Authors:
Julie Campbell Tremblay (Rio Tinto Metal Powders, Canada) Amir Shirani (Rio Tinto Metal Powders, Canada) Chantal Labrecque (Rio Tinto Metal Powders, Canada)
Abstract:
Various strategies can be explored to minimize costs in PM technology. These include increasing density to reduce the need for alloying elements. Higher density also results in greater strength, allowing for cost reduction by design. Another cost-reduction strategy is improving processability to increase production throughput. The pursuit of high-performance parts extends beyond developing higher alloyed materials to include comprehensive premix solutions. Binder treatment solutions and improved lubrication are essential for enhancing part properties.The current paper will present the results from a new chromium grade in an improved premix with improved lubricant solutions. It will detail the sinter hardening properties and compare the premix improvements to standardized grades.
DOI:
https://doi.org/10.59499/EP256767949
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Authors:
Katherine Pérez Zapata (Helmholtz Zentrum Hereon, Germany) Eshwara Nidadavolu (Helmholtz Zentrum Hereon, Germany) Thomas Ebel (Helmholtz Zentrum Hereon, Germany) Martin Wolff (Helmholtz Zentrum Hereon, Germany) Heike Helmholz (Helmholtz Zentrum Hereon, Germany) Regine Willumeit-Römer (Helmholtz Zentrum Hereon, Germany) Berit Zeller-Plumhoff (Helmholtz Zentrum Hereon, Germany)
Abstract:
The integration of 3D printing and Mg-5Gd alloys is revolutionizing biomedical applications, particularly in scaffolds for bone implants. Scaffolds facilitate bone growth and repair, requiring precise fabrication to achieve a balanced degradation rate that aligns with bone regeneration while maintaining mechanical support during healing. This study optimizes 3D printing parameters for Mg-5Gd alloy feedstock (40 vol.% binder loading) to produce high-quality magnesium structures with controlled degradation rates. Key parameters, including printing speed, extrusion rate, layer thickness, and post-processing techniques, were refined to achieve dense discs and scaffolds with pore sizes of 700–1250 µm, matching cortical bone structure. Using a 0.3 mm nozzle and printing speeds of 10–20 mm|s, structures with densities up to 97% and degradation rates below 1 mm|year were achieved. Results demonstrate that scaffold degradation rates can be tailored by adjusting geometry, pore size, and wall thickness, showcasing AM potential to advance regenerative medicine and biomedical implants.
DOI:
https://doi.org/10.59499/EP256767218
Authors:
Katsuyoshi Kondoh (Osaka University, Japan), Ammarueda Issariyapat (Osaka University, Japan), Shota Kariya (Osaka University, Japan)
Abstract:
The pre-mixed pure titanium (Ti) and zirconium hydride (ZrH2) powder was consolidated by PM process (sintering and hot extrusion) or AM process (selectively laser melting, SLM) to fabricate Ti-Zr alloys, which have excellent corrosion resistance and biocompatibility for human bodies. It was clarified that both materials showed uniform solid-solution of Zr atoms in a-Ti matrix and fine grains due to Zr solute drag, resulting in the significant improvement of tensile strength. In addition, the elongation more than 15% was also obtained in all samples. The quantitative analysis on Zr solution strengthening behavior of both materials was carried out using Labusch model.
DOI:
https://doi.org/10.59499/WP225367359
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Authors:
Olivier Tosoni (Univ. Grenoble Alpes, CEA, Liten, France), Elisa Borges Mendonça (Univ. Grenoble Alpes, CEA, Liten, France), Atte Antikainen (VTT Technical Research Centre of Finland, Finland), Lukas Schäfer (Technische Universität Darmstadt, Germany), Stefan Riegg (Technische Universität Darmstadt, Germany)
Abstract:
NdFeB permanent magnets are key components for the energy transition and the electrification of transportation, which causes their demand to grow at high pace. Yet, the supply risk for rare earth metals motivates the industry to look for an efficient use of magnets. Designing systems with complex-shaped magnets can help reducing the magnet use if accompanied by the development of net-shape processes. Powder Bed Fusion using Laser Beam of NdFeB has been studied since 2016 as a way to produce complex-shaped dense parts without any binder; most of the works are based on a commercial Nd-lean spherical powder. In the present work, a close-to-industrial process route was developed in order to produce a narrow-distributed 40-µm Nd-Fe-B powder with a composition close to the usual sintered magnet grades. This powder was used to additively manufacture parts and study the impact of changing the laser scanning strategy on the magnetic properties.
DOI:
https://doi.org/10.59499/WP225371993
Authors:
Nidhin George Mathews (1); Juha Lagerbom (2); Jarmo Laakso (3); Turkka Salminen (3); Mari Honkanen (3); Tomi Lindroos (2); Anssi Laukkanen (2); Elina Huttunen-Saarivirta (2); Gaurav Mohanty (1)
1- Materials Science and Environmental Engineering, Faculty of Engineering and Natural Sciences, Tampere University, Tampere 33014, Finland
2- VTT Technical Research Centre of Finland Ltd, Tampere 33720, Finland
3- Tampere Microscopy Center, Tampere University, Tampere 33014, Finland
Abstract:
High entropy carbides (HEC) are multi-metal carbides involving at least five types of metal atoms at near-equal concentrations. They exhibit crystalline periodicity and a precise carbon sublattice but display disorder in terms of metal cation packing, therefore, they also have unconventional mechanical and physical properties. Up till now, the high entropy carbide compositions presented in literature have been rich in critical raw materials (CRM), such as hafnium (Hf). We explore the feasibility of fabricating sustainable high-entropy carbide compositions, free of CRMs, using conventional ceramic processing techniques, such as mechanical milling and thermal treatments. Five compositions of multi-metal carbides were chosen based on their entropy forming ability from literature. Metal powders and carbon were mixed in stoichiometric proportions using ball milling and sintered at high temperatures (2000 ºC). X-ray and electron microscopy techniques were used to characterize the materials and verify the formation of single-phase multi-metal carbides and chemical homogeneity at micrometer length scales. In addition, the mechanical properties of a selected composition was studied using nanoindentation.
DOI:
https://doi.org/10.59499/EP235765276
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Authors:
Thorsten Middelhof (RHEWUM GmbH, Germany), Vito Huhn (RHEWUM GmbH, Germany)
Abstract:
The increasing scarcity of resources requires sustainable management of raw materials at all levels. Additive manufacturing is a process that conserves raw materials and offers further potential for saving raw materials such as metallic powder. In addition to the manufactured end product, residual powder in the form of agglomerated or dust remains. In order to achieve the desired quality of the metal powder, all impurities, undersized particles and dust need to be removed and agglomerates have to be loosened. This can be achieved in a screening machine that is tailored to the needs of the specific metal powder in order to maintain a high quality. The machine needs to be gas-tight for an inert gas atmosphere, shall be easy to access and clean and sieve the metal accurately at high throughputs. This paper presents the parameters such as different frequencies that have an impact on the screening efficiency.
DOI:
https://doi.org/10.59499/WP225372113
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Authors:
Faezeh Javadzadeh Kalahroudi (Karlstad University, Sweden), Katerina Chantziara (Karlstad University, Sweden), Fengxiang Lin (Karlstad University, Sweden), Giulio Maistro (Uddeholms AB, Sweden), Krishnan hariramabad Anantha (Uddeholms AB, Sweden), Jens Bergström (Karlstad University, Sweden), Thomas Mikael Grehk (Karlstad University, Sweden)
Abstract:
High-nitrogen-chromium alloyed powder metallurgy (PM) tool steels offer many attractive features including high strength and corrosion resistance. The PM route offers various advantages such as advanced alloy composition, high homogeneity, and well-defined size distribution of hard phase particles. This study presents microstructure and mechanical properties of a PM Cr-Mo-V-N alloy. The conventional manufacturing route for this alloy is hot isostatic pressing (HIP) followed by hot working. To investigate the possibility of near-net-shape manufacturing, a comprehensive comparison of the performance was made between steels produced by as-HIPed and HIPed followed by hot working. Both steel types were heat treated in the same way to obtain martensitic matrix with limited retained austenite. In the present investigation, microstructure and phase analyses were performed by X-ray diffraction and scanning electron microscopy. Mechanical tests were carried out by hardness measurements and tensile fatigue tests in the very high cycle fatigue regime using ultrasonic fatigue testing.
DOI:
https://doi.org/10.59499/WP225372091
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Authors:
Taiko Tanimoto (Kyushu University, Japan) Naoki Orita (Kyushu University, Japan) Zhenying Wang (Kyushu University, Japan) Chihiro Inoue (Kyushu University, Japan) Jun Horiuchi (JFE Steel, Japan) Takuya Takashita (JFE Steel, Japan) Kazutoyo Yamada (Iwate University, Japan) Noriharu Yodoshi (Kyushu University, Japan)
Abstract:
To elucidate the gas atomization process as a thermo-fluid phenomenon, we successfully performed high-speed Schlieren imaging up to one million frame per second for the first time to resolve deformation and fragmentation of a tin droplet subjected to a supersonic nitrogen jet at Mach number of 1.5. We identify two atomization processes by tracking the deforming ligaments in a Lagrangian manner. Inside the supersonic jet, the large aerodynamic force shears the droplet into tiny particles partially interacting with the shock waves inside the jet. Rebounded above the jet, the rest droplet deforms to be ligaments, which break dominated by the capillarity producing large particles. We find that the distinct atomization mechanisms result in a bi-modal distribution of the produced particle size. This fact indicates that the molten droplets in a practical apparatus collide with gas jets at multiple times, leading to a converged mono-modal distribution.
DOI:
https://doi.org/10.59499/EP256766631
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Authors:
Jannis Lemke (CNR Icmate, Italy) Carlo Biffi (CNR Icmate, Italy) Alberto Coda (CNR Icmate, Italy) Jacopo Fiocchi (CNR Icmate, Italy) Ausonio Tuissi (CNR Icmate, Italy)
Abstract:
Additive Manufacturing methods like laser-powder-bed-fusion are a promising preparation route for NiTi-based shape memory alloys as this class of material could benefit from the process inherent freeform capabilities to design a new generation of high-temperature transforming actuators. Powder quality and characteristics are crucial in achieving a stable high-temperature transformation, as it is sensitively affected by chemical composition and impurities. In addition, transformation temperatures can be shifted up by applying a stress to the material according to Clausius-Clapeyron’s law.In this study we report on the capabilities of NiTi-based Shape Memory Alloys powders processed by additive manufacturing for the realization of high temperature actuators. Particular emphasis is placed on the material transformation behaviour at high stresses. Differential Scanning Calorimetry, Scanning Electron Microscopy as well as mechanical tests in tensile and compression mode are performed to access microstructure, thermal properties and shape memory performance.
DOI:
https://doi.org/10.59499/EP256767895
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Authors:
V. Gauthier-Brunet (1); A. Zuber (1); J. Roger (2); J. Gonzalez-Julian (3); S. Dubois (1)
1- Institut PPRIME, CNRS/Université de Poitiers/ENSMA, UPR 3346, TSA 41126, 86073 Poitiers, France
2- Laboratoire des Composites ThermoStructuraux, Université de Bordeaux/CNRS/SAFRAN Ceramics, UMR 5801, 33600 Pessac, France
3- Institute of Mineral Engineering, RWTH Aachen University, 52074 Aachen, Germany
Abstract:
MAX phases are a family of nanolayered carbides and nitrides widely studied for their unique properties cumulating those of ceramics and metals. Cr2AlC is considered as one of the most promising MAX phase for its corrosion resistance properties. In this study, fine and coarse-grained Cr2AlC samples were respectively synthesized using spark plasma sintering and hot isostatic pressing techniques. The operating parameters were varied to optimize the purity and the density of the end-product.
Oxidation tests were carried out in dry air on fine and coarse-grained polycrystalline samples in the temperature range 800-1400 ◦C up to 1000h. Thermodynamic calculations were also performed to give further analysis of the experiments and to better understand the oxidation mechanisms. The effect of both the oxidation conditions and the MAX phases microstructural characteristics (grain size) were studied via the observation of the oxide layers morphology, the analysis of the oxidation products and the study of the oxidation kinetics.
DOI:
https://doi.org/10.59499/EP235763879
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Authors:
Håkan Pettersson (Seco Tools, Sweden)
Abstract:
Injection molding of hard metal inserts for cutting applications is used when making inserts with complex geometries. Inhomogeneity in the feedstock can cause defects in the inserts after sintering. An evaluation of the homogeneity of injection molding feedstock was made. The feedstock comprised a cemented carbide powder and a binder of polyolefins, paraffin wax, and petroleum jelly. Feedstocks with powder loading varying between 50 and 70 vol% were produced in steps of one vol%. Homogeneity was evaluated using visual inspection, mixing torque, feedstock density, and rotational and capillary rheometry. Switch over points, where the behavior of measured parameters of the feedstock rapidly changed between two feedstock samples with one vol% powder loading difference, were seen in most evaluation methods. Most switch over points were in the region around 58 to 60 vol% powder loading.
DOI:
https://doi.org/10.59499/WP225361766
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Authors:
Matteo Zanon (1), Andreas Förner (1), Darek Kossakowski (1)
1- Kymera International / Ecka Granules Germany, Germany
Abstract:
A new family of cobalt-free premixed materials for diamond cutting tools was developed as an alternative to both pure cobalt and "prealloyed" powders. This product family was designed to combine high mechanical properties with the compressibility and process simplicity intrinsic to the premixed approach. Hot pressing results are herein presented for several grades and compared to their free sintering performance. Influence of main processing parameters and their impact on physical and mechanical properties is discussed. The matrix interaction with synthetic diamonds and its degree of metallurgical bonding is studied as well, on both a qualitative and quantitative basis.
DOI:
https://doi.org/10.59499/EP235762765
