Publications Scientifiques

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Author: search.filters.author.Aknouche, Hamid

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    Improvement of the tribological behavior of TiN/CrN multilayer coatings by modulation wavelength variation
    (Elsevier, 2024) Atmani, Taous Doria; Bouamerene, Mohammed-Said; Gaceb, Mohammed; Nouveau, Corinne; Aknouche, Hamid
    Hard coatings are widely used in materials engineering as surface coatings to protect mechanical parts subject to friction. For a coating to be functionally successful, it should possess high wear resistance. Experimental work has been performed on TiN/CrN multilayer coatings with various modulated periods, deposited on XC48 steel substrates having two different surface roughnesses using reactive direct current magnetron sputtering. Their Tribological performances were investigated following dry sliding wear tests using a tribometer with ball-on-flat contact configuration. The prevailing wear mechanisms of TiN/CrN coatings are dominated by oxidation of wear debris and counter material transfer. The decreased wear rate was significantly influenced by both the reduction of the period thicknesses and the increase of substrate surface roughness. Nonetheless, varying thickness period in the multilayer and increasing the substrate roughness did not show any significant wear resistance improvement.
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    An ecological water‑based drilling mud (WBM) with low cost: substitution of polymers by wood wastes
    (Springer, 2019) Haider, Soumia; Messaoud‑Boureghda, Mohamed‑Zine; Aknouche, Hamid; Akkouche, Ali; Hammadi, Larbi; Safi, Brahim
    An ecologically friendly water-based drilling mud (WBM) was designed by using wood wastes (WP: wood powder) in order to substitute the organic polymers which are very expensive and often make the higher cost of the oil well drilling. This present work is dedicated on studying the rheological behavior and main rheological properties of WBM containing the wood powder at different contents and sizes by substitution of usually used polymers. The effect of wood powder on the drilling fluid filtrate was also analyzed. The drilling fluid that was developed has better rheological properties and fluid loss control which are required for a good functioning of oil well drilling. By a total substitution of polymers, the wood powder (300 μm at 850 kg/m3) can be used as a filtrate reducer of mud because the WBM filtrate obtained exhibits a minimum and having requested values for such formation
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    Effects of Nitrogen Content on the Structural, Mechanical, and Corrosion Properties of ZrN Thin Films Grown on AISI 316L by Radiofrequency Magnetron Sputtering
    (Wiley, 2021) Azibi, Mourad; Saoula, Nadia; Madaoui, Noureddine; Aknouche, Hamid
    Zirconium nitride films are deposited onto stainless steel AISI 316L and silicon (100) by radio frequency magnetron sputtering at different nitrogen flow ratios [N2 /(Ar+N2 )] varied between 0 and 0.25). Scanning electron microscope, atomic force microscopy, X-ray diffraction (XRD), and Raman are used to investigate the surface morphology and microstructure of the thin films. The mechanical and electrochemical properties of all coatings are evaluated and compared with the uncoated AISI 316L to explore the efficiency of surface modification. The XRD and Raman analysis show that all the films are crystalline. This shows that the increased nitrogen content leads to a transformation from hexagonal 𝜶-Zr phase to cubic c-Zr and then to mixed 𝜶-Zr and face centered cubic c-ZrN phases. The films deposited with nitrogen flow ratio of 0.2 show the highest hardness of 32.2 GPa. Using the potentiodynamic polarization method, the corrosion behavior of the films is studied in Hank’s solution. The comparison between uncoated and coated substrates shows a decrease in corrosion current density for all coated samples.
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    Bias voltage effect on magnetron sputtered titanium aluminum nitride TiAlN thin films properties
    (EDP Sciences, 2019) Ait-Djafer, Amina Zouina; Saoula, Nadia; Wamwangi, Daniel; Madaoui, Noureddine; Aknouche, Hamid
    In this study, a negative substrate bias voltage is used to tune the structural, morphological, mechanical and electrochemical properties of TiAlN coatings fundamental for protective coating applications. TiAlN thin films have been deposited on glass, (001)Si and stainless steel substrates by RF magnetron sputtering at a power density of 4.41 W/cm2. The deposition rate was determined from X-ray reflectivity measurements to 7.00 ± 0.05 nm/min. TiAlN films used in this work were deposited for 60 min to yield a film thickness of 420 nm. Structural analysis has shown that TiAlN coating forms a cubic (fcc) phase with orientations in (111), (200), (220) and (222) planes. The deposited coatings present maximum hardness (H = 37.9 GPa) at −75 V. The dependence of hardness and Young's modulus and corrosion resistance on microstructure has been established. Electrochemical studies by potentiodynamic polarization in aggressive environment (3.5 wt.% NaCl) have revealed that stainless steel substrate with TiAlN coating exhibits excellent corrosion resistance
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    The influence of substrate bias voltage on the electrochemical properties of ZrN thin films deposited by radio-frequency magnetron sputtering : biomedical application
    (De Gruyter Open Ltd, 2019) Azibi, Mourad; Saoula, Nadia; Aknouche, Hamid
    In order to study the influence of the substrate bias on the properties of ZrN thin films deposited by radio-frequency magnetron sputtering for biomedical application. Films of ZrN were grown onto 316L stainless steel substrate using radio-frequency (rf) magnetron sputtering from a pure zirconium target in Ar - N2 gas mixture. The substrate bias voltage was varied from 0 to -100 V, which produces a variation in the structural and electrochemical properties of the obtained films. The deposited films were characterized by X-Rays Diffraction, Atomic Force Microscopy, scanning force microscopy and potentiodynamic polarization
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    Parametric study of the mechanical properties of nanocrystalline TiN/CrN multilayer coatings with a special focus on the effect of coating thickness and substrate roughness
    (Elsevier, 2021) Atmani, Taous Doria; Gaceb, M.; Aknouche, Hamid; Nouveau, C.; Bouamrene, M.S.
    In a plot to improve the performance of steel mechanical parts subject to aggressive friction solicitations, three batches of deposits of TiN and CrN layers on steel substrates with two different roughnesses have been obtained using reactive DC magnetron sputtering. The present study was conducted to determine the effect of varying TiN/CrN multilayer coatings thickness (varying modulated period Λ and interlayer thickness), on their mechanical and tribological properties. The morphological and the structural properties were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The nanoindentation measurements displayed improvement in hardness (> 40 GPa) and Young's modulus (> 600 GPa) for the coating with Λ ≅ 12 nm (TiN Λ/2 ≅ 7.5 nm + CrN Λ/2 ≅ 4.5 nm) thickness and the higher number (300) of interfaces, deposited on the rougher substrate. Its low coating damage under the scratch test, associated with its estimated adhesion work (Wad), indicated a good cohesive/adhesive strength and improved structural and mechanical properties
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    Incorporation mode effect of Nano-silica on the rheological and mechanical properties of cementitious pastes and cement mortars
    (2018) Saf, Brahim; Aknouche, Hamid; Mechakra, Hamza; Aboutaleb, D.; Bouali, Khaled
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    Influence de l'angle d'inclinaison des cannelures sur le comportement à l'usure des cylindres broyeurs de blé
    (European Journal of Scientific Research, 2008) Aknouche, Hamid; Zerizer, A.; Chemani, B.
    Le suivi du comportement des équipements de l’industrie alimentaire, lors de leur exploitation est l’une des préoccupations majeures pour le maintien de la meilleure qualité des produits céréaliers. a perte des performances des mécanismes des machines alimentaires est due dans la plupart des cas à une dégradation importante causée par l’usure. Ce travail a pour finalité de répondre à des préoccupations liées à l’exploitation optimale des broyeurs à cylindres dans les entreprises algériennes de transformation des céréales. Les constructeurs de ces machines utilisent des caractéristiques de cannelures (les angles des cannelures) influençant leur blé local, ce qui déséquilibre leur exploitation dans les semouleries algériennes utilisant d’autres blés. Des relevés en milieu industriel ont été réalisés pour déterminer leurs durées de services. Une étude expérimentale faite sur un banc d’essai réalisé dans notre laboratoire, nous a permis de comparer le comportement à l’usure des cannelures de différentes pentes
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    Deposition and characterization of titanium aluminum nitridecoatings prepared by RF magnetron sputtering
    (Elsevier, 2015) Ait Djafer, Amina Zouina; Saoula, Nadia; Aknouche, Hamid; Guedouar, Bendiba