Euro PM2024 Proceedings

Authors:

Maria de Nicolás-Morillas (1), Alberto Meza (1,2), Sivagnana Venkatesh Kumaran (1), Adrian Cotobal (1), Diego Iriarte (1), Daniel Martín (1), Srdjan Milenkovic (1), José Manuel Torralba (1,2)

1- Sustainable Powder Technologies – IMDEA Materials Institute, Tecnogetafe, Madrid, Spain

2- GTP – Universidad Carlos III de Madrid, Madrid, Spain

Abstract:

The battle against climate change requires alternative and renewable energy supplies, where hydrogen has emerged as an excellent candidate. Its most cost-effective storage is in its gaseous form, with the use of metallic pressure vessels. Compared to traditional compositions, such as steels, High Entropy Alloys (HEAs) arise as promising materials with stable phases resistant to the phenomenon of hydrogen embrittlement. In this investigation, two HEA compositions have been studied: AlCoCrFeNi2.1, a biphasic-eutectic (BCC+FCC) alloy, and CoCrFeNiMo2.1, a monophasic (FCC) one. They were processed via Laser Powder Bed Fusion (LPBF). Moreover, an annealing treatment was applied to LPBF samples, seeking to study the variation of the microstructural scenario and its effect in the mechanical behaviour of the material in a hydrogen-pressurized atmosphere. In doing so, as-built and annealed samples were subjected to three-point bending tests in a range of 0-280 bar of H2, showing the superior behaviour of the monophasic-FCC HEA composition.

DOI:

https://doi.org/10.59499/EP246278417

Authors:

Carlos Belei (1), Zuzana Kovacova (1), Johannes Bieg (2), Erich Neubauer (1)

1-RHP-Technology GmbH, Technologie- und Forschungszentrum, Austria

2-ESA - European Space Research and Technology Centre (ESTEC), The Netherlands

Abstract:

This study investigated the hot pressing of three distinct high entropy alloy (HEA) powder compositions, namely CrMo0.5NbTa0.5TiZr (named HEA-01), AlCrMoNbTi (HEA-02) and AlCrFeNiTi (HEA-03). The experimental design focused on varying temperature and dwell time, while pressure remained constant. Density was adopted as a response, which was assessed through both quantitative (using Archimedes density test with theoretical densities as a reference) and qualitative analysis (via microstructural examination). Subsequent hardness testing was also performed. It was observed that for HEA-01 and 03, fully dense parts were achieved in conditions where reactions between the constituents occurred, which resulted in material loss via “squeezing” phenomenon (i.e., when excess material is expelled from the die during pressing). HEA-02 achieved densities above 99% without major squeezing or melting being reported. In any case, the observed microstructure was considered heterogeneous. Depending on processing conditions, HEA-01 and HEA-02 reached hardness values of 341 ± 25 and 429 ± 37 HV10, respectively, while HEA-03 was measured at 525 ± 25 HV10.

DOI:

https://doi.org/10.59499/EP246281334

Authors:

Montero-Sistiaga Maria (1), Osinga Timo (1), Haagsma Ralph (1), Bottazzi Olmo (2), Esveldt Vincent (2), Bautmans Ludo (3), Hamer Wouter (4), de Smit Marc (1)

1- NLR- Royal Netherlands Aerospace Centre, Marknesse, Netherlands

2- Mokveld Valves B.V., Gouda, Netherlands

3- Oerlikon Metco AM powders, Sint Truiden, Belgium

4- Shell Global Solutions International B.V., Amsterdam, Netherlands

Abstract:

Extensive research is currently done on microstructure and mechanical property characterisation of metal additive manufacturing technologies. However, there remains a limited focus on the combination of these technologies. This study addresses this gap by combining laser powder bed fusion (LPBF) and directed energy deposition (DED) technologies to produce a check valve. The interior of a valve requires high corrosion resistance which can be obtained using In718, while the exterior benefits from more cost effective material, in this case 316L. From the consolidation side, LPBF allows the production of small complex features and DED offers a higher production rate and the possibility of tailoring compositions and mechanical properties. The interface quality and microstructure of different multi-material combinations were studied in this work. Tensile properties were investigated of hybrid multi-material parts to select the best combination. In addition, the production route for producing a multi-material check valve combining LPBF and DED was developed.

DOI:

https://doi.org/10.59499/EP246281394

Authors:

Farshad Khorasani (1), Aydin Selte (2), Yu Cao (1)

1- Chalmers University of Technology, Sweden

2- Uddeholm AB, Sweden

Abstract:

Hybrid tool steels, designed to meet diverse specifications, offer superior fatigue life, toughness, and abrasion resistance. However, this may pose significant challenges in traditional manufacturing. The current study explores the use of Hot Isostatic Pressing (HIP) to bond a high-wear-resistant cold work tool steel powder (Vanadis 8 SuperClean) with a tough hot work tool steel bar (Orvar 2 Microdenodized). The effectiveness of HIP in creating hybrid tool steels is assessed. The impact on the microstructure and mechanical property in terms of hardness in the bonding zone has been examined by employing various analytical methods and simulations. The results confirm a strong bond achieved through HIP, with promising initial outcomes.

DOI:

https://doi.org/10.59499/EP246278227

Authors:

Thalita Queiroz e Silva (1), Meysam Mashhadikarimi (1), Pâmala Samara Vieira (1), Anderson Costa Marques (1), Gabriel Dos Santos Vasconcelos (1), Lucas Marques Dos Santos (2)

1-Materials Science and Engineering Postgraduate Program, Federal University of Rio Grande do Norte, Brazil.

2-School of Science and Technology, Federal University of Rio Grande do Norte, Brazil.

Abstract:

Composites formed by a copper matrix, reinforced by a ceramic and refractory material, stand out due to their relevance in electrical conductor applications. In this context, this study investigated the hardening of copper powder with the addition of different concentrations of tungsten carbide (5, 10, 15 and 20% by weight) prepared by high-energy milling (HEM) for 1, 2, 5, 10 and 20 hours. The powders were characterized by SEM, XRD and Vickers microhardness. The results showed that the milling method was efficient for obtaining Cu-WC composites, with strong bonds between the phases. The diffractograms showed characteristic copper and tungsten carbide peaks, with no secondary phases. The Vickers microhardness value is directly related to the amount of WC and the milling time; consequently, the 20% WC composite powder milled for 20 hours had a microhardness of 251 HV, exceeding the values of the other powders.

DOI:

https://doi.org/10.59499/EP246281184

Authors:

G. Riu-Perdrix (1,2), A. Isalgué (3), N. Cinca (4), L. Llanes (2), J.J. Roa (1)

1- Steros GPA Innovative S.L., Barcelona, Spain

2- CIEFMA-Department of Materials Science and Engineering – Universitat Politècnica de Catalunya – BarcelonaTech, Campus Diagonal Besos-EEBE, Barcelona, Spain

3- Dep. Física, Universitat Politècnica Catalunya, Barcelona, Spain

4- Hyperion Materials & Technologies, Pol. Ind., Martorelles, Spain

Abstract:

The surface integrity in terms of phase transformation for the metallic cobalt (Co) binder and compressive residual stresses (scomp) on ground WC-10wt.%Co specimens and sequentially dry-electropolished was studied by means of synchrotron radiation. In-situ heating up to 900ºC helped in monitoring the reverse transformation induced during the pre-processing process, from h.c.p- to f.c.c-Co. It was revealed that as the dry-electropolishing process time increased, the full width at half maximum of XRD peaks decreases, associated with slight reduction of the distribution of the scomp near the surface of the specimens. In addition, both ground and dry-electropolished specimens exhibited a release in scomp as result of the thermal treatment. Deeper study on the Co phase revealed that on heating, the h.c.p. peak intensity decreased, specially for the polished samples, while the f.c.c. one increased, confirming the h.c.p to f.c.c phase reversion reaction for the metallic Co binder.

DOI:

https://doi.org/10.59499/EP246286628

Authors:

Felix Großwendt (1), Nick Hantke (2), Santiago Benito (1), Jan T. Sehrt (2), Sebastian Weber (1) and Jonathan Lentz (1)

1- Chair of Materials Technology, Ruhr University Bochum, Germany

2- Chair of Hybrid Additive Manufacturing, Ruhr University Bochum, Germany

Abstract:

With many commercially available alloys, powder bed fusion of metals using a laser beam (PBF-LB/M) results in the formation of defects such as cracks due to high cooling rates. To obtain a broader variety of starting materials suitable for PBF-LB/M and specific applications, mixing powders, so-called in-situ alloying, using a modular powder design set is a promising approach. Unfortunately, in-situ alloying promotes chemically inhomogeneous components. In this work, different powder mixtures were analyzed and processed to obtain a carbon steel of specified composition. The samples were microstructurally characterized using several methods and compared to a pre-alloyed reference. The chemical homogeneity is statistically evaluated employing first-order variograms. It was found that the composition of the individual raw materials is decisive for the homogenization within the melt pool. Large scale homogenization is also influenced by the amount of raw material added. By carefully selecting the raw materials, almost complete in-situ homogenization was achieved in PBF-LB/M.

DOI:

https://doi.org/10.59499/EP246282740

Authors:

Lea Reineke (1), Regina Schlegel (1), Dr. Sebastian Boris Hein (1)

1- Fraunhofer IFAM, Bremen, Germany

Abstract:

Metal Binder Jetting (MBJ) has an increasing attention in Additive Manufacturing because of its serial production potential. The aim of this work is to get a better understanding of the powder-binder-interaction for better process control and consequently a reduction in the number of iteration stages in material-specific process development, which saves costs, effort as well as material resources and printing capacity. Depending on the binder characteristics, the equilibrium saturation and wetting behavior changes. A better understanding of binder viscosity and surface tension on the powder-binder-interaction will improve the part quality. A suitable parameterization of the MBJ printing processes for specific powder-binder combinations, based on the binder and powder characteristics as well as the powder-binder interaction will improve the part density, accuracy and surface quality. The results show that, depending on the binder characteristics, the equilibrium saturation and wetting behavior changes. A higher surface tension seems to cause a higher equilibrium saturation and a lower saturation rate. The effect of the surface tension on the initial wetting time was overlaid by the effect of the surface chemistry. A higher viscosity leads to a significant higher initial wetting time on the powder bed surface, significant higher equilibrium saturation and a significant lower saturation rate. The relationship between wetting behavior and printing parameters as well as the effect of drying and droplet impact must be investigated further in subsequent studies.

DOI:

https://doi.org/10.59499/EP246233737

Authors:

E. Guy (1,2), R. Guillou (1), X. Boulnat (2), M. Perez (2), J. Malaplate (1)

1- Université Paris-Saclay, CEA, Service de Recherche en Matériaux et procédés Avancés, France

2- Univ. Lyon, INSA-Lyon, UCBL, MATEIS UMR CNRS 5510, France

Abstract:

ODS steels are serious candidates for fuel cladding in 4th generation nuclear fast fission and fusion reactors. Meanwhile nano-precipitation is beneficial, the presence of a coarse precipitation (mostly carbides) usually known to deteriorate mechanical properties, could be detrimental. In this study, two ODS ferritic steels with different carbon contents (200 ppm and 700 ppm) have been elaborated by powder metallurgy and consolidated by Hot Isostatic Pressing, in order to evaluate C-rich precipitates influence on microstructural and mechanical properties. Nano-precipitates analysis revealed that nano-oxides size and density were similar in low and high carbon content materials. Microstructure examination showed a bimodal grain size for both materials, with equivalent mean size. Coarse precipitation of Cr23C6 only occurred in the higher C content material with an elongated shape, located at grain boundaries. Impact toughness properties are highly degraded when C content is increased, as C-rich precipitates act as initiation sites of failure.

DOI:

https://doi.org/10.59499/EP246277178

Authors:

Juan Cornide (1), Manuel Parra-Martínez (1), Daniel Cuenca-Fernandez (1), Emilio Frutos (1)

1- Department of Chemical and Materials Engineering, Faculty of Chemistry, Complutense University of Madrid (UCM), Madrid, Spain

Abstract:

Refractory Eutectic High Entropy Alloys (RHEAs) with body-centered cubic (BCC) single-phase structures have attracted extensive attention in hydrogen storage due to their unique structural characteristics and excellent performance. A general observation shows that BCC structures form more stable hydrides than Laves phase-based hydrides. In the present study, several Ti7Nb6Cr4-xNi(1+x)VAl (x=0,2) RHEAs obtained by high-energy mechanical alloying were investigated to understand the influence of the Chromium/Nickel ratio on the transition from BCC and C14 Laves phase into a single BCC phase. The research was conducted through SEM and X-ray diffraction analysis. Additionally, several thermodynamic parameters such as the enthalpy of mixing (ΔHmix), size difference (δ), valence electron concentrations (VEC), and electrons per atom ratio (e/a) have been correlated with the experimental data.

DOI:

https://doi.org/10.59499/EP246282478

Authors:

Aurélien Etiemble (1), Sandra Simon (1), Claire Rigollet (1)

1- LabECAM, ECAM Lasalle, Université de Lyon, France

Abstract:

Material extrusion additive manufacturing (EAM) offers a versatile range of applications for various metallic materials. In indirect processes, a mixture of metal powder and a polymer binder is extruded and deposited to shape the layers of the part, analogous to traditional polymer 3D printing. Subsequently, debinding and sintering steps are indispensable to achieve the final metallic component. Each of these stages may induce impurities and defects, significantly impacting geometric tolerances and mechanical properties. These defects such as warpage, shrinkage, porosity, residual carbon, and undesired phases result from complex mechanisms, due to insufficient or heterogeneous loading of feedstock, thermomechanical distortion during printing, partial debinding and inefficient sintering. This presentation will delve into these challenges, mechanisms, and EAM optimization strategies in the case of stainless and tool steels. The influence of feedstock formulation and associated process parameters on defects, microstructure, and resulting mechanical properties will be discussed.

DOI:

https://doi.org/10.59499/EP246281341

Authors:

Shahzad Salam (1), Ichiro Mitama (1), Takuma Sakata (2)

1- Technology Research Center, Sumitomo Heavy Industries Ltd., Japan

2- Corporate Planning Department, Sumitomo Heavy Industries Ltd., Japan

Abstract:

Powder quality is a critical processing parameter in powder-based metal additive manufacturing that can affect both the processability and mechanical properties of the manufactured parts. While commercially available powders come in various shapes, sizes, and distributions, it is essential to understand the impact of these powder characteristics on the finished product. This study investigates the correlation between powder characteristics and stress-rupture behavior of IN718 alloy. Test samples were fabricated using laser powder bed fusion (L-PBF) with powders of varying characteristics. The results indicate that the samples fabricated with powder of optimal characteristics contained fewer microstructural defects resulting in a significant 13-fold improvement in rupture-life. The aim of this article is to discuss these powder effects and provide a basis for producing final components with consistent mechanical properties.

DOI:

https://doi.org/10.59499/EP246278214