World PM2022 Proceedings

Authors:

Koki Nakamura (Toyohashi University of Technology, Japan), Atsushi Yokoi (Toyohashi University of Technology, Japan), Go Kawamura (Toyohashi University of Technology, Japan), Atsunori Matsuda (Toyohashi University of Technology, Japan), Hiroyuki Muto (Toyohashi University of Technology, Japan)

Abstract:

In nanocomposite materials fabrication, nanopowders are commonly used to obtain the desired properties. However, the drawbacks of nanopowders are agglomeration and poor handling ability. To overcome these issues, one solution is to fabricate composite granules using electrostatic integrated granulation of aqueous nanopowder suspension. By adjusting the surface charge potential of the nanopowders, electrostatic integration during the granulation process enabled the fabrication of monodispersed spherical composite granules, exhibiting good homogeneity of raw nanoparticles and improved handling ability. In this study, the parameters for composite granules formation using electrostatic integrated assembly method were investigated. From the results obtained, a process map, which enables the prediction of the granule’s formation is also proposed.

DOI:

https://doi.org/10.59499/WP225371880

Authors:

Didier Bouvard (Univ. Grenoble Alpes, France), Luis Olmos (Universidad Michoacana de San Nicolas de Hidalgo, Mexico), Jorge Chavez (Universidad de Guadalajara, Mexico), Rogelio Macías (División de Estudios de Posgrado e Investigación, TecNM|Instituto Tecnológico de Morelia, Mexico)

Abstract:

This works proposes a methodology for fabricating materials with specific characteristics tuned for replacing human bones. A Ti64 alloy powder is used as the base materials and it is mixed with Ag, Ta, TiN and salt particles to obtain different features. A knee-bone like component is fabricated, including a highly porous core of Ti64|25Ta|5Ag and compact outer of Ti64|5Ag that is supposed to improve corrosion and osseointegration. Besides, a harder top surface in Ti64|10TiN composite should increase the wear resistance. The green component is sintered at 1260°C in argon. Its stiffness is close to the one of bones thanks to the added porosity, which also provides a permeability close to the one reported for trabecular bones. Tribocorrosion behavior in simulated body fluid is improved by TiN addition. In conclusion, the proposed processing route is able to produce complex components fulfilling specific features required for human bone replacement.

DOI:

https://doi.org/10.59499/WP225371364

Authors:

Laura Grau (Pforzheim University, Germany), Carlo Burkhardt (Hochschule Pforzheim | STI, Germany)

Abstract:

The rare earths are some of the most critical raw materials, yet electromobility and green energy strongly rely on Rare Earth Permanent Magnets (REPM). To secure the supply and improve the ecological footprint of REPM, a hydrogen-aided powder-metallurgical reprocessing route was successfully established and continues to be improved. A remaining obstacle is the sourcing and demounting of REPM-containing scrap. Demounting must especially be optimized towards achieving a maximum yield of high-quality material in conjunction with economic efficiency.Electric traction motors, which will be an abundant but dissipated scrap REPM source in the future, are often very hard to demount. To exploit this important raw material source, their design must accommodate efficient recycling. This paper deals with how design choices of the most common rotor permutation, the V-shaped internal Permanent Magnet Synchronous Motor rotor (VPMSM), impact the recyclability of the integrated magnets and provides a design for recycling framework.

DOI:

https://doi.org/10.59499/WP225367983

Authors:

Markus Schneider (GKN Sinter Metals Engineering GmbH, Germany), Jack Schwarz (GKN Sinter Metals GmbH, Germany), Wolfgang Schütz (GKN Sinter Metals GmbH, Germany), Alessandro DeNicolo (GKN Sinter Metals Spa, Italy)

Abstract:

MIM 42CrMo4 is a versatile low alloy steel and commonly used in the forging industry. Its properties can be varied with a tailored hardening and tempering treatment over a wide range of strength|ductility combinations. Its high ductility is beneficial for gears, connecting rods, crankshafts, pistons and other automotive and machinery components. This makes that steel grade also attractive for the Metal Injection Molding and Additive Manufacturing industry. Therefore, MIM 42CrMo4 hardened was chosen as third material – after MIM 8620 case-hardened and MIM 100Cr6 hardened – for the internal high cycle fatigue and notch sensitivity study. As presented in the years before, two different injection molding methods and resulting weld line positions were compared. Moreover, the mean stress sensitivity, notch sensitivity, scatter and further s-N line parameters were discussed and compared with the previously characterized MIM steel grades. Its response on a variety of tempering regimes was investigated too.

DOI:

https://doi.org/10.59499/WP225369499

Authors:

Carlos Romero (Universidad Carlos III de Madrid, Spain), Davide Benedetto (Universidad Carlos III de Madrid, Spain)

Abstract:

Bipolar plate (BP) materials and designs are critical for the performance of a PEMFC and a PEMEC due to their role as reactant and product distributor and electron transporter between cells. With the goal of increasing the power density of the PEMFC stacks, especially for transportation, the weight of the bipolar plate is also an important parameter. Titanium is a material that is a promising alternative to stainless-steel to manufacture light, metallic-based BP if some of its challenges are addressed, one of them being the passivation of its surface during operation, that creates ohmic losses. The aim of this work is to assess the use of powder metallurgy to manufacture titanium-based bipolar plates with the ability to obtain alternative designs for the flow field and the use of suitable surface modification techniques that can improve the performance.

DOI:

https://doi.org/10.59499/WP225370544

Authors:

Valerie Goettgens (University of Innsbruck, Austria), Gerhard Leichtfried (University of Innsbruck, Austria), Stefan Mitsche (FELMI-ZFE, Austria)

Abstract:

Bulk metallic glass composites (BMGCs) overcome the unfavorable lack of plastic deformation of completely amorphous alloys by adding ductile metallic shares. This is the first study that attempts to produce a partially amorphous alloy in an inexpensive and straightforward system of Ti-6Al-4V – 15 wt.% Cu using laser powder bed fusion (LPBF) with in-situ alloying. Local chemical inhomogeneities are desired, as they allow simultaneous solidification of different microstructures. In the produced alloy, fabricated with a single melting and a pulsed remelting strategy, partly X-ray amorphous material was found. The remelting strategy led to the increase of the X-ray amorphous phase and caused the number of grains < 1 µm to increase from 7.8 % (single melting) to 14 %. This study shows the feasibility of producing a partly X-ray amorphous alloy in which the amount of X-ray amorphous shares can be controlled with process parameters.

DOI:

https://doi.org/10.59499/WP225367219

Authors:

Martin Bram (Forschungszentrum Jülich, Germany), Jesus Gonzalez-Julian (RWTH Aachen University, Germany), Jan W. Coenen (Forschungszentrum Jülich, Germany), Andrey Litnovsky (Forschungszentrum Jülich, Germany)

Abstract:

In future fusion power plants, plasma-facing materials for the first wall of the reactor have to withstand extreme conditions combining long-term stability during regular operation and suppressed oxidation in the case of an accident. Self-passivating metal alloys with reduced thermo-oxidation (SMART) are promising candidates. Based on tungsten as matrix material, the alloys contain chromium as passivating element and yttrium as active element. Recently, it has been shown that submicron grain sizes led to the best oxidation resistance. Processing of such kind of materials is challenging. Here, field assisted sintering technology|spark plasma sintering (FAST|SPS) of mechanically alloyed tungsten, chromium and yttrium powders was applied to produce submicron grained SMART materials with homogeneous microstructure and well-balanced properties. Main factors influencing the processing of SMART materials via FAST|SPS are discussed and first attempts to scale up the technology (100 x 100 mm2) are presented. Finally, oxidation resistance under accident conditions was investigated.

DOI:

https://doi.org/10.59499/WP225371906

Authors:

Juan Alfonso Naranjo (UCLM, Spain), Cristina Berges (UCLM, Spain), Javier Hidalgo (UCLM, Spain), Gemma Herranz (UCLM, Spain)

Abstract:

Fused filament fabrication is emerging as a promising sinter-based technology rivalling widespread beam-based approaches for the production of metal components. In the first step, a filament composed of a polymeric matrix with a high powder loading is extruded by a capillary die and deposited layer by layer to produce the desired geometry. Filament properties are critical for the printing performance, still, there is not a consensus on the range of filament properties adequate for printing. This work aims to establish threshold values for filament features leading to satisfactory printing by analysing the rheology and mechanical properties of filaments made of powders of diverse ferrous alloys. It is concluded that besides other consequences, filament rheology and mechanical properties have a strong impact on the shear stresses developed during printing, which limit the printing speed. These parameters can be engineered by solid loading and temperature to maximize the printing process.

DOI:

https://doi.org/10.59499/WP225372277

Authors:

Marco Zago (University of Trento, Italy), Alex Rambelli (Sacmi Imola s.c., Italy), Ilaria Cristofolini (University of Trento, Italy)

Abstract:

The influence of compaction strategy on compressibility and densification of metal powders has been extensively studied in previous work; effective compaction mechanics relationships and a densification model have been derived on experimental basis. Nevertheless, such studies also highlighted the need for further investigation concerning filling step, playing major role in obtaining high density, homogeneously distributed. This work focuses on filling step, considering the influence of both geometry, and filling strategy. Ring shaped parts with different height to thickness ratios (H|T) have been produced, also varying filling parameters as filling shoe speed, suction speed, and number of shakes of the filling shoe. Filling density was derived, as a function of above parameters, also highlighting the most critical parameters affecting filling density. Moreover, green density was measured in different points, referring to filling shoe movement, aiming at identifying the effect of filling strategy on flatness and parallelism of planes resulting from compaction.

DOI:

https://doi.org/10.59499/WP225368618

Authors:

Marion Coffigniez (UCLouvain, Institute of Mechanics Materials and Civil Engineering, IMAP, Belgium), Amandine Duchaussoy (UCLouvain, Institute of Mechanics Materials and Civil Engineering, IMAP, Belgium), Matthieu Marteleur (UCLouvain, Institute of Mechanics Materials and Civil Engineering, IMAP, Belgium), Justine Papillon (Univ Lyon, INSA Lyon, UCBL, CNRS, MATEIS, UMR 5510, France), Eric Maire (Univ Lyon, INSA Lyon, UCBL, CNRS, MATEIS, UMR 5510, France), Pascal Jacques (UCLouvain, Institute of Mechanics Materials and Civil Engineering, IMAP, Belgium)

Abstract:

ß-metastable Ti alloys exhibit a very large work hardening rate together with an outstanding resistance to damage nucleation, bringing a very high ductility. Such a behavior could enable to counteract the decrease of mechanical properties caused by solidification cracking|hot tearing, balling or porosity formation during laser powder bed fusion. The binary Ti-12 wt.% Mo grade was chosen as a case study, using powder mixture as a first approach. As-printed microstructures highlight the formation of structures related to the solidification scheme, as well as specific Mo solute partitioning depending on the printing parameters. Such a specific microstructure brings a large increase of the tensile strength compare to the cast reference. Furthermore, when the chemical homogenisation obtained is large enough to reach 95 % of ß-metastable microstructure, ductility comparable to the cast reference is reached after a simple flash heat treatment, as well as an outstanding low sensitivity to defects.

DOI:

https://doi.org/10.59499/WP225371687

Authors:

Tomo Takahashi (Pacific Sowa Corporation, Japan), Toshiko Osada (Tokyo Metropolitan University, Japan), Yoshiyuki Kato (Kato Professional Engineer office, Japan), Ken Yokoyama (ExOne KK, Japan)

Abstract:

Gas atomized powders are mainly used in binder jet (BJ) metal 3D printing. The cost of water-atomized powders is lower than that of gas-atomized powders. And surface roughness and mechanical properties of sintered body is improved by using Ultrafine powders obtained through water atomization. However, the flowability of gas atomized powder is lower and the use of them in BJ 3D printing is serious issue. In this study, the flowability of water atomized powders was controlled by addition of nano-silica powder to water atomized powders with different average particle sizes.

DOI:

https://doi.org/10.59499/WP225369747

Authors:

Elodie Cabrol (Centrale Lyon ENISE, France), Hocine Si-Mohand (Centrale Lyon ENISE, France), Agathe Deborde (MetaFensch, France), Jérôme Delfosse (SAFRAN TECH, France), Layla Sasaki (Aubert & Duval, France)

Abstract:

In this work, we have investigated the influence of the presence of satellites on the flowability properties of a TA6V powder. Thermal plasma treatments have been performed to spheroidize the powder at various feed rates (2 to 8 kg|h) under Ar|He atmosphere. The physical and chemical properties of the initial and treated powders have been characterized: morphology, particle size distribution, flow rate, apparent and tap densities, interstitial contents (oxygen, nitrogen and hydrogen). The results have shown that the best powder produced by plasma treatment was spherical, satellites-free and without noticeable effect on the particle size distribution. The Ar|He atmosphere leads to very low interstitial contamination. In addition, an improvement in flow rate of 30% was observed as well as an increase in apparent and tap densities of 20% and 8% respectively.

DOI:

https://doi.org/10.59499/WP225371983