References of "Dormal, Thierry"
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See detailTi alloys processed by selective laser melting and by laser cladding: microstructures and mechanical properties
Mertens, Anne ULg; Contrepois, Quentin ULg; Dormal, Thierry ULg et al

in proceedings of 12th EUROPEAN CONFERENCE ON SPACECRAFT STRUCTURES, MATERIALS & ENVIRONMENTAL TESTING, Noordwijk 20-23 mars 2012 (2012, March)

Selective laser melting (SLM) and laser cladding were developed in the late 1990s as economic layer-by-layer near-net-shape processes allowing for the production – and also, in the case of laser cladding ... [more ▼]

Selective laser melting (SLM) and laser cladding were developed in the late 1990s as economic layer-by-layer near-net-shape processes allowing for the production – and also, in the case of laser cladding, the restoration - of complex parts. Both techniques involve the melting of a metallic powder with a laser. In the case of SLM, the metallic powder is deposited layer by layer and then molten locally according to the desired shape, whereas in laser cladding the metallic powder is projected onto a substrate through a tube coaxial with the laser. In both processes, the metallic melt pools then cool down and solidify very rapidly, thus producing strongly out of equilibrium microstructures that might exhibit high internal stresses. In the present work, efforts have been made to enhance the flexibility of the laser cladding process: a second laser with a maximum power of 300W was installed beside the original laser (with a higher maximum power of 2000W), thus allowing for the processing of parts with thinner walls and/or coatings. Moreover, flexibility was also improved in relation with the geometry of the parts by use of a 5-axes displacement control. Samples of alloy Ti-6Al-4V, that is widely used in the aeronautic industry due to its high specific strength, have been processed both by SLM and by laser cladding. The resulting microstructures have been characterised in details by optical microscopy, SEM and EBSD so as to allow for a better understanding of the solidification process and of the subsequent phase transformations taking place upon cooling for both techniques. The influence of processing parameters such as the orientation of the deposition of the successive powder layers on the mechanical properties was also investigated by means of uniaxial tensile testing performed on samples with different deposition orientations in regard to the direction of mechanical solicitation. Moreover, some of the samples for mechanical testing had undergone an annealing treatment at 640°C for 4 hours to relieve internal stresses, in order to assess more precisely the effect of those stresses on the tensile properties. [less ▲]

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See detailDensity and porosity control of sintered 316L stainless steel parts produced by additive manufacturing
Verlee, Bruno; Dormal, Thierry ULg; Lecomte-Beckers, Jacqueline ULg

in Powder Metallurgy (2012), 55(4), 260-267

Additive manufacturing (AM) techniques offer the possibility to build complex geometries with integrated functionalities. Three-dimensional (3D) printing of metallic powder is probably the only AM ... [more ▼]

Additive manufacturing (AM) techniques offer the possibility to build complex geometries with integrated functionalities. Three-dimensional (3D) printing of metallic powder is probably the only AM technique that can build controlled porosity sintered parts, such as filter elements and fluid permeable components. Many building and sintering parameters can be set to adjust porous properties of the final part. The effects of particle size, paricul shape, sintering temperature and sintering time on the final properties of the sinteres parts have been analysed. Correlations have been established between these properties and process parameters [less ▲]

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See detailMANUFACTURING OF POROUS PARTS IN 316L STAINLESS STEEL BY 3D-PRINTING: SOME INDUSTRIAL CASE STUDIES
Verlee, Bruno; Dormal, Thierry ULg; Lecomte-Beckers, Jacqueline ULg

in Proceedings of AEPR’11, 16th European Forum on Rapid Prototyping and Manufacturing (2011, June)

Additive technologies offer the possibilities to build complex geometries with integrated functionalities, specific to target application. 3D-printing of metallic powder is an additive technology ... [more ▼]

Additive technologies offer the possibilities to build complex geometries with integrated functionalities, specific to target application. 3D-printing of metallic powder is an additive technology proceeding in 2 steps: a green part is first built layer by layer by printing a liquid binder on the powder bed, and then green part is debinded and sintered. As sintering occurs separately of shaping process, 3D-printing is one of the only additive techniques able to produce porous parts, as filters or other fluid permeable components. Different porous characteristics can be obtained by playing on process parameters (AEPR2010). Several industrial case studies are presented and detailed here with their specifications and characteristics that have been obtained. [less ▲]

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See detailLes matériaux intelligents: pièces à porosité contrôlée en acier inoxydable fabriquées par rapidprototyping
Verlee, Bruno; Dormal, Thierry ULg; Lecomte-Beckers, Jacqueline ULg

Scientific conference (2011, May 24)

Les techniques additives offrent la possibilité de fabriquer des géométries complexes avec des fonctionnalités intégrées spécifiques à l’application visée. L’impression 3D de poudre métallique est une ... [more ▼]

Les techniques additives offrent la possibilité de fabriquer des géométries complexes avec des fonctionnalités intégrées spécifiques à l’application visée. L’impression 3D de poudre métallique est une technique additive procédant en 2 étapes : une pièce verte est d’abord construite couche par couche par impression d’un liant liquide sur le lit de poudre, ensuite cette pièce verte est déliantée et frittée. Comme le frittage se déroule séparément de la mise en forme, l’impression 3D est une des seules techniques additives permettant la fabrication de pièces poreuses, comme par exemple des filtres ou autres composants perméables aux fluides. En jouant sur les différents paramètres du procédé, il est possible de faire varier les caractéristiques poreuses de la pièce finale. La première partie de l’exposé mettra en évidence les effets sur les propriétés finales de paramètres comme la granulométrie de la poudre utilisée, la température et le temps de frittage. La deuxième partie de l’exposé traitera de la fabrication de pièces par impression 3D au départ de mélanges bimodaux de poudre. Le comportement au frittage sera analysé en fonction de la composition du mélange et de sa compacité initiale. Les résultats seront comparés à des modèles trouvés dans la littérature. [less ▲]

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See detailContrôle de la porosité résiduelle dans les pièces en acier inoxydable fabriquées par rapid manufacturing selon la technologie 3D printing.
Verlee, Bruno; Dormal, Thierry ULg; Lecomte-Beckers, Jacqueline ULg

Conference (2010, June 15)

Additive technologies offer the possibilities to build complex geometries with integrated functionalities, specific to target application. 3D-printing of metallic powder is an additive technology ... [more ▼]

Additive technologies offer the possibilities to build complex geometries with integrated functionalities, specific to target application. 3D-printing of metallic powder is an additive technology proceeding in 2 steps: a green part is first built layer by layer by printing a liquid binder on the powder bed, and then green part is debinded and sintered. As sintering occurs separately of shaping process, 3D-printing is one of the only additive techniques able to produce porous parts, as filters or other fluid permeable components. Different porous characteristics can be obtained by playing on process parameters. [less ▲]

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See detailRapid prototyping
Verlee, Bruno; Dormal, Thierry ULg; Clarinval, Anne-Marie et al

Conference (2009, February 25)

In opposition to traditional machining in which part is manufactured by material removal, rapid prototyping techniques allow parts manufacturing by material addition. The part is built layer-by-layer and ... [more ▼]

In opposition to traditional machining in which part is manufactured by material removal, rapid prototyping techniques allow parts manufacturing by material addition. The part is built layer-by-layer and the sum of all layers creates the part. Currently, several techniques exist. They use different kind of materials (metals, ceramics, polymers) and technologies (laser melting, laser polymerising, 3D-printing, cladding, ...). Some of these techniques can deal with nanometric particles. In the case of which a near net shape part is built and must be sintered after shaping, the addition of nano-particles can be useful for sintering by increasing specific surface and reactivity of the batch or by improving the properties of the material. An overview about techniques of rapid prototyping allowing the processing of nanomaterials will be discussed. Tests have been done using Optoform process. This process uses a laser to polymerize a paste made of photo-curable resin loaded with powdered material. Nano-particles can be added and stabilized in the paste. In this presentation, the results obtained with both systems Al2O3 + nano Zr02 and SiC + Nano SiC will be discussed. [less ▲]

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See detailDevelopment of functional material for direct manufacturing for ceramic and metal parts by Optoform process
Clarinval, Anne-Marie; Carrus, Raoul; Vaneetveld, Grégory ULg et al

Conference (2004, September)

Optoform LLC developed a technology to process paste compositions based upon photo-curable resins and fillers. This new process is called by Optoform LLC : the direct composite manufacturing This ... [more ▼]

Optoform LLC developed a technology to process paste compositions based upon photo-curable resins and fillers. This new process is called by Optoform LLC : the direct composite manufacturing This technique is quite flexible and allows the development of very different materials(polymeric, metallic, ceramic). This paper is an overview of the use limitation and the advantages of materials developed by the CRIF or by other teams. Materials requiring or not a post-processing step have been developed. The limits or restrictions of use of these materials have been studied in order to meet the requirements and needs of various industrial sectors in the United States and in Europe (e.g. car racing, aerospace and aeronautical sectors, tooling industries, …). [less ▲]

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