Browsing by Author "Brioua Mourad"

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    Characterization of Mo–V–N Coatings Deposited on XC100 Substrate by Sputtering Cathodic Magnetron
    (Metallofiz. Noveishie Tekhnol, 2017-11-21) Chermime Brahim; Abboudi Abdelaziz; Djebaili Hamid; Brioua Mourad
    The aim of this work is the characterization of ternary molybdenum–vanadium nitride (Mo–V–N) coatings deposited on silicon and XC100 steel substrates by the reactive radiofrequency dual magnetron sputtering with different contents of the Mo and V targets and nitrogen as reactive gas. The metal-target bias voltages are varied from 300 to 900 V. The hardness, surface morphology, microstructure and composition are studied by nanoindentation, scanning electron microscopy, atomic-force microscopy, and x-ray diffractometry. The Mo–V–N films manifest pyramidal surface morphology, high roughness (of 13.5 nm), but low mechanical properties. Hardness and Young’s modulus are found in the ranges of 10–18 GPa and 100–335 GPa, respectively. The residual stresses of coatings are compressive and varied between 0.8 GPa and 2.5 GPa (calculated with the Stoney formula).
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    Effect of Broken Fiber on Stress Transfer of Short Fiber Reinforced Thermoplastic Matrix Composite
    (JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2019-08-22) Mansouri Khelifa; Brioua Mourad; Djebaili Hamid
    Short fibers are becoming increasingly popular reinforcing elements in products made by injection molding. Short-fiber reinforcement allows the polymer to be processed employing the same methods as those used for unreinforced polymers. The best mechanical performances are achieved in composites when fibers are aligned in the loading direction. There are different methods developed by researchers in order to manufacture aligned short fiber reinforced polymer composites. Unidirectional composites tend to be very stiff and strong in fiber direction but very weak in the transverse direction. Their weakness in transverse direction is attributable to presence of significant stress concentration at the interface of matrix and fiber. In short fiber composites, loads are not directly applied on the fibers but are applied to the matrix and transferred to the fibers through the fiber ends. The process of transfer of load between fibers and matrix in the neighborhood of a fiber break or a matrix crack depends on the strength of the interface. The objective of this study is to analyze the fiber breaking effect in composite made of nylon 66 (PA) matrix reinforced with short glass fiber, in which the fiber diameters of 4.76, 6.35, and 9.5 m were used. A fiber volume fraction of 20 % was assumed in each mode
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    Effect of MoZrN Coating on a Steel XC100
    (Metallofiz. Noveishie Tekhnol, 2016-11-22) Abboudi Abdelaziz; Meddour Belkacem; Chermime Brahim; Djebaili Hamid; Brioua Mourad
    The zirconium nitride ZrN coatings are deposited on substrates of XC100 steel using physical vapour deposition (PVD) technique. Coatings based on nitrides of transition metals (Nb, Zr, Ti, V, ) developed by PVD are known to increase the life of cutting tools, and so they naturally have seen a rapid industrial growth. It is possible to produce ZrN-coatings with variations of nitrogen partial pressure, the residual stresses, the thickness of the thin film, and the friction coefficient depending on the nitrogen content. Usage of nitrogen is a good way to enhance wear resistance and effectiveness in tribological applications.
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    Mechanical and Structural Studies of Ternary Mo–Zr–N Layers Deposited on Substrate by PVD
    (Metallofiz. Noveishie Tekhnol, 2017-07-04) Abboudi Abdelaziz; Chermime Brahim; Djebaili Hamid; Brioua Mourad
    Our study of ternary Mo–Zr–N thin layers is novel with the objective of improving certain mechanical and tribological characteristics and of finding the appropriate stoichiometry to have the microstructure, which orientates to the desired properties, using the characterization techniques: SEM, XRD, EDS, XPS, WDS and similar methods as well as nanoindentation, alternative tribometry and scratch test. The morphological study of ternary Mo–Zr–N coating shows that the (111) orientation of texture is preferred essentially due to residual internal stresses. During the development of the Mo–Zr–N deposits, we have noticed that the addition of Zr results in multiphases consisting of binary ZrN, MoN and MoZrN nitrides with a prism-shaped structure. The coefficient of friction is low for Mo–N coating and low zirconium levels. The Young’s modulus takes values almost very close that is indicated for values below 100 at.% of Zr. The crystalline structure does not affect the resistance capacity of the material. The introduction of zirconium particles destabilizes the compound because zirconium atomic radius (0.138 nm) is higher than that of molybdenum (0.126 nm), and the lattice is distorted that explains these residual stresses.
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    Mechanical Behavior of Particle Reinforced Thermoplastic Matrix Composites Using Finite Element Modeling
    (JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2020-01-12) Mansouri Khelifa; Djebaili Hamid; Brioua Mourad
    Particles are becoming increasingly popular reinforcing elements in products made by injection molding. Particles reinforcement allows the thermoplastic to be processed employing the same methods as those used for unreinforced thermoplastic. Ultrafine particles, whose diameters are comparable to the crystalline regions in the polymer, have a prominent reinforcing effect on the elastic properties of the polymer. Small particles adhere strongly to the polymer, which leads to a strong reinforcing effect. In particle reinforced thermoplastic matrix composites, loads are not directly applied to the particles but are applied to the matrix, and some of the applied loads are transferred to the particles. The process of transfer of load between particles and matrix depends on the strength of the interface. In this work, multiparticle composite model was analyzed under tensile load. The purpose of this work is to analyze the influence of particle diameter (the diameters of 19.61, 26.15, 39.22 and 78.45 m were used) on the Von Mises stress of glass particle reinforced thermoplastic nylon 66 matrix composite using finite element analysis (FEA). The second objective is to analyze the effect of particle packing (square, hexagonal and random arrangement) on nanocomposite behavior.