Euro PM2024 Proceedings

Authors:

Arnaud Leclef (1,2), Alexandre Mégret (1), Véronique Vitry (1), Arnaud Tricoteaux (2)

1- Metallurgy Unit, Faculty of Engineering, University of Mons, Belgium.

2- Céramaths, UPHF, France

Abstract:

The use of cobalt as binder for tungsten carbide raises more and more questions of environmental, health and societal ethics. The aim of this study is to find alternatives to cobalt as a binder for tungsten carbide. The binders investigated for this study were FeMn-based binders. The latter were carbon-doped to prevent the presence of eta-phase. Expected results required HV30 > 1600, and fracture toughness > 10 MPa·m1/2. The first aspect is to model the phases that were generated by the replacement of cobalt. Pseudo-binary phase diagrams have been performed. The second aspect was to process the alternative "WC – promising alternative binder" composites. The powder metallurgy method was chosen for this purpose. Vacuum sintering technology was used. The samples were then mechanically and morphologically characterized.

DOI:

https://doi.org/10.59499/EP246278247

Authors:

Alejo Avello (1,2), Ernesto Urionabarrenetxea (1,2), José Manuel Martín (1,2)

1- CEIT-Basque Research and Technology Alliance (BRTA), Donostia- San Sebastián, Spain

2- Universidad de Navarra, Tecnun, Donostia-San Sebastián, Spain.

Abstract:

Prediction of particle size distribution (PSD) in close-coupled gas atomization is of great interest to optimize nozzle designs and to accelerate the choice of optimum operational variables in first-time atomizations. Previous works have shown that CFD simulations based on simplifying assumptions can correctly predict trends of median particle size of copper powders produced at different nitrogen pressures. In this work, a refinement of the simulation procedure developed by the authors is pre-sented. Particle breakup is computed from a Discrete Phase Model (DPM), with injection input data calculated from an Eulerian model. The new model is used to compare, for the first time, simulated and experimental results of three different pairs metal-gas: copper with nitrogen, copper with argon and tin with nitrogen. Even for materials with such disparate melting points, the simulations predict quite accurately the median particle size for varying gas-to-metal mass flow rate ratios.

DOI:

https://doi.org/10.59499/EP246282819

Authors:

Kazi Sofia (1), Leach Lindsay (2), Hryha Eduard (1)

1- Chalmers University of Technology, Gothenburg, Sweden

2- Alfa Laval Technologies AB, Eskilstuna, Sweden

Abstract:

Powder degradation during additive manufacturing poses a significant challenge for achieving optimal part quality as well as maximal powder feedstock utilization and hence economy and sustainability of the process. Stainless steel 316L is a widely utilized material in powder bed fusion – laser beam (PBF-LB) due to its excellent processability, good corrosion resistance and mechanical properties of the PBF-LB processed components. This study investigates the influence of 316L powder properties and powder reuse on the powder surface oxide chemistry and hence processability by PBF-LB. Changes in powder surface chemistry were studied by HR SEM and X-ray Photoelectron Spectroscopy in virgin and reused state. Results indicate that there is evident degradation in powder properties during powder re-use with increase in oxygen content in the powder, connected to increase in thickness of iron-base surface oxide layer as well as fraction of Cr-rich particulate oxide phases.

DOI:

https://doi.org/10.59499/EP246282011

Authors:

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

1- Institut für strategische Technologie- und Edelmetalle, Hochschule Pforzheim, Germany

2- MetShape GmbH, Germany

3- Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS Dresden, Germany

4- Institut für Werkstoffwissenschaft, Technische Universität Dresden, Germany

Abstract:

The lithography-based metal manufacturing (LMM) process is a novel additive manufacturing technique that enables the sinter-based manufacturing of metal parts with high dimensional precision and exceptional surface quality. To effectively apply this technology, comprehending the relationship between mechanical properties and printing orientation is imperative. Given the relative novelty of this technology, our study seeks to explore the influence of manufacturing orientation on both the mechanical properties and shrinkage behaviour of stainless steel 17-4PH. In most additive manufacturing technologies typical variations in mechanical properties is observed in every axis, our investigation focuses on assessing the tensile properties of the material in all orientations. Tensile bars are fabricated accordingly and evaluated in terms of density and dimensions as both green and sintered components. Subsequent to the sintering process, an in-depth analysis of mechanical properties and microstructure is conducted to elucidate the inherent correlations between the technology and material.

DOI:

https://doi.org/10.59499/EP246278376

Authors:

Maxence Guillon (1), Xavier Boulnat (2), Pauline Lambert (1), Joël Lachambre (2), Thomas Elguedj (3), Christophe Desrayaud (1)

1- Mines Saint-Étienne, Université de Lyon, LGF, France

2- INSA Lyon, Université de Lyon, MATEIS, France

3- INSA Lyon, Université de Lyon, LaMCoS, France

Abstract:

Laser Powder bed Fusion is a strong process enabling the on-demand production of components with complex geometry and high added value. Despite its strengths, there are still significant challenges to fully understanding the interaction between laser and powder. The interaction between laser and material differs significantly between single tracks and multiple tracks. In a single track, the laser only interacts with the powder. In contrast, for multiple tracks, the laser interacts also with the previously laid tracks. This underscores the inadequacy of characterizing only a single track for a comprehensive understanding of the interactions between laser and powder. Moreover, previous analyses show a focal shift that cannot be neglected on the machine used. Hence, this works aims at characterizing the melt pool during the formation of a single and multiple tracks with 316L powder material. The consequence of the focal shift is observed and measured.

DOI:

https://doi.org/10.59499/EP246281572

Authors:

In-Seo Kim (1), Ye-Eun Lee (1), Sung-Jae Jo (1), Jong-Un Moon (1), Ji-Woon Lee (1), Dae-Hyeon Kim (1), Vasudevan Rathinam (1), Hyoung-Seop Kim (2), Soon-Jik Hong (1)

1- Division of Advanced Materials Engineering and Center for Advanced Materials and Parts of Powder (CAMP2), Kongju National University, Cheonan, Republic of Korea

2- Pohang University of Science and Technology, Pohang, Republic of Korea

Abstract:

The effect of as-received (original) and recycled powders on the microstructure and mechanical properties of the STS 316L alloy manufactured using the direct energy deposition (DED) process was explored. The original and recycled powder formed around the additively manufactured material during the DED process was collected and used as starting materials. Two rectangular STS 316L specimens with dimensions of 30x30x20 mm3 were produced using original and recycled powders. The gas-atomized STS 316L powder possesses a spherical shape, and dendrite structure and pores were found in the recycled powder. STS 316L bulk alloy exists in the single-phase FCC crystal structure, and δ-ferrite residual was observed for the recycled powder. The tensile test revealed no significant difference in the maximum tensile strength for both original and recycled powder; however; there was a notable decrease of 50% in elongation for the as-built sample manufactured with the recycled powder.

DOI:

https://doi.org/10.59499/EP246282795

Authors:

Christian-Gierl-Mayer (1), Herbert Danninger (1)

1- TU Wien, Austria

Abstract:

Additives in PM steels are widely used to improve machinability in turning or other machining operations. Commonly, MnS is added because it is cheap and does not have an excessive influence on the mechanical properties. However, MnS tends to form agglomerates and increases the susceptibility to corrosion in the sintered products. Potential alternatives could be sulfides of chromium or tungsten. In the present study these were compared with MnS at two different sintering temperatures. In addition to the thermal stability, both the machinability in turning and the mechanical properties were investigated. It turned out that at least Cr2S3 is a potential candidate as a cutting aid when sintering is done at belt furnace temperatures. Although WS2 seems to be effective, detailed analysis shows that this effectiveness is in fact due to the presence of MnS, which is formed during sintering by an internal getter effect.

DOI:

https://doi.org/10.59499/EP246281579

Authors:

S.A. Razavi (1,2), M. Morales (1,2), I. Serrano (2,3), L. Llanes (1,2), J. Llorca (2,3), G. Fargas (1,2)

1- CIEFMA-Department of Materials Science, Universitat Politècnica de Catalunya, Barcelona-Tech, Spain.

2- Centre for Research in Multiscale Engineering of Barcelona, Universitat Politècnica de Catalunya, Barcelona-Tech, Spain.

3- Institute of Energy Technologies and Department of Chemical Engineering, Universitat Politècnica de Catalunya, Barcelona-Tech, Spain.

Abstract:

Direct Ink Writing (DIW) is an innovative technique for fabricating complex ceramic catalysts with several advantages compared with traditional catalysts. However, these catalysts still face challenges in achieving adequate catalytic performance and structural integrity. This study focuses on DIW-fabricated 3mol% yttria-stabilized zirconia (3YSZ) monoliths coated with a cobalt-3YSZ catalytic functional layer. After the sintering process, the monoliths were coated by the dip-coating technique, using inks based on cobalt (II) acetate tetrahydrate and 3YSZ, and re-sintered. The microstructure of coated monoliths was characterized by field emission scanning electron microscopy equipped with an EDX detector and Raman spectroscopy. Finally, the catalytic performance of monoliths was investigated by conducting the Ethanol Steam Reforming (ESR) reaction. Results show that the dip-coating process uniformly coated the monoliths. The coated monolith significantly enhanced catalytic performance and reduced the temperature of the complete ethanol conversion compared with the uncoated one.

DOI:

https://doi.org/10.59499/EP246280837

Authors:

Magnusson Anders (1), Shipley James (1), Gårdstam Johannes (1)

1- Quintus Technologies AB, Västerås, Sweden

Abstract:

Additive Manufacturing (AM) technology naturally benefits from Hot Isostatic Pressing (HIP) post-processing to enhance reliability and mechanical properties for components in high-risk, mission-critical applications. Over recent years, investigations have explored combining AM and HIP to reduce manufacturing time and costs and improve mechanical properties of AM builds, utilizing innovative concepts such as speed, shell, and Lack of Fusion (LoF) printing coupled with final densification using HIP. This paper gives an initial compilation and highlights the potential benefits and pitfalls of these innovative strategies for high-volume AM manufacturing of high-performance components from various metal alloys.

DOI:

https://doi.org/10.59499/EP246219721

Authors:

Hossein Rajaei (1), Alberto Molinari (1), Iñigo Agote (2), Miguel Ángel Lagos (2), Daniele Ferrari (3), Marta Dai Pré (4)

1- Department of Industrial Engineering, University of Trento, Italy

2- TECNALIA, Basque Research and Technology Alliance (BRTA), Spain

3- DELLAS SPA, Italy

1- Plumake, Italy

Abstract:

This study explores the effectiveness of Field Assisted Sintering Technology (FAST) in producing cutting tools using a Bronze 90/10, Co, Fe, and W powder mix in granulated and non-granulated conditions. The goal is to evaluate and demonstrate FAST efficiency by comparing results obtained on the same system using a conventional sintering approach. For the characterization of the samples, a Rietveld refinement XRD patterns combined with microstructural analysis, based on SEM and EDXS, was considered. The study revealed that the sintering process significantly influenced microstructural characteristics. The FAST process, known for rapid heating and short sintering periods, maintained a consistent ratio of starting phases, unlike conventional sintering prone to reactions, diffusion, and intermetallic compound formation. Conventional sintering resulted in cobalt polymorphs also exhibited a lattice expansion with respect to the starting powder, resulting mainly from the atomic rearrangement during prolonged sintering process. FAST samples showed a lower volume change, due to short sintering time.

DOI:

https://doi.org/10.59499/EP246281338

Authors:

Christian Berger (1), Johannes Pötschke (1), Uwe Scheithauer (1)

1- Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Dresden, Germany

Abstract:

Binder-jetting (BJT), a sinter and powder-based additive manufacturing technology, is becoming more and more established on the market due to its high productivity and the wide variety of materials it can process. The production of WC-Co based hardmetals is being promoted by well-known hardmetal and powder manufacturers using the BJT technology. Within this study, five different binder jetting printers from four different manufacturers were tested and compared for their suitability to produce hardmetals. In addition to hardmetal properties, printing performance and green part handling are compared and the investigated differences discussed. The study shows, that all tested BJT printers show the principle feasibility of producing hardmetal green parts which can after sintering yield dense samples.

DOI:

https://doi.org/10.59499/EP246281340

Authors:

Maxime Stephan (1), Guilhem Roux (1), Carine Ablitzer (2), Jean-Paul Garandet (1), Alexis Burr (1)

1- Univ. Grenoble Alpes, CEA, LITEN, DTNM, L3M, Grenoble 38000, France

2- CEA, DES, IRESNE, DEC, Cadarache, Saint-Paul-lez-Durance 13108, France

Abstract:

The powder spreadability partly drives the robustness of powder-bed-based additive manufacturing processes as well as material performances of the printed parts. The full comprehension of the mechanisms involved during powder spreading is therefore paramount. Literature showed that the impact of friction between the powder and previous layers is significant on powder bed quality. Thus, this work presents an experimental test bench that captures the heap profile during spreading in real time. Indeed, it is found that the heap profile and recoating angle are sensitive to the platform surface roughness and powder properties. Improving the interaction of the powder with the platform results in a larger recoating angle, and improves the powder bed density. This is done by increasing the friction through cleverly oriented ridges or by reducing powder rolling friction through sphericity. Our test bench is relevant for understanding powder deposition experimentally, and has interest for further spreadability optimizations.

DOI:

https://doi.org/10.59499/EP246276968