Browsing by Author "Djebaili Hamid"
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Item 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 MouradThe 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).Item Characterization of precipitates in a 7.9Cr–1.65Mo–1.25Si–1.2V steel during tempering(Materials Characterization(Elsevier), 2009-09-01) Djebaili Hamid; Zedira Hamma; Djelloul AbdelkaderIn this paper, the precipitates formed during the tempering after quenching from temperature 1150 °C for 7.90Cr–1.65Mo–1.25Si–1.2V steels are investigated using an analytical transmission electron microscope (A-TEM).The study of this tempering is carried out in isothermal and anisothermal conditions, by comparing the results given by dilatometry and hot hardness. Tempering is performed in the range of 300–700 °C. Coarse primary carbides retained after heat treatment are V-rich MC and Cr–Mo-rich M7C3 types. In turn, it gives a significant influence on the precipitation of fine secondary carbides, that is, secondary hardening during tempering. The major secondary carbides are Cr–Mo–V-rich M′C (and/or) Cr–Mo-rich M2C type. The peak hardness is observed in the tempering range of 450–500 °C. In the end, we observe between 600 and 700 °C, that this impoverished changes the phase. At these high temperatures of tempering, we observe that there is a carbide formation of the types M6C developing at the expense of the fine M7C3 carbides previously formedItem 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 HamidShort 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 modeItem Effect of Broken Glass Particle on Stress Transfer of Nylon Matrix Composite(JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2023-10-30) Mansouri Khelifa; Chitour Mourad; Berkia Abdelhak; Rebai B; Khadraoui Fayçal; Djebaili HamidSome of the material demands in the advanced industries cannot be fulfilled by monolithic materials. Therefore, composite materials have been developed. The combination of desired properties of thermoplastics and glass particles (high strength and high modulus) is the aim of composites production Particles are becoming increasingly popular reinforcing elements in products made by injection molding. Particles reinforcement allows the polymer to be processed employing the same methods as those used for unreinforced polymers. The loads are not directly applied to the reinforcements, but they are applied to the matrix and some of the loads applied are transferred to the particles. The development of micromechanics equations for the particulate composites follows along the same lines as those for the short fiber reinforced composites. Particles are used to increase the strength or other properties of inexpensive materials during reinforcement with other matrix materials. The objective of this study is to analyse the particle breaking effect in composite made of nylon 66 (PA) matrix reinforced with glass particles, in which the particles diameters of 19.61, 26.15, 39.22 and 78.45 m were used. A volume fraction of 20 % was assumed in each model.Item Effect of Film Thickness on the Structural and Tribo-Mechanical Properties of Reactive Sputtered Molybdenum Nitride Thin Films(Metallurgical and Materials Engineering Association of Metallurgical Engineers of Serbia AMES, 2022-06-05) Abboudi Abdelaziz; Aissani Linda; Saoudi Abdenour; Djebaili HamidThe current study aims to examine the impact of nitrogen content and film thickness on the structural and tribo-mechanical characteristics of reactive sputtered MoN thin films. Molybdenum nitride thin films with thicknesses ranging from 0.2 to 1.25 m have been applied to steel and silicon substrates for this purpose, with various amounts of controlled atmosphere (Ar+N2). Then, the films are characterized using XRD (X-ray diffraction), EDX (energy dispersive X-ray analysis), SEM (scanning electron microscopy), FTIR (Fourier-transform infrared spectroscopy), and nanoindentation. The residual stress was measured using the Stoney formula. Results show that a high compressive residual stress of -5.7 GPa is present in the film with a 0.3 μm thickness and gradually decreases with increasing film thickness. Above 1 µm of film thickness, there is no change in the density of the MoN films. Also, the coating hardness and Young’s modulus vary between 9.5 and 35 GPa, and 266 and 320 GPa, respectively, depending on nitrogen content and film thickness. Lastly, the friction of the MoN thin films is estimated to be around 0.55, which proves that the oxide is being slowly removed.Item Effect of Heat Treatments on the Mechanical Properties of a Form Tool(JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2018-06-25) Chermime Brahim; Abboudi Abdelaziz; Djebaili HamidDuring the follow-up of the cutting tools in the production workshops, we noticed that the cutting tools operate in severe conditions, for this we thought to improve their mechanical characteristics and increase their yield. Two key factors influencing these tools, namely geometry and heat treatment. In this study we chose the heat treatment, from a basic fast steel form tool, after making the milling cutter in the tool shop we proceeded to a revenue treatment to remove austenite residues. The purpose of our work is to increase the machining quota of a Z80WCV 18-04-01 high speed steel mill, for this reason our study is based on the reduction of residual austenite by incomes. cumulated after prior quenching for different austenitization temperatures (1240, 1260 and 1270 °C)Item Effect of MoZrN Coating on a Steel XC100(Metallofiz. Noveishie Tekhnol, 2016-11-22) Abboudi Abdelaziz; Meddour Belkacem; Chermime Brahim; Djebaili Hamid; Brioua MouradThe 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.Item Effect of Reinforcing Particle Shape on the Behavior of Composites Materials(JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2021-12-02) Mansouri Khelifa; Chermime Brahim; Saoudi Abdenour; Djebaili HamidIn this paper, the effect of particle shape on the mechanic behavior of glass particle reinforced composites is evaluated. Small particles adhere strongly to the polymer, which leads to a strong reinforcing effect. When the total contact surface increases, more loads are transferred to the reinforcing particles. In our previous studies, it has been shown that addition of circular particles with decreasing diameter does not affect the composite. The objective of this research is to investigate the mechanical behavior of thermoplastic matrix composite nylon 66, reinforced with glass particles, under unidirectional tensile loading using finite element analysis. Numerical results are presented for a variety of particle shapes, including circular, triangular, square, rhombic, pentagonal and hexagonal. The results show that Von Mises stresses consistently increased as the shape of the reinforcing particles changed from triangular to square, rhombic, pentagonal, hexagonal and circular in this order.Item EFFECT OF SALT BATH NITRIDING ON SURFACE ROUGHNESS BEHAVIOUR OF AISI 4140 STEEL(Acta Metallurgica Slovaca, 2017-01-23) Ghelloudj Elhadj; Hannachi Med Tahar; Djebaili HamidIn the present research, AISI 4140 steel was nitrided in salt bath to study and analyze the behaviour of the surface roughness. The structural surface characterization behaviour of the nitrided steel was compared to the behaviour of the same steel which was untreated. The nitriding process was implemented in the salt bath component at ten different times (from 1 h to 10 h) when the temperature was constant at (580ºC). The influence of nitriding treatment on structural properties of the material was studied by scanning electron microscopy (SEM), microhardness tester and surface profilometer. It was found that salt bath nitriding was effective in improving the surface properties behaviour of this steel. Experimental results showed that the nitrides ε-Fe2-3(N,C) and γ’-Fe4(N,C) present in the compound layer increase the microhardness (406–502 HV0.3), the initial surface roughness values of nitrided samples were higher than those of unnitrided specimens, it also observed that the increasing the nitriding time increases the surface roughness parameters (Ra, Rq and Rz).Item EFFECT OF TIME ON THE COMPOUND LAYER FORMED DURING SALT BATH NITRIDING OF AISI 4140 STEEL(Acta Metallurgica Slovaca, 2018-12-01) Ghelloudj Elhadj; Hannachi Med Tahar; Djebaili HamidThis research was carried out to study the effect of time on the compound layer of AISI 4140 steel in salt bath nitriding. The nitriding process were implemented on AISI 4140 steel in salt bath component for different times (from 1 h to 10 h) at 580 °C. Samples of AISI 4140 steel were treated and characterized (at surface and core of samples) through the following technique: optical microscopy, scanning electron microscopy, X-ray diffraction (XRD) and microhardness tester. Shows that thick compound layers are formed during continuous salt bath nitriding. The thickness of the compound layer and surface hardness increases with increasing time.Item Experimental Investigation on Roughness Parameters of 42CrMo4 Steel Surface During Nitrocarburizing Treatment(Tribology in Industry, 2022-10-01) Ghelloudj Elhadj; Hannachi Med Tahar; Djebaili HamidTo evaluate the performance characteristics of various surfaces, a detailed and precise description of the surface's micro-geometry properties is required. In this context, roughness is a reliable indicator of the possible behavior of mechanical piece performance, since distortions on the surface can form a direct cause for cracks or corrosion. As a result, characterization of surface roughness is very important for zero-defect fabrication. This paper investigates the 2D roughness parameters of a 42CrMo4 steel surface before and after nitrocarburizing treatment. The latter was accomplished at 580 °C for 10 hours in a salt bath containing sodium cyanates and potassium carbonates. A surface profilometer was used to analyze the influence of nitrocarburizing treatment on the material's surface roughness parameters behavior. The parameters that comprehensively describes the surface structure, namely the amplitude, spacing, hybrid parameters, and material ratio parameters were highlighted. The results of the experiments indicated that the nitrocarburizing treatment was effective in increasing almost all the 2D roughness parameters of the 42CrMo4 steel surface.Item Improvement of the Abrasive Wear Resistance of Pump Shaft (AISI 316L stainless steel) by Salt Bath Nitriding(Journal of Chemistry and Materials Research, 2017-06-28) Ghelloudj Elhadj; Hannachi Med Tahar; Djebaili HamidCentrifugal pumps are prevalent for many different applications in the industrial or other sectors. The paper reviews the literature available on the improvement of efficiency of centrifugal pump through improvement in performance of pump shaft (AISI 316L stainless steel). The paper discusses the available material of performance improvement through amelioration of tribological characteristics of pump shaft and mainly focuses on the abrasive wear resistance of AISI 316L stainless steel. In order to improve the abrasive wear resistance of stainless steel components, carbide-hardened surfaces were produced on AISI 316L austenitic stainless steel by salt bath nitriding. Nitriding of AISI 316L austenitic stainless steel was carried out at high temperature (580°C) for 10 h. The microstructures, abrasive wear resistance, as well as its surface hardness, were investigated using optical microscopy, tribometer tester and microhardness tester. The results confirmed that salt bath nitriding was effective in improving the abrasive wear resistance.Item Influence of the carburization time on the structural and mechanical properties of XC20 stee(Mater. Res. Express, 2021-08-21) Saoudi Abdenour; Aissani Linda; Chahaoui Oualid; Bestandji Ali; Louafi Med Salah; Djebaili HamidThis study focuses on the effect of carburization time on the structural and mechanical properties of low carbon XC20 mild steel(C. Wt.% <0.25). The XC20 steel was carburized with activated carbon with a carbon potential Cp1 = 1.1%, at 910 °C at different carburization times of 2, 4 and 6 h. The results obtained show that XC20 steel(non-carburized) has a ferrite-pearlitic structure with a hardness and a Young’s modulus of the order of (150 HV, 26 KN/mm2 ). After carburization, the structure of the carburized layer is transformed in martensite (Fe γ)in which cementite (Fe3C)is imbricated. The depth of the carburized layer and the amount of carbon on the surface gradually increase with increasing carburization time. In addition, the carburized XC20 steel becomes hard and brittle where the hardness and Young’s modulus have been increased for a high holding time until reaching maximum values(845 HV, 48 KN mm−2 ) after 6 h of carburization . However, the toughness of XC20 steel has been reduced from 163 to 40 J cm−2 .Item 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 MouradOur 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.Item 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 MouradParticles 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.Item Modélisation de la rupture d’un pli unidirectionnel perforé(Revue des Composites et des Matériaux Avancés, 2009) BREK Samir; Manaa Rabah; Zidani Kamel; Zedira Hamma; Djebaili HamidThe Composite materials are the subject of several studies because of their high specific characteristics and advantages of the latter to adapt to mechanical stress from a judicious preparation of matrix and reinforcement, particularly laminates of Unidirectional Carbon / Epoxy, are increasingly used for the realization of structures. However, the holding of composite structures can be greatly reduced by the addition of geometric singularitie. This work is to determine the critical distance between two holes in one ply unidirectional carbon / epoxy, tensional and study the effect of the factor of stress concentration on the total ruin and brutal (that is to say wide mixture of fiber and matrix for a unidirectional ply).Item One Dimensional Modeling of the Shape Memory Effect(Modeling and Numerical Simulation of Material Science, 2013-03-24) Meddour Belkacem; Zedira Hamma; Djebaili HamidThis paper aims to build a constitutive model intended to describe the thermomechanical behavior of shape memory alloys. This behavior presents many facets, among them we have considered the simple way of shape memory, which is one of most important properties of shape memory alloys. Because of numerous stages of this effect, the subject was divided into three independent parts. For each part, we built the corresponding thermodynamic potential and we deduced the constitutive equations. To make this model workable, we have developed an algorithm. The simulation was performed using the NiTi as shape memory alloy.Item One Dimensional Modeling of the Shape Memory Effect(Modeling and Numerical Simulation of Material Science, 2013-03-24) Meddour Belkacem; Zedira Hamma; Djebaili HamidThis paper aims to build a constitutive model intended to describe the thermomechanical behavior of shape memory alloys. This behavior presents many facets, among them we have considered the simple way of shape memory, which is one of most important properties of shape memory alloys. Because of numerous stages of this effect, the subject was divided into three independent parts. For each part, we built the corresponding thermodynamic potential and we deduced the constitutive equations. To make this model workable, we have developed an algorithm. The simulation was performed using the NiTi as shape memory alloy.Item Prévision de la ruine des composites stratifiés perforés sous chargement thermomécanique(Revue des composites et des matériaux avancés, 2011) BREK Samir; Zidani Kamel; Djebaili Hamid; Manaa Rabah; Zedira HammaThe laminated composite structures in the form of plates are increasingly used for the design of mechanical structures. These are generally resistant structures, capable of withstanding mechanical loading and thermo mechanical important. Although the analysis of composite structures is required to a key point in the design of structures, there is lack of studies for laminated composite perforated, especially for high gradient structures are sought by monotonic or cyclic thermo mechanical loading, the transverse cracking is usually the first damage observed in the matrix as a fold disoriented relative to the axis of solicitation. In this work we propose a numerical study to calculate the critical distances between two holes in the plates laminated carbon / epoxy loaded by thermomechanical loadings, we used a software structural analysis by finite element method (Castem2009).Item THE INFLUENCE OF SALT BATH NITRIDING VARIABLES ON HARDNESS LAYER OF AISI 1045 STEEL(Acta Metallurgica Slovaca,, 2016-09-27) Ghelloudj Elhadj; Djebaili Hamid; Hannachi Med Tahar; Saoudi AbdenourThe aim of this paper is to study and analyze the effects of a surface controlled salt bath nitriding on the microhardness of AISI 1045 steel. The nitriding process was implemented in the salt bath component at ten different times (from 1 h to 10 h) when the temperature was constant at (520ºC). The nitriding process repeated of other specimens at the same times, but the temperature was (580ºC).The microstructure of the surface layers was investigated by scanning electron microscopy (SEM) and optical microscopy. Hardness profiles were measured with lowload hardness testing to determine the growth of the case depth after nitriding. Microhardness testing was carried out on samples to investigate the hardness profile at the transition from the compound to the diffusion layer. The microhardness of the surface of the nitrided sample at 520ºC and 580ºC was observed in the range of 318–430 HV0.3 and 329–421 HV0.3, respectively. Experimental results showed that the nitrides ε-Fe2-3(N, C) and γ’-Fe4(N,C) present in the compound layer increase the microhardness , It also showed that the Increasing the salt bath nitriding parameters (treatment time and temperature) increases the surface hardness and hardness profile.