https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Mon, 16 Mar 2026 03:04:35 GMT 2026-03-16T03:04:35Z http://hdl.handle.net/10985/14158 Temperature measurement inside and near the weld pool during laser welding LHOSPITALIER, Sylvie; BOURGES, Philippe; BERT, Alexandre; QUESADA, Jean; LAMBERTIN, Michel The work in this article deals with the measurement of temperature fields inside and near the weld pool during laser welding. The laser source used for this study is a 7.5 kW CO2 laser, and the welded material is a UNS N08904 austenitic stainless steel. The principle behind the actual experimentation is relatively simple: the welding operation is recorded with a charge coupled device camera equipped with infrared filters; after calibrating the camera sensor and image processing, the temperature distribution in the weld pool and near the melted zone is revealed. Fri, 01 Jan 1999 00:00:00 GMT http://hdl.handle.net/10985/14158 1999-01-01T00:00:00Z LHOSPITALIER, Sylvie BOURGES, Philippe BERT, Alexandre QUESADA, Jean LAMBERTIN, Michel The work in this article deals with the measurement of temperature fields inside and near the weld pool during laser welding. The laser source used for this study is a 7.5 kW CO2 laser, and the welded material is a UNS N08904 austenitic stainless steel. The principle behind the actual experimentation is relatively simple: the welding operation is recorded with a charge coupled device camera equipped with infrared filters; after calibrating the camera sensor and image processing, the temperature distribution in the weld pool and near the melted zone is revealed. http://hdl.handle.net/10985/7534 Hardness and scratch response of PVD multilayer coatings TLILI, Brahim; BENLATRECHE, Yacine; MUSTAPHA, Nasri; LAMBERTIN, Michel; NOUVEAU, Corinne In the present investigation, novel Cr/CrN, CrN/CrAlN and Cr/CrN/CrAlN multilayered coatings thin films have been developed by dual RF magnetron sputtering. They consist of superposing Cr, CrN and CrAlN layers of 50–500nm thick, up to a total thickness of 0.45–1μm. These coatings were grown on AISI4140 steel samples. The mechanical properties of these coatings were studied by scratch-tests and nano-indentation measurements. The hardness of the films reaches 15.8 GPa for a Cr/CrN multilayered coating sputtered at a bias voltage of -900V. High peak load tests were used to estimate the film adhesion on steel substrates; critical loads (Lc2) of 11N showed weak adhesion properties of the film. Moreover, an inventory of the major scratch-tests failure modes was established, which were classified into plastic deformation and different forms of cracking, spallation and coating perforation events. No evidence of interfacial failure(s) of the sub-layers was observed after the adhesion and nanoindentation tests. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/10985/7534 2009-01-01T00:00:00Z TLILI, Brahim BENLATRECHE, Yacine MUSTAPHA, Nasri LAMBERTIN, Michel NOUVEAU, Corinne In the present investigation, novel Cr/CrN, CrN/CrAlN and Cr/CrN/CrAlN multilayered coatings thin films have been developed by dual RF magnetron sputtering. They consist of superposing Cr, CrN and CrAlN layers of 50–500nm thick, up to a total thickness of 0.45–1μm. These coatings were grown on AISI4140 steel samples. The mechanical properties of these coatings were studied by scratch-tests and nano-indentation measurements. The hardness of the films reaches 15.8 GPa for a Cr/CrN multilayered coating sputtered at a bias voltage of -900V. High peak load tests were used to estimate the film adhesion on steel substrates; critical loads (Lc2) of 11N showed weak adhesion properties of the film. Moreover, an inventory of the major scratch-tests failure modes was established, which were classified into plastic deformation and different forms of cracking, spallation and coating perforation events. No evidence of interfacial failure(s) of the sub-layers was observed after the adhesion and nanoindentation tests. http://hdl.handle.net/10985/8361 Experimental investigation of the mechanical micro structural and thermal properties of thin CrAIN layers deposited by PVD technique for various aluminum percentages GHRIB, Taher; TLILI, Brahim; BENLATRECHE, Yacine; LAMBERTIN, Michel; YACOUBI, Noureddine; ENNASRI, M.; NOUVEAU, Corinne The thin film of chromium nitride and their derivatives obtained by the filing process physical vapor deposition attract more and more attention from industry given their high resistance to wear. This quality of these coatings may be linked to their good mechanical and tribological properties. Several experimental investigations have led to the development of CrAlN (Chronium Aluminum Nitride) hard coatings by varying the aluminum target bias voltage, in preference to the traditional CrN coating. The present work is based on the investigation of physical and mechanical properties of CrAlN coating deposited on a silicon substrate and the effect of the aluminum proportion on their variation. The results demonstrate that variation in aluminum proportion alters the resulting columnar morphology, porosity and the thermal properties. The correlation between aluminum proportions in CrAlN coatings and his thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by decrease of the stitch parameter dimension. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/10985/8361 2009-01-01T00:00:00Z GHRIB, Taher TLILI, Brahim BENLATRECHE, Yacine LAMBERTIN, Michel YACOUBI, Noureddine ENNASRI, M. NOUVEAU, Corinne The thin film of chromium nitride and their derivatives obtained by the filing process physical vapor deposition attract more and more attention from industry given their high resistance to wear. This quality of these coatings may be linked to their good mechanical and tribological properties. Several experimental investigations have led to the development of CrAlN (Chronium Aluminum Nitride) hard coatings by varying the aluminum target bias voltage, in preference to the traditional CrN coating. The present work is based on the investigation of physical and mechanical properties of CrAlN coating deposited on a silicon substrate and the effect of the aluminum proportion on their variation. The results demonstrate that variation in aluminum proportion alters the resulting columnar morphology, porosity and the thermal properties. The correlation between aluminum proportions in CrAlN coatings and his thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by decrease of the stitch parameter dimension. http://hdl.handle.net/10985/8016 Correlation between thermal properties and aluminum fractions in CrAlN layers deposited by PVD technique TLILI, Brahim; MUSTAPHA, Nasri; BENLATRECHE, Yacine; GUILLEMOT, Gildas; LAMBERTIN, Michel; NOUVEAU, Corinne The CrAlN coatings are a good alternative to conventional CrN coatings especially for high temperature oxidation-resistance applications. Different CrAlN coatings were deposited on silicon (100) by PVD (Physical vapor deposition) technique from two targets (chromium and aluminum) in a reactive nitrogen atmosphere at aluminum applied negative voltage ( 300, 500, 700 and 900 V). The composition, structural, mechanical and thermal properties of the as-deposited coatings were systematically characterized by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, and the ‘‘Mirage effect’’ experiments. The X-ray diffraction (XRD) data show that in general CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1) and (2 0 0) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing aluminum proportion the coatings became more compact and denser and their increased correspondingly, showing a maximum hardness of about 36 GPa (30 at% of Al) which is higher than that of CrN. Moreover, the results in this work demonstrate that the variation of aluminum fraction alter the resulting columnar grain morphology and porosity of the coatings. However, the thermal properties are greatly affected by these morphological alterations. The correlation between aluminum fraction in CrAlN coatings and its thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by a decrease of the stitch parameter dimension. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/8016 2010-01-01T00:00:00Z TLILI, Brahim MUSTAPHA, Nasri BENLATRECHE, Yacine GUILLEMOT, Gildas LAMBERTIN, Michel NOUVEAU, Corinne The CrAlN coatings are a good alternative to conventional CrN coatings especially for high temperature oxidation-resistance applications. Different CrAlN coatings were deposited on silicon (100) by PVD (Physical vapor deposition) technique from two targets (chromium and aluminum) in a reactive nitrogen atmosphere at aluminum applied negative voltage ( 300, 500, 700 and 900 V). The composition, structural, mechanical and thermal properties of the as-deposited coatings were systematically characterized by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, and the ‘‘Mirage effect’’ experiments. The X-ray diffraction (XRD) data show that in general CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1) and (2 0 0) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing aluminum proportion the coatings became more compact and denser and their increased correspondingly, showing a maximum hardness of about 36 GPa (30 at% of Al) which is higher than that of CrN. Moreover, the results in this work demonstrate that the variation of aluminum fraction alter the resulting columnar grain morphology and porosity of the coatings. However, the thermal properties are greatly affected by these morphological alterations. The correlation between aluminum fraction in CrAlN coatings and its thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by a decrease of the stitch parameter dimension. http://hdl.handle.net/10985/7491 Effect of duplex treatments by plasma nitriding and triode sputtering on corrosion behaviour of 32CDV13 low alloy steel CHALA, Abdelouahad; DJOUADI, Mohamed Abdou; STEYER, Philippe; MILLET, Jean-Pierre; SAIED, Chahinez; AIDA, Mohammed Salah; LAMBERTIN, Michel; NOUVEAU, Corinne This paper presents corrosion behaviour of duplex treated low alloy steel. Different kinds of samples were tested: non-treated, plasma nitrided, ZrBN-triode sputtered and ZrBN-duplex treated samples. The corrosion behaviour was evaluated by electrochemical techniques (corrosion potential and polarisation resistance evolutions versus immersion time, potentiodynamic curves). The corrosion tests were carried out in neutral aqueous saline solution (NaCl 30 g L−1), naturally aerated. The composition and the structure of layers were determined by EDS and XRD, respectively, while the morphology was observed by SEM. Experimental results showed that the corrosion current density Icorr increased with decreasing white layer thickness in plasma nitrided specimens. The nitrides ε-Fe2 − 3N and γ′-Fe4N present in the white layer are nobler than the substrate but may promote, by galvanic effect, a localised corrosion through open porosity. The duplex treated specimens (nitriding+ZrBN coating) present better corrosion protection and enable to overcome the drawbacks of both techniques, mainly the porosity of the deposited films. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/10985/7491 2006-01-01T00:00:00Z CHALA, Abdelouahad DJOUADI, Mohamed Abdou STEYER, Philippe MILLET, Jean-Pierre SAIED, Chahinez AIDA, Mohammed Salah LAMBERTIN, Michel NOUVEAU, Corinne This paper presents corrosion behaviour of duplex treated low alloy steel. Different kinds of samples were tested: non-treated, plasma nitrided, ZrBN-triode sputtered and ZrBN-duplex treated samples. The corrosion behaviour was evaluated by electrochemical techniques (corrosion potential and polarisation resistance evolutions versus immersion time, potentiodynamic curves). The corrosion tests were carried out in neutral aqueous saline solution (NaCl 30 g L−1), naturally aerated. The composition and the structure of layers were determined by EDS and XRD, respectively, while the morphology was observed by SEM. Experimental results showed that the corrosion current density Icorr increased with decreasing white layer thickness in plasma nitrided specimens. The nitrides ε-Fe2 − 3N and γ′-Fe4N present in the white layer are nobler than the substrate but may promote, by galvanic effect, a localised corrosion through open porosity. The duplex treated specimens (nitriding+ZrBN coating) present better corrosion protection and enable to overcome the drawbacks of both techniques, mainly the porosity of the deposited films.