Individual Papers

Authors:

Francisco Canillas (1), Nerea Ordas (2), Ernesto Urionabarrenetxea (2), Marcelo Roldan (1), Evelin Cardozo (2), Carlos Bloem (3), Edgar Leon-Gutierrez

1- Ciemat, National Fusion Laboratory, Madrid, Spain

2- Ceit-BRTA and Tecnun (Universidad de Navarra), Donostia-San Sebastián, Spain

3- AIDIMME, Paterna, Spain

Abstract:

CuCrZr is a precipitation-hardenable Cu alloy that combines high thermal conductivity and mechanical strength, along with thermal stability up to 350 °C. In this work we demonstrate the feasibility to obtain dense Cu-(0.6-0.9)Cr-(0.07-0.15)Zr (in wt.%) with densities of 99.5%, high thermal conductivity (>80-85% IACS) and enhanced mechanical strength compared to pure Cu, already in the as-built condition, using Powder Bed Fusion Electron Beam (PBF-EB). Further densification was achieved after HIP. Mechanical characterization showed outstanding results, similar or even superior to those reported in the literature for conventional wrought CuCrZr. Microstructural analysis by SEM, EBSD and TEM revealed a multi-scale hierarchical microstructure of ultra-fine Cr-rich precipitates as well as grain and subgrain boundaries, contributing to the excellent mechanical properties achieved. The microstructural stability of the CuCrZr alloy was evaluated by heat treatments in the range of 350 – 550 °C for up to 1080 hours.

DOI:

https://doi.org/10.59499/EP246300683

Authors:

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

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.

Abstract:

Efficient simulation of close-coupled gas atomisation can nowadays be used to improve machine designs and to gain understanding of the complex phenomena taking place in the atomisation process. Two-stage multiphase models can predict particle size distributions by using an Eulerian approach for the primary atomisation and Lagrangian particle tracking for the secondary atomisation. Previous numerical results confirm that these models correctly predict trends of median particle size for varying gas-to-melt mass flow rate ratios, although significant differences between predicted and measured particle size distribution spreads indicate that models need to be improved. In this work, different coupling hypotheses between the primary and secondary atomisation stages are addressed to optimize the model’s capacity to predict the entire particle size distribution. By comparing experimental results with simulations obtained with varying surfaces of particle injections and corresponding boundary conditions, an improved model with better predictive capacity has been obtained.

DOI:

https://doi.org/10.59499/EP235779996

Authors:

Barbara Rivolta (1), Riccardo Gerosa (1), Davide Panzeri (1), Paolo Veronesi (2)

1- Politecnico di Milano, Department of Mechanical Engineering, Milano, Italy

2- Università degli Studi di Modena e Reggio Emilia, Dipartimento di Ingegneria “Enzo Ferrari”, Modena, Italy

Abstract:

Additive manufacturing is nowadays increasingly adopted to produce a large variety of components, especially with complex geometries. A deep investigation and optimization of the mechanical and corrosion performance of the selective laser melted Alloy 625 is extremely useful to support designers in the transition from the conventional to the additive manufacturing technology. Even though the selective laser melting technique is still associated with too high production costs and low productivity to enable a broader expansion, it permits to obtain excellent mechanical and corrosion properties compared to those of the conventionally manufactured alloy. Despite the additively produced material shows outstanding performance already in the as-built condition, aging treatments permit further strength improvement enabling possibility of reducing thicknesses, mass, resources consumption and environmental emissions. However, the balance between the mechanical and corrosion properties is critical and it requires a careful tuning of the heat treatment parameters.

DOI:

https://doi.org/10.59499/EP246281709

Authors:

Ribeiro, Bernardo L.(1,2); Santos, Rúben F. (1,2,3); Barbosa, Maria (2); Sequeiros, Elsa W.(1,2)

1- LAETA/INEGI - Institute of Science and Innovation in Mechanical and Industrial Engineering, Portugal

2- Departamento de Engenharia Metalúrgica e de Materiais da Faculdade de Engenharia da Universidade do Porto, Portugal

3- CCF – Centro de Competências Ferroviário, Portugal

Abstract:

In recent years, High Entropy Refractory Alloys (RHEAs) have been presented as possible alternatives to the state-of-art Ni-based superalloys, due to an outstanding combination of properties under high-temperature service conditions. The MoNbTaW system has been particularly explored due to its considerable high yield strength at temperatures around 1200 °C. Yet, these alloys present a brittle behaviour at room temperature, narrowing their applications. To improve the MoNbTaW properties, in-situ alloying with additions of Vanadium (V) by Direct Energy Deposition (DED) assisted by thermodynamical simulations (CALPHAD) has been explored to accelerate the screening of promising compositions. In this contribution, we present the room temperature microstructural and mechanical characterisation to evaluate the influence of V on the MoNbTaW system.

DOI:

https://doi.org/10.59499/EP235765551

Authors:

Hans-Wolfgang Seeliger (1), Tillmann R. Neu (2), Paul H. Kamm (2), Francisco García-Moreno(2)

1- Gränges Powder Metallurgy GmbH, Germany

2- Institute for Applied Materials, Helmholtz Zentrum Berlin for Materials and Energy, Germany

Abstract:

For the purpose of the application for an on-tank valve, various Al alloy series were produced and tested, to which different contents of up to 0.3 wt% Sc and Zr were added. The hardening curves were plotted for different temperatures and correlated with the corresponding mechanical tests. The alloys were characterized by hardness measurements, tensile tests. By characterizing the materials, transferring them to simulation models and developing design guidelines, the foundations are laid for technology transfer to other applications of these materials. In order to produce these new materials, the Spray Forming process was used on the systems of the Gränges Powder Metallurgy company. This has the advantage that both the metal powder and the solid material for the forged part can be produced in one manufacturing step.

DOI:

https://doi.org/10.59499/EP246278515

Authors:

Federico Simone Gobber (1), Antonio Pennacchio (1), Marco Actis Grande (1), Paolo Priarone (2)

1- Department of Applied Science and Technology, Politecnico di Torino, Alessandria, Italy

2- Department of Management and Production Engineering, Politecnico di Torino, Torino, Italy

Abstract:

Sustainability in production processes is a crucial topic that ensures the responsible use of resources, minimizes environmental impact, fosters long-term viability, and aligns economic success with ecological and social well-being. Regarding powder production via gas-atomization, powder quality and powder yield represent the main aspects to be maximized in order to achieve a robust process. However, gas-atomization energy consumption varies depending on gas-atomization pressure, heating time, power, and consumable reuse. This study proposes a methodology to optimize gas-atomized powder production by reducing the equivalent carbon generated per kilogram of powder. The methodology incorporates particle size distribution, morphology, and environmental impact considerations. The article reports a comprehensive case study for super-duplex steel powders produced by a lab-scale inert gas atomizer. The purpose of the study is to present a general methodology to evaluate the sustainability of gas – atomized powder.

DOI:

https://doi.org/10.59499/EP246282648

Authors:

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

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

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

Abstract:

Laser Powder Bed Fusion/Metal (PBF-LB/M) shows great promise for industrial applications, but its extended production time remains a challenge. To address this, innovative methods such as the shell-core approach have been developed. In this procedure, a component is created with a dense outer shell surrounding a core of either unexposed or minimally exposed powder, drastically reducing processing time. Full densification and specific property adjustment are achieved by subsequent hot isostatic pressing (HIP). This study demonstrates the use of shell-core specimens made from a powder blend of austenitic stainless steel and Si3N4 to produce high-nitrogen steel components that are otherwise difficult to produce due to limited nitrogen solubility in the steel melt. During HIP, Si3N4 dissolves into the austenitic matrix, enriching it with nitrogen and circumventing solubility issues. This results in a material with increased strength and potentially improved corrosion resistance due to the beneficial impact of nitrogen on steel properties.

DOI:

https://doi.org/10.59499/EP246252913

Authors:

Merlin Thamm (1), Inge Lindemann-Geipel (1), Christoph Höhnel (1,2), Thomas Hutsch (1), Shufan Wang (3), Yuanbin Deng (3,4), Christoph Broeckmann (3,4), Thomas Wentzlik (5), Tobias Trupp (5), Thomas Weißgärber (1,2)

1- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany

2- TUD Dresden University of Technology, Faculty Mechanical Engineering, Institute of Materials Science, Chair Powder Metallurgy, Germany

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

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

5- Magnetec GmbH, Germany

Abstract:

Within the public founded project “NanoKompakt”, the powder of initial amorphous soft magnetic alloy Vitroperm (Fe73.6Si15.5B6.9Cu1.0Nb3.0) is compacted to nanocrystalline components by FAST/SPS. The aim is to manufacture industrially relevant components such as E-cores that cannot be produced from wounded ribbon. The increased mechanical stability allows for omitting a polymer case, which increases the possible application temperature. Firstly, small toroidal cores were compacted. A high permeability of 20 000 and a low coercivity of 3 A/m are achieved. Based on the thermal and electrical properties of the compacted toroidal cores, a larger pressing tool is also designed and optimized by simulation. The simulation is necessary because the temperature range for compaction is only a few Kelvin wide and the precipitation of hard magnetic phases must be prevented. In the second step, E-cores are cut from compacted slices and analyzed.

DOI:

https://doi.org/10.59499/EP246279398

Authors:

A.V. Shulga

National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 31 Kashirskoe Sh., Moscow 115409, Russian Federation

Abstract:

Based on the results of a multiscale experimental study of the behavior of boron, carbon, and micro-structure of HIP PM compacts of the high temperature Ni-based superalloys, during various heat treatments, as well as compression and tensile tests, performed in particular by the method autora-diography, was constructed the firstly proposed TTT diagram. Study of boron and carbon behavior in relation to microstructure was carried out by direct methods track autoradiography on boron and activation autoradiography on carbon, metallography, SEM, EDX, OIM methods. Formation of solid solution of boron, segregation of boron, and precipitation of borides, in particular, along grain bound-aries as a result of heat treatment of compacts, have been revealed and analyzed. Therefore, the time -temperature conditions for the precipitation of the boride phase were determined as the main parameters of the proposed TTT-diagram of the boride phase in comparison with the TTT-diagrams of the carbide and gamma-prime phases.

DOI:

https://doi.org/10.59499/EP235753737

Authors:

Sibel Yöyler (1), Andrei Surzhenkov (1), Maksim Antonov (1), Mart Viljus (1), Rainer Traksmaa (1), Kristjan Juhani (1)

1- Department of Mechanical and Industrial Engineering, Tallinn University of Technology, Tallinn

Abstract:

Fe-based hardfacing with TiC reinforcement receives considerable attention due to the optimal quality-price ratio. The present research focuses on the investigation of microstructure and abrasive wear behavior of Fe-based hardfacing with TiC, in-situ synthesized from TiO2. The plasma transferred arc (PTA) cladding method was used for in-situ synthesis of TiC on the S235 steel substrate using 72 hours ball-milled AISI 316L stainless steel (ss), TiO2, and graphite powders. Scanning electron microscopy (SEM) was used to analyze the microstructure, and energy dispersive spectroscopy (EDS) analysis was used to determine the distribution of TiC. XRD analysis was used to define the phase composition. Vickers hardness was measured, and ASTM G65 abrasion test was applied to evaluate the wear resistance of the hardfacings. Wear mechanisms were studied under SEM.

DOI:

https://doi.org/10.59499/EP235762969

Authors:

Laura Cordova (1), Fouzi Bahbou (2), Eduard Hryha (1)

1- Chalmers University of Technology, Chalmersplatsen 4, 412 96 Göteborg, Sweden.

2- Arcam AB/GE Additive, 435 33 Mölnlycke, Sweden

Abstract:

Processability in Powder Bed Fusion - Electron Beam (PBF-EB) depends on the number of factors, covering homogeneous powder bed, powder chemistry and interaction of the electron beam with the metal powder. For a good, consolidated part to be processed, the powder must be smoothly applied on the powder bed and the beam transmits the electrons throughout the powder layers. Only with powder of specific characteristics, e.g. narrow PSD, smooth and spherical morphology, high chemical purity this is possible. In this study two different TI6Al4V powder batches are analyzed, where one batch presented challenges with processability even in virgin state. For both powders, an assessment of the morphology, particle size, rheology, and chemistry will determine the feasibility to achieve optimal processability and the possibility to reuse in consecutive cycles.

DOI:

https://doi.org/10.59499/EP235765563

Authors:

Stefan Marschnigg (1), Christopher Herzig (1), Andreas Limbeck (1), Herbert Danninger (1), Christian Gierl-Mayer (1); Thomas Weirather (2,3), Thomas Granzer (2)

1- Technische Universität Wien, Institut für Chemische Technologien und Analytik, Getreidemarkt 9/164, A-1060 Wien, Austria

2- Plansee Composite Materials GmbH, Siebenbürgerstrasse 23, D-86983 Lechbruck, Germany

3- CERATIZIT Austria GmbH, Metallwerk-Plansee-Straße 71, A-6600 Reutte, Austria

Abstract:

Tungsten heavy alloys are liquid phase sintered two-phase materials in which tungsten grains are embedded in an austenitic base matrix. While the solubility of W in the binder phase is high both at sintering temperature, when the binder phase is liquid, and also after cooling, the solubility of the binder elements in the W phase is very low, but the exact content has been a matter of discussion for a long time. In the present study, laser ablation induction coupled plasma mass spectrometry (LA-ICP-MS) has been employed for analyzing the Ni and Fe content in the W phase of W-Ni-Fe heavy alloys, using specifically prepared low-binder specimens for calibration. It showed that the binder element content is in fact significantly lower than presented in the literature, LA-ICP-MS yield-ing contents of approx. 340 µg/g for Fe and 60 µg/g for Ni.

DOI:

https://doi.org/10.59499/EP235755779