The EPMA Keynote Papers for Euro PM2018 are:
Tailor-made Functional Composite Components Using AM and HIP
Session 9 Monday 15 October 16:50 - 17:20 Room 2 (Level 5)
Dipl-Ing Sebastian Riehm
RWTH Aachen University IWM, Germany
The combination of Additive Manufacturing (AM) and Hot Isostatic Pressing (HIP) offers great potential for industrial applications. Skillfully connecting AM and HIP creates a manufacturing process that unites the advantages of both processes. We demonstrate a production route for composite components by AM + HIP. A capsule made of wear-resistant or corrosion-resistant steel is additively manufactured by Laser-Powder Bed Fusion (LPBF). Before building the geometry of the capsule is optimized by FEM simulation to obtain a desired shape. In a second step the capsule is filled with structural steel powder and sealed in a conventional powder HIP process. The capsule remains on the component as an outer layer. In this way a complex-shaped functional net shape composite component is produced. The composite components created by this route are characterized by metallographic investigations.
Development of Ti-Nb And Ti-Nb-Fe Beta Alloys from TiH2 Powders
Session 25 Tuesday 16 October 10:50 - 11:20 Atrium Room 1 (Level 1)
Ing Chirico Caterina
Universidad Carlos III de Madrid, Spain
Ti-Nb β alloys are a promising alternative as an implant material due to their good properties and low Young’s modulus compared to other Ti-alloys currently employed as biomaterials. In this study three materials of the Ti-Nb and Ti-Nb-Fe systems were produced by powder metallurgy techniques starting from TiH2 (TH) powder. Several sintering cycles were employed to evaluate the H2 elimination and the effect of sintering temperature on densification and fraction of β-Ti phase. Also the influence of alloying element size using two kinds of Fe powder was evaluated. The highest loss of H2 was achieved decreasing heating rate at the temperature range of hydride decomposition. SEM images and XRD results show mainly a β-Ti phase for TH40Nb and TH5Fe25Nb samples. The TH12Nb sample shows (α+β) microstructure. Fe addition with smaller particle size seems to improve the diffusion of Nb into Ti what promotes a higher β-phase fraction and sample homogeneity.
Potential Workers Exposure Measurement in Metal Additive Manufacturing and How to Manage it
Session 24 Tuesday 16 October 10:50 - 11:10 Auditorium 1 (Level 4)
Mrs Cecile Philippot
CEA de Grenoble, France
When setting up a new additive manufacturing line into an industrial workshop dust exposure is one of the main risk to take in consideration for risk analysis. The aim is to ensure the lowest possible workers exposure to powder. Currently this analysis is focused on the micronic part of the metallic powder used. Several measurements campaign done by CEA-PNS teams have underlined the importance of the nanometric fraction which is a by-product of the laser beam melting. To prevent any potential worker exposure to aerosol all emissions occurring during the different phases (preparation fabrication cleaning maintenance …) have been analysed in real-time (particles concentrations size distributions ...) and characterized by microscopy observations (morphology chemical composition …). These results combined with CEA good practices and EHS recommendations allow to adjust the protocols in consequence and propose CPE and PPE adapted to the emissivity of each working.
Four-dimensional (4D) Observation of Ductile Fracture in Sintered Iron Using Synchrotron X-ray Laminography
Session 47 Wednesday 17 October 08:20 - 08:40 Room 1A (Level 5)
Prof Dr Ozaki Yukiko
Kyushu University, Japan
Synchrotron X-ray laminography was used to reveal the time evolution of the three-dimensional (3D) morphology of micropores in sintered iron during a tensile test. 3D snapshots showed networked open pores growing wider than 20 µm along the tensile direction resulting in internal necking of the specimen. Finally these pores initiated cracks perpendicular to the tensile direction by coalescing with surrounding preexisting microvoids or secondary-generated voids immediately before fracture. Topological analysis of the barycentric positions of these microvoids showed that they formed two-dimensional networks within a ~20 µm-radius area. This indicates that microvoid coalescence could occur on shear planes formed close to the enlarged open pores or between closed pores by strain accumulation and play an important role in crack initiation.