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Unité Matériaux et Transformations
CNRS UMR 8207 - Université de Lille

Les séminaires de l'UMET

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Séminaire UMET
Vendredi 6 Avril 2018 10:00 - ENSCL, amphi Petit
Intervenant DGSI
  La protection des informations scientifiques stratégiques
Séminaire UMET
Mecredi 4 Avril 2018 14:00 - salle 202
Prof. Dr. K. Vanmeensel
Department of Materials Engineering, University of Leuven (KU Leuven), Leuven 3000, Belgium
  Fabrication additive de multi matériaux (superalliage, nanocomposites à matrice métallique, aciers HEA et amorphe). II: Selective laser melting of Nickel based superalloys
The current talk will overview the state-of-the-art on SLM of nickel based superalloys. Both alloy design, microstructural evolution, room temperature as well as high temperature mechanical properties will be discussed.
Special emphasis will go to the role of each of the alloying elements within nickel based superalloys. Their influence on the rapid solidification behavior as well as the mechanical properties of parts will be discussed.
Within the framework of rapid solidification processes, the specific interaction between a superalloy based powder and a laser beam will be discussed. Relevant aspects such as melt pool behavior, build rate and internal stress-build up will be discussed.
The major challenges and future prospects related to rapid solidification of nickel based superalloys will be discussed and a comparison will be made with nickel based superalloys processed by more conventional manufacturing methods.
Séminaire UMET
Mecredi 4 Avril 2018 14:00 - salle 202
Dr. Xiaopeng LI
School of Mechanical and Manufacturing Engineering, Faculty of Engineering, The University of New South Wales, Sydney NSW 2052 Australia
  Fabrication additive de multi matériaux (superalliage, nanocomposites à matrice métallique, aciers HEA et amorphe). I: Composite materials and multi-component alloys for additive manufacturing
This talk will focus on one of key research areas in additive manufacturing, i.e., the materials development for additive manufacturing. In detail, two parts will be covered as below: (1) An in-situ nano-TiB2 decorated AlSi10Mg composite (NTD-Al) powder was fabricated by gas-atomisation for selective laser melting (SLM). Fully dense and crack-free NTD-Al samples were produced using SLM. In contrast to the NTD-Al powder without cell-like microstructure, the SLMed NTD-Al had a textureless microstructure, consisting of fine grains and cells, with well dispersed nano-TiB2 particles inside the grains and rod-like nano-Si precipitates inside the cells. Both nano-TiB2 particles and nano-Si precipitates exhibited a highly coherent interface with the Al matrix, indicative of a strong interfacial bonding. The formation of this microstructure was attributed to the sequential solidification of non-equilibrium and eutectic Al-Si upon rapid cooling during SLM. As a result, the SLMed NTD-Al showed a very high ultimate tensile strength app. 530 MPa, excellent ductility app. 15.5% and high microhardness app. 191 HV0.3, which were higher than most conventionally fabricated wrought and tempered Al alloys, previously SLMed Al-Si alloys and nano-grained 7075 Al. The underlying mechanisms for this strength and ductility enhancement were discussed and a correlation between this novel microstructure and the superior mechanical properties was established. This study provides new and deep insights into the fabrication of metal matrix nanocomposites by SLM from in-situ pre-decorated composite powder. (2) Bulk metallic glasses (BMGs) and high entropy alloys (HEAs) are both important multi-component alloys with novel microstructures and unique properties, which make them promising for applications in many industries. However, certain hindrances have been identified in the fabrication of BMGs and HEAs by conventional techniques due to the intrinsic requirements of BMGs and HEAs. With the advent of metal additive manufacturing, new opportunities have been perceived to fabricate geometrically complex BMGs and HEAs with tailorable microstructure theoretically at any site within the specimen, which are not achievable using conventional fabrication techniques. After providing some background and introducing the conventional fabrication techniques for BMGs and HEAs, this talk will focus on the current status, development, and challenges in metal additive manufacturing of BMGs and HEAs including different additive manufacturing techniques being used, microstructure design and evolution, as well as properties of the fabricated BMGs and HEAs. A future outlook of metal additive manufacturing of BMGs and HEAs will also be provided at the end.
Séminaire UMET
Mecredi 21 Mars 2018 14:00 - C6 - 202
Cosmin Mihai Cotrut
University Politehnica of Bucharest, Roumanie
  Surface engineering - prosthetic dentistry approach

The clinical success of the dental restorations depends on the bonding between NiCr or CoCr alloys and the ceramic layer. In clinical practice, numerous metal-ceramic dental restorations fail due to the ceramic fracture, leading to an earlier removal of the restoration. The aim of this work is to improve the bond strength between metal and dental ceramics in prosthetic restorations by addition of TiSiON coatings as interlayers between these two.

The coatings were deposited on two dental alloys (NiCr and CoCr) using the cathodic arc technique by varying bias voltage values from -100 V to -200 V. The elemental composition, crystalline structure, mechanical properties, surface roughness and corrosion resistance of the coatings were investigated. The bond strength of the metal–ceramic system, with and without TiSiON interlayers, was evaluated by using a three-point bending test.

The coatings prepared at -100 V and -150 V exhibited the maximum hardness (32 GPa). All of the coatings had a superior corrosion resistance in artificial saliva (pH = 5.2) than both uncoated alloys, independent on the deposition parameters. The best corrosion performance was found for coatings prepared at -100 V and -150 V. The bending test showed that the addition of a TiSiON layer between CoCr or NiCr alloy and ceramic, enhance the adherence of the ceramic on both alloys. By increasing bias voltage, the bond strength increased.

Lundi 12 Mars 2018 14:00 - Polytech'Lille
  Assemblée générale du laboratoire
Séminaire UMET
Lundi 26 Février 2018 10:00 - Bât C6 - Salle 202
Claire Negrell
Institut Charles Gerhardt, Montpellier
  Développement de nouveaux synthons phosphorylés
Vendredi 23 Février 2018 9:00
  Tout ce que vous avez voulu savoir sur .... la microscopie
Séminaire UMET
Jeudi 22 Février 2018 9:00 - Amphitheatre Francis Petit, Batiment C7 ENSCL
Nittaya HANSUPO soutient sa thèse
  Fundamental aspects of intumescent systems for fire protection of steel structures
Séminaire UMET
Vendredi 16 Février 2018 13:30 - Bât C6 - Salle 202
Alberto Vitale
IMPMC - Sorbonne Université
  Serpentinisation et méthanogenèse abiotique dans les zones de subduction
Séminaire équipe
Jeudi 15 Février 2018 14:00 - salle 202 bâtiment C6
Antoine Ruffini
  Couplage plasticité / microstructures - Délaminage de couches minces métalliques & Annihilation des pores dans les superalliages à base nickel
Séminaire UMET
Jeudi 8 Février 2018 11:00 - Amphi Loison, ENSCL
Ludwik Leibler
Laboratoire Matière Molle et Chimie, ESPCI, Paris
  Vitrimères, une nouvelle classe de matériaux organiques
Séminaire UMET
Mardi 6 Février 2018 10:45 - C6, salle 202
Christophe Chassenieux
Université du Maine (Le Mans)
  Hydrogels formés par auto-assemblage de polymères amphiphiles en peigne cationiques : une histoire de peignes et de cheveux.
Séminaire UMET
Mardi 6 Février 2018 9:30 - C6, salle 202
Christophe Chassenieux
Université du Maine (Le Mans)
  La diffusion dynamique de la lumière
Séminaire UMET
Jeudi 18 Janvier 2018 11:00 - Salle du conseil du département de physique
Kajetan Koperwas
Institute of Physics, University of Silesia
  The Attractive Intermolecular Forces and The Crystallization of the Van Der Waals Liquids
Séminaire UMET
Jeudi 18 Janvier 2018 10:00 - Salle du conseil du département de physique - BAT P5
Karolina Adrjanowicz
Institute of Physics, University of Silesia
  Changing Crystallization Tendency of Glass-Forming Liquids - Increased Pressure, Geometrical Nano-confinement, High-Electric Field
Séminaire UMET
Mecredi 17 Janvier 2018 14:00 - Salle du conseil du département de physique - BAT P5
Marian Paluch
Institute of Physics, University of Silesia
  Structural Dynamics of Pharmaceuticals in the Glassy State
Vendredi 12 Janvier 2018 9:00 - Amphi Migeon, Polytech
  Journée des doctorants
UMET - Unité Matériaux et Transformations
Université de Lille
Bâtiment C6
59655 Villeneuve d'Ascq
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