@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} }