Euro PM2023 Proceedings

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

Authors:

Zahid Anwer (1); Jef Vleugels (1); Shuigen Huang (1)

1- Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, box 2450 - 3001, Leuven, Belgium

Abstract:

Fully dense high entropy carbide (Nb0.2Ta0.2V0.2Ti0.2W0.2)C - 10.64 wt.% Ni-based cermets were prepared by in-situ carbothermal reduction of mixtures of transition metal oxides from Group IV, V and VIB by a one-step reactive sintering technique. The molar ratio of metal oxides and graphite in the starting powder mixtures was varied and the evolution of the microstructure, grain size and morphology of the HEC phase was studied in detail. The in-situ carbothermal reduction of oxides resulted in a high entropy carbide phase with a homogeneous backscattered electron atomic number contrast with an extremely faint core-rim structure. This study demonstrates a facile and cost-effective alternative synthesis approach to prepare chemically complex high entropy carbide based cermets in a one-step pressureless sintering cycle. The two-phase HEC-Ni cermets exhibits an excellent hardness around 16.5 GPa and an acceptable fracture toughness around 7.5 MPa.m1/2.

DOI:

https://doi.org/10.59499/EP235763795

Authors:

Felix Radtke (1); Louis Becker (2); Simone Herzog (1); Jonathan Lentz (2); Sebastian Weber (2); Christoph Broeckmann (1)

1- Institute of Applied Powder Metallurgy and Ceramics (IAPK) Aachen, Germany

2- Chair of Materials Technology (LWT) Bochum, Germany

Abstract:

Additivated powders for powder bed fusion – laser beam (PBF-LB/M) process allow for innovative materials, which cannot be produced by conventional manufacturing techniques. In this study, Si3N4 powder is added to an austenitic steel powder for the manufacturing of high nitrogen steels (HNS). Therefore, two different types of additivation are investigated using tumbling mixers with and without grinding balls. Variations in the oxygen content and particle size distribution of the ceramic powder are analyzed to gain knowledge regarding influences on the rheological and reflective properties of the additivated powder. The flowability and packing density are determined as a function of humidity and drying parameters of the powder. The first samples of the investigated powders were processed by PBF LB/M. Microscopic investigation reveals new insights into the melting mechanisms of metal/ceramic mixtures. An analysis of the residual powder gives first indications regarding recyclability.

DOI:

https://doi.org/10.59499/EP235764243

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

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

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

Authors:

Faraz Deirmina (1), Lorenzo Quarzago (2), Eleonora Bettini (1), Matthew Ritche (3), Daniel Butcher (3), Shahin Mehraban (3), Nicholas Lavery (3), Massimo Pellizzari (2)

1- Powder R&D Group, Sandvik Additive Manufacturing, Sweden

2- University of Trento, Dept. of Industrial Engineering, Italy

3- Swansea University, MACH1 Laboratories, Dept. of Mechanical Engineering, United Kingdom

Abstract:

Hot work tool steels with medium C contents are known to be difficult to process by laser powder bed fusion (L-PBF). Cold and, to a lesser extent, hot cracking occurs in these alloys. Cold cracks are attributed to the low ductility and large residual stresses due to the complex thermal profiles. These can be avoided by platform preheating, which may introduce additional costs and side-effects on microstructure and properties. Therefore, the market trend is to develop new steel grades with improved 3D-printabilty. In this work, a prototype alloy with a leaner C content is proposed. To compensate for the negative effect of reduced C, computational thermodynamics was used to define chemistries with an optimized balance of carbide forming elements, and Si. The prototype tool steel shows enhanced L-PBF processability, and properties meeting and/or exceeding those of wrought AISI H13 in terms of hot strength, tempering and thermal fatigue resistance.

DOI:

https://doi.org/10.59499/EP235765264

Authors:

Lucas Vogel (1,2) ; Qaiser Ali Khan (2) ; Martina Zimmermann (3,4) ; Carlo Burkhardt (1)

1- Institut für strategische Technologie- und Edelmetalle, Hochschule Pforzheim, Tiefenbronner Str. 65, 75175 Pforzheim, Germany

2- Metshape GmbH, Tiefenbronner Str. 59, 75175 Pforzheim, Germany

3- Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS Dresden, Winterbergstr. 28, 01277 Dresden, Germany

4- Institut für Werkstoffwissenschaft, Technische Universität Dresden, Helmholtzstraße 7, 01069 Dresden, Germany

Abstract:

The need for additive manufactured parts with high dimensional accuracy and high surface quality leads to innovation in sinter-based AM. A promising approach is the emerging lithography-based metal manufacturing (LMM) which combines powder metallurgy and stereolithography. As this is a novel technology, this study aims to investigate the printing parameters: degree of powder filling of the feedstock, layer thickness, coating speed, coating mode and size of the material roll, with the help of a DoE. After the previously published investigation of green part characteristics, the samples are debound and sintered. These parts are analysed with focus on geometrical accuracy and densification. The DoE enables analysis of correlations between printing parameters and densification behaviour. Therefore, it improves the understanding of the technology and enables further optimization.

DOI:

https://doi.org/10.59499/EP235762089

Authors:

Naiqi Shang (1), Thomas Dahmen (1), Thomas Lundin Christiansen (1), Venkata Karthik Nadimpalli (1)

1- Department of Civil and Mechanical Engineering, Technical University of Denmark, Denmark

Abstract:

Low green strength of binder-jetted parts can lead to potential damage during depowdering and thus complicates green part handling. Understanding and optimizing green strength is therefore essential for the overall control and repeatability of the process. This study systematically investigates the effect of different saturation levels, layer thicknesses and part orientation on the mechanical properties, via compression testing, of binder-jetted cylindrical green parts. The results indicate excellent suitability of the spray-formed powder as binder jetting feedstock due to the uniform spherical particle morphology and high flowability. Mechanical testing indicated that higher binder saturation levels and loading direction perpendicular to the build direction are found to improve the compressive green strength, whereas the layer thickness only has a minor influence. The maximum compressive green strength was achieved as 7.67 MPa on average under the condition of 120% saturation and 90 µm layer thickness. Injection Molding requirements.

DOI:

https://doi.org/10.59499/EP235764032

Authors:

Hanna Nilsson Åhman (1,2), Pelle Mellin (1), Francesco D’Elia (2), Cecilia Persson (2)

1- Swerim AB, Sweden

2- Div. of Biomedical engineering, Dept. of Materials Science and Engineering, Uppsala University, Sweden

Abstract:

Powder bed fusion – laser beam (PBF-LB) of Mg alloys has great potential, both for producing patient specific implants and lightweight structures. However, the relationship among PBF-LB parameters, microstructure, and resulting material properties is poorly understood. As a first step towards a better understanding, the effect of various process conditions on the melt pool geometry and the microstructure formed is herein investigated. From the results it can be concluded that a lower scanning speed or a higher power result in deeper melt pools and more dendritic grains due to a warmer process. Similarly, thinner wall thickness also resulted in dendritic grains. A change in laser scanning line rotation between each layer showed that the grains tend to grow within the melt pool, rather than across several layers as seen for other alloys. These results show the importance of the parameters studied, and future work should investigate the resulting material properties.

DOI:

https://doi.org/10.59499/EP235762947

Authors:

Linus Lidman (1), Ralf Carlström (1), Joakim Lundh (1)

1-Höganäs AB, Sweden

Abstract:

17-4PH is the most used alloy in the metal injection molding (MIM) industry due to its high strength and hardness combined with modest corrosion resistance. Particle size distribution (PSD) of the powder used in a feedstock is key in how the end product will perform mechanically, feedstock processability and the appearance of the final components produced. Therefore, choosing a relevant powder fraction for a certain application becomes vital. This work focused on a special water atomized powder lot of the alloy 17-4PH sieved in different size fractions. A catalytic feedstock with identical powder loading was used for all grades. Properties evaluated were Sintered Density (SD), Melt Flow Index (MFI) and surface roughness. A simple way to boost the ductility and the repeatability in static properties of hydrogen sintered 17-4PH was successfully implemented.

DOI:

https://doi.org/10.59499/EP235765406

Authors:

Ángel Sota Muñoz (1,2), Nerea Burgos (1,2), Valentina Zhukova (3), Mihail Ipatov (3,4), Jose Manuel Martín (1,2), Julián González (3), Mikel Osinalde (5)

1- CEIT-Basque Research and Technology Alliance (BRTA), Manuel Lardizabal 15, 20018 Donostia/San Sebastián, Spain

2- Universidad de Navarra, Tecnun, Manuel Lardizabal 13, 20018 Donostia/San Sebastián, Spain

3- Department of Advanced Polymers and Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country, UPV/EHU, Manuel Lardizabal 3, 20018 Donostia/San Sebastián, Spain

4- SGIker (Magnetic Measurements), University of the Basque Country, Tolosa 72, 20018 Donostia/San Sebastián, Spain

5- Elesa, Abendaño 191, Zarautz, 20800, Spain

Abstract:

FeSiBNbCu amorphous powder has been fabricated via gas atomization. Two size fractions with 7:1 average particle size ratio have been mixed in a proportion of 73:27 vol.% respectively to improve particle packing. As a result, compact density has been increased up to ~10%, thus increasing magnetic saturation in the same proportion. The magnetic permeability of the compacts pressed from the mix increased a 70% compared with the compacts from one-size fraction powders. The power losses of mixed particle compacts consolidated at 800 MPa without heat treatment were 692 mW/cm3 (at 100 kHz and B=50 mT), whereas they were 548 mW/cm3 (at 100 kHz and B=50 mT) in the case of the same powder annealed at 535 ºC for 30 min.

DOI:

https://doi.org/10.59499/EP235765316