“SAFRAN's Vision of 3D Printing Application development”
Dr. Thierry THOMAS
Vice President, Safran Additive Manufacturing, France
Additive Manufacturing covers a set of rapidly expanding technologies that have the potential to profoundly transform the way in which the aviation industry develops, manufactures, or maintains its products. These technologies enable designers to access to new shapes, materials and functions that are unattainable by conventional means. Furthermore, Additive Manufacturing may drive main change in our traditional industries as well as main impacts on business models.
Safran is using 3D printing since the early stage of the technology in the 80’s to make prototypes and photoelastimetry studies. In 2004, 2005, metal has started to be used first for trials and then more systematically in new developments. To take quickly and fully benefit from additive manufacturing technologies, a real game-changer, and have an organization able to help Safran companies to be ready to introduce it in their new challenges, Safran has decided to create a multidisciplinary competence center dedicated to AM within SafranTech: "Safran Additive Manufacturing”.
The proposed presentation will give us the opportunity, starting from the historical experience of Safran group on rapid prototyping, to present the current axes of development, as well as scientific and technical challenges that Safran will have to face to support AM development.
Born in 1962, Thierry Thomas is Associate Professor in Mechanical of the Ecole Normale Supérieure de Cachan and Doctor of Science in Science and Materials Engineering from the Ecole Nationale Supérieure des Mines de Paris. During 14 years at the General Delegation for Armaments, he held various positions that allow him to strengthen its expertise in materials, processes and detonation. Notably, he piloted the UMR-CNRS research DGA UMR114 -The LALP- (laser applications laboratory) and technological field Materials and Processes of the Arcueil Center. In 2001 he joined Snecma as Director of Materials and Processes and will set up within the group what is now the Materials and Processes Safran Directorate. In 2006, he was appointed Director at Messier-Dowty, Vélizy design office. Then, in 2008, he was appointed Engineering Executive Vice President of Messier-Dowty and at its creation in 2011, the Engineering EVP of Messier-Bugatti-Dowty. In April 2015, Safran Additive Manufacturing has been created and its management has been entrusted. He is a member of the High Committee mechanics of the French Association of Mechanics and member of the Academy of Air and Space.
“Wire + arc additive manufacture (WAAM), latest developments and future prospects”
Professor Stewart WILLIAMS
University of Cranfield, UK
Additive manufacture of metre scale engineering structural parts is currently of great interest to industry in many sectors including aerospace, defence, energy and construction. The only realistic processes for these applications are those based on wire feed technologies and the status of these will be briefly reviewed. Wire + Arc Additive Manufacture (WAAM) shows the highest level of business benefit and examples of systems, capabilities and associated material properties will be given. There are many potential applications of WAAM for production of which will be highlighted. Developments required for WAAM to allow industrial application including the approach towards qualification and commercialisation will be discussed.
Stewart Williams spent five years at Edinburgh Instruments building lasers and laser systems. In 1987 he moved to the Advanced Technology Centre of BAE Systems where he ran a group whose main area of research was laser processing of aerospace materials. Currently he is Director of the Welding Engineering and Laser Processing Centre (WELP) at Cranfield University. The main areas of research at the WELP are additive manufacturing, laser and laser-arc hybrid welding, weld metal engineering and residual stress control/management.
“Roadmap from welding to additive manufacturing: Challenges & Perspectives"
Emeritus Professor Surendar MARYA
Ecole Centrale Nantes, France
Welding is millennia old technology assimilated to blacksmithing in ancient times. The last century witnessed a dramatic surge in welding innovations with to date more than thirty processes that generate an estimated global product market approaching 12 billion USD. In contrast, though literature cites different precursors such as fabrication of 3D artistic objects by Baker (US patent 1925) by layered metallic depositions as in welding, the additive manufacturing in its present form started in1980’s, coinciding with the development of computers and graphic software.
In spite of strong process resemblance, AM and welding have different end objectives and some minor differences that refer to the role of digital technology in AM. Whereas welding inherently implies feedstock deposition in a constrained space in between the parts to be welded, the additive manufacturing is a free form technology. Herein, the constrained space is defined by free form boundaries only. Thus in welding, the design has to be adapted to the applied technology, whereas in AM, the design becomes the lead parameter. This is a dramatic change from design for manufacturing (welding) to manufacturing for design (AM). Notwithstanding this difference, both bring in to action a multitude of physical phenomenon such as heat transfer, fluid and continuum mechanics, melting, solidification, phase transformations, textures which are conditioned by equally divers process variables namely energy density, feedstock chemistry, delivery system and displacement strategy, among others.
More fundamentally, the material chemistry and thermal cycles imposed by the processing strategy constituent the main factors that support the integrity of welded as well additively manufactured parts. Porosity, solidification cracking, distortions and residual stresses constitute some of the important problems encountered both in welding and additive manufacturing. Surface roughness and textures are additional defining characteristics of additively manufactured parts. Milling, polishing, and post processing via thermal treatments and HIP is often required to meet the characteristics of parts obtained by conventional forming technologies. The paper proposes to establish the bridge between welding and additive manufacturing of metallic parts by illustrating some case studies that comprise additive manufactured parts, welded structures, repair, surface functionalization and fabrication of materials with site specific properties (MSP) by applying laser based direct energy deposition. The road map of metallic additive manufacture would thus be examined through the prism of welding science and technology.
Professor Surendar Marya is University Emeritus Professor of Ecole Centrale Nantes providing teaching, research and consulting services for some major French & international Companies. He was the Head & Coordinator of High Power laser Centre, sponsored by State & Central Government from 1992 to 2001. Amongst the first of its kind in France designed to diffuse laser technology, he promoted technology transfer to small & medium-size companies, particularly laser-assisted manufacturing, welding & Joining technologies, and promote the usage of titanium. He has published over 150 technical and scientific publications and has given over 30 invited presentations at welding, materials, manufacturing societies worldwide.. His interest and assignment portfolio covers manufacturing with core focus on metallic materials.
“CFD simulations of keyhole welding and additive manufacturing by laser and electron beam”
Professor Suck-Joo NA
KAIST, South Korea
In laser keyhole welding and selective laser melting process, one ray can have several reflections and absorptions during process, which is called the multiple-reflection and considered as one of the important physical phenomena in laser materials processing. This paper first investigates the numerical simulations of laser welding and selective melting with the ray tracing by Progressive Search Method (PSM). PSM uses the real equation of surface and ray direction vector, while reflected ray starts from the real contact point and is moved step by step. Moreover, PSM can depict the multi-path of ray effectively, if combined with the concept of the set of sub-rays, which has a good physical ground to depict the various phenomena, such as transmission and scattering. Absorption and back scattering are adopted for numerical simulations of keyhole electron beam welding of thick plates and selective electron beam melting of micro metallic particles.
All simulations are performed with the Computational Fluid Dynamics (CFD) method including the Volume-Of-Fluid (VOF) technique for deep keyhole welding of thick plates and selective melting of micro particles by laser and electron beam. The results of CFD simulations are then applied to investigate the heating, melting, flow, mixing and cooling process, which will be then used further for the mechanical analysis of parts manufactured by laser and electron beam. Experimental results of melting zone shapes are compared with the CFD simulation results to evaluate the validity of the process and simulation models adopted in CFD simulations.
Professor Suck-Joo Na graduated from Seoul National University for B.Sc., from KAIST for M.Sc., and has got Dr.-Ing. degree from IFS of TU Braunschweig, Germany in 1983. Since then Professor Na is working at KAIST, Korea, in the field of simulation and optimization of arc, laser and laser arc hybrid welding process, in which he links the arc physics and multiple reflections in keyhole with weld pool dynamics. Recently, he has commenced with the CFD simulation of FSW and SLM/EBM process, and also with the metallurgical and mechanical optimization of thermal processed structures using advanced digital simulation technologies. He has published more than 165 research papers in international journals and presented more than 135 papers at international welding conferences.
Professor Na has been awarded various prizes of KWJS, KSME, AWS and IIW, and recently FiDiPro Professorship and Humboldt research award, and has served as the president of KWJS and AWF, and is serving as the fellow of AWS and the fellow of the Korean Academy of Science and Technology.
“Review of NDT and process monitoring techniques usable to produce by welding or additive manufacturing high quality parts”
Fellow NDT and Monitoring Methods, Institut de Soudure, France
The main objectives of applying NDT techniques are to ensure the quality of an assembly or a part according to a given specification including known acceptance criteria. It generally enables not only to detect an indication, but also to classify it (size, position, nature...). Many non-destructive testing (NDT) techniques are effective in testing welded components. Radiography, Ultrasonic Testing, Penetrant testing and magnetic particle testing are widely used and standardized. Phased arrays, TOFD and multi-elements eddy current are more and more extensively applied.
Tomographies, Acoustic Emission, guided waves, laser ultrasonic, optical techniques continue to be a topic of interest. Each of these techniques is based on different physical principles to detect defects on the surface of the part or over its whole volume. However, the geometry, physical and material properties of the part being tested are key factors in the applicability and performance of a given NDT technique.
To date, the development of reliable NDT methods for additive manufacturing part is still a major challenge. The process may generate various defects such as cracks, voids, inclusions and porosities. NDT techniques need to be optimized or developed to address singular features of the AM processes: complex geometry, special internal structures, anisotropic material properties, typical defects. Knowledge of the potential occurring flaws produced by the various AM process need to be improved in order to be able to select the best suited NDT techniques.
This paper reviews:
Example of NDT applications on welded and AM parts will be given as a short focus on the NDT standardization progress.
Daniel CHAUVEAU has an engineer's degree in applied physic from INSA (National Institute for Applied Sciences) in Rennes. He joined Institut de Soudure in 1983 as Project leader to manage a 5 years NDT group sponsored project. Then he worked for 15 years as the head of the NDT laboratory. He joined the headquarters in 2002 as NDT Expert to ensure technical support for the Institut de Soudure Group. He is from 2006 the NDT Fellow of the IS Group and he has also in charge to manage the expert network. He is the innovation manager since 2011. He is involved in CEN and ISO standardisation from the 2000s, member of the Scientific and technical committee of the French National Society (COFREND). He chairs the IIW Commission VC (Ultrasonic testing) since 2012.