Publications Internationales

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Author: search.filters.author.Bezzazi, BoudjemaHas files: No

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    Oxidation and property evolution of AISI T5 steel under varying heat treatments
    (2025) Dadou, Abdenour; Dilmi, Hamid; Bezzazi, Boudjema; Aribi, Chouaib; Daoud, Ismail
    This study evaluates the effect of heat treatment on the mechanical, tribological, and oxidation behavior of AISI T5 steel. The chemical composition was first characterized using spectroscopy and SEM. A two-year oxidation test conducted in humid and relatively dry atmospheres showed strong environmental sensitivity: in humid air, the oxidation rate reached 11.27×10-2 P/P0 per month with a sharp increase after 25 days, whereas in dry air it remained below1.35×10-2 P/P0 per month, following a linear and nearly flat trend indicative of a protective oxide scale. Heat treatment significantly increased hardness from 34.15 ± 0.59 HRC (untreated) to 62.70 ± 0.66 and 60.80 ± 0.48 HRC for water and oil quenched steels, respectively. Impact strength decreased accordingly, with oil quenching offering the best hardness-toughness balance (60.8 HRC, 2.08 Kcv). Instrumented indentation confirmed substantial surface strengthening, with HIT rising to 17.39 ± 0.29 uced by 81.3% (Q. Water) and 62.5% (Q. Oil), with faster run-in in the water-quenched condition. XRD revealed tempered martensite with Fe3W3C/Cr7C3 (Q. Water) and Co3W3C (Q. Oil), consistent with thermal conditions. This study provides new experimental data on the effects of 15-minute austenitization followed by oil or water quenching on the properties of AISI T5 steel, highlighting its potential for process optimization.
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    Assessment of friction stir welding joints of aa2017-t4 aluminum by disc pressure mechanical tests
    (2023) Djili, Abderrahmane; Bezzazi, Boudjema; Haboussi, Mohamed; Zioui, Nadjet
    Precipitation hardening aluminium alloy sheets AA2017-T4 are welded by FSW on a conventional FSW tool. A macrograph of the cross section of the butt-welded joint shows the classical zones for such welding, namely the nugget zone, the thermo-mechanically affected zone and the heat affected zone. Scanning Electron Microscopy displays a grain refining and a re-formation of the precipitates in the nugget zone. Micro-hardness measurements on the cross-section perpendicular to the welding direction give the standard W-profile of the hardness for such welding, with as expected, the relatively highest value at the joint center (nugget zone). To assess the mechanical performance of the FSW welded joint, the Disk Pressure Test (DPT) is used. It shows a failure pressure for the welded specimen that is 17% lower than the base material. The fracture surface micrographs clearly show a thickness reduction at break that is ~36% higher for the base material than the welding joint and a ductile fracture mode for both specimens.
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    Characterization of the interface of a Non-Ferrous dissimilar realized by rotary friction welding
    (Springer, 2021) Mebtouche, A.; Bezzazi, Boudjema; Ramou, N.; Aboudi, D.; Faci, Y.; Latef, M.
    The need for assembly between dissimilar materials often arises in complex industrial applications. It avoids problems inherent in conventional welding. Therefore, in this study the performance of welded joints developed using a rotary friction welding machine, between Cu/Al, are characterized. The interface of the welded assembly of dissimilar copper Cua1 and AA2014 aluminum, consists of several intermetallic compounds mainly CuAl2, CuAl and Cu9Al4. Dendrites have been revealed, this structure is known to be the result of solidification. While rotary friction welding is done at the solid state. In this work, we seek to know the phenomena that take place during the entire process and in the creation of the interface. This article presents the study of the Al/Cu interfacial structure of welded joints made by rotary friction in a modified cycle with two steps
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    Etude expérimentale du comportement diélectrique et thermique des nano composites hybrides à matrice époxyde chargée
    (2014) Irekti, Amar; Bezzazi, Boudjema; Aribi, Chouaib; Zibouche, Fatima