Euro PM2023 Proceedings

Authors:

Mélanie Charteau (1); Véronique Gauthier-Brunet (1); Valérie Audurier (1); Jean-François Silvain (2,3); Anne Joulain (1)

1- Institut Pprime - Université de Poitiers, CNRS, ISAE-ENSMA, France

2- Univ. Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, 33600 Pessac, France

3- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA

Abstract:

Electronic devices present a large coefficient of thermal expansion (CTE) mismatch between the copper thermal drain and the ceramic and silicon parts. This CTE mismatch causes thermomechanical stresses at the component interfaces (solder joint) resulting in component and/or solder joint failure. Copper composites reinforced with carbon fibres are materials of choice to overcome this drawback due to their expected adaptive CTE. To ensure good transfer of properties, chemical bonding between the matrix and reinforcement is necessary. The challenge of this work is to synthesize these composites, by hot uniaxial pressing, and to produce in-situ Zr-based interphase during the densification step. The microstructure and the chemistry of the matrix and of the interfacial zones, will be finely characterized by optical, scanning and transmission electronic microscopy.

DOI: 

https://doi.org/10.59499/EP235754770

Authors:

Neyder A. Sandoval (1), Sergio Sánchez Delgado (2), Daniel Serrano Garcia (2), Sophia A. Tsipas (1)

1- Materials Science and Engineering Department, IAAB, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911, Leganes, Madrid, Spain

2- Department of Thermal and Fluid Engineering, Universidad Carlos III de Madrid, Avda. Universidad, 30, 28911, Leganes, Madrid, Spain

Abstract:

Additive manufacturing (AM) is booming at an industrial level due to the possibility of producing components of complex geometry, while reducing use of raw materials, cost and time. However, in many processes there is still a lack of understanding of the composition-processing-microstructure relationship and a limited range of raw material compositions, as well as reproducibility problems. In search of improving these problems, surface modification of an aluminium alloy powder (Al2024) for its use in AM is proposed. A fluidized bed reactor was used for the surface functionalization with SiC nanoparticles. SiC nanoparticles were produced by milling and dispersed in colloidal suspensions. Homogeneity, stability, and rheology of the suspensions was studied. A homogeneous deposition of the nanoparticles on the host particles in the fluidized bed was obtained. The properties of samples produced with the modified powders were evaluated in comparison with samples produced with unmodified powders.

DOI:

https://doi.org/10.59499/EP235765429

Authors:

A. Colaneri (1), Y. M. El Sayed (1), L. Fransesini (1), S. Lionetti (1), F. Sciarrabba, P. Romeo (2), C. Burattini (2), G. Pispola (2)

1- RINA Consulting – Centro Sviluppo Materiali Spa, Italy

2- Umbragroup S.p.A., Italy

Abstract:

The effect of surface roughness on heat transfer capacity is still an active research area in the sector of heat exchanger manufacturing. Management of roughness is important because on one hand it has been demonstrated that a rough surface can increase the heat exchange, when this value is comparable to the height of the laminar layer, and on the other hand increasing surface roughness increase pressure drop which can reduce the performance of the heat exchanger. AM allows for the production of components with complex geometry (e.g. heat exchangers with internal cooling channels) but also with high surface roughness; thus it is necessary to refine the final product in order to reduce and optimize this aspect. The possibility of applying surface treatment methods to internal cooling channels of different dimensions in AlSi7Mg components obtained through Selective Laser Melting (SLM) technology is studied. The application of tumbling and electropolishing (ECP) is evaluated through an experimental campaign. Different tumbling and ECP conditions are applied with the aim of evaluating the penetration effect of the treatment into the channels of the component.

DOI:

https://doi.org/10.59499/EP235764667

Authors:

Hyrum D. Lefler (1), Mari Gilmore (1), Z. Zak Fang (1)

1- IperionX Limited, U.S.

Abstract:

Titanium (Ti) is often a preferred metal for its superior strength-to-weight ratio, corrosion resistance, bio-compatibility, and its high melting point. Despite these advantages, titanium’s high cost and high environmental burden have relegated its use almost exclusively to niche, high-dollar applications such as the aerospace and medical sectors. The rise of additive manufacturing has brought with it an increasing demand for low-cost and sustainable spherical Ti-6Al-4V (Ti64) metal powders. Current commercial spherical Ti64 powders are produced through melt atomization techniques, which are not suitable for recycling Ti scrap with high oxygen content, and thus are not adequate for achieving corporate and consumer sustainability goals. A novel technique for production of such powders from high oxygen Ti scraps has been developed using Hydrogen Assisted Metallothermic Reduction (HAMR) technology to minimize oxygen content. This approach has the potential to substantially decarbonize the global titanium metal industry.

DOI:

https://doi.org/10.59499/EP235764483

Authors:

Raquel de Oro Calderon (1); Milad Hojati (1); Robert Hellein (2); Stefan Geroldinger (1); Christian Gierl-Mayer (1); Herbert Danninger (1)

1- Technische Universität Wien (TU Wien), Austria

2- Miba Sinter Austria GmbH, Dr.-Mitterbauer-Str. 1; A-4655 Vorchdorf, Austria

Abstract:

The use of recyclable, non-toxic and non-critical alloying elements has become increasingly important in the last years. In particular, the volatile prices of Ni and Cu, and the increasing demand for these elements from the electromobility sector can eventually boost the prices, eliminating the price-competitiveness advantage of PM-steels. This work shows the newest advances in the investigation of PM-steels produced from more sustainable base powder alternatives (such as AstCrS), combined with Fe-Mn-Si-based masteralloys (i.e. a hybrid-alloy approach). Chemical analysis, CCT diagrams and mechanical properties are presented for steels with different hybrid compositions, sintered and heat-treated under different conditions. The results show how, by properly adapting the starting materials and sintering conditions and by combination with sinter hardening treatments, the use of more sustainable alloy compositions could be extended to additional PM application areas.

DOI:

https://doi.org/10.59499/EP235765115

Authors:

Aleš Nagode (1), Nejc Velikajne (2), Anemarie Veber (1), Irena Paulin (2), Matija Zorc (1), Borut Kosec (1), Borut Zorc (1), Milan Bizjak (1)

1- University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, SI-1000 Ljubljana, Slovenia

2- Institute of Metals and technology, Lepi pot 11, SI-1000 Ljubljana, Slovenia

Abstract:

AlSIMg10 is a heat-treatable hypoeutectic alloy with good castability and weldability, which makes it interesting for additive manufacturing (AM). In the present work, selective laser melting (SLM) technology was used to fabricate samples of AlSi10Mg alloy. One of the main challenges, however, is to produce an alloy with good microstructural homogeneity and as little porosity, residual stresses and cracks as possible. The main objective of this experimental research was to find the optimal process parameters for the fabrication of AlSiMg10 samples by SLM, which have a suitable microstructure and mechanical properties. Since defects in microstructure are usually due to inadequate process parameters, the effect of laser power and scanning speed were studied. Microstructural analysis was performed using LM and SEM/EDS. The changes in microstructure during post-processing heat treatment were followed in-situ by thermoelectrometric measurements based on electrical resistivity.

DOI:

https://doi.org/10.59499/EP235748755

Authors:

Giorgio Valsecchi (1), Elena Colombini (2), Magdalena Lassinantti Gualtieri (2), Cecilia Mortalò (3), Silvia Maria Deambrosis (3), Francesco Montagner (3), Valentina Zin (3), Enrico Miorin (3), Monica Fabrizio (3), Paolo Veronesi (4)

1-TAV VACUUM FURNACES SPA, Caravaggio, Italy

2-Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, Italy

3-National Research Council of Italy - CNR Institute of Condensed Matter Chemistry and Technologies for Energy – ICMATE, Padova, Italy

4-CNR Engineering ICT and Technologies for Energy and Transportation Department National Research Council of Italy, Roma, Italy

Abstract:

The development of tailored microstructures of Multi-principal element alloys (MPEAs) is currently a hot topic in physical metallurgy. The most targeted systems are equimolar alloys composed of 3d transition metals including the so-called Cantor alloy (i.e. CoCrFeMnNi) and derivatives such as CoCrFeNi and CoCrFeNiAlx. Powder metallurgy is a promising route for this purpose and include manufacturing techniques such as hot pressing of mechanically activated or prealloyed powders or the less popular press-sinter route of mixed powders. In this work, cold pressing followed by fast vacuum sintering (1h) at various temperatures (Tmax =1100-1300 °C) of mixed powders of CoCrFeNi and CoCrFeNiAl0.4 were explored for the synthesis of structurally and chemically homogeneous alloys. This approach is promising for the synthesis of bulk alloys of higher purity with respect to hot pressing of mechanically prealloyed powders. Microstructural investigations were performed by X-ray Powder diffraction (XRPD) and Scanning electron microscopy (SEM). It will be shown that the reactive sintering kinetics of the investigated systems require a Tmax of 1200 °C for effective alloying at the short holding time employed for CoCrFeNi. Instead, 1300 °C is needed for CoCrFeNiAl0.4.

DOI:

https://doi.org/10.59499/EP235762930

Authors:

Maheswaran Vattur Sundaram (1), Michael Andersson (1)

1- Höganäs AB, Höganäs, SE-26383, Sweden

Abstract:

The performance of PM steels is directly related to the material properties which is a consequence of the input alloying addition and processes involved. However, it is of significance to understand the hardenability requirements, specific to the component size/dimensions and the selected material for the specific heat treatment (HT) processes where gas and oil are used for quenching. Processes such as sinter-hardening, casehardening, and through-hardening are commonly performed to enhance the performances. In this work, quenching simulations were performed and a tool for hardenability calculation is developed with respect to the materials, components size, and different quenching mediums. For given component dimensions this tool predicts the suitable material and the cooling rate required to transform the microstructure into fully martensitic. This allows for minimising the number of trials required for optimising the HT process for PM steels.

DOI:

https://doi.org/10.59499/EP235755706

Authors:

Peter Nahringbauer (1), Markus Fürst (1), José Maria Tarrago (2), Reinhold Wartbichler (2), Steven Moseley (2), Walter Lengauer (1)

1- Vienna University of Technology, Austria

2- HILTI AG, Schaan, Liechtenstein

Abstract:

In a first part of this study 13 commercial cermet grades for use in saw blades were characterised with respect to hardness, fracture toughness, microstructure, grain size distribution, and a full chemical analysis was employed. Subsequently, various Ti(C,N) cermet grades of similar composition were prepared by a conventional powder-metallurgical route. For each of these laboratory grades the starting powder formulation was varied with respect to grain size and alloy status of the hard phases while keeping the overall starting composition identical. In addition, different sintering atmospheres were applied which influenced the mechanical properties and alloy status of the binder. The influence of sintering atmosphere, powder type and alloy status, and carbon doping on hardness, fracture toughness and concentration of dissolved elements in the binder is discussed. A broad range of properties was achieved with the identical overall starting composition but different hard-phase powders and sintering conditions. With some laboratory grades close agreement with properties of industrial grades could be achieved.

DOI:

https://doi.org/10.59499/EP235763624

Authors:

György Attila Harakály (1), Santiago Cano Cano (1), Johannes Bosters (1), Christian Gierl-Mayer (2), Gerald Mitteramskogler (1)

1- Incus GmbH, Austria

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

Abstract:

The Lithography-based metal additive manufacturing (LMM) is a sinter-based additive manufacturing (AM) technology to produce metallic components using a photocurable polymeric resin, filled with metal powder. The LMM printer uses this feedstock to fabricate parts by selective polymerization with a digital light processing engine layer by layer. No support structures are needed, as the feedstock resolidifies between layers and the parts are supported with unpolymerized material. Thanks to its high feature resolution and surface quality, common to Vat Photopolymerization AM, the LMM process enables part qualities unmatched with other metal AM methods for applications such as jewellery, electronics and microprinting. Here, the material properties of 316L stainless steel parts were analysed, with focus on the microstructure and mechanical properties. The results show that with an optimized debinding and sintering process, the LMM process enables the manufacturing of parts with properties above the Metal Injection Molding requirements.

DOI:

https://doi.org/10.59499/EP235765340

Authors:

Emir Poskovic (1,5), Marta Ceroni (2,5), Fausto Franchini (1,5), Luca Ferraris (1,5), Claudio Sangregorio (3,4,5), Andrea Caneschi (3,5), Marco Actis Grande (2,5)

1- Energy Department, Politecnico di Torino, Alessandria Campus, Viale T. Michel 5, 15121 Alessandria, Italy

2- Department of Applied Science and Technology, Politecnico di Torino, Alessandria Campus, Viale T. Michel 5, 15121 Alessandria, Italy

3- Department of Chemistry, Università di Firenze, Laboratory of Molecular Magnetism, via della Lastruccia, 13, 50019 Sesto Fiorentino (FI), Italy

4- Institute for the Chemistry of OrganoMetallic Compounds, Italian National Council for Research, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy

5- National Interuniversity Consortium of Materials Science and Technology (INSTM), Via G. Giusti 9, 50121, Florence, Italy

Abstract:

Rare Earth magnets have been used in different industrial sectors: household utilities, automotive applications, informatics sensors, etc. Rare Earth magnets show the best magnetic performance, predominantly in the case of Neodymium magnets. However, the economic aspect concerning the raw magnetic materials affects many of the magnet devices, mainly considering the instability of the raw material market. For these reasons, recycling NdFeB magnets is considered a promising solution. Different techniques are available, but they are generally expensive or very dangerous. This work proposes a new approach to recycling the NdFeB sintered magnets using a particular mechanical technique without using Hydrogen, resulting in a safer, less complicated and cheaper process than chemical methods. Based on an impact mill, the process has been performed to grind the magnets recovered from the hard disks. The operation was conducted in a vacuum. Finally, some bonded magnets with recycled powder have been prepared and characterized.

DOI:

https://doi.org/10.59499/EP235765549

Authors:

J J Dunkley (1), D Aderhold (1), T Williamson (1), A Mellor (1), J Westnedge (1)

1- Atomising Systems Ltd, Sheffield UK

Abstract:

The ever-increasing interest in additive manufacturing (both binder jetting and LPBF) has led to a renewed interest in gas atomising research across the globe. As this is being done by workers with different atomising equipment, the opportunity arises to test both theoretical and empirical correlations on a variety of designs. This paper reviews some relevant literature and sets out some basic equations and the relevant parameters that should ideally Figureure in all reports on gas atomisation tests. A methodology is proposed to standardise reporting of date, e.g. mass-median, standard deviation, graphical methods and operating parameters to allow some benchmarking by gas atomiser operators and allow improvements to be clearly identified. Remaining unanswered questions on gas atomisation will be discussed, which would surely benefit from more comprehensive publication, in particular the question of the importance of gas pressure in determining “efficiency” of atomisation, and how “efficiency” might be assessed and compared.

DOI:

https://doi.org/10.59499/EP235761079