Authors:
Ernesto Urionabarrenetxea (CEIT-BRTA, Spain) Alejo Avello (CEIT-BRTA, Spain) José Manuel Martín (CEIT-BRTA, Spain) Enrique Manuel Huerta (CEIT-BRTA, Spain)
Abstract:
Since gas atomized powders can exhibit significant variations depending on the scale of the atomization unit, powders produced in laboratory-scale units may differ noticeably from those obtained in industrial-scale units, even under seemingly identical atomization conditions. In this work, the initial experimental results obtained with a new industrial-scale atomization unit using the original gas and melt nozzles are firstly presented. It was observed that the resulting powders were coarse, the primary disintegration stage was far from optimal and premature solidifications were formed. In order to increase the productivity of the process, several melt nozzles were designed, simulated using CFD techniques and tested. The new designs enabled the production of powders with similar characteristics to those obtained with the laboratory-scale atomization unit. Numerical and experimental results are presented, analyzing the influence of key operational variables, including the preheating of the atomizing gas, on productivity and energy consumption.
DOI:
https://doi.org/10.59499/EP256767701
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Authors:
Federico Simone Gobber (Politecnico di Torino, Italy) Paolo C. Priarone (Politecnico di Torino, Italy) Antonio Pennacchio (Politecnico di Torino, Italy) Marco Actis Grande (Politecnico di Torino, Italy)
Abstract:
Additive manufacturing could offer promising advantages for sustainable production, particularly through material efficiency and innovative feedstock solutions. This study investigates the feasibility of producing AM powders from industrial waste, specifically AA5183 aluminum alloy chips from metal forming processes, using vacuum inert gas atomization (VIGA). Briquetted chips were melted under vacuum to minimize oxidation, and the molten metal was atomized with argon gas. The process achieved an overall powder yield of approximately 66% relative to the initial feedstock, with ~35% of the starting mass recovered as powder in the 20-63?µm size range suitable for laser powder bed fusion (PBF-LB|M). The obtained powders demonstrated chemical composition and morphology comparable to powders from conventional ingot feedstock, with only a slight increase in oxygen content due to chip surface oxides. Despite inherent challenges, such as dross formation reducing melting yield and persistent alloy hot-cracking tendencies, this work identifies a potential sustainable recycling route towards resource usage efficiency in AM applications.
DOI:
https://doi.org/10.59499/EP256764726
Authors:
Zhenghua Yan (1), Yan Liu (1), Zhoujin Lv (2), Jiawei Li (2), Chang Gao (2), Wen Qi (2), Anders Eklund (2)
1- Simtec Soft Sweden AB, Sweden
2- CISRI-HIPEX TECHNOLOGY CO., LTD, China
Abstract:
Hot Isostatic Pressing (HIP) is an increasingly used heat treatment process for densifying and enhancing the material properties of components in the aerospace, energy, medical, and additive manufacturing industries. Optimizing HIP cycles and designing efficient HIP furnaces are critical to determine hot-spots, and the computer simulation of the furnace’s processes is indispensable. In this study, which addresses the common convergence and the time-consuming issues of traditional simulations, a novel, fully coupled, and highly efficient Computational Fluid Dynamics (CFD) simulation method was employed. This method was utilized to model a complete 25-hour HIP cycle for a three-dimensional, full-scale furnace, including heating, holding, and cooling phases, based on the given furnace power. The advanced approach enables detailed, fully coupled and full-scale 3D computations of all critical processes, such as gas flow, pressure build-up, thermal radiative heat transfer, convective heat transfer, and conjugate heat conduction in solids. The simulation delivers results in a good agreement with the measurement. By avoiding the common pitfalls of error-prone simplifications, this method lays the groundwork for optimizing HIP furnace design and operations.
DOI:
https://doi.org/10.59499/EP246206006
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Authors:
Sandra Tedeschi (1), Fransisca Pirone (1), Mattia Garabelli (1), Domenico Ruggiero (1), Gian Pietro De Gaudenzi (1)
1- F.I.L.M.S. S.p.A. – OMCD Group, Anzola d’Ossola (Italy)
Abstract:
The application of the Functionally Graded Materials concept to cubic carbide-free hardmetals is commonly associated with achieving optimized mechanical properties in different regions of an article. In this work, special attention is given to maximize the corrosion and wear resistance of an outer layer while keeping the toughness values of the bulk material. This involves a detailed examination of gradients in the alloying of the metallic binder. A Ni-based outer layer, featuring a composition known for corrosion resistance, is sintered over a Co-based bulk with a medium WC grain size distribution. The concentration gradients of Ni and Co, along with the influence on mechanical properties and corrosion resistance, are thoroughly assessed. This analysis extends to the effects of additives such as chromium, molybdenum, with copper considered as an additional additive. The results reveal a promising path for the development of innovative hardmetal solutions in demanding applications.
DOI:
https://doi.org/10.59499/EP246278565
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Authors:
Christoph Höhnel (TU Dresden, Germany) Inge Lindemann-Geipel (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany) Bruno Weise (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany) Markus Schneider (GKN Sinter Metals Engineering GmbH, Germany) Thomas Weißgärber (TU Dresden, Germany)
Abstract:
Contrary to common understanding of die-compacted powder metallurgy parts, the strength of soft magnetic composites (SMCs) compacted to very high densities does not increase with rising density. Instead, SMCs exhibit a reduction in transverse rupture strength (TRS) when high green densities are achieved during compaction. This phenomenon has been investigated across six distinct SMC materials, varying in coating systems and particle sizes, alongside pure iron powder. The observed decline in TRS is consistent across all powders studied, primarily due to reduced oxygen penetration during the debinding process and subsequent heat treatment. Notably, powders with smaller particle size distributions demonstrate a more pronounced decrease in TRS at earlier stages. To address this issue, strategies aimed at minimizing the reduction in TRS will be explored and discussed, offering potential solutions for improving the performance of SMCs in practical applications.
DOI:
https://doi.org/10.59499/EP256767851
Authors:
Matteo Zanon (1); Armin Müller (1); Darek Kossakowski (1); Aljoscha Roch (2); Joseph R. Croteau (3); Tom Pelletiers (3)
1- Kymera International / Ecka Granules Germany, Germany
2- AM Extrusion GmbH, Germany
3- Kymera International / SCM Metal Products, USA
Abstract:
Among the sinter-based technologies, Fused Filament Fabrication (FFF) is proving itself as a low capital investment, small series approach to 3D printing. Firmly established for plastics, it can be extended to metals by composite filaments with around 60% metal loading by volume. The large quantity of binder, necessary for the filament compounding and extrusion, poses special challenges to the debinding process. This becomes especially true with reactive materials such as aluminium, but also when targeting high electrical conductivity in copper, which is extremely sensitive to residual impurities. Metal powder and binder expertise must then be brought together to enable this technology to compete in the 3D printing market.
The current joint work presents results with both aforementioned classes of non-ferrous powders, highlighting the impact of debinding procedure and powder characteristics on the final sintered and microstructural properties. Effect of heat treatment is also investigated.
DOI:
https://doi.org/10.59499/EP235761372
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Authors:
Vanzetti Matteo (1), Pavel Michael (2), Perez Andrade Lorena (2), Padovano Elisa (1), Aversa Alberta (1), Weaver Mark (2), Brewer Luke (2), Bondioli Federica (1)
1- Politecnico di Torino, Torino, Italy
2- University of Alabama, Tuscaloosa, USA
Abstract:
Metallic powders are one of the most common feedstock materials for metal additive manufacturing (MAM). Nowadays, only few alloys can be processed by these technologies and most of them are casting alloys. This work is focused on the characterization of a novel aluminum alloy produced by a close coupled gas atomizer (CCGA) with composition AlSi10Mg + X Cu (X= 4, 8, 20 wt%). These compositions are very attractive because copper is a well-known strengthener for aluminum alloys. The produced powders were characterized in terms of morphology, flowability, particle size distribution (PSD) and density. Furthermore, the powders microstructures were analyzed to evaluate the composition and the morphology of the phases generated by the rapid solidification that characterized the gas-atomization process.
DOI:
https://doi.org/10.59499/EP235763134
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Authors:
Daniel Rodrigues (1), Suzilene Real Janasi (1), Fábio Miranda (2), Fernando dos Santos Ortega (3)
1- BRATS Sintered Filters and Metallic Powders, Cajamar, Brazil.
2- University of São Paulo – Polytechnic School – EPUSP – PMR, São Paulo, Brazil.
3- UNIVAP, São José dos Campos, Brazil.
Abstract:
Gelcasting has been successfully used to produce high-performance sintered ceramic components, and large shrinkages during sintering at high temperatures are common for obtaining high-density parts, since very fine ceramic powders are used as raw material. The same approach can be applied for cemented carbides (hardmetals), and near net shaped parts can be produced using moulds and, if necessary, additional turning operations before sintering can be used. Fine niobium carbide, nickel and tungsten carbide powders were used to produce aqueous slurries, which were adjusted to mold samples to obtain sintered cemented carbides with homogeneous microstructure and with a good combination of hardness and toughness. The slurry stability was investigated mainly considering the loading of solids. The nature and amounts of monomers, dispersants and additives were also investigated. Samples and prototypes were sintered at high temperature in vacuum, and characteristics such as density, microstructure and hardness were evaluated.
DOI:
https://doi.org/10.59499/EP235764239
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Authors:
Magdalena Nowak-Coventry (Toyota Motor Europe, Belgium) Artur Jojczyk (Toyota Motor Europe, Poland) Nicola Casari (ToffeeX, United Kingdom)
Abstract:
In this study, a physics-driven generative AI software was employed to design conformal cooling for a casting tool. The cooling performance was analysed using casting simulation software and compared to current pin cooling and self-designed conformal cooling. The results demonstrated significant improvements in temperature, heat transfer coefficient (HTC) and soldering. Additionally, the time required to design appropriate cooling can be reduce by 50%. The optimized tool was subsequently printed and is scheduled for testing in production.
DOI:
https://doi.org/10.59499/EP256779436
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Authors:
Soundariya Ravi (1), Mária Fáberová (1), Radovan Bureš (1), Vladyslav Kostiuk (1), Vasily Milyutin (1), Róbert Džunda (1), Zuzana Birčáková (1)
1- Institute of Materials Research, Slovak Academy of Sciences, Košice, Slovakia
Abstract:
Soft magnetic composites are materials based on ferromagnetic particles surrounded by secondary electrical insulating components. The geometric size&shape of the ferromagnetic particles are crucial for the functional properties of consolidated SMC materials. Modern electronic and engineering applications create pressure for the development of materials applicable at increasingly higher frequencies of alternating magnetization. An increase in the frequency stability of the magnetic properties can be achieved by reducing the size of the ferromagnetic particles and/or by increasing the thickness of the electrical insulation layer. In any case, permeability and magnetic flux density decrease. The subject of this research is the preparation of FeSiAl particles realized by several methods of resonant acoustic and ball milling. Spherical and flake-like ferromagnetic particles with different distributions of Si and Al were prepared. Coercivity as well as changes in density and compressibility were studied depending on the structural and geometrical characteristics of the powders.
DOI:
https://doi.org/10.59499/EP246281454
Authors:
Robert Teuber (Fraunhofer IFAM Dresden, Germany), Thomas Weißgärber (Fraunhofer IFAM Dresden, Germany), Thomas Studnitzky (Fraunhofer IFAM Dresden, Germany)
Abstract:
The MoldJet process is a new and innovative, sinter-based additive manufacturing process that combines two generative process steps. This synergy enables an enormous variety of shapes from small filigree to large-volume 3D-printed metal parts. Many comparable AM processes specialise in just one spectrum of geometries or are limited by the printing process and following process steps. The MoldJet process offers the possibility of producing different component geometries not only simultaneously, but also without the use of support structures made of part material. In this paper, the application range of the process is presented. On the basis of evaluation geometries, it is analysed where the minimum for wall thicknesses at the printing process lies. On the other hand, component geometries with large external dimensions on the one hand and large-volume component areas on the other hand are produced and limitations with regard to the printing process are also determined here.
DOI:
https://doi.org/10.59499/WP225368437
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Authors:
Ricardo Chávez-Vásconez (1,2), Nicolás Acevedo (1), Cristina Arévalo (2), Sergio Sauceda-Martínez (2,3), Eva Pérez-Soriano (2), Yadir Torres (2), Sheila Lascano Farak (1)
1- Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Santiago, Chile
2- Departamento de Ingeniería y Ciencia de los Materiales y del Transporte, Escuela Politécnica Superior, Universidad de Sevilla, Sevilla, Spain
3- Departamento de Ingeniería de Materiales, Universidad de Concepción, Concepción, Chile
Abstract:
High entropy alloys (HEAs) are potential materials for biomedical applications due to their unique properties. Also, the use of functionally graded porous materials (FGPM) presents an interesting approach that could help to decrease the Young’s modulus while simultaneously mimicking highly hierarchical porosity of the bone structure. In this study, Field Assisted Sintering Technology/Spark Plasma Sintering (FAST/SPS) and space-holder techniques were used to determine the viability of its use for produce HEAs which exhibit radially graded porous structures from Ti, Nb, Ta, Hf and Mo powders, using NH4HCO3 as space-holder. Results have shown that the radially porous gradient was formed when sintering at 1450°C and 10 min, but the sintering necks were not sufficient to provide adequate mechanical properties and achieve the desired porosity levels. Hence, future studies have to be carried out to determine the adequate sintering parameters to achieve good diffusion between particles.
DOI:
https://doi.org/10.59499/EP246283678
