• 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:

    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:

    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

  • Authors:

    J. Horky (1), E. Ariza-Galván (1), A. Zunghammer (2), N. Moser (2), C. Edtmaier (2), T. Klein (3), M. Schmitz-Niederau (4), E. Neubauer (1)

    1- RHP-Technology GmbH, Seibersdorf, Austria

    2- Institute of Chemical Technologies and Analytics, TU Wien, 1060 Vienna, Austria

    3- LKR Light Metals Technologies Ranshofen, Austrian Institute of Technology, 5282 Ranshofen, Austria

    4- Voestalpine Böhler Welding Germany GmbH, 59067 Hamm, Germany

    Abstract:

    Plasma Metal Deposition is a manufacturing technology which allows the fabrication of large structures. Especially for space relevant components with sizes larger than 0.5 meter, it offers a potential to fabricate parts made from light-weight metals with enhanced stiffness. The PMD process uses a plasma welding torch where powder or wire is used as a feedstock. The layer-by-layer processing allows to realize near-net-shape structures. Especially by using powder as a feedstock, there is a large flexibility in creating various alloys as well as metal matrix composites with modified properties. The aim of this study was to improve the specific modulus (ratio of Young´s modulus/density) by introducing ceramic particles into a titanium matrix. Besides addressing the main challenges in the manufacturing of composites by blown powder methods, an overview on various particles is provided. Based on microstructural analysis and mechanical testing, the influence of the different ceramic fillers is discussed.

    DOI:

    https://doi.org/10.59499/EP235765700

  • Authors:

    E. Carreño-Morelli (1),L. Meylan (1), M. Rodriguez-Arbaizar (1), R. Constantin (2), M. Stucki (3), G. Wälder (3)

    1- HES-SO Valais-Wallis, University of Applied Sciences and Arts Western Switzerland, CH-1950 Sion.

    2- HES-SO He-ARC, University of Applied Sciences and Arts Western Switzerland, CH-2400 Le Locle

    3- HES-SO HEPIA, University of Applied Sciences and Arts Western Switzerland, CH-1202 Geneva

    Abstract:

    Ti(C,N)-MoNi cermets cutting tool inserts have been produced by cold compaction and sintering of commercial ready to press granules. The inserts have been characterized by hardness, density measurements and SEM observations. The cutting edges of sintered inserts were sharpened by laser grinding before coating with a PVD nitride layer by High power impulse magnetron sputtering. Instrumented scratch tests were conducted to evaluate the coating adhesion on both reference cemented carbide and experimental cermet inserts.

    DOI:

    https://doi.org/10.59499/EP235763911

  • Authors:

    Dominik Schmid (1) ; Paul Prichard (2)

    1- Kennametal Shared Services GmbH, Germany

    2- Kennametal Inc., United States of America

    Abstract:

    Additive manufacturing provides new opportunities for cutting tools, enabling geometric freedom to enhance functionality and performance. The challenge in realizing the full potential is multifarious: additive manufacturing needs to match the material quality of existing processes while creating these complex geometries. At the same time the engineered tool designs have to make use of the geometric freedom to exceed the capabilities of conventional tools. This work will highlight some challenges and solutions in processing cemented tungsten carbide as well as hot work tool steel. The presentation will also discuss opportunities with respect to tool design and show examples of innovative structures.

    DOI:

    https://doi.org/10.59499/EP235763604

  • Authors:

    B. Guimarães (1), C. M. Fernandes (2), D. Figueiredo (2), F. S. Silva (1), G. Miranda (3)

    1- Center for MicroElectroMechanical Systems (CMEMS-UMinho), University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal

    2- Palbit S.A., P.O. Box 4, 3854-908 Branca, Portugal

    3- CICECO, Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal

    Abstract:

    During machining processes, a large amount of heat is generated, especially in the cutting zone, due to the deformation of the material and to the friction of the chip along the surface of the cutting tool, resulting in, a wear increase and consequent reduction of tool life. Surface texturing can help improve these tools tribological performance by increasing their load carrying capacity, providing a more efficient lubricant supply at the tool-chip interface and reducing the tool-chip contact area. In this context, the fabrication of cross-hatched micropatterns on WC-Co cutting tools by laser surface texturing of green compacts is proposed, aiming to improve these tools performance and life. This work is focused on evaluating the morphology of the chip obtained when turning 316L stainless steel with tools textured with different cross-hatched micropatterns, these findings being benchmarked against conventional cutting tools and correlated with the tool wear. For such purpose, morphological characterization using optical and scanning electron microscopy was used.

    DOI:

    https://doi.org/10.59499/EP235765436

  • Authors:

    Reinhard Steinhilber (1); Christian Staudigel (1); Christian Fischer (1)

    1- Headmade Materials GmbH, Germany

    Abstract:

    Headmade Materials pushes the Powder Metallurgy further into the Metal AM market with its sinter-based AM-technology called ColdMetalFusion. Furthermore, Headmade Materials partners with industry leaders in the ColdMetalFusion Alliance to leverage the potential of reliable serial production in Metal AM. Since the ColdMetalFusion process runs on standard machines of AM and PM, the robustness and reliability of the process is unmatched and is proven by investigations on dimensional accuracy and reproducibility in this study. Multiple jobs with the same part arrangement were built and characterised. The test bars were aligned in X-, Y-, and Z-direction over the whole build volume. Outstanding results were achieved due to the combination of mature SLS technology and low, homogeneous shrinkage in all three dimensions during sintering.

    DOI:

    https://doi.org/10.59499/EP235762586

  • Authors:

    Alexander Medina Peschiutta (1,2), Marvin Just (1,2), Ralph Useldinger (2), Jörg Baller (1)

    1- Department of Physics and Materials Science, University of Luxembourg, 162A Avenue de la Faiencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg

    2- CERATIZIT Luxembourg S.à r.l., 101 Route de Holzem, L-8232, Grand Duchy of Luxembourg

    Abstract:

    We present a comparative study on determining the critical binder volume concentration (CBVC) of a hard metal paste using the following techniques: theoretical calculation, density method, oil titration, binder titration, and Reddy's model. The theoretical calculations involve density measurements to discern the carbide powder-free volume. The titration methods consist of a stepwise increase of the organic content while the mixer torque is recorded. In contrast, Reddy's model requires the preparation of several feedstocks at varying solid loadings, which are tested in a capillary rheometer to obtain the CBVC. The paste consists mainly of nano-sized tungsten carbide-cobalt (powder phase) and a macromolecular multiphase system (organic phase). The accuracy and expenditure of experimental work of the different methods are discussed.

    DOI:

    https://doi.org/10.59499/EP235764669