Euro PM2024 Proceedings

Authors:

Federico Simone Gobber (1), Giorgia Lupi (2), Antonio Pennacchio (1), Marco Actis Grande (1), Riccardo Casati (2)

1- Department of Applied Science and Technology, Politecnico di Torino, Italy

2- Department of Mechanical Engineering, Politecnico di Milano, Milano, Italy

Abstract:

In recent years, Laser Powder Bed Fusion (L-PBF) has emerged as a promising alternative manufacturing technique for hypereutectic Aluminum-Silicon alloys. Aluminium alloys containing high silicon are of special importance in terms of thermal management applications owing to their low density, high thermal conductivity and tailorable coefficient of thermal expansion (CTE). In this work, an alloy design, backed by thermodynamic simulation to determine the effect of silicon content on CTE, was carried out with the aim of reaching a CTE value compatible with that of the standard Ni plating. Following the results of simulation, hypereutectic aluminum-silicon powders were produced by gas atomizing. The powders were characterized in terms of microstructure and composition (by SEM and EDS), granulometry, rheology, and laser absorbance by UV-Vis-NIR.

DOI:

https://doi.org/10.59499/EP246282638

Authors:

Hagai Peled (1), Matti Ben Moshe (1)

Tritone Technologies Ltd., Israel

Abstract:

High-temperature materials with low thermal expansion are of interest for various applications such as shields, lenses, and microelectronics. Silicon carbide (SiC) is a hard, strong, and thermally conductive structural ceramic that retains its properties at high temperatures. Molybdenum refractory metal is also a strong corrosion-resistant material with low thermal expansion. Additive manufacturing (AM) of printed pure SiC and Molybdenum parts is uncommon. Existing AM processes of SiC parts produce porous SiC structures that go through a silicon infiltration procedure to produce hybrid silicon-SiC structures. This study demonstrates the production of molybdenum metal and SiC ceramics by the MoldJet process, which utilizes a slurry-based feedstock to fill, layer-by-layer, inkjet-printed mold to produce high-density green parts with a volume density in the range of 60%. The SiC and Molybdenum green parts are than debinded and sintered to density volumes of over 99% and 95%, respectively, resulting in parts with exceptional properties.

DOI:

https://doi.org/10.59499/EP246275441

Authors:

Kunal H Kate (1), Krishna Sai Aparna Munjuluri (1), Kameswara Pavan Kumar Ajjarapu (1), Thomas J Roussel (2), Bikram Bhatia (3)

1-Materials Innovation Guild, Department of Mechanical Engineering, University of Louisville, USA

2-Department of Bio Engineering, University of Louisville, USA

3-Department of Mechanical Engineering, University of Louisville, USA

Abstract:

This study explores the utilization of two types of gyroid lattice structures in the design of copper heat sinks manufactured through extrusion metal 3D printing. Feedstocks and filaments of copper powder-polymer system with 61 vol% were made and used to 3D print circular and rectangular gyroid lattice structures. After fabrication, the heat sinks underwent crucial processes including debinding, sintering, and HIP treatments to ensure structural robustness and density. The efficiency of the heat sinks was assessed based on their stabilization temperature and time required for stabilization under a constant power supply of 1W. Furthermore, the impact of glass bead blasting on overall efficiency was investigated. Results revealed that the rectangular gyroid lattice heat sink outperformed its circular counterpart, exhibiting a greater temperature reduction post-glass bead blasting treatment. This suggests that post-processing techniques like bead blasting can significantly enhance heat sink performance by augmenting surface area with micro-pit sites.

DOI:

https://doi.org/10.59499/EP246275809

Authors:

Santiago Cano Cano (1), Paul Peritsch (1), Johannes Bosters (1), Atul Anand (2), Christian Gierl-Mayer (2), György Attila Harakály (1)

1- Incus GmbH, Austria

2- Institute of Chemical Technologies and Analytics, Research Unit of Chemical Technologies, TU Wien, Austria

Abstract:

The high thermal and electrical conductivity properties of copper position it as the optimal choice for a diverse range of electronic, electrical, and energy components. In applications like thermal management, incorporating small and intricate copper structures enhances component efficiency due to an increased surface area. Lithography-based Metal Manufacturing (LMM) facilitates the production of such geometries in a flexible and scalable manner, thereby unlocking the potential for innovative commercial copper products. Nevertheless, several challenges need to be addressed to manufacture high-quality copper components, ranging from the selection of suitable materials to ensuring stability during production and developing optimal processing parameters. This study focuses on evaluating the feedstock properties and processability of copper powders from different sources using LMM. Finally, the properties of the sintered components are measured to assess their effectiveness in thermal and electrical management applications.

DOI:

https://doi.org/10.59499/EP246281350

Authors:

W. Limberg (1), M. W. Rackel (2), T. Ebel (1), R. Willumeit-Römer (1), F. Pyczak (2)

1- Institute of Metallic Biomaterials, Helmholtz-Zentrum Hereon, Germany

2- Institute of Material Physics, Helmholtz-Zentrum Hereon, Germany

Abstract:

An economic drawback of powder based additive manufacturing methods is the high cost of powder compared to cast materials. However, the use of recycled materials, which do not originate from the primary powder production cycle, offers potential for cost reduction. In the present contribution, the use of Ti-6Al-4V powder generated via recycling is combined with Fused Granulate Fabrication FGF and MIM processing. The starting chip material comes from aviation production leftovers. The cleaned chips were formed into cylindrical electrodes and spherical powder was produced using the EIGA process. The tensile test properties of the parts made from the recycled Ti-6Al-4V powder were validated against parts produced from commercial plasma atomized Ti-6Al-4V powder. The parts produced from recycled powder show a higher oxygen content and therefore a higher tensile strength, but only a slightly lower plastic elongation to fracture, compared to parts made from plasma atomized powder.

DOI:

https://doi.org/10.59499/EP246281880

Authors:

Altenberend Jochen (1), Bailly Ophélie (2), Cabrol Elodie (3), Dolbec Richard (2), Si Mohand Hocine (3), Van Wijk Pierre (1), Vert Romain (1)

1- Tekna Plasma Europe, Macon, France

2- Tekna Plasma Systems Inc, Sherbrooke, Canada

3- Centrale Lyon ENISE/LTDS, Saint Etienne, France

Abstract:

In most additive manufacturing (AM) processes, a significant fraction of the non-consolidated powder collected at the end of a printing cycle can be reintroduced into the process using one of the various powder recycling strategies that exist. However, after several cycles, altered flowability and/or oxygen pick up make such powders unsuitable for their reuse and, consequently, they become waste material. Radio Frequency (RF) plasma treatment can increase the flowability of these powders and for many materials, it can even reduce oxygen content. As a result, powders initially considered as waste can now be transformed into high quality powders. In this study we review the literature related to RF plasma treatment for powder recycling and powder reconditioning and the physical and chemical phenomena are discussed. The limits and opportunities for the use of RF plasma for powder reconditioning of different materials are deduced.

DOI:

https://doi.org/10.59499/EP246251254

Authors:

Liviu Brabie (1), Sofia Kazi (2), Annika Strondl (1), Pelle Mellin (1), Tatiana Fedina (1), Lindsay Leach (3), Eduard Hryha (2)

1- Swerim AB, Kista, Sweden

2- Chalmers University of Technology, Goteborg, Sweden

3- Alfa Laval Technologies AB, Eskilstuna, Sweden

Abstract:

This study focuses on advancing the sustainability of powder-based metal additive manufacturing (AM), with focus on powder bed fusion – laser beam (PBF-LB). As a result of numerous reuse cycles during PBF-LB, powder degradation occurs due to the spatter accumulation and hence increase in bulk oxygen content. Hence, heavily reused 316L powder and scrap material from PBF-LB processing (support structures, failed components, etc.) were re-melted into ingots. High-pressure gas atomization trials for 316L material were performed at Swerim AB. The powder produced was classified to PBF-LB size fraction (15-45 µm) and had a total oxygen content of 234 ppm, characterized by excellent processability by PBF-LB. Subsequent investigation of powder properties before and after re-atomization was performed to evaluate the possibility of utilizing scrap as feedstock material in AM. Results indicate high potential for powder recycling in the case of 316L.

DOI:

https://doi.org/10.59499/EP246277177

Authors:

Indeevar Singh (1),Vikram Dabhade (1), Mayadhar Debata (2), Ajit Panigrahi (2)

1- Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Uttarakhand, India

2- Advanced Materials Technology, CSIR-Institute of Minerals and Materials Technology, Odisha, India

Abstract:

The potential advantage of adding niobium to tungsten heavy alloys owing to its lower thermal conductivity and specific heat beneficiary for kinetic energy penetrator is still unexplored. To explore this uncharted area, the effect of Nb addition in WHA for its sinterability, densification and microstructure attributes is investigated. In this study two different compositions of 90W – 7:3(Ni:Fe) and 90W – 6:2:2 (Ni:Fe:Co) were blended with 2.5 wt % Nb followed by compaction and sintered in a reducing atmosphere at 1500 oC. The finding suggested larger tungsten grain formation with Nb addition in both the alloy compositions along with formation of Nb-oxides and W-Nb intermetallics. Increasing Nb concentration hindered sinterability and densification for alloys due to Nb-Oxide formation. This study offer insight into the use of niobium as a promising alloying element in tungsten-heavy alloys (WHA).

DOI:

https://doi.org/10.59499/EP246281538

Authors:

S. Sainz (1,2), J. Pérez de Arriluzea (1,2), I. Iglesias (1,2), E. Cardozo (1,2), O. Ruiz (1,2), N. Ordás (1,2), I. Iturriza (1,2)

1- CEIT-Basque Research and Technology Alliance (BRTA), Spain

2- Universidad de Navarra, Tecnun, Spain

Abstract:

In sinter-based AM the printing is just a shaping process for the powder, separated from the high temperature densification step. After printing, the density of a part will be around 55-60 % TD. In addition, most of the applications need final densities higher than 95 %TD. Consequently, the sinterability of the powder is a key factor that has to be carefully studied. Solid state or liquid phase sintering, thermal profile, interaction with the sintering atmosphere, reduction of superficial oxides, compositional homogeneity, shrinkage … need to be studied for each powder grade. Solid State Sintering is effective at relatively high temperatures for materials like Cu and its alloys whereas Liquid Phase Sintering allows reducing sintering temperature and opens different scenarios for the AM BJ massive production of metal parts. These alternatives are discussed in the present paper together with an in-depth microstructural characterization.

DOI:

https://doi.org/10.59499/EP246301454

Authors:

Giorgio Valsecchi (1)

1- TAV VACUUM FURNACES SPA, Caravaggio, Italy

Abstract:

Sintered stainless-steel components are widely adopted in the automotive, biomedical, electronics and fashion industries. For complex shaped sintered stainless-steel parts, metal injection molding (MIM) has been the primary production technology for decades but, in past few years, sinter-based additive manufacturing (SBAM) has grown significantly in popularity. Both metal injection molded and additively manufactured stainless-steel parts are often sintered in vacuum furnaces to prevent oxidation, contamination and obtain high densities with bright surfaces. In that case, a partial pressure of inert or reactive gas is commonly adopted to suppress evaporation of volatile alloying elements (i.e. chromium and nickel) and to help remove binder residuals. During sintering, the gaseous atmosphere interacts with the steel influencing its final mechanical and corrosion properties. In this experiment, the effects of sintering on vacuum furnaces with different atmospheres (argon or hydrogen) on 316L parts manufactured through MIM and metal binder jetting SBAM were investigated.

DOI:

https://doi.org/10.59499/EP246278273

Authors:

Ava Azadi (1), Eoin D. O’Cearbhaill (1), Mert Celikin (1)

1- School of Mechanical and Materials Engineering, University College Dublin, Ireland

Abstract:

Bioresorbable magnesium (Mg) alloys have been receiving increased attention as an emerging class of biomedical metallic materials due to their high biocompatibility. The potential use of additive manufacturing (AM) for biomedical Mg-based alloys will allow the processing of bioresorbable patient-specific implants. However, the low sinterability of Mg-based alloys is a key issue limiting the efficiency of post-processing required for the low-temperature AM techniques (i.e., extrusion-based techniques). This study aims to fundamentally evaluate the sinterability of the alloys based on Mg-Sr-Ca system designed via thermodynamic calculations. Powder metallurgical route with in-house powder processing was applied and final porosity levels were determined to assess sinterability where thermodynamic calculations along with the differential scanning calorimetry (DSC) were used to select the sintering parameters.

DOI:

https://doi.org/10.59499/EP246280993

Authors:

Fırat MEMU (1), Nuri DURLU (1)

1-TOBB University of Economics and Technology, Department of Mechanical Engineering, Turkey

Abstract:

The Powder Bed Fusion (PBF) techniques allow for the production of complex-shaped components, yet geometric variations lead to varying mechanical properties within the fabricated structures. Despite employing the same manufacturing process, specimens of different sizes exhibit distinct microstructures. This study compares the microstructures of Electron Beam Melted (EBM) Ti-6Al-4V samples with build diameters of 6, 7.5, and 15 mm by examining alpha (α) phase thickness, dislocation densities, and hardness. Lattice parameters of phases and dislocation densities in the specimens are compared through X-ray diffraction (XRD) analysis. Notably, the study finds that α phase thickness increases with an increase in build diameter. The results demonstrate that size-induced differences in microstructure led to variations in mechanical properties. This highlights the crucial need to consider size effects in the design and assessment of complex PBF-fabricated structures.

DOI:

https://doi.org/10.59499/EP246276978