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32 results on '"Christine BOHER"'

1. On the tribological behavior of cobalt-based nanocomposite coatings containing ZnO@Graphene oxide core-shell nanoparticles

Author

Manuelle Romero, Valdicleide Mello, Christine Boher, André P. Tschiptschin, Cherlio Scandian, Federal University of Espírito Santo, Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Polytechnic School of the University of São Paulo (Brazil), and Universidade de São Paulo = University of São Paulo (USP)

Subjects
Core-shell, [SPI]Engineering Sciences [physics], Mechanics of Materials, Cathode plasma electrolysis deposition, Cobalt coatings, Materials Chemistry, Surfaces and Interfaces, Condensed Matter Physics, Sliding wear, Surfaces, Coatings and Films
Abstract

Issu de : 24th International Conference on Wear of Materials, 16-20 avril 2023, Banff, Alberta, Canada; International audience; A hybrid nanocrystalline cobalt-based coating was prepared by cathode plasma electrolytic deposition (CPED). Zinc oxide and graphene oxide (GO) nanoparticles were mixed to form a core-shell structure through electrostatic self-assembly by using (3-aminopropyl)triethoxysilane (APTES) modifier. ZnO@GO nanoparticles were used as additives to improve wear and friction properties of deposited coatings. The concentration effect of core-shell ZnO@GO addition (0.1, 0.2 and 0.3 %wt) on the friction, wear, coating thickness and mechanical properties was investigated. The composition and microstructure of deposited coatings were studied by scanning electron microscope (SEM), X-ray diffraction (XRD), Raman spectroscopy and energy dispersive spectroscopy (EDS). Reciprocating sliding wear tests using a ball-on-plate configuration were carried out on a PLINT TE67 tribometer. AISI 52100 steel was used as ball and the coating deposited onto a AISI 304 stainless steel substrate was used as plate. Coatings were dense, nanocrystalline and uniform with a FCC metastable cobalt structure. Core-shell concentration above to 0.2 %wt resulted in a decrease of grain size and an increase of hardness and wear resistances. Nanoparticles act as nucleation sites for grain formation, decreasing grain sizes. Samples using 0.3% ZnO@GO displayed the lowest wear and friction coefficients. ZnO@GO nanoparticles enables the formation of a protective layer consisting of oxide and exfoliated GO on the top of worn surfaces.

Published
2023
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2. Investigations on the material flow and the role of the resulting hooks on the mechanical behaviour of dissimilar friction stir welded Al2024-T3 to Ti-6Al-4V overlap joints

Author

Thomas Pottier, Morgane Geyer, Vanessa Vidal, Christine Boher, Farhad Rezai-Aria, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
0209 industrial biotechnology, Digital image correlation, Materials science, fracture behaviour, 02 engineering and technology, Welding, Industrial and Manufacturing Engineering, Friction stir lap welding, law.invention, Stress (mechanics), [SPI]Engineering Sciences [physics], 020901 industrial engineering & automation, 0203 mechanical engineering, law, digital image correlation, Composite material, Stress concentration, Material flow, Metals and Alloys, Rotational speed, hook, Computer Science Applications, 020303 mechanical engineering & transports, Lap joint, Modeling and Simulation, Ceramics and Composites, Fracture (geology), X-ray tomography
Abstract

International audience; During friction stir lap joint welding, hooks are systematically formed at the interface of dissimilar Al2024/Ti-6Al-4V plates. Various hooks dimensions and shapes are observed according to the welding parameters (welding speed, rotational speed and double-pass). Based on digital image correlation (DIC) during tensile shear tests, it is found that hooks features govern the fracture behaviours and, hence, the mechanical properties of the overall welds. In particular, three fracture behaviours are obtained: at the interface, in the Al2024 and across the Ti-6Al-4V plate, which was never reported in dissimilar Al/Ti studies. The aim of this work is (i) to study the influence of FSW parameters on the mechanisms of hooks formation and (ii) to understand the role of both AS and RS hooks on the mechanical behaviour of the welds, by the means of two new approaches. First, hooks are investigated by X-ray tomography which provided some innovative insight into the material flow (3D viewing). Based on these qualitative and quantitative results, hooks are used as tracers and two new scenarios of AS and RS generation are proposed. Then, the contribution of both hooks on the stress distribution is clearly revealed by some calculations of the stresses reached around AS and RS hooks. Contrary to RS hook, AS hook is sharp and, hence, the stress reached at the top of AS hook is characterized by a stress concentration. The results showed that the fracture behaviours are greatly influenced by hooks size and the formation of microstructural defects inside the Ti-6Al-4V, which depend on the welding parameters. In conclusions, this work revealed the relationship between the achievable parameters, the resulting hooks dimensions and the fracture behaviours. In addition, based on the understanding of the material flow, some ways of optimization of the mechanical properties are proposed.

Published
2021
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3. Shear mode M3 in the first sites of ductile metallic alloys: Some considerations on the physical mechanisms leading to internal particle flows

Author

Yves Berthier, E. Cabrol, Vanessa Vidal, Farhad Rezai-Aria, Christine Boher, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Ecole Nationale d'Ingénieurs de Saint Etienne, Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Ecole Nationale d'Ingénieurs de Saint Etienne (ENISE), Laboratoire de Tribologie et Dynamique des Systèmes (LTDS), École Centrale de Lyon (ECL), and Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne (ENISE)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Friction, Alloy, Ductile alloys, 02 engineering and technology, Plasticity, engineering.material, Shear Mode M3, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, Stacking-fault energy, Materials Chemistry, Shear stress, Composite material, Surfaces and Interfaces, Mechanisms of plasticity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Third‐Body, Surfaces, Coatings and Films, 020303 mechanical engineering & transports, Mechanics of Materials, engineering, Hardening (metallurgy), Partial dislocations, Dislocation, 0210 nano-technology, Contact area
Abstract

WOM 2019 - 22nd International Conference on Wear of Materials, 14-18 April 2019, Hyatt Regency Miami, Miami, FL, USA; International audience; This paper examines plastic mechanisms that lead to damage to the sub-surfaces of ductile metallic contact areas and, by extension, to the creation of wear particles. The word “damage” is used here as a generic term to designate all topological, morphological and/or microstructural modifications to the surfaces that are the consequence of interfacial shear stress under friction. During friction, the accommodation mechanisms of plastic deformation by the M3 mode in the contact area can be different, depending on the microstructures of the alloy and the first sites (bulk materials).For example, for tempered martensitic steels under frictional stresses, plasticity strain occurs in Tribologically Transformed Surfaces (TTS) under dislocation gliding. The creation of new dislocations and the rearrangement of all these dislocations into a “bamboo”-type structure leads to a decrease in hardness, or softening of the steel.Otherwise, depending on the stacking fault energy in alloy microstructures, plasticity may occur through mechanisms involving either perfect dislocation gliding and/or partial dislocation gliding. In addition to hardening, the mobility and morphology of dislocations are also related to stacking fault energy, which can promote phase transformation leading to shear strain in TTS. These shear strain mechanisms have a great influence on the internal flow of wear particles and on the formation of the “Third-body layers”. These findings are given in a review of tribological results of measurements carried out on a wrought X38CrMoV5 grade steel and on cobalt-base thick coatings, using tribometers, under various loadings, test temperatures and sliding speeds. The cobalt-base thick coatings are deposited on steel by several processes which modify the nominal chemical composition of the cobalt alloy and make it possible to study the influence of the iron content on shear strain under friction stresses.

Published
2019
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4. A correlation between tribological behavior and crystal structure of cobalt-based hardfacings

Author

F. Touratier, E. Cabrol, Vanessa Vidal, Farhad Rezai-Aria, Christine Boher, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Aubert & Duval, Laboratoire de Tribologie et Dynamique des Systèmes (LTDS), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne (ENISE)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Materials science, chemistry.chemical_element, Hardfacing, 02 engineering and technology, Surfaces and Interfaces, Plasticity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, [SPI]Engineering Sciences [physics], 020303 mechanical engineering & transports, 0203 mechanical engineering, chemistry, Mechanics of Materials, Stacking-fault energy, Stellite, Materials Chemistry, Partial dislocations, Composite material, 0210 nano-technology, Cobalt, Tribometer, Electron backscatter diffraction
Abstract

WOM 2019 - 22nd International Conference on Wear of Materials, 14-18 April 2019, Hyatt Regency Miami, Miami, FL, USA; International audience; This paper deals with the influence of the mechanisms of plasticity on the evolution of the friction coefficient in cobalt-based hardfacings. Particularly depending on the alloying element content and so on the stacking fault energy, plasticity in Co-based alloys may occur through mechanisms involving either perfect dislocations gliding and/or partial dislocation gliding. As the coalescence of stacking faults by partial dislocations promotes the phase transformation of the Co, this study focus on the impact of this phase transformation on the evolution of the friction coefficient.Stellite 21 (Co-27Cr-5Mo-0.25C) hardfacings deposited on a steel substrate by two different processes, namely metal inert gas (MIG) and laser, are studied. The tribological properties are evaluated with a ring on disc tribometer under high load (800 daN) and continuous sliding (5 mm/s) at room and high temperatures (450 °C and 600 °C). The wear volume is characterized by confocal microscope. From micro-hardness measurements and SEM observations the work-hardening and the plastic strain of the Tribological Transformations of Surfaces are identified in relationship with chemical analysis (by EDS). Moreover X-rays diffraction and EBSD reveal the crystal structure evolution.As-deposited Co-based hardfacings have a face-centered cubic (FCC) structure. Meanwhile depending on the process of deposition on the steel substrate, the nominal composition of the Stellite 21 can be modified due to dilution effect. So, the iron content is found to be higher in the MIG hardfacing than in the laser one, leading to different mechanisms of plasticity, respectively by perfect dislocations gliding and by phase transformation (FCC to hexagonal closed-packed (HCP)). Moreover, a significant influence of the phase transformation on the friction coefficient has been evidenced: without phase transformation the cobalt remains in the FCC structure and the friction coefficient is stable during the test, while a decrease of its value occurs during the FCC to HCP phase transformation.

Published
2019
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5. Plastic strain of cobalt-based hardfacings under friction loading

Author

Franck Touratier, Christine Boher, Vanessa Vidal, Farhad Rezai-Aria, E. Cabrol, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
business.product_category, Materials science, Hardfacing, chemistry.chemical_element, 02 engineering and technology, Work hardening, Forging, Strain-induced phase transformation, Cobalt-based alloy, [SPI]Engineering Sciences [physics], Work-hardening, 0203 mechanical engineering, Materials Chemistry, High load tribological test, Plastic strain, Metallurgy, Surfaces and Interfaces, Tribology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, 020303 mechanical engineering & transports, chemistry, Mechanics of Materials, Stellite, Die (manufacturing), 0210 nano-technology, business, Cobalt, Tribometer
Abstract

20th International Wear of Materials Conference (WOM), Toronto, CANADA, APR 12-16, 2015; International audience; Aeronautic forging dies are subjected to very high loads and temperatures for a long contact time between the pre-heated parts and dies. Cobalt-based hardfacings are commonly deposited on dies and their main wear mechanism is large plastic deformation of the die radii. This paper deals with the wear damage mechanisms of three different cobalt-based hardfacings: Stellite 21 deposited by a MIG process, Stellite 21 and Stellite 6 deposited by a LASER process. The tribological tests are carried out on a high load Ring on Disc tribometer at room temperature. The postmortem investigations are undertaken by SEM observations, micro-hardness measurements as well as by X-ray diffraction analyses. Results show that the increase of the hardness, in order to improve the wear behaviour, can be achieved by a higher carbon content and by a lesser iron dilution that depends on the deposition process. A very important work-hardening, up to 90%, is also observed under sliding conditions and a relationship is established between the increase of the micro-hardness and the plastic strain level. Two different plastic strain mechanisms are observed. For high (MIG) or low (LASER) iron dilution levels, the plastic strain causes respectively a reorientation of grains or a FCC to HCP phase transformation; the latter being associated with a lower friction coefficient.

Published
2015
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6. Investigation and FEA-based simulation of tool wear geometry and metal oxide effect on cutting process variables

Author

Tchadja Kagnaya, Thierry Cutard, Laurence Lambert, Christine Boher, Myriam Lazard, Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers

Subjects
Materials science, Carbon steel, Oxide, Geometry, 02 engineering and technology, engineering.material, Flank wear, chemistry.chemical_compound, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, Machining, Tool wear, Oxidized adhesion layer (Fe2O3/Fe3O4/FeO), Cutting tool, Chip formation, Finite element analysis (FEA), Metallurgy, 021001 nanoscience & nanotechnology, Finite element method, 020303 mechanical engineering & transports, chemistry, Crater wear, 13. Climate action, Hardware and Architecture, Modeling and Simulation, Heat transfer, engineering, 0210 nano-technology, Software
Abstract

In machining, it is clearly noticed that the cutting tool wear influences the cutting process. However, it is difficult with experimental methods to study the effects of tool wear on several machining variables. Thus, in the literature, some earlier studies are performed separately on the effect of tool flank wear and crater wear on cutting process variables (such as cutting forces and temperature). Furthermore when the workpiece material adheres in cutting tool, it affects considerably the heat transfer phenomena. Accordingly, in this work the finite element analysis (FEA) is performed to investigate the influence of combination of tool flank and crater wear on the local or global variables such as cutting forces, tool temperature, chip formation on the one hand and the effects of the oxidized adhesion layer considered as oxide (Fe 2 O 3 /Fe 3 O 4 /FeO) on the heat transfer in cutting insert on the other hand. In this investigation, an uncoated cutting insert WC–6Co and medium carbon steel grade AISI 1045 are used. The factorial experimental design technique with three parameters (cutting speed Vc, flank wear land VB, crater wear depth KT) is used for the first investigation without adhesion layer. Then, only linear investigation is performed. The analysis has shown the influence of the different configurations of the tool wear geometry on the local or global cutting process variables, mainly on temperature and cutting. The simulation’s results show also, the highly influence of the oxidized adhesion layer (oxide Fe 2 O 3 /Fe 3 O 4 /FeO) on the heat transfer.

Published
2014
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7. A wear damage assessment of high temperature forging tool

Author

Vanessa Vidal, E. Cabrol, F. Touratier, Farhad Rezai-Aria, Christine Boher, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)

Subjects
plastic deformation, Materials science, Hardfacing, 02 engineering and technology, Welding, Forging, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, Stacking-fault energy, law, Shear stress, MIG welding process, [PHYS]Physics [physics], Stellite 21, Metallurgy, General Engineering, [PHYS.MECA]Physics [physics]/Mechanics [physics], Tribology, 021001 nanoscience & nanotechnology, 020303 mechanical engineering & transports, Stellite, tribological test, 0210 nano-technology, Hardfaced hot forging die, texture, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [STAT.ME]Statistics [stat]/Methodology [stat.ME], Tribometer
Abstract

Issu de : ICTMP 2014 - 6th International Conference on Tribology in Manufacturing Processes & joining by plastic deformation, Darmstadt, GERMANY, June 22-24, 2014; International audience; High temperature forging tools are highly damaged by wear shearing under cyclic loading which reduces the life of tools. In real conditions, depending upon the tool areas, the level of wear can change. The surfaces of tools can be treated by cobalt-based hardfacing using different welding processes. This study focuses on tribological damages of Stellite 21 deposited by MIG process. Wear tests are carried out at room and high temperature on a ring on disc tribometer under high normal load. Different testing conditions are examined. The surface plastic strain due to the friction shear stresses is demonstrated by different methods like SEM observations, micro-hardness measurements and XRD analyses. More particularly, it is shown that the initial (200) crystallographic preferred orientation due to the welding process is modified into (111) crystallographic preferred orientation due to shear stresses regardless the loading. Moreover, a relationship between the gradient of the plastic shear strain at the friction subsurface and the level of the micro-hardness measurement has been established. In regard of the results, when the shear strain exceeds a threshold, the micro-hardness measurement is stabilised. The ultimate value could be induced by the stacking fault energy that is considered as weak in Stellites.

Published
2014
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8. Microstructural analysis of wear micromechanisms of WC-6Co cutting tools during high speed dry machining

Author

Laurence Lambert, Thierry Cutard, Myriam Lazard, Tchadja Kagnaya, Christine Boher, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Built up edge, Materials science, Turning, Scanning electron microscope, Metallurgy, Energy-dispersive X-ray spectroscopy, Temperature, Microstructure, Abrasion (geology), Carbide, [SPI]Engineering Sciences [physics], Wavelength-dispersive X-ray spectroscopy, Machining, Tool-chip contact, WC-6Co, Composite material, Wear mechanism
Abstract

SCIE Article le 06/02/14; International audience; This original study investigates the damages of WC-6Co uncoated carbide tools during dry turning of AISI 1045 steel at mean and high speeds. The different wear micromechanisms are explained on the basis of different microstructural observations and analyses made by different techniques: (i) optical microscopy (OM) at macro-scale, (ii) scanning electron microscopy (SEM), with back-scattered electron imaging (BSE) at micro-scale, (iii) energy dispersive spectroscopy (EDS), X ray mapping with wavelength dispersive spectroscopy (WDS) for the chemical analyses and (iv) temperature evolution during machining. We noted that at conventional cutting speed Vc ≤ 250 m/min, normal cutting tool wear types (adhesion, abrasion and built up edge) are clearly observed. However, for cutting speed Vc > 250 m/min a severe wear is observed because the behavior of the WC-6Co grade completely changes due to a severe thermomechanical loading. Through all SEM micrographs, it is observed that this severe wear consists of several steps as: excessive deformation of WC-6Co bulk material and binder phase (Co), deformation and intragranular microcracking of WC, WC grain fragmentation and production of WC fragments in the tool/chip contact. Thus, the WC fragments accumulated at the tool/chip interface cause abrasion phenomena and pullout WC from tool surface. WC fragments contribute also to the microcutting and microploughing of chips, which lead to form a transferred layer at the tool rake face. Finally, based on the observations of the different wear micromechanisms, a scenario of WC-6Co damages is proposed through to a phenomenological model

Published
2014
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9. Modèle phénoménologique de circulation des particules d'usure dans un contact à haute température

Author

Pauline Lepesant, Christine BOHER, Yves Berthier, Farhad Rezai-Aria, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Tribologie et Mécanique des Interfaces (TMI), Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2011

10. Damage mechanisms of HSM work roll grades for roughing stands -Tribological approach

Author

Catherine Vergne, Olivier Joos, Claude Gaspard, José Tinoco, Mohammed Moujib, Christine BOHER, Farhad Rezai-Aria, Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

11. Endommagement du WC-Co en usinage

Author

Tchadja Kagnaya, Laurence Lambert, Christine Boher, CUTARD Thierry, Myriam Lazard, Laurent Velnom, Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2010

12. Effect of molybdenum and chromium contents in sliding wear of high‐chromium white cast iron: The relationship between microstructure and wear

Author

J.D.B. de Mello, Cherlio Scandian, Farhad Rezai-Aria, Christine Boher, Federal University of Espírito Santo, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Federal University of Uberlândia [Uberlândia] (UFU), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
High‐chromium cast iron, Materials science, Friction, Alloy, chemistry.chemical_element, 02 engineering and technology, engineering.material, Carbide, Chromium, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, Wear, Materials Chemistry, Austenite, Metallurgy, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Surfaces, Coatings and Films, 020303 mechanical engineering & transports, chemistry, Mechanics of Materials, Molybdenum, engineering, Molybdenum content, Cast iron, 0210 nano-technology, Tribometer
Abstract

17th International Conference on Wear of Materials, Las Vegas, NV, APR 19‐23, 2009Extrait de : WOM 09 / sous la dir. de K.C. LUDEMA et S.J. SHAFFER; International audience; High‐chromium white cast irons are commonly used in applications requiring excellent abrasion resistance, as in the mining and mineral ore processing industry. Their excellent abrasion resistance is mainly due to their solidification microstructures. During their solidification, high levels of chromium (16‐32%) lead to the formation of a high‐volume fraction of eutectic M(7)C(3)‐carbides, which may or may not be associated with primary carbides in a heterogeneous austenitic/martensitic dendritic structure. Generally, in common white high‐chromium cast iron, the molybdenum content is less than 3 wt.% (by weight) so as to avoid a perlitic transformation. It is reported that by addition of molybdenum in quantities of more than 3 wt.%, new carbides (M(2)C, M(6)C) are formed which greatly increase the high‐temperature wear resistance. In this paper, 15 high‐chromium white cast alloys containing different chromium contents (16 wt.%Cr to 32 wt.%Cr) and molybdenum (Mo free to 9 wt.%Mo) are examined. For each alloy, the chemical composition and volume fraction of carbides and matrix have previously been determined. The matrix microstructure and the type of carbides depend on the relative contents of molybdenum and chromium. The wear experiments are carried out on a pin‐on‐disc tribometer at room temperature. The pin is made of cast iron. The wear mechanisms are observed by scanning electron microscopy (SEM). It is observed that the pin height loss, the evolution of friction versus time curves and the mean friction coefficient are largely dictated by the matrix microstructure. The carbides volume fraction and the macroscopic hardness both play only a minor role. The pin height loss is significant for a single‐phased matrix and the mean friction coefficient is high. When the matrix is multiphased, the pin height loss tends towards zero and the coefficient of friction is lower. Detailed SEM observations and analysis of the evolution of the friction versus time curves indicate the substantial contribution of the large carbides in friction contact.

Published
2009
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13. Wear mechanisms of WC-Co cutting tools from high-speed tribological tests

Author

Laurence Lambert, Christine Boher, Thierry Cutard, Tchadja Kagnaya, Myriam Lazard, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Materials science, 02 engineering and technology, Dry friction, Cemented carbide, Abrasion (geology), [SPI]Engineering Sciences [physics], 0203 mechanical engineering, Machining, Wear, Materials Chemistry, Forensic engineering, Surface roughness, Composite material, Tool wear, High sliding speed, Cutting tool, Temperature, Surfaces and Interfaces, Tribology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, 020303 mechanical engineering & transports, Mechanics of Materials, 0210 nano-technology, Tribometer
Abstract

17th International Conference on Wear of Materials, Las Vegas, NV, APR 19-23, 2009; International audience; In machining processes, surface roughness and dimensional accuracy of machined parts depend on tool wear. Cemented carbide based cutting tools remain widely used in machining processes for their wear resistance. The aim of this paper is to study wear mechanisms of a WC-Co cutting tool grade under tribological conditions. Dry friction experiments are carried out on a high-speed pin-on-disc tribometer considering WC-Co pins against steel discs made of an AISI 1045 grade. Furthermore, two type-K thermocouples are embedded in WC-Co pins in order to estimate the contact temperature during sliding tests. A large sliding speed range is considered: from 60 up to 600 m/min. Results deal with wear rate versus tribological conditions, evolution of friction coefficient and temperature versus sliding speed and evolution of wear mechanisms. WC-Co tribological pins exhibit different wear mechanisms: abrasion, adhesion, transgranular WC micro-cracking and WC/WC debonding. Circulation of debris in the friction contact depends on sliding speed and on test duration. The evolution of surface temperature versus friction coefficient is studied too. Furthermore, a particular attention is paid on the relationship between the thermal energy in the pin and the mechanical energy in the contact. The thermal energy is calculated from the temperature values of K-thermocouples and the mechanical energy dissipated in the pin is calculated from friction coefficient evolutions. Relationships are established through modelling approaches.

Published
2009
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14. An investigation of the crack propagation in tool steel X38CrMoV5 (AISI H11) in SET specimens

Author

Catherine Mabru, Masood Shah, Farhad Rezai-Aria, Christine Boher, S. Leroux, Ecole nationale supérieure des Mines d'Albi-Carmaux - IMT Mines Albi (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Département Génie Mécanique Ecole Nationale Supérieure d'Ingénieurs de Constructions Aéronautiques 1 Place Emile Blouin 31056 Toulouse Cedex 5, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Département de Mécanique des Structures et Matériaux (DMSM), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institut Clément Ader ( ICA ), Institut Supérieur de l'Aéronautique et de l'Espace ( ISAE-SUPAERO ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ) -IMT École nationale supérieure des Mines d'Albi-Carmaux ( IMT Mines Albi ), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi)

Subjects
0209 industrial biotechnology, Materials science, Plasticity, Matériaux, Surface damage, 0211 other engineering and technologies, 02 engineering and technology, engineering.material, Fatigue crack propagation, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], 020901 industrial engineering & automation, Finite element, Materials Chemistry, [ SPI ] Engineering Sciences [physics], Physical and Theoretical Chemistry, Stress intensity factor, Fatigue, 021102 mining & metallurgy, Tension (physics), business.industry, Crack propagation, Metals and Alloys, Hot work, Fracture mechanics, Structural engineering, Condensed Matter Physics, Finite element method, Hot work tools, Tool steel, engineering, Mécanique des matériaux, business
Abstract

International audience; An approach is proposed for the evaluation of surface fatigue damage of hot forming tools that undergo severe thermo mechanical loading. Fatigue crack propagation in a hot work tool steel X38CrMoV5‐47HRC is investigated using single‐edge cracked tension specimens with 3 different thicknesses (2.5, 1, 0.6 mm) and two R‐values. The stress intensity factor is evaluated with ABAQUS (R). Paris curves are established for the crack propagation experiments.

Published
2009
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15. Experimental investigation of friction and wear in hot stamping of Usibor 1500P

Author

Christine Dessain, Philipp Hein, Joël Wilsius, Luc Penazzi, Christine Boher, Jan Weikert, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2008

16. Contribution to the determination of the thermal contact resistance : algorithm of evaluation of the number of asperities involved in the contact

Author

Guy Léon Kaza, Christine Boher, Gilles Dour, Luc Penazzi, Tahar Loulou, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Institut Brestois du Numérique et des Mathématiques (IBNM), and Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2008

17. Wear mechanism of WC-Co cutting tool from turning experiments and high speed tribological tests

Author

Tchadja Kagnaya, Christine Boher, Laurence Lambert, Myriam Lazard, CUTARD Thierry, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Biochimie de l'Ecole polytechnique (BIOC), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2007

18. A wear model based on tribological transformations of surfaces

Author

Olivier Barrau, Christine BOHER, René Gras, Farhad Rezai-Aria, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2006

19. Évolution des propriétés tribocorrosives du 316L dans un milieu NaCl

Author

N. Celati, Pierre Ponthiaux, Christine Boher, J. Vial, G. Lederer, Centre Matériaux - Ecole des Mines Albi-Carmaux, IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], 020208 electrical & electronic engineering, 0202 electrical engineering, electronic engineering, information engineering, General Materials Science, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

International audience

Published
1997
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20. A study of polymer-mold contact during injection molding cycle

Author

Maelle Guichon, Christine Boher, Fabrice M. Schmidt, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and IMT Mines Albi, IMT Mines Albi

Subjects
[SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics]
Abstract

International audience; Injection molded parts often show several types of surface defects. Different authors mentioned that those defects are due to the interaction between the mold and the melt. This contact has a strong influence on the flow front behavior, and depends on processing parameters like melt and mould temperatures, ram speed during injection, mould surface properties and roughness, mould thickness and polymer melt rheological properties … After a literature review of "flow marks" defect, it appears that the "alternate flow marks" are caused by an instability of the Fountain flow front. An assumption proposed by some researchers is that the slip is the formation mechanism of this instability. We assume that this mechanism is the start of the flow front instability during the filling stage. We use numerical simulations performed with Forge2  commercial software, in order to generate non-symmetrical contact boundaries conditions. We introduce some sliding conditions at the wall during a flow between two parallel plates. Our preliminary computations confirm that the instability is created in this way.

Published
2005

21. Wear behaviour on the radius portion of a die in deep-drawing: Identification, localisation and evolution of the surface damage

Author

Luc Penazzi, Djelali Attaf, Christine Boher, Christophe Levaillant, Centre de Recherche Outillages, Matériaux et Procédés ( CROMeP ), IMT École nationale supérieure des Mines d'Albi-Carmaux ( IMT Mines Albi ), FAURECIA, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Surface (mathematics), business.product_category, Materials science, Mechanical engineering, 02 engineering and technology, Metal sheet, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, friction coefficient, Materials Chemistry, [ SPI ] Engineering Sciences [physics], Tool wear, Deep drawing, Composite material, Surfaces and Interfaces, Radius, Tribology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, simulation, Surfaces, Coatings and Films, deep-drawing, wear process-simulator, 020303 mechanical engineering & transports, Mechanics of Materials, Die (manufacturing), 0210 nano-technology, business, Intensity (heat transfer), wear mechanisms
Abstract

Issu de : WOM 05 - 15th International Conference on Wear of Materials; International audience; The tribology behaviour of the die radius, in the deep-drawing process, results from surface interactions between the metal sheet and the tool under contact pressure. Friction, degradation of the sheet, surface quality and tool wear are a result of this interaction. This article aims to study degradations of the radius portion of a die in the deep-drawing process. The study on an industrial press is complex, so we developed our own test facility, an experimental device, which represents a deep-drawing process-simulator. It allows friction between the metal sheet and a die radius. It can dissociate the diverse mechanical effects exerted on the die radius by enabling a study of the component conditions found in deep-drawing (effect of the blankholder, of the pulling forces, the sliding rate, etc.). An experimental study was conducted on a low-carbon steel sheet and a X160CrMoV12 steel die radius. It revealed that the die radius surface was degraded by ploughing and transfer mechanisms. The distribution of these degradations on the die radius was localised in two areas but varied in intensity depending on the exit angle between the sheet and the die radius. The die radius friction coefficient has been modelled with respect to the mechanical characteristics of the deep-drawing process-simulator. This model leads to a correlation between the friction coefficient and the degradation evolutions on the die radius.

Published
2005
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22. Microwave PACVD of low friction a-SiC coatings : from plasma characterization to material mechanical property

Author

Laurent Thomas, Francis Teyssandier, Michel Ducarroir, Christine BOHER, Laurent Autrique, Jean Marie Badie, René Berjoan, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2003

23. Contribution des oxydes dans le frottement en mise en forme à chaud : application au laminage à chaud

Author

Catherine Vergne, Christine BOHER, Christophe Levaillant, René Gras, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2001

24. Etude et analyse de la dégradation d'un bord de matrice d'outil en emboutissage

Author

Djelali Attaf, Luc Penazzi, Christine Boher, Pascal Lamesle, Christophe Levaillant, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2001

25. Tribology in metal forming at elevated temperatures: review

Author

Numpon Mahayotsanun, Christine Boher, Kuniaki Dohda, Farhad Rezai-Aria, Northwestern University [Evanston], Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Faculty of Engineering [Khon Kaen University], and Khon Kaen University [Thailand] (KKU)

Subjects
Materials science, Metal forming, oxidation, Mechanical Engineering, Metallurgy, Forming processes, tribometer, Stamping, engineering.material, Tribology, Surfaces, Coatings and Films, [SPI]Engineering Sciences [physics], Coating, elevated temperature, engineering, Lubrication, tribology, Experimental work, Tribometer, hot forming
Abstract

The tribo-characteristics of metal forming at high temperatures have not yet been well understood due to the complex nature of thermal, microstructural, interaction, and process parameters. This is a review paper on the effects of temperature, coating, and lubrication to the tribological characteristics in hot forming as well as the tribometers for different metal forming processes at elevated temperatures mainly based on the experimental work. The tribological behaviors of oxides in hot forming, such as rolling and stamping, were reviewed and presented. Some commonly used surface coatings and lubricants in hot forming were given. Many types of tribometer were selected and presented and some of them provided a great potential to characterize friction and wear at elevated temperatures. Nevertheless, more testing conditions should be further investigated by developing new tribometers. Eventually, experimental results obtained from reliable tribometers could be used in theory and model developments for different forming processes and materials at high temperatures. The review also showed the great potential in further investigations and innovation in tribology.

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26. Etude de la dégradation d'un bord de matrice d'outil en emboutissage : corrélation entre pression de contact et transfert de particules

Author

Djelali Attaf, Luc Penazzi, Christine Boher, Christophe Levaillant, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

27. Mechanical study of a sheet metal forming dies wear

Author

Djelali Attaf, Luc Penazzi, Christine BOHER, Christophe Levaillant, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

28. Etude des oxydes et analyse de leur comportement dans le frottement d'acier à outil de travail à chaud : application au laminage à chaud

Author

Catherine Vergne, Christine BOHER, René Gras, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

29. Surface damage comparison of forming tools in function of strip metal

Author

Christine Boher, Luc Penazzi, Pascal Lamesle, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

30. Full scale wear study of polymer injection moulding tool surface

Author

Pierre Devos, Christine BOHER, Raymond, J. J., Sabine Le Roux, Jean-Paul Arcens, Matthias Wesselmann, Centre Matériaux - Ecole des Mines Albi-Carmaux, IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

31. X-Ray analysis of a tribological contact between two materials involving in hot strip mill

Author

Vergne, C., Lamesle, P., Christine BOHER, Centre de Recherche Outillages, Matériaux et Procédés (CROMeP), IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

32. Etude des oxydes et analyse de leur comportement dans le frottement d'acier à outil de travail à chaud : synthèse bibliographique

Author

Catherine Vergne, Christine BOHER, Christophe Levaillant, René Gras, Centre Matériaux - Ecole des Mines Albi-Carmaux, IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
[SPI]Engineering Sciences [physics]
Abstract

Extrait de : Matériaux, usures et corrosion - 38èmes Journées du cercle d'études des métaux, Liège, BELGIQUE, 26-27 mai 1999; International audience

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