Euro PM2024 Proceedings

Authors:

Veera Marttila (1), Päivi Kivikytö-Reponen (1), Juha Lagerbom (1), Elina Huttunen-Saarivirta (1)

1- VTT Technical Research Centre of Finland Ltd, Finland

Abstract:

Up to date, the environmental benefits of recycling cemented carbides, such as tungsten carbide cobalt (WC-Co), in comparison to their primary production, have been addressed only by a few research groups globally. However, the recycling of key elements, tungsten and cobalt, is crucial for supply security, as they are identified as Critical Raw Materials (CRM) by the European Commission [1]. Primary production of WC-Co, besides relying on scarce raw materials, requires high amounts of chemicals and energy. In this study, we focus on the recycling of WC-Co through zinc processing, for which the environmental impacts have not been reported earlier in the open literature. This study presents a life cycle assessment (LCA) for sintered WC-Co cemented carbide “bits” made from recycled WC-Co. The benefit of recycling WC-Co products is illustrated by comparing the LCA results to existing literature based on the primary production and alternative circular route of recycling.

DOI:

https://doi.org/10.59499/EP246277236

Authors:

Inge Lindemann-Geipel (1), Kay Reuter (1), Tillmann Simon (1), Bruno Weise (1), Torsten Mix (1), Thomas Studnitzky (1), Thomas Weißgärber (1,2)

1- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany

2- TUD Dresden University of Technology, Faculty Mechanical Engineering, Institute of Materials Science, Chair Powder Metallurgy, Germany

Abstract:

Screen printing offers great potential to print electrical steel sheets directly in desired shapes with exceptional low thickness (d < 350 μm) without typical constraints regarding materials ductility. Therefore, current demands in electric motor design can by addressed with the manufacturing of very thin sheets and high alloying contents. Furthermore, materials waste is neglectable using screen printing which is a crucial benefit as electrical steel is already a critical raw material. In this contribution, additive manufacturing of electrical motor components from isolated electrical steel sheets will be shown. Multi-material printing of metal and ceramic is used to shorten the manufacturing process avoiding elaborate multistep packaging processes and negative influence of mechanical processing of each electrical steel sheet. Additionally, the effects of the powder properties on the magnetic characteristics will be elucidated.

DOI:

https://doi.org/10.59499/EP246281537

Authors:

Saba Mohammadpour Kasehgari (1,2), Lisa Toller-Nordström (1), Annika Borgenstam (1,2)

1- Department of Materials Science and Engineering, KTH Royal Institute of Technology, Sweden

2- Wallenberg Initiative Materials Science for Sustainability, KTH Royal Institute of Technology, Sweden

Abstract:

Cemented carbides, which are one of the most important composites produced by powder metallurgy, exhibit an excellent performance within metal cutting and rock drilling tools when their hard phase, tungsten carbide, is bound by cobalt. However in recent years, due to health and ethical concerns related to cobalt, there has been a significant focus on designing alternative binders. The martensitic transformation in high-strength steel and its subsequent transformation-induced plasticity effect present a solution to substitute cobalt and improve the overall properties of cemented carbides. However, factors including residual stresses induced by tungsten carbide grains and confined dislocation mean free path significantly affect the martensitic transformation in these composites. In this study, a thermodynamic-based model for the martensitic transformation in steels has been utilized to predict the martensitic start temperature in cemented carbides. The model coupled with a CALPHAD-based approach presents a systematic solution for designing new steel-based binders.

DOI:

https://doi.org/10.59499/EP246280791

Authors:

Khalil Chaaban (1,2), Mostapha Ariane (2), Victor Szczepan (3), Jean-Philippe Chateau-Cornu (1)

1- ICB, UMR 6303 CNRS/Université de Bourgogne, Dijon, France

2- SINTERMAT SAS, Venarey Les Laumes, France

3- SAFRAN TECH, Magny-Les-Hameaux, France

Abstract:

Spark plasma sintering (SPS) technology is used to sinter a large range of materials in a very short time. One of the challenges of using this process is to control the final dimension of complex shaped parts. In order to predict the compaction of the powder during a SPS cycle, we develop numerical models which take into account several physical laws involved during sintering such as creep behavior at high temperatures (viscoplasticity). In this study, the deformation model is fitted on an experimental densification curve of a nickel-based superalloy and implemented via the Abaqus® software in a thermal-electrical-mechanical model of the SPS process. A comparison of the numerical outputs with the experimental data shows a good agreement. The results demonstrate the capability to simulate accurately the sintering of powder with a limited number of experimental adjusted parameters compared to literature and to decrease significantly simulation run-time.

DOI:

https://doi.org/10.59499/EP246281603

Authors:

Paul Schneider (1), Christophe Szabo (1), Karin Ljung (2)

1- Höganäs GmbH, Germany

2- Höganäs AB, Sweden

Abstract:

Sinterhardening is a commonly applied cost-effective process for producing higher loaded structural P/M parts. Generally, a prealloyed base powder is combined with further external alloying elements such as Ni or Cu in order to maintain the compressibility of the base powder. Astaloy® CrS is a newly developed low alloyed base powder prealloyed with 0,85% Cr and 0,15%Mo. This paper is investigating the mechanical properties after sinterhardening of various graphite and Ni additions admixed to Astaloy® CrS.

DOI:

https://doi.org/10.59499/EP246281794

Authors:

J. Pijuan (1), H. Maicas(1), S.A. Cegarra(1), R. Hernández(2), T. Baldi(3), S. Font(4), J. Nin(4)

1- Eurecat, Centre Tecnològic de Catalunya, Unit of Metallic and Ceramic Materials, Spain

2- Jorcar Titanium, Spain

3- GrupalArt SL, Spain

4- TMComas, Spain

Abstract:

In this study it is proposed to use machining metal chips with a pre-established and controlled chemical composition as raw material for metal powder production. The centrifugal atomization technology is used to produce this metal powder, bridging the gap between collecting recyclable metal scraps and obtaining the final powder, therefore enhancing the overall sustainability of the process. This study involves the collection of metal chips, their treatment for the removal of cooling liquids and other residues, and their subsequent use as raw material for metal powder manufacturing. Three different case studies are presented, including AlSi7Mg aluminium alloy, a Sn-based alloy also called White Metal alloy or Babbitt alloy, and a Ti6Al4V titanium alloy, illustrating the versatility and applicability of the proposed approach.

DOI:

https://doi.org/10.59499/EP246278293

Authors:

Geethapriyan Thangamani (1), Matteo Vanzetti (1), Stefano Felicioni (1), Anna Köll (2), Elisa Padovano (1,3), Federica Bondioli (1,3)

1-Politecnico di Torino, Italia

2-Research & Development Engineer, METALPINE, Austria

3-Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), Italia

Abstract:

GRCop-42 samples were additively manufactured by varying the electron beam powder bed fusion (EB-PBF) process parameters in a volumetric energy density (VED) range from 112.9 – 213.3 J/mm3: laser scan speed was varied from 450–850 mm/s, while voltage, power, line-offset and layer thickness were fixed parameters, to study their influence on the density, melt pool structure, and microstructure. Under the optimal conditions, the microhardness of the GRCop-42 samples achieved the highest value of 112.5 ± 6.3 HV. In addition, the microstructural evolution as a function of VED variation on additive manufactured GRCop-42 samples was examined using scanning electron microscopy (SEM) and X-ray Diffraction. From the microstructure observation, Cr2Nb precipitates, formed in the alloy during the printing process, reinforce the Cu matrix by preventing dislocation motion and impeding grain development.

DOI:

https://doi.org/10.59499/EP246281101

Authors:

Giovanni Carlucci (1), Edoardo Ferrario (1), Giorgia Lupi (1), Andrea Bianchi (2), Giulia Maranini (2), Mauro Coduri (2), Umberto Anselmi-Tamburini (2), Riccardo Casati (1)

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

2- Department of Chemistry, University of Pavia, Italy

Abstract:

Over the past decade, refractory high-entropy alloys (RHEAs) have been intensively studied due to their excellent high-temperature performances. Significant effort has been dedicated to reducing their density, aiming to make them competitive with Ni-based superalloys. However, RHEAs are typically produced through casting methods, which, given the high melting temperatures of their constitutive elements, may lead to inhomogeneous and coarse microstructures, thereby compromising their mechanical properties. Given this context, powder metallurgy would be a preferable route for manufacturing high-performing RHEA components. In this study, spark plasma sintering was employed to produce the biocompatible MoNbTaTiZr RHEA, later modified with the addition of aluminum to reduce its density. The microstructure and the mechanical properties of both alloys were investigated. Eventually, a component with a gradient of aluminum was also manufactured by a diffusion couple, allowing a more in-depth investigation on the effect of aluminum content on the properties of the RHEA.

DOI:

https://doi.org/10.59499/EP246274524

Authors:

Dr Jaroslav Kovacik (1), PhD.Eng. Dariusz Kołacz (1), PhD. Eng. Marcin Lis (1), Dr Eng. Joanna Kulasa (1)

1- Łukasiewicz Research Network-Institute of Non-Ferrous Metals, Gliwice, Poland

Abstract:

Mechanical properties of copper-graphite composites ought to be considered when designing their industrial applications in synergy with high electrical and thermal conductivity, low friction coefficient and coefficient of thermal expansion. Copper-graphite composites in range of 15-75 vol.% of graphite were densified using SPS technology at 900℃. Microstructures confirmed certain anisotropy for prepared composites. Random orientation is in cross section perpendicular to applied pressure, aligned graphite is in cross sections parallel to applied pressure. Compression properties: 0.2% yield stress, compression strength, reduction of height and modulus of elasticity were determined. Compression properties of copper-graphite system are nonlinear on composition, with increasing graphite volume fraction they are decreasing. Fracture surfaces were investigated: At 15 vol.% of graphite composite fracture is via ductile tearing, with increasing vol.% of graphite, intergranular fracture takes place. Some cleavage fracture paths are also partially observed. Finally, cross properties of compression properties to electrical conductivity were investigated.

DOI:

https://doi.org/10.59499/EP246282053

Authors:

Gaëlle Raveu (1), Jérémy Bischoff (1), Frédéric Viry (2), Julie Perard (2), Patrick Namy (2), Keerthanan Kandeepan (3), Adrien Collin De L’hortet (3)

1- Framatome, Romans-sur-Isère, France

2- SIMTEC, Grenoble, France

3- Framatome, Lyon, France

Abstract:

Framatome manufacturing plants use walking-beam furnaces to sinter large productions of fuel pellets. The sintering process of different products in the same equipment is complex with sublimation and reduction reactions involved, but also densification and grain-growth. Hence, Framatome started to model it with several benefits: - Increase reactions knowledge - Perform parametric studies without using the production equipment - Increase performance by process optimization - Compare the different equipment within Framatome and use the best developments - Create teaching tools through theoretical description of the process and its key influencing parameters The modelling is a step-by-step approach: first the geometry, gas flows and temperatures were established, then adding more detailed pieces. Validation of the model is then done with experimental data from production campaigns. Afterwards parametric sensitivity calculations can be performed to evaluate the influence of different parameters such as gas mixture, temperatures and therefore optimize the sintering.

DOI:

https://doi.org/10.59499/EP246281370

Authors:

Michael Andersson (1), Pernilla Johansson (2), Heike Heinrich (2)

1- Höganäs AB, Sweden

2- Höganäs Sweden AB

Abstract:

Sinter hardening is a cost efficient manufacturing process for press and sinter. At the same time material selection is crucial to make sure sufficient hardenability is reached. By selecting a higher alloyed material, hardenability can easily be satisfied, however this also increases the material cost. Thus, it’s interesting to be able to optimize the composition. In this paper the potential to use Astaloyâ CrS, a newly developed lean chromium grade, is investigated for sinter hardening with different combinations with nickel and graphite. A model is presented, where the cooling rates for sinter hardening conditions are calculated and combined with a calculation of the martensite transformation from a Time Temperature Transformation diagram (TTT). It’s demonstrated how the martensite content after heat treatment can be estimated by taking factors such as material composition, component size and quenching conditions into account. The calculated results are also compared with experiments in the paper. In the end, the tool can help making sure a component is properly hardened while optimizing the material composition cost.

DOI:

https://doi.org/10.59499/EP246277150

Authors:

Antoine Marie (1), Cédric Nicollet (1), Jeremy Bischoff (1), Frédéric Viry (2), Patrick Namy (2)

1- Framatome, France

2- SIMTEC, France

Abstract:

The ceramic-grade nuclear powder can be produced under two main routes, dry or wet "reconversion" processes, consisting in transforming crystalline UF6 as UO2 powder usable to produce fuel pellets. The dry conversion processes, used in Framatome, are divided in two steps: pyrohydrolysis and reduction by thermal treatments. The process used in Romans manufacturing plant has been studied years ago, but the improvements applied since and the product evolution associated have not been modelled. First, the UF6 to UO2F2 reaction and vessel are being modelled, with as benefits: • Better understanding of the process, • Set-up parametric tests without using industrial equipment, • Development of a numerical twin to be used as a training tool. In a further extent, the purpose is to be able to model the whole reaction vessel and calciner, including the chemical and thermic reactions, in order to correlate the final UO2 properties to the process parameters.

DOI:

https://doi.org/10.59499/EP246281691