Publications Internationales

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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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    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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    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
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    Tool wear effect on cutting forces : in routing process of aleppo pine wood
    (2009) Aknouche, Hamid; Outahyon, A.; Nouveau, C.; Marchal, R.; Zerizer, A.; Butaud, J.C.
    This paper uses the cutting forces in a routing process of Aleppo pine wood to estimate the tool wear effect. The aim is to obtain further information about the tool wear effect by monitoring the variation in the cutting forces. A Kistler 9257A 3 axes Dynamometer was positioned under the workpiece to measure the cutting forces at frequencies up to 10,000 Hz. The experiments were carried out on a CNC routing machine RECORD1 of SCM. A carbide tool was used and the cutting parameters were fixed. The cutting speed was approximately 25 m/s. Dasylab software was used to capture the data. The results show a correlation between the tool wear and the computed angle ( ), between the tangential and cutting forces. In fact, the variation of ( ) is unstable in the running period and stable in the linear wear zone, included in the interval [−1.11◦; −1.10◦]. This study was performed as part of a development program for the Algerian wood industry, hence the selection Aleppo pine wood as the working material
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    Physical and mechanical properties of CrAlN and CrSiN ternary systems for wood machining applications
    (2009) Benlatreche, Y.; Nouveau, C.; Aknouche, Hamid; Imhoff, L.; Martin, N.; Gavoille, J.; Rousselot, C.; Yves Rauch, J.; Pilloud, D.
    Nowadays, almost all the cutting tools in metal machining are protected with a surface treatment. Nevertheless, this is not the case in woodmachining where no tools are protected, except by thermal treatments, and so they present a previous wear because of the use of steel or carbide materials in milling, sawing, routing, etc. During these processes, the tools are particularly exposed to abrasive and shock wear. To enhance their wear resistance, one solution is to protect them with hard coatings. The present study deals with the development of ternary systems (CrAlN and CrSiN) obtained by two PVD different magnetron sputtering systems [‘A’ (laboratory where CrAlN layers have been obtained) and ‘B’ (laboratory where CrSiN layers have been obtained) in the following text] on carbide WC–Co tools used in second transformation of wood to be compared to the binary CrN one. CrAlN and CrSiN films were deposited with different Al and Si contents, respectively, in order to check the effect of the additive element (Al or Si) on the different properties of the Cr–N system. The different coatings were characterized by SEM and EDS for thickness measurements, morphology and composition analyses, respectively, by nanoindentation for hardness and Young’s modulus measurements and by pin-on-disc to determine their friction coefficient. Routing of medium density fibreboard (MDF) was realized employing untreated or modified carbide WC–Co tools in order to compare their wear resistance. We observed that the Al and the Si addition improved the hardness and the Young’s modulus of the Cr–N system (‘A’: 29 and 410 GPa, respectively, ‘B’: 18 and 280 GPa, respectively). Indeed, the hardness values are 15–36GPa for CrAlN and 15–24 GPa for CrSiN coatings. Besides, the Young’s modulus values are 331–520GPa for CrAlN and 260–320 GPa for CrSiN coatings. The friction coefficient of the CrAlN layers varied between 0.6 and 0.7 and it increased slightly with the Al content. For the CrSiN coatings, the friction coefficient was lower and about 0.4. In both cases, the CrN layers ‘A’ and ‘B’ presented similar friction coefficient than CrAlN and CrSiN, respectively. During the routing of MDF, the CrN ‘A’ coating has a similar wear behaviour than the optimized CrAlN one (5 at.% of Al) while the optimized CrSiN coating (1.2 at.% of Si) showed a better behaviour against wear than the CrN ‘B’ one. The wear resistance of CrAlN- and CrSiN-coated carbide tools decreased when the Al and Si contents increased