Euro PM2023 Proceedings

Authors:

Joni Reijonen (1); Juan Silva (1); Oskar Pulli (2); Kasper Hahtonen (2); Jari Ulkuniemi (2); Jari Niskanen (2); Pasi Puukko (1); Sini Metsä-Kortelainen (1)

1- VTT Technical Research Centre of Finland Ltd., Finland

2- University of Oulu, Finland

Abstract:

Additive manufacturing is often referred to as resource-efficient or even sustainable manufacturing with very little reliable scientific data to support the claims. Here we have made a comparative life cycle inventory of the energy and raw material flows during PBF-LB AM and CNC machining of three components having different geometrical features and functionalities: gear, impeller and manifold. The scope of this study was on the manufacturing phase of the components (from gate-to-gate). The energy and material consumptions were measured, with emphasis on providing accurate, transparent and reliable data of the most important input flows through direct measurement. For all the three studied components, PBF-LB consumed more energy, but required less material, than CNC machining. Geometry of the component had the most significant impact on the energy and material consumption in these processes. Optimizing part geometry and process parameters in PBF-LB to minimize resource consumption showed much potential for improvement.

DOI:

https://doi.org/10.59499/EP235761105

Authors:

Kameswara Srikar Sista (1), Bilal Murtuza Pirjade (1), Abhijeet Premkumar Moon (1), Srinivas Dwarapudi (1)

1- Research and Development, Tata Steel Ltd, India

Abstract:

Iron powder is one of the prominent materials in today’s world. Among various methods of synthesis, iron powders from reduction route stands unique in process flexibility as well as powder properties. Possibility of using carbon free reductant like hydrogen makes this process route further attractive. In the present work, synthesis of iron powders from mill scale by product of steel industry is explored by use of hydrogen as reducing gas. Experiments were performed at temperature range of 750 0C to 850 0C and time range of 30 min to 90 min. Variation in properties of iron powders synthesized form conventional heating and microwave heating are explored and obtained powders are characterized for physical (particle size, apparent density, tap density), chemical (purity, chemical phases) and morphological (scanning electron microscopy) attributes. This work paves path to a modern, green, and sustainable method for iron powder synthesis from a steel industry by-product.

DOI:

https://doi.org/10.59499/EP235750577

Authors:

Maziyar Azadbeh (1); Samira Eslami (1); Mahsa Golchinfard (1); Faezeh Gaffari (1); Herbert Danninger (2); Christian Gierl Mayer (2)

1- Faculty of Materials Engineering, Sahand University of Technology, P.O. Box 51335-1996, Tabriz, Iran

2- Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9/164, A-1060 Wien/Vienna, Austria

Abstract:

This study focuses on the influence of adding Molybdenum to Ti on properties, microstructure and presumably formation of beta phase. For this purpose, specimens from plain Ti powder and Ti-10Mo mixed elemental powders, respectively, were fabricated by selective laser melting (SLM) under the same parameters in argon atmosphere. The laser power, scanning speed and hatch distance were 95 W, 600 mm.s-1 and 0.088 mm, respectively. Ti-10Mo alloy was prepared successfully by SLM of elemental powder mix, a few undissolved but uniformly distributed Mo particles remaining. The molten pools are clearly visible in the micrographs of Ti-10Mo, but surprisingly not in Ti. In the as-built state, the UTS of Ti was 637 MPa, and Mo addition caused an increase to approx. 945 MPa and of the hardness to 464 HV30, whereas the elongation of Ti was considerably higher than that of Ti-10Mo, which failed in a brittle manner.

DOI:

https://doi.org/10.59499/EP235765041

Authors:

Martin Wolff (1), Eshwara Nidadawolu (1), Wolfgang Limberg (1), Thomas Ebel (1), Regine Willumeit-Römer (2)

1- Helmholtz-Zentrum hereon GmbH

2- Christian Albrechts Universität, Kiel

Abstract:

Recent research attests MgGd-alloys high suitability as biodegradable biomaterial due to its good strength, low stiffness and excellent biocompatibility. Moreover, novel investigations have proven that Mg-alloys can be successfully processed by binder based sintering technologies like MIM and Fused Granular Fabrication (FGF). While MIM intends to near net shape mass production, the latter one applies mainly to prototyping and production of individual patient specific implants; even with a scaffold-like strut structure inside of a dense shell. This study compares mechanical properties and microstructures of the binary alloy Mg-6.3Gd, processed by MIM and by FGF, respectively. It is shown that today’s FGF technique achieves mechanical properties up to 217 MPa ultimate tensile strength (UTS) at 13 % elongation at fracture, comparable to the MIM processed reference material. Both processes, MIM and FGF lead to almost the same microstructure. Hence, novel FGF technique could overcome current challenges in 3D-printing of Mg-alloys.

DOI:

https://doi.org/10.59499/EP235763609

Authors:

Lukas Kaserer (1); Jakob Braun (1); Daniel Brennsteiner (1); Peter Singer (2); Benedikt Distl (2); Karl-Heinz Leitz (2); Heinrich Kestler (2); Wolfgang Schafbauer (2); Gerhard Leichtfried (1)

1- Faculty of Engineering Sciences, Department of Mechatronics, Materials Science, Universität Innsbruck, Innrain 52, 6020 Innsbruck, Austria

2- PLANSEE SE, Metallwerk–Plansee–Straße 71, 6600 Reutte, Austria

Abstract:

The Additive Manufacturing (AM) process Laser Powder Bed Fusion (LPBF) makes it possible to produce Mo components with highly complex geometries in a resource-efficient way. Such complex components enable optimal functionalization and are of considerable industrial interest.

The disadvantage of LPBF is that it is currently impossible to produce pure Mo components that achieve a similar strength and quality compared to their traditionally powder-metallurgically produced counterparts. Pure Mo components suffer from a coarse-grained, columnar, and cracked microstructure. Material adaptation to tolerate the unique solidification-boundary conditions in LPBF is necessary to improve component quality.

In the present work, different alloying concepts to trigger grain refinement, to engineer grain boundary chemistry, and a combination of both are discussed. Furthermore, the effects on the microstructure and component quality are compared based on experimental results.

DOI:

https://doi.org/10.59499/EP235764236

Authors:

Christian Gierl-Mayer (1), Stefan Geroldinger (1), Raquel de Oro Calderon (1), Herbert Danninger (1)

1- Technische Universität Wien, Austria

Abstract:

Low alloyed steel powder Fe-0.85Cr-0.15Mo-C is dedicated to substitute Fe-Cu-C for PM steel precision parts. It is conceived as a sustainable option to counter recycling and price problems of copper It is known from previous research that the introduction of oxygen sensitive elements like chromium leads to a change in deoxidation behaviour during the sintering process of PM steels compared to classical alloying elements like copper, nickel or molybdenum. This behaviour strongly depends on the chromium content of the powder. By DTA/MS and DIL/MS experiments in different atmospheres, this powder is compared to classical Fe-Cu-C and higher chromium alloyed powders to reveal significant changes during the heating stage of the sintering process and to show if special measured are needed to sinter these steels compared to Fe-Cu-C. Thermal treatment to simulate dewaxing is performed to investigate the change in surface chemistry of the pressed compacts. The thermoananalytical experiments are accompanied by analysis of carbon and oxygen content and by microstructural characterization.

DOI:

https://doi.org/10.59499/EP235762746

Authors:

Bruce Lindsley (1); Neal Kraus (1)

1- Hoeganaes Corporation, NJ, USA

Abstract:

Lamination sheet steel used for magnetic stator cores have excellent magnetic properties within individual sheets. The comparison of these individual sheet properties, such as maximum saturation and permeability, with powder-based soft magnetic composites appears unfavorable for SMC use. The properties of lamination assemblies, however, is lower than individual sheets due to stacking factor and the presence of insulation layers. Further, it is commonly understood that these stacks tend to work best at lower frequency, whereas SMC is more suited to higher frequency. The number of direct comparisons of SMC and lamination steel stacks is limited in the literature, resulting in broad generalizations. In this study, test rings made with assemblies of 2 lamination steel grades and 2 grades of SMC will be evaluated under different test conditions. The direct comparison will enable users of the technology to understand the benefits and limitations of each approach, leading to the best engineering solutions.

DOI:

https://doi.org/10.59499/EP235756235

Authors:

Oliver Schenk (1), Yuanbin Deng (1), Anke Kaletsch (1), Christoph Broeckmann (1)

1- RWTH Aachen University, Institute for Materials Applications in Mechanical Engineering (IWM), Augustinerbach 4, 52062 Aachen, Germany

Abstract:

The powder metallurgical (PM) process chain stands out by its ability to produce precise components at low cost. However, the inherent porosity of PM components, which has a particular impact on fatigue behavior, is crucial for components such as gears. Hence, cold rolling is commonly applied to densify the surface of sintered components. This induced densification can be modelled by a constitutive law introduced by Gurson, Tvergaard and Needleman. In this work, a modified GTN model was derived to simulate the densification behavior of Astaloy 85Mo sintered steel. The stress-strain-behavior of sintered samples with different densities was deduced from compression tests according to Rastagaev. A synthesized description of the plasticity of the dense material was then combined with the densification behavior during compression to obtain a density-dependent GTN model. The model was validated by comparison with experimental data on the densification during sizing and cold isostatic pressing of sintered samples.

DOI:

https://doi.org/10.59499/EP235763767

Authors:

Giuseppe Vecchi (1), Eleonora Atzeni (1), Luca Iuliano (1), Alessandro Salmi (1)

1- Politecnico di Torino, Department of Management and Production Engineering (DIGEP), Corso Duca degli Abruzzi 24, 10129 Torino, Italy.

Abstract:

Recent improvements in the Laser Powder Directed Energy Deposition (LP-DED) process for repair applications shift the focus to the analysis of possible alterations in the substrate, which is subjected to repeated thermal cycling during deposition of the material. In general, thermal loads can be controlled by changing process parameter. In this work, a two-step bi-directional spiral deposition strategy, alternating between deposition from inward to outward and backfill, is analyzed to evaluate the heating of the substrate and the resulting porosity of the added material. The outcomes indicate the potential of this strategy to control heat flow and achieve a more uniform thermal field. Porosity is minimized by optimizing the hatch spacing, and benefits are observed also in terms of top surface roughness.

DOI:

https://doi.org/10.59499/EP235762610

Authors:

Sasha Cegarra (1), Jordi Pijuan (1), María Dolores Riera (2)

1- Eurecat, Centre Tecnològic de Catalunya, Unit of Metallic and Ceramic Materials, Plaça de la Ciència 2, 08243, Manresa, Spain

2- Department of Mining, Industrial and ICT Engineering, Technical University of Catalonia-(UPC), Av. De les Bases de Manresa, 61-73, 08242, Manresa, Spain.

Abstract:

Centrifugal atomization technique to produce metal powder offers many advantages in terms of spherical morphology of the powders, high production yield and narrow particle size distribution. Centrifugal atomization is also considered a rapid solidification technique. The final microstructure of the atomized particles is closely linked with the thermal history and cooling rates experienced during the atomization process. In this work, Al-4%Cu alloy was atomized via centrifugal atomization under different atomization conditions. Gas composition and melt superheat temperature were investigated as processing parameters that influence in the cooling history of the atomized droplets. Cooling rate was experimentally evaluated by means of the Secondary Dendrite Arm Spacing (SDAS) technique using four measurement methods found in the literature, and a numerical model was implemented to study the heat transfer between the droplets and the surrounding gas once the particles have been expelled from the disk, to identify the correlation between theoretical and experimental results.

DOI:

https://doi.org/10.59499/EP235765262

Authors:

Christian Berger (1), Johannes Pötschke (1), Uwe Scheithauer (1), Markus Krause (2), David Wonn (2)

1- Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Winterbergstraße 28, 01277 Dresden, Germany

2- ExOne GmbH, Daimlerstrasse 22, 86368 Gersthofen, Germany

Abstract:

For some years now, the production of WC-Co hardmetals via the powder-based additive manufacturing process binder jetting has been pursued. Compared to alternative AM processes Binder jetting offers the possibility of high production. Due to the powder-based process, the green bodies usually have a low green density, which means that only higher Co contents with lower resulting hardness’s are possible. By choosing the right starting powder and a suitable post-processing, the previous limits can be extended, and the appropriate powder can be chosen depending on the application. In the context of this study, the correlation between different WC-Co starting powders with different morphologies is investigated and evaluated for their processability in the BJT process and for the resulting mechanical properties of sintered components.

DOI:

https://doi.org/10.59499/EP235765382

Authors:

Prabin A (1); Anvitha K S (1); Sathish R (1)

1-Kennametal India Limited, India

Abstract:

Cemented tungsten carbide (WC-Co) materials are made of tungsten-carbide grains embedded in a cobalt matrix and are used for making metal cutting and mining tools through powder metallurgical processes. Cobalt is known to be prone to corrosion in aqueous environments. Various surface preparation processes for cemented carbide exposes the cobalt phase in multiple aqueous environments where the corrosion mechanism is not well understood. Therefore, this study aims to understand the corrosion behavior of cemented carbides with different inhibitors in varying pH and temperature environments. The study also evaluates conditions where the corrosion inhibitor can be removed or reduced for different surface conditions for cemented carbide processes, and for alternate corrosion inhibitors with lesser health and environmental impacts. The results of this study will help improve cemented carbide tool performance in highly demanding service conditions and applications in oil and gas extraction in tetra-phasic conditions (seawater, sand, liquid, and gaseous hydrocarbons).

DOI:

https://doi.org/10.59499/EP235763660