, R{\´e}gis and Obrosov, Aleksei and Rasheed, Mohammed}, title = {High photocatalytic capacity of porous ceramic-based powder doped with MgO}, series = {Journal of the Korean Ceramic Society}, journal = {Journal of the Korean Ceramic Society}, number = {60}, issn = {2234-0491}, doi = {10.1007/s43207-022-00254-5}, pages = {155 -- 168}, abstract = {To purify water at low cost for our daily life, the effect of ceramic-based (mullite-cristobalite) and (mullite-zircon) powders doped with different amounts of magnesium oxide (MgO) (10 and 20 wt\%) was studied. These compounds are made of a local raw material DD3 with addition of zirconia (ZrO2) to create an open porosity. The powders were prepared by the traditional mixing method with the help of an automated crushing. The effect of MgO doping on structural, morphological and photocatalytic properties of the material was studied by various analytical techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared, and UV-visible spectrometry. The results of XRD proved that there was a deformation in the crystal structure of the two types of ceramics after addition, which resulted in a shift of the spectra to the right, while SEM proved the presence of pores with a larger size as the proportion of MgO increases. The chemical composition of the basic components of the ceramic compounds as well as the additive was confirmed with EDS and IR spectra. The final results show that ceramics with added zirconia (DD3Z) and doped with 10\% of MgO have a better photocatalytic efficiency than ceramics without zirconia. This important effect could be related to the higher rate of porosity, which provides a more active surface. The 10\% MgO content showed a high photoactivity of 77.33\% in only 15 min. The maximum hydrolysis rate obtained with Orange II was 92.95\% after a period of 45 min with DD3Z/MgO powders.}, language = {en} } @misc{MorozovaKehmObrosovetal., author = {Morozova, Iuliia and Kehm, Christian and Obrosov, Aleksei and Yang, Yitong and Miah, Kamal Uddin Mohammad and Uludintceva, Elena and Fritzsche, Sebastian and Weiß, Sabine and Michailov, Vesselin}, title = {On the Heat Treatment of Selective-Laser-Melted 316L}, series = {Journal of Materials Engineering and Performance}, volume = {32 (2023)}, journal = {Journal of Materials Engineering and Performance}, number = {10}, issn = {1544-1024}, doi = {10.1007/s11665-022-07404-0}, pages = {4295 -- 4305}, abstract = {The effect of heat treatment at various temperatures (650, 850, 1050, and 1100°C) and dwell times (10 min and 1 h) on the metallurgical and microstructural evolution as well as on the related tensile properties of stainless steel 316L processed by selective laser melting (SLM) has been systematically evaluated. The metallurgical and microstructural features such as defects, stability of the columnar-cellular structure and substructure, second phase particles, and phase transformation imparted by SLM and heat treatment have been discussed. It has been shown that the processing conditions specific to SLM significantly alter the kinetics of phase evolution compared to standard welding techniques which affects the accuracy of the prediction. The influence of these characteristics on tensile properties and hardness was elucidated. It was disclosed that with increasing heat treatment temperature there was a gradual increase in elongation but a decrease in strength related to the dislocation density and the development of the microstructure.}, language = {en} } @misc{MorozovaKrolickaObrosovetal., author = {Morozova, Iuliia and Kr{\´o}licka, Aleksandra and Obrosov, Aleksei and Yang, Yitong and Doynov, Nikolay and Weiß, Sabine and Michailov, Vesselin}, title = {Precipitation phenomena in impulse friction stir welded 2024 aluminium alloy}, series = {Materials Science and Engineering: A}, journal = {Materials Science and Engineering: A}, issn = {0921-5093}, doi = {10.1016/j.msea.2022.143617}, pages = {1 -- 11}, abstract = {Microhardness variations across the friction stir welded (FSW) and impulse friction stir welded (IFSW) AA2024-T351 joints have been elucidated by the transformations of the S-Al2CuMg phase with a special focus on a distinguished hardness peak within the heat-affected zone (HAZ) of the impulse welds. The increase in hardness within the stir zone (SZ) originated from the partial re-precipitation of the initial Guinier-Preston-Bagaryatsky zones (GPB) and metastable S needles, previously dissolved.) Formation and growth of stable S precipitates via coalescence accounted for the softening through the thermo-mechanically affected zone (TMAZ). The peak strengthening within the HAZ of the IFSW joints was mainly caused by the dense needle-shaped S particles, which can be explained by a mutual influence of the process specific temperature and strain cycles. Dislocations and subgrain boundaries introduced to the material due to plastic deformation facilitated the nucleation of strengthening S precipitates in the HAZ. It demonstrates that the impact of deformation should be considered by the characterization of the precipitation development in the HAZ.}, language = {en} } @misc{FigielBiedunkiewiczJachetal., author = {Figiel, Paweł and Biedunkiewicz, Anna and Jach, Katarzyna and Obrosov, Aleksei and Garbiec, Dariusz and Bik, Maciej and Sitarz, Maciej and Kucia, Zofia and Pawlyta, Mirosława and Weiß, Sabine}, title = {Ti-Mo-xTiC composites manufactured by U-FAST reactive sintering}, series = {International Journal of Refractory Metals and Hard Materials}, journal = {International Journal of Refractory Metals and Hard Materials}, number = {108}, issn = {0263-4368}, doi = {10.1016/j.ijrmhm.2022.105960}, pages = {1 -- 14}, abstract = {The paper presents the characteristics of Ti-Mo-xTiC composites manufactured under experimentally selected conditions using the upgraded field-assisted sintering technique (U-FAST). Mixtures of microstructural titanium powders and nc-Ti0.9Mo0.1C/C carbide powders protected from oxidation by a carbon shell were subjected to sintering. The powders with nc-Ti0.9Mo0.1C/C contents of 10 and 20 wt\% were used. The content of carbon forming the carbon shell was approximately 3 or 40 wt\%. Composites with near full density were reinforced with titanium carbides in a Ti-Mo matrix. The composites with the highest content of reinforcing phase are characterized by the highest values of hardness, Young's modulus and wear resistance. Although the hardness of these composites is similar to that of ceramics, their nature is not brittle. Despite the high value of the Young's modulus, the addition of hard particles of the reinforcing phase to the titanium matrix significantly increases the values of the H/E ratio of the composites compared to the reference samples of cp-Ti and Ti6Al4V. A comparison of the research results for the composites with the highest share of titanium carbides showed that lowering the sintering temperature from 1300 to 1150 °C resulted in the inhibition of grain growth, a reduction in composite heterogeneity, composite roughness and hardness as well as a rise in the Young's modulus. An increase in the sintering temperature from 1150 to 1300 °C contributed to the higher high angle grain boundaries (HAGB) content.}, language = {en} } @misc{HezilAissaniFellahetal., author = {Hezil, Naouel and Aissani, Linda and Fellah, Mamoun and Samad, Mohammed Abdul and Obrosov, Aleksei and Chekalkin, Timofey and Marchenko, Ekaterina}, title = {Structural, and tribological properties of nanostructured α + β type titanium alloys for total hip}, series = {Journal of Materials Research and Technology}, journal = {Journal of Materials Research and Technology}, number = {19}, issn = {2238-7854}, doi = {10.1016/j.jmrt.2022.06.042}, pages = {3568 -- 3578}, abstract = {Titanium alloys are in demand for various biomedical applications and the most popular among them being, Ti-6Al-4V. Hence, in this study, Ti-6Al-7Nb are fabricated through the route of mechanical milling using different sintering temperatures. X-ray diffraction and hardness tests were conducted to characterize the developed sams to evaluate the effect of sintering temperatures on the structural and mechanical properties. It is observed that the sams sintered at a temperature of 1250 °C had the smallest crystallite and pore size, with enhanced relative density and mechanical properties. Tribological tests were conducted at varying normal loads to characterize the wear and frictional behaviour and showed that the sams sintered at 1250 °C presented the lowest friction coefficient and wear rate.}, language = {en} } @misc{PetkovBakalovaObrosovetal., author = {Petkov, Nikolay and Bakalova, Totka and Obrosov, Aleksei and Kashkarov, Egor B. and Kormunda, Martin and Kejzlar, Pavel and Bahchedzhiev, Hristo and Dadourek, Karel and Weiß, Sabine}, title = {Structural, mechanical, and tribological properties of CrCN coatings obtained by cathodic arc physical vapour deposition technology at different CH4/N2 gas ratio}, series = {Thin Solid Films}, volume = {766}, journal = {Thin Solid Films}, issn = {1879-2731}, doi = {10.1016/j.tsf.2022.139669}, abstract = {Chromium carbonitride coatings were deposited by cathodic arc physical vapor deposition technology at a temperature of 300 °C, as were used the reactive gasses CH4 and N2. The structural analysis of the CrN coating showed a polycrystalline structure with mixed CrN and Cr2N phases. All studied coatings, including the CrC exhibits fcc structure. The phases were confirmed by X-ray photoelectron spectroscopy measurements where a surface oxidation was also detected. The increase of the CH4 gas flow during the deposition process leads to a parabolic trend with the highest hardness of 33.5 GPa for the coating deposited at CH4 / N2 = 0.53. At the same time the lowest coefficient of friction for both counterparts Al2O3 and ZrO2 (0.28 and 0.26, respectively) were measured at CH4 / N2 = 1.86. The tribological tests reveal that the wear of the coatings increases with an increasing CH4 flow rate, whereas the coefficient of friction decreases. This observed contradiction is explained by a phenomenon described as the effect of Rebinder.}, language = {en} } @misc{AissaniBelgrouneSaoudietal., author = {Aissani, Linda and Belgroune, Ahlam and Saoudi, Abdenour and Hmima, Abdelhamid and Fellah, Mamoun and Obrosov, Aleksei and Alhussein, Akram}, title = {Tribo-mechanical performance and antibacterial activity in (Cu, Zr)-alloyed Ti(Al)N coatings synthesized by reactive magnetron sputtering}, series = {Journal of Materials Science}, volume = {57}, journal = {Journal of Materials Science}, issn = {1573-4803}, doi = {https://doi.org/10.1007/s10853-022-07804-6}, pages = {19612 -- 19630}, abstract = {In this work, copper and zirconium were added into the Ti(Al)N matrix to form deposited on TiAl(Cu, Zr)N coating using RF magnetron sputtering system in order to improve the mechanical, wear performance, and antibacterial activity. Results revealed that the TiAl(Cu, Zr)N coatings have a dense structure with (111) preferential orientation. The deposited TiAl(Cu, Zr)N coatings exhibited fcc-TiN structure, whereas the addition of Zr and Cu into the Ti(Al)N induced the appearance of Cu and ZrN. The solid solution strengthening and the increase in compressive residual stress (- 2.54 GPa) of Ti(Al, Zr)N coating with higher lattice strain (+ 0.1520) by the addition of Zr improved the hardness from 20.9 GPa. For the tribological property, the friction coefficient and wear rate decreased from (0.45, 5.9 × 10-3mm3/Nm) for the TiAlN to (0.29, 4.2 × 10-5mm3/Nm) for the Ti(Al, Zr)N, respectively, with high elasto-plastic H/E, H3/E2 (0.076, 0.121 GPa) ratios due to the low surface roughness, high adhesion, and nanocomposite structure. The results indicated the addition of Zr improves the friction property of Ti(Al)N coating. Although with their lower hardness than Ti(Al)N coating, the Ti(Al, Cu)N coating with 9.2 at.\% Cu exhibited an excellent wear resistance and good antibacterial activity, which demonstrates its potential as a candidate material for biomedical application.}, language = {en} } @misc{GrudininBleykherKrivobokovetal., author = {Grudinin, V. A. and Bleykher, G. A. and Krivobokov, V. P. and Semyonov, O. V. and Obrosov, Aleksei and Weiß, Sabine and Sidelev, D. V.}, title = {Hot target magnetron sputtering enhanced by RF-ICP source: Microstructure and functional properties of CrNx coatings}, series = {Vacuum}, volume = {200}, journal = {Vacuum}, issn = {1879-2715}, doi = {10.1016/j.vacuum.2022.111020}, abstract = {CrNx coatings were deposited at high rates (100-130 nm/min) using hot Cr target magnetron sputtering enhanced by a radio-frequency inductively coupled plasma (RF-ICP) source in an Ar + N2 atmosphere. Besides separation of inert and reactive atmosphere, the RF-ICP source can be an effective tool for ion assistance in case of coating growth and to tailor film parameters. The effects of nitrogen flow rate and substrate bias potential on microstructure and functional properties of the CrNx coatings were investigated. An increase in nitrogen flow rate favored the formation of a looser microstructure of the coatings, while substrate biasing had the opposite effect. The functional properties were strongly dependent on the phase composition of the CrNx coatings. The change in coating microstructure significantly affected hardness, elastic modulus, adhesion, friction coefficients and corrosion resistance. The results indicated that ion assistance can be a key feature for regulating functional properties in the considered type of coating deposition. Cr2N and CrN compound coatings with high hardness (∼20 GPa) and low corrosion current density (icorr ∼ 3-5·10-9 A/cm2) in a 3.5 wt\% NaCl solution were obtained by high-rate deposition.}, language = {en} } @misc{MarchenkoYasenchukKlopotovetal., author = {Marchenko, Ekaterina and Yasenchuk, Yuri and Klopotov, Anatoliy and Ustinov, Artem and Abzaev, Yuri and Vetrova, Anna and Chekalkin, Timofey and Obrosov, Aleksei}, title = {Study of macroplastic flow in surface layers of porous SHS-TiNi by digital image correlation}, series = {ISSS Journal of Micro and Smart Systems}, volume = {11}, journal = {ISSS Journal of Micro and Smart Systems}, number = {2}, issn = {2509-7997}, doi = {10.1007/s41683-022-00104-w}, pages = {343 -- 347}, abstract = {In this work, we studied the evolution and features of localized strain fields in porous SHS-TiNi samples. Using the Vic-3D optical system and spayed speckle patterns, a localized plastic flow on the surface of porous plates of 0.85 mm and 2.7 mm thick loaded up to fracture in a quasi-static mode was traced and characterized. As seen, a 0.85 mm thick specimen indicated two strain-hardening distinctive parts in the stress-strain curve. Moreover, regions of localized strain are found that be wider than that of a 2.7 mm thick sample. It can be argued that by combining speckle patterns and quasi-static tension, one can effectively explore and predict the deformation behavior of a designing bone substitute made of porous SHS-TiNi.}, language = {en} } @misc{BoukhalfaHezilOuanesetal., author = {Boukhalfa, Chaima and Hezil, Naouel and Ouanes, Miyada and Fellah, Mamoun and Baccouche, Mostefa and Obrosov, Aleksei and Dahmani, Marwa}, title = {Structure-property correlation in a Nanostructured Ti-6Al-4V alloy designed for biomedical applications}, series = {First National Conference on Materials Sciences and Engineering MSE-22}, journal = {First National Conference on Materials Sciences and Engineering MSE-22}, editor = {Fellah, Mamoun and Hezil, Naouel}, publisher = {Abbes Laghour University}, address = {Khenchela, Algeria}, isbn = {978-9931-9603-2-4}, pages = {703 -- 703}, abstract = {The use of powder metallurgy techniques for manufacturing near net shape components for the biomedical field is on a continuous development. Evaluating the effect of different process parameters such as milling time on the properties of these newly developed alloys leads to enhancing their properties, Hence, in this paper, the influence of structural parameters on the mechanical proprieties of a nanostructured Ti-6Al-4V alloy was investigated, considering the milling duration variation.}, language = {en} } @misc{BoukhalfaHezilOuanesetal., author = {Boukhalfa, Chaima and Hezil, Naouel and Ouanes, Miyada and Fellah, Mamoun and Baccouche, Mostefa and Obrosov, Aleksei and Dahmani, Marwa}, title = {The effect of surface properties on the wear resistance of Ti-6Al-4V biomedical alloy manufactured via mechanical alloying}, series = {First National Conference on Materials Sciences and Engineering MSE-22}, journal = {First National Conference on Materials Sciences and Engineering MSE-22}, editor = {Fellah, Mamoun and Hezil, Naouel}, publisher = {Abbes Laghour University}, address = {Khenchela, Algeria}, isbn = {978-9931-9603-2-4}, pages = {543 -- 543}, abstract = {The Ti-6Al-4V alloy is one of the common used titanium alloys in prosthetic applications, due to its significant proprieties, however, its wear performance is questionable, hence, the present study aims to evaluate the wear resistance of a Nanostructured Ti-6Al-4V alloy manufactured via high energy ball milling, with varying milling duration in order to investigate the correlation between surface proprieties and the wear performance of the alloy so as understanding its wear mechanisms.}, language = {en} } @misc{FellahHezilHamadietal., author = {Fellah, Mamoun and Hezil, Naouel and Hamadi, Fouzia and Iqbal, Amjad and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Effect of Fe content on physical, tribological and photocatalytical properties of Ti-6Al-xFe alloys for biomedical applications}, series = {Tribology International}, volume = {191}, journal = {Tribology International}, issn = {1879-2464}, doi = {10.1016/j.triboint.2023.109146}, abstract = {The aim of the current study is to evaluate the effect of iron content (0, 2, 4, 6 and 10 wt\%) on the structural, tribological and photocatalytical properties of a nanostructured ternary alloy Ti-6Al-XFe, prepared by high energy milling. The alloys' characteristics such as lattice parameters, powder morphologies, surface roughness, relative density/porosity, and microhardness, were evaluated using X-ray diffraction (XRD), scanning electron microscope (SEM), surface profilometry, porosimeter and micro durometer, respectively. The W-H method was utilized to determine the crystallite size. Micro strain was also calculated, which is produced in the lattice due to the diffusion of iron atoms. The photocatalytical characterization was conducted by measuring their absorbance as a function of time using spectrophotometer of visible and ultraviolet light in the wavelength range of 500-800 nm. The tribological characterization was performed using an oscillating tribometer under wet conditions, simulating the human body environment using Phosphate Buffered Saline (PBS) solution with neutral pH 7.4, under different applied loads of 2, 6 and 10 N, respectively. Results showed that the addition of Fe has a significant effect on the structural properties of the developed alloys. The lattice parameter (aα) decreased with increasing Fe content from 2.9493 {\AA} (0 wt\% Fe) to 2.9491 {\AA} (10 wt\% Fe), while the average grain size increased considerably from 6.965 nm (0 wt\% Fe) to 44.42 nm (10 wt\% Fe). The wear test results showed that, friction coefficient and wear rate considerably decreased due to the formation of protective films such as TiO2. The photocatalytical characterization showed that, the degradation of methylene blue (MB) increased with increasing Fe content. The Ti-6Al-4Fe -catalyst gave the best degree of degradation of 90.76\% within 60 min, which meant that the decolorization process could be operated rapidly at a relatively low cost without UV irradiation.}, language = {en} } @misc{AlontsevaSafarovaYantsenVoinarovychetal., author = {Alontseva, Darya and Safarova (Yantsen), Yuliya and Voinarovych, Sergii and Obrosov, Aleksei and Yamanoglu, Ridvan and Khoshnaw, Fuad and Yavuz, Hasan Ismail and Nessipbekova, Assem and Syzdykova, Aizhan and Azamatov, Bagdat and Khozhanov, Alexandr and Weiß, Sabine}, title = {Biocompatibility and Corrosion of Microplasma-Sprayed Titanium and Tantalum Coatings versus Titanium Alloy}, series = {Coatings}, volume = {14}, journal = {Coatings}, number = {2}, issn = {2079-6412}, doi = {10.3390/coatings14020206}, abstract = {This study investigates the in vitro biocompatibility, corrosion resistance, and adhesion strength of a gas abrasive-treated Ti6Al4V alloy, alongside microplasma-sprayed titanium and tantalum coatings. Employing a novel approach in selecting microplasma spray parameters, this study successfully engineers coatings with tailored porosity, roughness, and over 20\% porosity with pore sizes up to 200 μm, aiming to enhance bone in-growth and implant integration. This study introduces an innovative methodology for quantifying surface roughness using laser electron microscopy and scanning electron microscopy, facilitating detailed morphological analysis of both the substrate and coatings. Extensive evaluations, including tests for in vitro biocompatibility, corrosion resistance, and adhesive strength, revealed that all three materials are biocompatible, with tantalum coatings exhibiting superior cell proliferation and osteogenic differentiation, as well as the highest corrosion resistance. Titanium coatings followed closely, demonstrating favorable osteogenic properties and enhanced roughness, which is crucial for cell behavior and attachment. These coatings also displayed superior tensile adhesive strengths (27.6 ± 0.9 MPa for Ti and 28.0 ± 4.9 MPa for Ta), surpassing the ISO 13179-1 standard and indicating a robust bond with the substrate. Our findings offer significant advancements in biomaterials for medical implants, introducing microplasma spraying as a versatile tool for customizing implant coatings, particularly emphasizing the superior performance of tantalum coatings in terms of biocompatibility, osteogenic potential, and corrosion resistance. This suggests that tantalum coatings are a promising alternative for enhancing the performance of metal implants, especially in applications demanding high biocompatibility and corrosion resistance.}, language = {en} } @misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Bouchareb, Nabila and Larios, Alejandro Perez and Obrosov, Aleksei and El-Hiti, Gamal A. and Weiß, Sabine}, title = {Investigating the effect of Zr content on electrochemical and tribological properties of newly developed near β-type Ti-alloys (Ti-25Nb-xZr) for biomedical applications}, series = {Journal of Science: Advanced Materials and Devices}, journal = {Journal of Science: Advanced Materials and Devices}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2024.100695}, abstract = {In order to create alloys with exceptional properties for orthopedic uses, this study focuses on the impact of zirconium (Zr) content on the structural, electrochemical, and tribological qualities of nanostructured Ti-25Nb-xZr [x = 5, 10, 15, 20, 25, and 30 atomic (at.) \%] alloys. The structural evolution was investigated using XRD and SEM techniques. The mechanical characteristics of the produced alloys, including Vickers hardness and Young's modulus, were measured. In addition, the corrosion tests were performed using the OCP, EIS, and PD methods in Ringer's solution within the independent pH range at 37 °C. A ball-on-disc tribometer was used to investigate the tribological behavior of the alloys under various loads and wet conditions using the Ringer solution. It has been verified that Zr content (at. \%) in the alloys had an impact on their morphologies, structural evolution, and mechanical characteristics. According to the morphological analysis, the particle and crystallite size decreases with increasing Zr content. Young's modulus and Vickers hardness show the same tendency. The EIS data demonstrated that a single passive film formed on the alloy surfaces, and the addition of Zr enhanced the corrosion resistance of the passive films. The polarization curves demonstrate that the alloys had low corrosion current densities and large passive areas without the passive films disintegrating. Likewise, the inclusion of Zr resulted in a reduction in the corrosion and passive current densities values. All of these results suggested that the titanium alloys exhibit a more noble electrochemical activity caused by Zr. From the tribological perspective, it was found that the friction coefficient of the alloys reduced with increasing Zr content.}, language = {en} } @misc{FellahBoucharebHeziletal., author = {Fellah, Mamoun and Bouchareb, Nabila and Hezil, Naouel and Merah, Ne{\c{c}}ar and Alashkar, Yasser and Imran, Mohd and Obrosov, Aleksei and Weiß, Sabine}, title = {Electrochemical analysis of mechanically alloyed Ti50\%-Ni50\% alloy for bone implants use}, series = {Journal of Alloys and Compounds}, journal = {Journal of Alloys and Compounds}, number = {1010}, issn = {1873-4669}, doi = {https://doi.org/10.1016/j.jallcom.2024.178046}, pages = {1 -- 13}, abstract = {The corrosion resistance of an implant material is an essential element of its biocompatibility. This research focuses on studying the effect of grinding/milling time on the corrosion behavior of the mechanically alloyed Ti50 \%-Ni50 \% (at\%) alloy, for bone implant use, at varying milling times of 2, 6, 12, and 18 h. The powder particles' size, shape, and homogeneous chemical content were examined employing scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The alloyed particles' structural characteristics were determined by X-ray diffraction (XRD). Moreover, the characterization of the electrochemical properties was performed utilizing open-circuit potential (OCP) measurement, the Potentiodynamic Polarization (PD), and the Electrochemical Impedance Spectroscopy (EIS) technique. Electrochemical tests were conducted in physiological mediums simulating the human body: Hank's solution. The results revealed that; as the grinding time increased the crystallite size reduced from 57 nm to 29 nm, whereas the lattice parameters increased slightly from 3.18 to 3.22 {\AA}, while the microstrain increased from 0.32 \% to 0.99 \%. Moreover, the hardness and Young's Modulus increased by about 70 and 16 \%, respectively with milling period going from 2 to 18 h. The findings of the electrochemical test demonstrated that as milling progressed, corrosion resistance increased. The evolution of OCP curves as a function of the duration of immersions indicated that OCP increased with the duration of immersion up to 2500 s; this is due to a stable passive layer that has formed on the samples' surface. The results of potentiodynamic polarization curves revealed that both corrosion current density (icorr) and corrosion rate (CR) decreased reaching a value of 3.6945E-07 A/cm2 and 0.0074722 mm/year, respectively, at longer milling time (18 h). While, corrosion potential (Ecorr) increased from -0.51255 V/SCE to -0.29997 V/SCE with increasing grinding time. Additionally, the EIS data indicated that the resistance of the passive film increased with increasing milling times. The samples of Ti50-Ni50 produced at longer milling time exhibited excellent corrosion resistance due to the formation of a stable passive film which makes them useful for bone implants.}, language = {en} } @misc{AlontsevaSafarovaYantsenVoinarovychetal., author = {Alontseva, Darya and Safarova (Yantsen), Yuliya and Voinarovych, Sergii and Obrosov, Aleksei and Yamanoglu, Ridvan and Khoshnaw, Fuad and Nessipbekova, Assem and Syzdykova, Aizhan and Yavuz, Hasan Ismail and Kaliuzhnyi, Sergii and Krasavin, Alexander and Azamatov, Bagdat and Khozhanov, Alexandr and Olzhayev, Farkhad and Weiß, Sabine}, title = {Microplasma-Sprayed Titanium and Hydroxyapatite Coatings on Ti6Al4V Alloy: in vitro Biocompatibility and Corrosion Resistance: Part I}, series = {Johnson Matthey Technology Review}, volume = {69}, journal = {Johnson Matthey Technology Review}, number = {1}, doi = {10.1595/205651325X17201903387613}, pages = {45 -- 58}, abstract = {This two-part paper investigates the bioactivity and mechanical properties of coatings applied to Ti6Al4V, a common titanium alloy used in endoprosthetic implants. Coatings made from hydroxyapatite (HA) powder and commercially pure titanium (CP-Ti) wires were applied using microplasma spraying. The study focuses on the responses of rat mesenchymal stem cells (MSCs), which are essential for bone healing, to these coatings. Part I shows how adjusting the microplasma spraying process allows coatings with varying porosity and surface roughness to be achieved.}, language = {en} } @misc{AlontsevaSafarovaYantsenVoinarovychetal., author = {Alontseva, Darya and Safarova (Yantsen), Yuliya and Voinarovych, Sergii and Obrosov, Aleksei and Yamanoglu, Ridvan and Khoshnaw, Fuad and Nessipbekova, Assem and Syzdykova, Aizhan and Yavuz, Hasan Ismail and Kaliuzhnyi, Sergii and Krasavin, Alexander and Azamatov, Bagdat and Khozhanov, Alexandr and Olzhayev, Farkhad and Weiß, Sabine}, title = {Microplasma-sprayed titanium and hydroxyapatite coatings on Ti6Al4V alloy: in vitro biocompatibility and corrosion resistance : part II coatings enhance cell proliferation, corrosion resistance and implant integration}, series = {Johnson Matthey Technology Review}, volume = {69 (2025)}, journal = {Johnson Matthey Technology Review}, number = {1}, issn = {2056-5135}, doi = {10.1595/205651325X17290035905758}, pages = {59 -- 75}, abstract = {Part II presents the results which show that HA coatings significantly enhance MSC proliferation by 13\% compared to the titanium alloy base, while titanium coatings also exhibit an 11\% increase. Porosity inversely affects CP-Ti's elasticity. Coatings with lower porosity demonstrate better corrosion resistance. HA coatings promote osteogenic activity and angiogenesis, which is crucial for implant integration.}, language = {en} } @misc{RimHezilFellahetal., author = {Rim, Imen and Hezil, Naouel and Fellah, Mamoun and Saoudi, Adel and Obrosov, Aleksei and El-Hiti, Gamal A.}, title = {Enhancing kaolin performance through organic molecule modification and assessing its efficiency for lead and copper adsorption}, series = {Environmental Technology \& Innovation}, volume = {36}, journal = {Environmental Technology \& Innovation}, number = {November 22024}, issn = {2352-1864}, doi = {10.1016/j.eti.2024.103904}, pages = {1 -- 19}, abstract = {The research aimed to enhance the efficacy of kaolin in water treatment by incorporating diphenylamine (DPA) and to evaluate its effectiveness in adsorbing lead and copper in wastewater in comparison to natural kaolin (Nat-kaolin). This entailed modifying kaolin with DPA to create DPA-kaolin and conducting comprehensive characterization utilizing a range of techniques, including X-ray diffraction analysis (XRD), scanning electron microscope (SEM), energy dispersion X-ray (EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analysis. The results demonstrated the successful modification of DPA, as evidenced by an increase in BET-specific surface area of about 25 \% (from 66.69 m².g-1 to 71.35 m².g-1), indicating enhanced adsorption capacity. XRD analysis confirmed the composition of the samples, while TGA/DTA indicated changes in water adsorption and dehydroxylation. SEM and EDX illustrated the tubular nature of the clay with a decrease in the amount of Al, about 10.76 \%, and the amount of Si, about 10.38 \%, on the DPA-kaolin. Notably, the FTIR spectrum of DPA-kaolin showed the presence of new vibration bands at 1248 cm-1, indicating the presence of DPA. In terms of adsorption, the DPA-kaolin exhibited significantly higher maximum adsorption capacities for Pb(II) and Cu(II) compared to the nat-kaolin, with values of 151 µmol/g and 134 µmol/g, respectively.These values were significantly higher than those observed for Nat-kaolin, which demonstrated adsorption capacities of 103 µmol/g for Pb(II) and 91 µmol/g for Cu(II). The adsorption kinetics indicated that the pseudo-second-order kinetic model described the sorption mechanism for both Pb(II) and Cu(II). This was evidenced by the values of R², which were 0.999 and 0.996, respectively. The study provides clear evidence that DPA-kaolin is more effective than Nat-kaolin in removing lead (Pb(II)) and copper (Cu(II)) from wastewater. Through rigorous experimentation, it was observed that DPA-kaolin exhibited notably enhanced adsorption capabilities for both Pb(II) and Cu(II) compared to Nat-kaolin. These findings serve to emphasize the practical importance and potential utility of the modification, offering promising prospects for the development of more efficient wastewater treatment methodologies.}, language = {en} } @misc{BourasFellahBarilleetal., author = {Bouras, Dikra and Fellah, Mamoun and Barille, Regis and Obrosov, Aleksei and Ikbal, Amjad and Avramov, Pavel V. and El-Hiti, Gamal A.}, title = {Multiple layers, porous surface, and their role in increasing the efficiency of photocatalytic coating on (DD3, DD3+ZrO2) ceramics and glass}, series = {Ceramics International}, volume = {50}, journal = {Ceramics International}, number = {21, C}, issn = {1873-3956}, doi = {https://doi.org/10.1016/j.ceramint.2024.08.239}, pages = {43854 -- 43873}, abstract = {Magnesium-doped zinc oxide thin films were dip-coated onto porous ceramic and glass substrates under identical conditions (50 layers, same doping ratio). Structural, morphological, and photocatalytic properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), UV-visible spectrophotometry, and confocal microscopy. XRD analysis indicated a shift in peak positions towards higher angles, increased grain size, and lattice distortion on both substrates. Unique flower-shaped crystalline granulates were observed exclusively on the ceramic substrate (DD3Z). The energy gap decreased on the ceramic and increased on the glass substrate. The photocatalytic activity was evaluated using an aqueous orange II solution, showing significantly higher decomposition (80 ± 0.53 \% after 6 h) on the ceramic compared to the glass substrate (30 \%). The enhanced performance on ceramic substrates, particularly with DD3+ZrO2, was attributed to increased microporosity, surface roughness, and active material incorporation, facilitating greater photocatalytic efficiency. The findings suggest promising applications of these materials for efficient and cost-effective photocatalysis, with potential for reuse after thermal treatment at 500 °C.}, language = {en} } @misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Habeeb, Majeed Ali and Hamadi, Fouzia and Bouchareb, Nabila and Laouini, Salah Eddine and Larios, Alejandro Perez and Obrosov, Aleksei and El-Hiti, Gamal A.}, title = {Microstructural and photocatalytic properties of nanostructured near-β Ti-Nb-Zr alloy for total hip prosthesis use}, series = {Kuwait Journal of Science}, volume = {51}, journal = {Kuwait Journal of Science}, number = {4}, publisher = {Elsevier}, issn = {2307-4116}, doi = {https://doi.org/10.1016/j.kjs.2024.100276}, pages = {1 -- 12}, abstract = {With its unique corrosion resistance, light weight, mechanical strength, and biocompatibility, TNZ is a versatile metal alloy that is used in the aerospace and medical industries. The current study aims to investigate the effect of milling time (2, 12, 24, and 36 h) on the nanostructured ternary alloy Ti-25Nb-25Zr (TNZ) prepared by high energy ball milling, a process involving the use of a high-energy ball mill to mix and grind the alloy powders, on its structural, physical, and photocatalytic characterizations. The alloys' characteristics, such as morphology, structural properties, relative density/porosity, surface roughness, hardness, and Young's modulus, were evaluated using SEM, XRD, surface profilometer, and microdurometer, respectively. The photocatalytic characterization was conducted by measuring their absorbance as a function of time using a spectrophotometer of visible and ultraviolet light in the wavelength range of 250-650 nm. Results showed that the crystallite and mean pore size reduced with increasing milling time, with the smallest values of 25 nm and 34 μm, respectively, after 36 h. This indicates that longer milling times result in a more compact and uniform structure, which could enhance the mechanical properties of the alloy. Structural characterization shows that the amount of the β-Ti phase increased with increasing milling time, resulting in the spherical morphology and texturing of the synthesized alloys. The milled alloys' structural evolution and morphological changes were sensitive to their milling times. Also, the relative density, Young's modulus, and hardness increased, reaching values of 89 \%, 105 GPa, and 352 HV, respectively, due to grain size decreasing with increasing milling time. This suggests that longer milling times lead to a denser and harder alloy, which could be beneficial for its use in total hip prostheses. The photocatalytical characterization demonstrated that the degradation of orange II (OII) increased with increasing milling time. The Ti-25Nb-25Zr catalyst gave the best degree of degradation, which meant that the decolorization process could be operated rapidly and at a relatively low cost without UV irradiation.}, language = {en} } @misc{BourasFellahBarilleetal., author = {Bouras, Dikra and Fellah, Mamoun and Barille, Regis and Obrosov, Aleksei and El-Hiti, Gamal A.}, title = {Production of novel Zr-Mg nanoceramics based on kaolinite clay with strong antibacterial activity}, series = {Ceramics International}, volume = {50}, journal = {Ceramics International}, number = {16}, publisher = {Elsevier}, issn = {1873-3956}, doi = {https://doi.org/10.1016/j.ceramint.2024.05.091}, pages = {27949 -- 27960}, abstract = {Gram-negative bacteria Pseudomonas putida, Gram-positive Bacillus subtilis, and Staphylococcus aureus were utilized as test samples to evaluate the antibacterial characteristics of DD3-clay/MgO and DD3+38 wt\% ZrO2-clay/MgO nanoparticles. The ceramic powders prepared by a thermal autoclave method are characterized before and after Mg addition by SEM, EDX, XRD, IR, UV-visible, and TEM in order to investigate microstructure, phase, and surface morphology. The results showed that after adding Mg, it led to the deformation of the crystal lattices of (mullite, zirconium silicate, and zirconium oxide) together with a decrease in particle size (75-103 nm) and a complete change in its shape from nanotube to nanospherical, as observed by SEM and TEM analyses. It also confirmed by UV-visible spectroscopy that the addition of Mg increases the absorbance accompanying a decrease in the energy gap of 1.91, 1.74, 1.73, and 1.43 eV corresponding to DD3, DD3Z, DD3/30 wt\% Mg and DD3Z/30 wt\% Mg respectively. The antibacterial mechanism is related to the size of the particles, the solvent used for powder dissolution, the nanoparticle's size when they come into touch with bacteria, and the generation of reactive oxygen species (ROS: ˙O2-, ˙OH, and H2O2). It was observed that the anti-bacterial activity is enhanced with 10 wt\% and 30 wt\% of Mg added to a modified ceramic powder. Also, more O2- is formed on the surface of the prepared powder, which penetrates the bacterial cell and destroys it. The nanocomposite particles showed remarkable antibacterial activity when they were dissolved in DMSO compared to methanol and chloroform as organic solvents. The aim is to enrich knowledge on the antibacterial activities of metal nanoparticles (ZrSiO4 and MgO) on three bacterial strains with different Grams due to their extensive involvement in the phenomena of contamination and infection encountered in the medical field. The synthesized nanoparticles have good antimicrobial activity against all strains tested. A maximum inhibition zone of 35 ± 0.2 mm was obtained with S. aureus, a zone of 23 ± 0.46 mm with P. putida and a zone of 27 ± 0.46 nm with B. subtilis for DD3/30 wt\% Mg and an inhibition zone of 38 ± 0.93 mm, 26 ± 0.24 nm and 17 ± 0.33 nm was obtained with same strains for DD3Z/30 wt\% Mg, respectively.}, language = {en} } @misc{SellamAziziBourasetal., author = {Sellam, Manel and Azizi, Soulef and Bouras, Dikra and Fellah, Mamoun and Obrosov, Aleksei and El-Hiti, Gamal A.}, title = {Degradation of rhodamine B dye under visible and solar light on zinc oxide and nickel-doped zinc oxide thin films}, series = {Optical Materials}, volume = {151 (2024)}, journal = {Optical Materials}, publisher = {Elsevier}, issn = {1873-1252}, doi = {https://doi.org/10.1016/j.optmat.2024.115316}, pages = {1 -- 17}, abstract = {The kinetic investigation of rhodamine B dye's photocatalytic degradation, chosen as a model pollutant, was conducted at room temperature using Zinc oxide (ZnO) and nickel-doped zinc oxide (Zn0.97Ni0.03O) photocatalysts synthesized through the spray pyrolysis method. XRD analysis confirmed the formation of hexagonal ZnO and Zn0.97Ni0.03O films, with crystallite sizes ranging from 19 to 29 nm and varying in mean average grain size from 72 nm to 88 nm. The surface morphology of the Ni-doped ZnO films was influenced by nickel doping, observed through SEM and TEM micrographs, revealing a dense structure of spherical-shaped crystals. Light transmission and optical band gap energy of the films ranged between specified values, ranging from 3.27 to 3.24 eV. The degradation process was assessed under various conditions, including different light sources (UV lamp and solar irradiation), pH levels, and substrate concentrations. Degradation followed a pseudo-first-order kinetic model, with rate constants (k) and half-life times (t1/2) calculated accordingly. The degradation efficiency of undoped ZnO and ZnO doped with nickel decreased with increasing concentration under UV irradiation from (0.1-0.5 M) under UV irradiation decreased from (34.29-45.02) (49.61-56.61), while under visible light are (40-45.07 \%) (58.46-60.24 \%), removal rates ranged within specific percentages. The porous Zn0.97Ni0.03O synthesized at 0.5 M exhibited the highest photocatalytic efficiency due to its enhanced crystallinity, resulting in degradation rates of 9.22 and 11.22 × 10-3 min-1 and half-life times of 75.18 and 61.77 min at 90 min specified for both UV and solar light irradiations, respectively. Acidification of the reaction medium accelerated the photocatalytic degradation kinetics, while alkalization slowed it down. These findings mark a significant advancement in the utilization of oxide semiconductors for water pollutant degradation under natural sunlight.}, language = {en} } @misc{BoucharebFellahHeziletal., author = {Bouchareb, Nabila and Fellah, Mamoun and Hezil, Naouel and Hamadi, Fouzia and Montagne, Alex and Obrosov, Aleksei and Yadav, Krishna Kumar and El-Hiti, Gamal A.}, title = {Effect of milling time on structural, physical and photocatalytical properties of Ti-Ni alloy for biomedical applications}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {131 (2024)}, journal = {The International Journal of Advanced Manufacturing Technology}, publisher = {Springer}, issn = {1433-3015}, doi = {https://doi.org/10.1007/s00170-024-13207-5}, pages = {3539 -- 3553}, abstract = {Ti-Ni shape memory alloys (SMA) are used extensively in the field of orthopedics owing to their unique physical and mechanical features, excellent corrosion resistance, and good biocompatibility in the human body environment. This study aims to investigate how milling time affects the characteristics of Ti-Ni alloys which were synthesized with equal atomic percentages by using a high-energy ball milling type (Planetary Micro Mill Pulverisette P7, Fritsch GmbH, Germany) under varying milling periods (2, 6, 12, and 18 h). The duration of the grinding process refines the grain and diminishes the material's porosity, improving the material's physical and structural characteristics as well as its photocatalytic activity. The milled powders of Ti50-Ni50 alloys underwent characterization employing scanning electron microscopy (SEM) associated with an energy dispersive spectrometer (EDS), X-ray diffraction (XRD), and spectrophotometery of visible and ultraviolet light (UV-VIS) to measure the solution absorbance of methylene blue (MB). The results revealed that the milling process influences the particle size and shape of powders, where the proportion of fine particles increased with increasing grinding times from 2 to 18 h due to severe deformation and fracturing. The crystallite size was reduced, and the microstrain increased, attaining values of 29 nm and 0.99\%, respectively. In addition, the pores of samples were decreased to 10 nm at higher milling times. Furthermore, solutions of MB containing powders of Ti50-Ni50 milled at 18 h exhibited good photocatalytic activity with a degradation rate value of 93.23\% after 60 min of irradiation time because of a greater surface area. The improved properties of Ti50-Ni50 alloys make them clinically useful for biomedical implantation in humans. Plus, they are considered to be effective materials for photocatalytic applications.}, language = {en} } @misc{BelgrouneAissaniAlhusseinetal., author = {Belgroune, Ahlam and Aissani, Linda and Alhussein, Akram and Zaabat, Mourad and Obrosov, Aleksei and Rtimi, Sami}, title = {In Vitro Corrosion and Wear Investigation of Multifunctional TiAlMoN Sputtered Coatings on Cold-Sprayed SS316L}, series = {ACS Applied Engineering Materials}, volume = {2}, journal = {ACS Applied Engineering Materials}, number = {2}, issn = {2771-9545}, doi = {https://doi.org/10.1021/acsaenm.3c00672}, pages = {345 -- 359}, abstract = {Although TiAlN has been thoroughly studied, there is still an ongoing demand for developing new-based TiAlN films with enhanced protection efficiency for a long lifetime and high load-bearing capability linked to friction and corrosion mechanisms. This work aims to present the effect of Mo content by studying the structural tribo-mechanical, wettability, and corrosion behaviors in TiAlMoN coatings deposited by magnetron sputtering on cold-sprayed stainless steel 316L substrates. TiAlMoN coatings showed a dense columnar structure with the coexistence of titanium and molybdenum nitrides, and TiN (200) preferred orientation changed to TiN(111) with increasing Mo content. The surface energy of the TiAlMoN coatings decreased gradually with the increase in Mo content. The TiAlMoN coating containing 16.09 atom \% Mo possesses the highest hardness and Young's modulus (29.5 and 334.5 GPa, respectively) and the maximum H/E and H3/E2 of 0.092 and 0.237, respectively. Formations of tribolayer oxides reduced the friction and enhanced the wear resistance of TiAlMoN coatings in atmospheric conditions and reached the minimum values of 0.3 and 0.849 × 10-6 mm3/N, respectively, at 16.09 atom \% of Mo under 5 N load charge. Corrosion examination in simulated seawater revealed that TiAlMoN coating-coated SS316L exhibited a significant positive shift of about -16 mV in corrosion potential with a notable reduction in corrosion current density (1.41 nA/cm2), confirming the improved corrosion performance. The combination of both cold spray and magnetron sputtering techniques for producing this kind of component is shown to have great potential in processing applications.}, language = {en} } @misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Obrosov, Aleksei and Samad, Mohammed Abdul and Montagne, Alex and Abd-Elmonem, Assmaa and Din, Sayed M El and Weiß, Sabine}, title = {Structural, mechanical and tribological performance of a nano structured biomaterial Co-Cr-Mo alloy synthesized via mechanical alloying}, series = {Journal of Materials Research and Technology}, volume = {25}, journal = {Journal of Materials Research and Technology}, issn = {2214-0697}, doi = {10.1016/j.jmrt.2023.06.031}, pages = {2152 -- 2165}, abstract = {The influence of milling time on the tribological behavior of a Co-Cr-Mo alloy designed for biomedical applications, synthesized via mechanical alloying is investigated. Elemental Co, Cr and Mo powders are milled using different milling times (2, 6, 12 and 18 h) in a high-energy ball mill. The resulting powders were subjected to cold uniaxial and hot isostatic pressing respectively, followed by sintering to obtain cylindrical samples, which were evaluated for their structural, mechanical and the wear behavior. Results showed that the grain and crystallite sizes of the powders decreased with increasing milling time, reaching low values of <10 μm and 32 μm respectively, at higher milling times. Furthermore, the wear rates and the coefficients of friction were lower, at higher milling times due to high densities (96\%), and higher elasto-plastic resistance, as presented by the H/E and H3/E2 values of 0.026 and 0.0021 GPa, respectively. Increased milling time enables the refinement of grains and reduction in porosity in the Co-Cr-Mo alloy, which in turn increases the alloy's elasto-plastic resistance and enhances its wear resistance.}, language = {en} } @misc{CelikAtapekPolatetal., author = {{\c{C}}elik, G{\"u}l{\c{s}}ah Akta{\c{s}} and Atapek, Şaban Hakan and Polat, Şeyda and Obrosov, Aleksei and Weiß, Sabine}, title = {Nitriding Effect on the Tribological Performance of CrN-, AlTiN-, and CrN/AlTiN-Coated DIN 1.2367 Hot Work Tool Steel}, series = {Materials}, volume = {16}, journal = {Materials}, number = {7}, issn = {1996-1944}, doi = {10.3390/ma16072804}, abstract = {In this study, heat-treated and multisurface engineered DIN 1.2367 tool steel was subjected to room and elevated temperature wear tests, and the effect of nitriding on its tribological behavior was investigated. CrN, AlTiN, and CrN/AlTiN coatings with a total thickness of 2 µm were obtained by arc cathodic physical vapor deposition on conventional heat-treated and gas-nitrided steels. The white layer formed during nitriding was removed, and a diffusion layer (100 µm) was achieved in the cross section of the steel having a tempered martensitic matrix. The highest surface hardness was attained with an integral coating (CrN/AlTiN), and surface hardness increased even more after nitriding due to the formation of a multicomponent ceramic layer on top of the diffusion layer. The room temperature wear tests performed against an alumina counterpart revealed that (i) CrN/AlTiN-coated steel had the highest friction coefficient of 0.26, which further increased to 0.33 by nitriding due to the increase in shear strength, and that (ii) with increasing surface hardness, the specific wear rates (W) of the heat-treated and coated steels could be ranked as follows: WCrN/AlTiN < WAlTiN < WCrN. The wear rates decreased when nitriding was carried out prior to coating. In order to simulate the aluminum extrusion conditions, hot wear behavior of the surfaces against AA6080 alloy at 450 °C was investigated. The hot wear tests revealed that (i) high friction coefficients were reached due to the adhesive characteristic of aluminum to the surfaces, (ii) the nitrided and CrN/AlTiN-coated sample exhibited the lowest wear rate among all studied surfaces, and (iii) the film damage on the worn surfaces mostly occurred in the form of droplet delamination.}, language = {en} } @misc{DahmaniFellahHeziletal., author = {Dahmani, Marwa and Fellah, Mamoun and Hezil, Naouel and Benoudia, Mohamed-Cherif and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Structural and mechanical evaluation of a new Ti-Nb-Mo alloy produced by high-energy ball milling with variable milling time for biomedical applications}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {129}, journal = {The International Journal of Advanced Manufacturing Technology}, number = {11-12}, issn = {1433-3015}, doi = {10.1007/s00170-023-12650-0}, pages = {4971 -- 4991}, abstract = {The main focus of this work is to investigate the impact of varying milling times (2 to 18 h) on the structural and mechanical properties of the developed Ti-Nb-Mo alloy. The morphology, phase composition, microstructure, and mechanical behavior of milled and sintered Ti-25Nb-25Mo alloy samples were characterized systematically using x-ray diffraction, scanning electron microscope, optical microscope, and Vicker microhardness. It was noted that the quantity of the β-Ti phase increased as the milling time increased. After 12 h of milling, the synthesized alloys exhibited a spherical morphology and texture with homogeneous distribution. The milled alloys' structural evolution and morphological changes were found to be dependent on their milling duration. Morphological analysis revealed that the crystallite size and mean pore size decreased when the milling duration increased, reaching minimum values of 51 nm and < 1 μm, after 12 and 18 h respectively. As the milling time increased, the grain size decreased, resulting in an increase in density, microhardness, and elastic modulus. Ti-25Nb-25Mo will presents good anti-wear ability and higher resistance to plastic deformation due to enhanced mechanical characteristics (H/E, and H3/E2). Hence, the developed Ti-25Nb-25Mo alloys with reduced elastic modulus and desirable mechanical properties were found to be a promising option for biomedical applications.}, language = {en} } @misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Montagne, Alex and Obrosov, Aleksei and Jamshed, Wasim and Ibrahim, Rabha W. and Iqbal, Amjad and El Din, Sayed M. and Khalifa, Hamiden Abd El-Wahed}, title = {Investigating the effect of milling time on structural, mechanical and tribological properties of a nanostructured hiped alpha alumina for biomaterial applications}, series = {Arabian Journal of Chemistry}, volume = {16}, journal = {Arabian Journal of Chemistry}, number = {10}, issn = {1878-5379}, doi = {10.1016/j.arabjc.2023.105112}, abstract = {In this work was prepared α-Al2O3 alloys from laboratory aluminum oxide powder that was milled for different periods of time and sintered at a temperature of 1450 °C. The difference between the prepared samples was studied using several experimental measurement techniques, including X-ray diffraction, scanning electron microscopy and measurement of physical and mechanical properties. Moreover, the effect of milling time on the formation and sintering of alpha-alumina, by milling the mixture at different times using high energy crushing technique was studied. An influence of milling time on density, open spaces and microstructure of the samples was analyzed. The obtained results showed that longer milling duration led to alloys with higher hardness (H) and modulus of elasticity (E). This improvement is due to lower porosity and corresponding higher density at high temperatures. A noticeable decrease in the size of the particles with the increase of the milling time led to an increase in the lattice parameter accompanied by a decrease in defects and ionic voids. The percentage of pores reached 0.04 \% within 24 h of grinding after it was approximately 0.20 \%, while the density reached 96 \% after the same highest grinding time. Tests showed that the value of friction coefficient decreases, while it increases with the increase in the applied pressure force and this was confirmed by SEM images of the samples. the main factor to reduce friction is the increase in grinding time, regardless of the value of the applied load. The results showed that the Al2O3 alloy applied to it with a load of 2 N and milled for 24 h had a minimum value of 1.94 µm3 wear volumes and a wear rate of 1.33 (µm3∙N-1∙µm-1). The sample milled for 24 h showed the best result, characterized by the lowest wear size, specific wear rate and the highest hardness with extraordinary density of 96 \%, which is important in the field of biomaterials applications.}, language = {en} } @misc{BourasFellahBarilleetal., author = {Bouras, Dikra and Fellah, Mamoun and Barille, Regis and Weiß, Sabine and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Improvement of photocatalytic performance and sensitive ultraviolet photodetectors using AC-ZnO/ZC-Ag2O/AZ-CuO multilayers nanocomposite prepared by spin coating method}, series = {Journal of Science: Advanced Materials and Devices}, volume = {9}, journal = {Journal of Science: Advanced Materials and Devices}, number = {1}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2023.100642}, abstract = {Morphological and optical properties of a multilayer film (CAZO/CZAO/ZACO) prepared by spin-coating method and deposited on a glass substrate were evaluated. The study was initially carried out for each layer, individually and then as a multilayer subsequently. Structural properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectra (IR) and X-ray photoelectron Spectroscopy (XPS) showed the presence of three phases of zinc, copper and silver oxides at different levels. The CZAO sample observed with scanning electron microscope (SEM) showed an excellent porous surface with a large deformation in the multilayer configuration. Doping with zinc and copper in the silver crystal lattice improved the crystal structure and reduced the optical energy gap, thus increasing the optical absorbance and refractive index. The dielectric constants and showed an increase in the optical polarization values for lower photonic energies. The maximum degradation rate for photocatalysts of methylene blue was 89 \% for a 5-h exposure period with CAZO/CZAO/ZACO while it reached 71 \% for the CZAO sample during the same time period. The sensitivity of samples to light proved that the presence of ultraviolet radiation increases the number of holes trapped by oxygen ions and causes more free electrons and contribute to a better production of photocurrent than in darkness.}, language = {en} } @misc{HamadiFellahHeziletal., author = {Hamadi, Fouzia and Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Laouini, Salah Eddine and Montagne, Alex and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei and El-Hiti, Gamal A. and Yadav, Krishna Kumar}, title = {Effect of milling time on structural, physical and tribological behavior of a newly developed Ti-Nb-Zr alloy for biomedical applications}, series = {Advanced Powder Technology}, volume = {35}, journal = {Advanced Powder Technology}, number = {1}, issn = {1568-5527}, doi = {https://doi.org/10.1016/j.apt.2023.104306}, abstract = {Titanium (Ti)-based alloys with only a β-phase have attracted academic and industrial interest for orthopedic application, due to their close properties to those of tissues. The current study aims to investigate the effect of milling time (2 h, 6 h, 12 h and 18 h) on the nanostructured ternary alloy Ti-25Nb-25Zr prepared by high energy milling, on its structural, physical and tribological behaviors. The alloys' characteristics such as relative density/porosity, surface roughness, were evaluated using XRD, SEM, surface profilometry, and microdurometer, respectively. The tribological characterization was done using an oscillating tribometer under wet conditions, simulating the human body environment. Results showed that the crystallite and mean pore size reduced with increasing milling time, with the smallest values of 26 nm and 40 µm, respectively after 18 h. Structural characterization shows that the amount of the β-Ti phase increased with increasing milling time, resulting in spherical morphology and texturing of the synthesized alloys. The milled alloys' structural evolution and morphological changes were sensitive to their milling times. Also, the relative density, Young's modulus and hardness, increased due to grain size decreased with increasing milling time. Tribological results showed that the effect of milling has a significant effect on both nanomaterial formation and friction-wear behavior of the alloys. The results showed that, friction coefficient and wear rate significantly decreased due to the increased formation of protective films such as TiO2, Nb2O5 and ZrO2 phases. The wear mechanism of the Ti-25Zr-25Nb system was dominated by abrasion wear accompanied by adhesion wear.}, language = {en} } @misc{DahmaniFellahHeziletal., author = {Dahmani, Marwa and Fellah, Mamoun and Hezil, Naouel and Benoudia, Mohamed-Cherif and Obrosov, Aleksei and El-Hiti, Gamal A. and Weiß, Sabine}, title = {Bioactivity and tribological performance of a novel nano-biomaterial beta-type Ti-alloy}, series = {Journal of materials research and technology}, volume = {36}, journal = {Journal of materials research and technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2214-0697}, doi = {https://doi.org/10.1016/j.jmrt.2025.03.180}, pages = {2297 -- 2316}, abstract = {This study investigates the bioactivity; wear performance, and topography of a novel beta-type titanium-based alloy using techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and 2D and 3D analysis. The tribological test was evaluated using a ball-on-disk tribometer in a wet environment. Different loads of 2, 6, and 10 N were applied during the evolution. The data results indicate a significant effect of the milling process on the formation of the hydroxyapatite layer on the surfaces of the Ti-Nb-Mo alloy. Both the wear volume and rate showed a consistent trend of decrease as the milling time increased from 2 to 12 h for all applied loads. The minimum values of wear and volume were reached after 12 h of milling. The improvement in tribological behavior can be attributed to the improved mechanical properties of the alloys. In addition, the significant presence of niobium (Nb) and molybdenum (Mo) plays a critical role in achieving high coefficient of friction values. The primary wear mechanism observed in the Ti-25Nb-25Mo system was adhesive wear in addition to abrasive wear. With its lower Young's modulus and favorable biological and tribological properties, the Ti-25Nb-25Mo alloy represents a promising option for bone tissue applications in orthopedics.}, language = {en} } @misc{MorozovaObrosovNaumovetal., author = {Morozova, Iuliia and Obrosov, Aleksei and Naumov, Anton and Michailov, Vesselin and Doynov, Nikolay}, title = {Factors affecting mechanical properties of impulse friction stir welded AA2024-T351 under static and cyclic loads}, series = {Machines}, volume = {13}, journal = {Machines}, number = {6}, editor = {Markopoulos, Angelos P. and Astolfi, Davide}, publisher = {MDPI}, address = {Basel}, issn = {2075-1702}, doi = {10.3390/machines13060529}, pages = {1 -- 16}, abstract = {This study investigates the factors affecting the mechanical performance of conventional and impulse friction stir welded (FSW and IFSW) AA2024-T351 joints under static and cyclic loading. Emphasis is placed on the influence of fracture-inducing features such as oxide inclusions, constituent particle distributions, crystallographic texture, and precipitation state. A series of IFSW welds produced at varying impulse parameters were compared to conventional FSW welds in terms of microhardness, tensile strength, fatigue life, and Taylor factor distribution. IFSW joints demonstrated a significant improvement in tensile strength and elongation, particularly at higher impulse frequencies. Enhanced material mixing due to the reciprocating tool motion in IFSW resulted in finer particle distribution, more favorable crystallographic texture, and reduced weld pitch, all contributing to increased ductility and strength. Fractographic analyses revealed that fatigue failures primarily initiated in the stir zone, typically at unplasticized metallic inclusions. However, IFSW joints displayed longer fatigue lives, particularly when impulse parameters were optimized. These findings underline the complex interplay of microstructural and textural factors in determining weld performance, highlighting IFSW as a promising technique for enhancing the durability of high-strength aluminum welds.}, language = {en} }