World PM2022 Proceedings

Authors:

Gunnar Walther (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany), Tilo Büttner (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany), Christian Imanuel Bernäcker (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany), Lars Röntzsch (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany), Thomas Weißgärber (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany), JungSuk Bae (Alantum Corporation, Korea, Republic of), Lars Torkuhl (Alantum Europe GmbH, Germany), Andreas Tillmann (Alantum Europe GmbH, Germany)

Abstract:

Open cell metallic foams are suitable for a wide range of applications as materials for filters, catalyst supports for heterogeneous catalysis and electrodes in batteries, fuel cells and electrolyzers due to their excellent heat and mass transfer, low pressure drop, good electrical conductivity and high chemical resistance. The foam can be produced in a wide range of pure metals like nickel, iron, silver and copper. Depending on the application, high high-temperature, oxidation and corrosion resistance can be achieved by a patented powder metallurgical alloying process in industrial scale.In the current paper, results for applications of NiFeCrAl foam as catalyst for Steam Methane Reforming and silver foam for the formaldehyde synthesis are discussed. Another focus is on the application as electrode material in electrolysis. Electrochemical investigations show that modified nickel foam exhibit a much lower overvoltage than nickel sheets and thus the operating costs of electrolyzers can be significantly reduced.

DOI:

https://doi.org/10.59499/WP225371743

Authors:

Kai Zissel (Linde GmbH, Germany), Elena Bernardo Quejido (Linde GmbH, Germany), Pierre Forêt (Linde GmbH, Germany), Eduard Hryha (Chalmers University of Technology, Sweden)

Abstract:

Binder Jetting (BJT) is a binder-based Additive Manufacturing technology, where only a small fraction of the processed powder is bonded inside the green parts after printing. Unbound powder, which is recovered during the BJT process, is reused for printing. For powder reuse, the resulting changes in the physical and chemical powder properties along with the powder surface conditions strongly affect the reproducibility of the BJT process and its final part properties. In this study, the powder degradation and its impact on the reusability of 17-4 PH stainless steel powder are evaluated for the BJT process. Powder characteristics are analyzed after multiple reuse cycles after different process steps, namely drying, sieving, printing and curing. The influence of reused powder on print quality and green densities is investigated and compared to virgin powder. Furthermore, the effect of inert and reducing atmospheres on the powder reusability during curing is examined.

DOI:

https://doi.org/10.59499/WP225371888

Authors:

Abdolreza Simchi (Sharif University of Technology, Iran), Frank Petzolfdt (Fraunhofer Institute IFAM, Germany), Sebastian Boris Hein (Fraunhofer Institute IFAM, Germany), Lea Reineke (Fraunhofer Institute IFAM, Germany), Bastian Barthel (Fraunhofer Institute IFAM, Germany), Daniel Hosseini (Sharif University of Technology, Iran)

Abstract:

Sintering anisotropy is the major challenge limiting the fabrication of large and complex-shaped parts by binder jet additive manufacturing. We employed 3D shell binder jetting to fabricate green parts with a minimum heterogeneity in the pore structure. The advantages of the process include fast printing speed, minimum consumption of the binder, easier de-powdering|de-binding processes, and homogeneous sintering shrinkage. The applicability of the shell printing process for the fabrication of 316L and Ti-6Al-4V parts is demonstrated. Using dilatometric analysis, we show that the sintering shrinkage in different directions only varies by about 1%; hence, deflection during high-temperature sintering is prohibited. The fine and uniform pore structure also renders reduced sintering temperature and time, yielding finer microstructural features and superior mechanical properties. The 3D shell printing could overcome the main limitations of the 3D binder jetting process; hence, it has a great potential to be employed for versatile materials systems.

DOI:

https://doi.org/10.59499/WP225371865

Authors:

Naiara Azurmendi (Tecnalia, Spain), Asier Lores (Tecnalia, Spain), Andoni Laskurain (NUEVA HERRAMIENTA DE CORTE (TIVOLY), Spain)

Abstract:

Binder Jetting Additive Manufacturing technology permits the processing of a wide range of different metallic alloys which cannot be easily manufactured by other AM means, as they may present undesired microstructures or anisotropic functional properties. For this reason, it has been found that BJ can be a suitable AM technology for processing tool steels and obtaining high quality parts with isotropic properties. In the present work, commercial M2 tool steel powder was studied and processed by Binder Jetting under different processing conditions. After some optimization work, near full density was achieved (>99%), together with MIM-like microstructure and hardness (51 HRC). Therefore, this study demonstrates that good quality M2 parts can be obtained by means of BJ, opening new design and manufacturing possibilities for more complex and advanced tooling applications.

DOI:

https://doi.org/10.59499/WP225371923

Authors:

Naiara Azurmendi (TECNALIA, Basque Research and Technology Alliance (BRTA), Spain), Iñigo Agote (TECNALIA, Basque Research and Technology Alliance (BRTA), Spain), Cristina Fernandes (PALBIT S.A., Portugal), Daniel Figueiredo (PALBIT S.A., Portugal)

Abstract:

Additive manufacturing of hardmetals is gaining attention due to the possibility of fabricating complex shaped parts and new functional designs. Comparing to laser-based AM processes, binder jetting appears to be more promising technology due to its low-cost, fast manufacturing process that produces stress and crack-free parts with isotropic properties. In the present work, properties of two different plasma spherodized commercial powders (AMWC701 and AMWC702 grades), have been characterized and printed with binder jetting technology. In addition, final properties of the printed parts sintered in a Sinter-HIP furnace at two different temperatures (1455°C and 1480°C) have been evaluated. Density, shrinkages, microstructure and hardness have been analysed. Best results were obtained with AMWC702 grade sintered at 1455°C, where near full density was obtained (>99%). Measured Vickers hardness was 1227 HV30, which is coherent with the microstructural analysis and close to medium grained commercial products.

DOI:

https://doi.org/10.59499/WP225371945

Authors:

Georg Poehle (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany), Antje Schauer (Technische Universität Dresden, Germany), Jakob Scheibler (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany), Thomas Weissgaerber (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany), Peggy Barthel (Technische Universität Dresden, Germany), Anita Maennel (Technische Universität Dresden, Germany), Volker Adams (Technische Universität Dresden, Germany), Axel Linke (Technische Universität Dresden, Germany), Peter Quadbeck (Offenburg University of Applied Sciences, Germany)

Abstract:

Biodegradable metals have entered the implant market in recent years, but still do not show fully satisfactory degradation behaviour and mechanical properties. In contrast, it has been shown that pure molybdenum has an excellent combination of the required properties in this respect. We report on PM based screen printing of thin-walled molybdenum tubes as a processing step for medical stent manufacture. We also present data on the in vivo degradation and biocompatibility of molybdenum. The degradation of molybdenum wires implanted in the aorta of rats was evaluated by SEM and EDX. Biocompatibility was assessed by histological investigation of organs and analysis of molybdenum levels in tissue extracts and body fluids. Degradation rates of up to 13.5 µm|y were observed after 12 months. No histological changes or elevated molybdenum levels in organ tissues were observed. In summary, the results further underline that molybdenum is a highly promising biodegradable metallic material.

DOI:

https://doi.org/10.59499/WP225371879

Authors:

Johannes Trapp (Fraunhofer IFAM, Germany), Thomas Schubert (Fraunhofer IFAM, Germany), Dumitru Mitrica (National Research & Development Institute for Non-ferrous and Rare Metals, Romania), Ioana Anasiei (National Research & Development Institute for Non-ferrous and Rare Metals, Romania), Thomas Weißgärber (Fraunhofer IFAM, Germany)

Abstract:

Aluminum-based metal-matrix-composites (AMCs) show attractive properties to meet the growing demand for lightweight construction for example in the automotive and aerospace industries. Limiting factors are difficulties in processing and machining as well as comparably low operating temperatures. The first issue is addressed using spark plasma sintering (SPS) to produce fully dense net-shape compacts. Therefore, the electrical properties of the powders must be understood and adjusted. To increase operation temperature, alloys with thermally more stable Al3Fe dispersoids, certain intermetallic phases, or complex constitutional alloys have been investigated. The latter are developed with the help of a systematic selection process to calculate the thermodynamic and kinetic criteria to predict the phases formed. Those AMCs show melting temperatures above 1000 °C while keeping the density below 4,5 g|cm³. Aiming for compressive strength > 800 MPa and elongation to fraction >1 % makes the materials suitable e.g. for front wheel brake disc applications.

DOI:

https://doi.org/10.59499/WP225371604

Authors:

Axel Müller-Köhn (Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Germany), David Werner (Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Germany), Tamara Aleksandrov Fabijanić (University of Zagreb, Croatia), Ivan Jeren (Alfa Tim d.o.o., Croatia)

Abstract:

Water and cellulose-ether-based extrusion of hardmetals give the opportunity of an environmentally friendly processing. Furthermore, water as a solvent significantly reduces the demands in occupational safety and also costs in suction systems and drying processes.Use of water requires specific binders and additives to achieve the desired processing behavior of extrusion feedstocks as well as the necessary hardmetal properties after sintering. Additionally, water removal during drying of extruded parts demands well controlled conditions to ensure shape retention and defect free green parts.In this presentation necessary organics and processes for a successful feedstock preparation and extrusion will be shown. As an example, it was possible to apply submicron (d50 < 1 µm) WC-10 Co and binder free, nano scaled WC powders. Finally, resulting material properties of extruded and sintered parts will be demonstrated.

DOI:

https://doi.org/10.59499/WP225371900

Authors:

Prathviraj Upadhyaya (South Eastern Applied Materials (SEAM) Research Centre, Ireland), Sinéad M. Uí Mhurchadha (Waterford Institute of Technology, Ireland), Tríona Kennedy (Stryker European Operations Limited, Ireland), Ramesh Raghavendra (South Eastern Applied Materials (SEAM) Research Centre, Ireland)

Abstract:

WE43 magnesium alloy is a low density, biocompatible material that has been identified as a viable option for temporary orthopaedic implants due to its favourable mechanical and biodegradation properties. This bioresorbable material eliminates the requirement for an invasive second surgery to remove a traditional bioinert temporary implant after the bone has regenerated. Additive manufacturing allows for complex structures with biomimicry features to be produced. However, the additive manufacturing of Magnesium and its alloys is not a trivial task due to challenges associated with the processability of Magnesium. This paper presents a methodology to additively manufacture WE43 components. Furthermore, an additively manufactured demonstrator orthopaedic fixture is presented and the microstructure evolved within the part and the resulting mechanical and corrosion properties are characterised. This research is aimed towards the development of additively manufactured, bioresorbable orthopaedic implants, with potential to improve clinical outcomes for patients.

DOI:

https://doi.org/10.59499/WP225372016

Authors:

Mohammad Ibrahim (University of Agder, Norway), Tor Oskar Saetre (University of Agder, Norway), Ragnhild Elizabeth Aune (Norwegian University of Science and Technology, Norway)

Abstract:

In general, silicide-based materials offer efficient improvement of turbines and offshore systems due to their exceptional oxidation, corrosion, and wear resistance. The standard requirement of materials used in these systems is the ability to withstand high temperatures. Nickel silicide (NiSi) is commonly known to possess these abilities, however, its inherent brittleness makes large scale production difficult using standard metal forming techniques. Laser Metal Deposition (LMD) is an Additive Manufacturing (AM) technique similar to cladding that allows pore-free microstructure formation of the metal with refined grains, enabling excellent mechanical properties. In the present study, NiSi16 is deposited on structural steel and nickel substrates, and microstructural development is observed in both cases. The deposited beads are characterised using conventional analytical techniques, i.e., LVFESEM, EDX and XRD, and the results are discussed in the context of changes in chemical composition.

DOI:

https://doi.org/10.59499/WP225372124

Authors:

Angel Sota-Munoz (CEIT-BRTA, Spain), Nerea Burgos (CEIT-BRTA, Spain), Mihail Ipatov (UPV|EHU, Spain), Jose Manuel Martin (CEIT-BRTA, Spain), Julian Gonzalez (UPV|EHU, Spain)

Abstract:

Iron silicon gas atomized powder was coated with iron phosphate, epoxy resin and a mix of both to make soft magnetic composites (SMC). Iron phosphate composites were consolidated by cold pressing at 800 MPa or hot pressing at 825 ºC and 50 MPa. Composites made from epoxy resin or a mix of epoxy|phosphate were consolidated by cold pressing at 800 MPa. The microstructural characterization of the new cores was carried out by high resolution scanning electron microscopy. Differential scanning calorimetry showed that a degradation of the phosphate coating occurs at temperatures above ~880 ºC due to a reaction with silicon, limiting the maximum temperature for hot pressing. The best combination of properties was obtained for the hot-pressed iron phosphate composite, reaching high density (6.59 g|cm3), high electrical resistivity (~105 µO·cm), high saturation magnetization (1.75 T) and a low coercive field (~315 A|m).

DOI:

https://doi.org/10.59499/WP225371898

Authors:

Marta Ceroni (Politecnico di Torino, Italy), Lorenza Maddalena (Politecnico di Torino, Italy), Marco Actis Grande (Politecnico di Torino, Italy)

Abstract:

Cu powders show high reflectivity when exposed to a laser having wavelengths in the range of 1064-1080 nm, hindering the processability when manufacturing by red-light laser powder bed fusion. Green or blue lasers help overcoming this issue, as well as the change of the chemical composition of the powder. However, other approaches may also be used. The present paper analyses the effect of coatings applied on elemental Cu-powders on the absorbance of the resulting material. Different amounts of Graphite Oxide have been deposited on the surface of metal powders by a nanocoating approach. The prepared powders have been characterized evaluating the absorbance in the red, green, and blue light wavelengths using UV-Vis spectroscopy. The uniformity of GO coating was also evaluated by scanning electron microscopy and Raman spectroscopy.

DOI:

https://doi.org/10.59499/WP225372154