Publications Scientifiques
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Item Determination of elasticity modulus of aleppo pine wood (pinus halepensis mill) with the ultrasound method(2008) Daoui, Abdelhakim; Zerizer, Abdellatif; Marchal, RemyWith a view to determining the mechanical properties - specifically the modulus of elasticity - of fibrous composites, the nondestructive methods present certain advantages. The ultrasound technique, based on measuring the propagation velocity of an impulse and considering the elasticity coefficients of the material, enabled us to deal with the study of a well-known local species, namely Aleppo pine (Pinus halepensis Mill.), with consideration of its physical parameters such as moisture and density. The mean goal of this step is to find correlations between the acoustic behavior of the material and its physical and mechanical characteristicsItem Traceability in wood production(2013) Zerizer, A.; Nacereddine, H.; Aknouche, HamidItem Characterization of algerians oak wood by x-Ray tomographic scanner and free software image-J(Statny Drevarsky Vyskumny Ustav, 2014) Zerizer, A.; Sitouah, N.; Aknouche, A.; Mothe, F.; Kennouche, S.Item 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 materialItem 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 increasedItem Modeling rot in wood by replacement of wood with sand : an experimental study(2006) Zerizer, A.; Ouis, D.Rot is known to affect the strength properties of wood. At the same time, the damping properties of the attacked material have also been shown to change. This article presents the results of an experimental study in which rot in wood was modeled by the replacement of wood with sand. The procedure entailed the drilling of holes in the body of a wooden beam, filling the holes with sand, and monitoring the changes induced by the sand-filled holes on the values of the modulus of elasticity (MOE) and of the loss factor. The MOE was calculated from the resonance frequency of the first longitudinal mode of vibration, and the loss factor was obtained indirectly from the impulse response by means of a room acoustical technique. The results show that the MOE value, and hence the strength characteristic of the wood specimen, decreases at the same time as the loss factor increases