Euro PM2024 Proceedings

Authors:

Jan Johannsen (1), Sachin Abraham (1), Torben Dorbandt (1), Maximilian Kluge (1), Sebastian Matthes(2), Ma-ximilian Streinz (2)

1- Fraunhofer Research Institution for Additive Manufacturing Technologies IAPT, Hamburg, Germany

2- Günter-Köhler-Institut für Fügetechnik und Werkstoffprüfung GmbH, Jena, Germany

Abstract:

The impact of powder moisture on the quality of additively manufactured parts through laser beam powder bed fusion (PBF-LB/M) is investigated in this study. Pre-alloyed AlSi10Mg powder was artifi-cial moistened by aging in a climate chamber under regulated conditions of relative humidity and temperature. Various powder batches, ranging from 85 ppm to 1767 ppm water content, were pre-pared and processed by PBF-LB/M using diverse sets of process parameters. The printed speci-mens were examined for relative density, mechanical properties, and oxygen content. The findings demonstrate a correlation between the moisture content in the powder and both me-chanical properties and oxygen content. Notably, a decline in the quality of printed AlSi10Mg speci-mens is observed when the moisture content exceeds 189 ppm water content in the powder. This study sheds light on the criticality of moisture in powder, providing valuable insights for ensuring the production of high-quality additively manufactured components.

DOI:

https://doi.org/10.59499/EP246275270

Authors:

Saviot Adrien (1), Le Gallet Sophie (1), Sallamand Pierre (1), Geoffroy Nicolas (1), Herbst Frédéric (1), Jouvard Jean Marie (1)

1- Laboratoire ICB, Dijon, France

Abstract:

The study focuses on AlCoCrFeNi high entropy alloy, known for its mechanical and high-temperature properties. The influence of mechanical activation, pressure, and high temperature treatments on phase transformations of a pre-alloyed powder was investigated. Both milling and annealing promote the formation of FCC whereas SPS limits the BCC-FCC transformation, favoring intragranular BCC/B2 spinodal decomposition. This was attributed to the pressure when applied at high temperature. Intragranular precipitation of the sigma phase was observed when lowering the cooling rate. Milling of the powder leads to a more homogeneous phase distribution but also to precipitation of the sigma phase.

DOI:

https://doi.org/10.59499/EP246265975

Authors:

Angel Biedma (1), Marcos García (1), Maria de Nicolás (2), Elena Gordo (1)

1- GTP – Department of Materials Science and Engineering, IAAB, Universidad Carlos III de Madrid, Spain

2- Sustainable Powder Technologies – IMDEA Materials Institute, Spain

Abstract:

Ti(C,N) cermets with Fe-based binders have shown promising potential as substitutes for Co-containing cermets and traditional hardmetals, offering reduced dependence on critical raw materials while maintaining comparable properties. However, certain aspects of Ti(C,N)-FeNiCr require further investigation to enhance its properties and understanding. This research explores the effects of sintering pressure through the development of combined cycles, which involve regulating vacuum levels and gas partial pressures. These cycles aim to address challenges such as N2 degassing from ceramic particles, binder volatilization, and densification. A combination of CALPHAD (CALculation of PHAse Diagrams) and experimental studies has been employed. Results demonstrate significant improvements achieved through combined cycles and controlled partial pressures, particularly in enhancing densification and controlling mass loss. This study has shown promising results, with mechanical properties comparable to other processing techniques. Overall, this study provides initial insights into optimizing sintering processes for Ti(C,N)-based cermets with no secondary carbides addition.

DOI:

https://doi.org/10.59499/EP246278433

Authors:

Neyder A. Sandoval (1), Alejandro Santos Villanueva (2), Joaquin. Rams (2), Belén Torres (2), Pilar Rodrigo-Herrero (2), Sandra C. Cifuentes (2), Sophia A. Tsipas (1)

1- Materials Science and Engineering Department, IAAB, Universidad Carlos III de Madrid, Madrid, Spain

2- Área de Ciencia e Ingeniería de Materiales, ESCET, Universidad Rey Juan Carlos, Madrid, Spain

Abstract:

The improvement of beam-based additive manufacturing processes, such as selective Laser Melting (SLM) is currently generating industrial and scientific momentum because of the great advantages it offers in terms of design, flexibility, and efficiency. Although SLM is widely studied, it has certain disadvantages in part due to the limited availability of raw metal or metal-ceramic powders used, prone to processing issues like microstructural defect and low reproducibility. To partly address these challenges, in this work, powders were surface modified using a fluidised bed to improve the characteristics and processability and adapt them to the SLM using a scalable process. The modified powders were characterized by different techniques and the influence of the surface modification on their processability was analysed. In addition, the effect of printing parameters was investigated. Finally, the microstructure of parts obtained by SLM using the modified powders were studied.

DOI:

https://doi.org/10.59499/EP246282776

Authors:

Dariusz Kołacz (1), Marcin Lis (1), Katarzyna Bilewska (1), Karol Krukowski (1), Małgorzata Kamińska (1), Joanna Kulasa (1)

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

Abstract:

The article presents the properties of Ti0.50Co0.50 and Ti0.65W0.35 sintered materials after the Spark Plasma Sintering process. The pressure sintering process was conducted using three different sintering temperatures: for Ti0.50Co0.50 - 1100°C, 1200°C, 1300°C and for Ti0.65W0.35 - 1200°C, 1300°C, 1400°C. The process was carried out using the following sintering parameters: sintering pressure 35 MPa, sintering time 10 minutes, heating rate 100°C/min. Ti-Co and Ti-W mixtures were made by wet mixing of metal powders using acetone. After the sintering process, the phase composition, microstructure, density, hardness, and electrical conductivity were examined. Appropriate selection of the SPS sintering parameters allows obtaining good-quality sintered materials intended mainly for sputtering targets.

DOI:

https://doi.org/10.59499/EP246283958

Authors:

Jonas Koob (1), Markus Mirz (1), Marie Luise Scheck (2), Anke Kaletsch (1), Christoph Broeckmann (1)

1- Institute for Materials Applications in Mechanical Engineering (IWM), RWTH Aachen University, Aachen, Germany

2- Institute for Applied Powder Metallurgy and Ceramics (IAPK) at RWTH Aachen e. V., Aachen, Germany

Abstract:

Duplex stainless steels (DSSs) exhibit excellent mechanical properties due to their austenitic-ferritic microstructure, which, for example, leads to higher impact toughness compared to fully ferritic steels. The phase equilibrium is dependent on solidification conditions and chemical composition, with elemental nitrogen stabilizing the austenitic phase. To better understand the influence of pro-cess gases during processing by laser-based powder bed fusion (PBF-LB) on microstructure and mechanical properties, in this study, DSS AISI 318LN was processed with PBF-LB with different shielding atmospheres (argon and nitrogen) and subsequently, some of the samples were hot-isostatically post-densified before final heat treatment. The impact toughness of the different condi-tions was tested and complemented by microstructural and fractographic analysis. To completely exclude the influence of process gases, samples were also built up by electron-beam powder bed fusion (PBF-EB) under vacuum as a reference and subjected to the same post-processing strategies for comparison with the samples produced by PBF-LB.

DOI:

https://doi.org/10.59499/EP246282914

Authors:

Mathias von Spalden (1), Johannes Pötschke (1)

1- Fraunhofer IKTS, Germany

Abstract:

The substitution of cobalt in hardmetals has a crucial economic role, since increasing costs driven by the demand for Li-ion batteries can lead to higher prices for the majority of hardmetal grades which depend on cobalt as binder metal. Nickel has already proven to be a possible substitute. However, so far it cannot compete with cobalt in terms of mechanical properties. Therefore, in this work a systematic investigation on various alloying elements in nickel-based binder systems for hardmetals was done. A further goal of this study was the reduction of needed sintering temperatures which can lead to less energy consumption for the sintering process. The trials were carried out using field assisted sintering. Subsequent SinterHIP treatment was done to investigate the quasi thermodynamically stable state. The chosen alloying elements are iron, manganese, copper, silicon, and germanium. For some combinations, hardmetals with a novel nickel-based binder alloy could be successfully prepared.

DOI:

https://doi.org/10.59499/EP246281346

Authors:

T.Hajeck (1), C. Weiß (2), C. Broeckmann (1), C. Häfner (2)

1- Institute for Materials Applications in Mechanical Engineering RWTH University, Aachen

2- Fraunhofer Institute for Laser Technology ILT, Aachen

Abstract:

The mechanical properties, especially the strength of a component under cyclic loading, depend on factors such as the chosen material, component geometry and manufacturing history. In Laser Powder Bed Fusion (LPBF), metal powder is deposited and selectively melted using focused laser radiation. The properties of additively manufactured components exhibit a strong dependence on process-related conditions, such as component position and orientation within the build space, or the chosen process parameters. In particular, the density, type and distribution of defects show significant variability depending on parameter selection, which in turn has a notable impact on the mechanical properties of the components. Present work focuses on fatigue strength, as many mechanical components undergo cyclic stress, which is particularly sensitive to internal defects.

DOI:

https://doi.org/10.59499/EP246281349

Authors:

Sacha Cegarra (1), Jordi Pijuan (1), Sergi Dosta (2), Vicente Albaladejo-Fuentes (3), Maria Dolores Riera (4)

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

2- Departament de Ciència dels Materials i Química Física. Universitat de Barcelona, Barcelona, Spain

3- Thermal Spray Centre (CPT). Departament de Ciència dels Materials i Química Física. Universitat de Barcelona, Barcelona, Spain

4- Department of Mining, Industrial and ICT Engineering, Technical University of Catalonia-(UPC), Manresa, Spain

Abstract:

Centrifugal atomization is a rapid solidification process for producing metal powders traditionally limited to common metals and their alloys. This paper aims to introduce notable modifications in the development of centrifugal atomization as the research shift its focus to the production of novel materials such as metallic glasses. Emphasizing on the process parameters of atomization, mathematical calculations, and powder characterization, this research details the advancements in centrifugal atomization for Al-based amorphous powder production. The suitability of the centrifugal atomization cooling rate values for the production of Al-based metallic glasses was assessed using both theoretical and experimental approaches. This study has been accompanied by a comprehensive SEM, XRD, and DSC characterization analysis of the Al-based metallic glasses powders produced via centrifugal atomization. Overall, this paper summarizes the technical difficulty and application prospects of metallic glasses by centrifugal atomization and discusses the challenges and unresolved problems.

DOI:

https://doi.org/10.59499/EP246281374

Authors:

Jordan Lacorne (1,2,3), Aurélien Etiemble (2), Sandra Simon (2), Romain Faye (1), Xavier Boulnat (3), Eric Maire (3)

1- Nanoe SAS, Ballainvilliers, France

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

3- Université de Lyon, INSA Lyon, MATEIS UMR CNRS 5510, Villeurbanne, France

Abstract:

In sinter-based additive manufacturing, such as metallic fused filament fabrication (mFFF), the sintering mechanism must be carefully understood and controlled to end up with the expected density, microstructure, and mechanical behaviour. In the case of mFFF of H13 tool steel, the considerations especially include carbon content, due to binder residue, porosity, and pore size, associated with the densification step, as well as martensitic and carbide formations. This work will discuss the influence of sintering parameters (temperature, ramp rate and atmosphere) on its mechanism, based on in situ shrinkage measurements and the characterization of green, brown and sintered parts. The outcome on the final composition, microstructure and hardness will be highlighted.

DOI:

https://doi.org/10.59499/EP246281354

Authors:

Ananthakrishna Sajithkumar (1,2,3), Jordi Pijuan (1), Maria Niubó (2), Yunhui Chen (3), Mark Easton (3)

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

2- Department of Mining, Industrial and ICT Engineering, Universitat Politècnica de Catalunya, Spain

3- Royal Melbourne Institute of Technology, Melbourne, Australia

Abstract:

Centrifugal atomisation efficiently produces spherical metal powders. Although less understood, internal porosity in metal powders is crucial in determining quality in metal additive manufacturing (AM). In this work, the Al6060 alloy was atomised via centrifugal atomisation under various conditions. The atomisation pressure and holding time during the melting stage were investigated as processing parameters to study their influence on internal pores in the produced powders. Cross-sections were analysed to understand the internal porosity of the alloy powders. Image analysis was performed to quantify and estimate the pore morphology. Preliminary results suggest that in the finer size fraction of powder, reducing the atomisation pressure and holding time can help in reducing the pores.

DOI:

https://doi.org/10.59499/EP246278563

Authors:

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

1- Technische Universität Wien, Institut für Chemische Technologien und Analytik, Austria

Abstract:

Carbon is typically introduced into sintered steels through admixed fine graphite, the dissolution dur-ing sintering however being relatively slow. An alternative route would be the introduction via a car-bon-rich Fe-C powder containing carbon as cementite. In the present study it is shown that already addition of a minor proportion of carbon through atomized Fe-4.5%C masteralloy powder activates carbothermal reduction of the surface oxides, shifting the CO formation temperature to lower levels, as well as dissolution of graphite in the matrix. This is particularly noticeable in steels prepared from prealloyed steel powder Fe-3%Cr-0.5%Mo. The property most sensitive to carbon dissolution is the coercive force, which offers the chance to nondestructively characterize this important process.

DOI:

https://doi.org/10.59499/EP246206688