Euro PM2024 Proceedings

Authors:

Philipp Scholzen (1), Michael Andersson (2)

1- Höganäs Germany GmbH, Germany

2- Höganäs AB, Sweden

Abstract:

The powder metallurgical (PM) process chain is a great opportunity for gear manufacturing regarding both material and energy consumption when compared to the conventional gear production. However, the remaining porosity after pressing and sintering results in a lower load capacity of the tooth flank and tooth root. Therefore, PM gears for high performance applications are surface densified to increase the density of the surface of the tooth. This paper presents a new general approach of modelling the surface densification rolling process of PM gears. Using the finite element analysis, the material behavior, geometry, and process kinematics are modelled. The method leads to a prediction of the densification profile as well as geometry and can be used as a tool to optimize the rolling process. The results are evaluated and discussed in relation to the process parameters and material behavior.

DOI:

https://doi.org/10.59499/EP246278535

Authors:

Thomas Studnitzky (1), Thomas Weißgärber (1,2), Kay Reuter (1), Chongliang Zhong (1), Michael Höft (3), Patrick Boe (3)

1- Fraunhofer IFAM Dresden, Germany

2- TU Dresden, Germany

3- Kiel University, Germany

Abstract:

Rectangular waveguides are widely used in communications satellites due to its low insertion loss and high power-handling. Additionally, near field communication in the upcoming 5G and 6G mobile communication standards are in this frequency range. As high quantities and tight tolerances are required for future applications, only a few manufacturing technologies come into consideration. In this work, the mass productive and cost-effective 3D Screen Printing was successfully used for this purpose. To achieve the goals, both a master alloy route tungsten-copper and a printing of tungsten with subsequent copper infiltration were investigated. Structures sizes of 300 µm with deviation of about 1-2 µm were successfully printed and sintered. The manufactured waveguides were characterised metallographically, tested for their function and compared with the design simulation. The specifications were well achieved, proving that 3D screen printing is an important candidate for digital communication technology.

DOI:

https://doi.org/10.59499/EP246283017

Authors:

Jazmina Navarrete-Cuadrado (1,2), Tomas Soria-Biurrun (1,2), Lorena Lozada-Cabezas (1,2), Steven Moseley (3), Patricia Alveen (4), Jose M. Sanchez-Moreno (1,2)

1- CEIT-Basque Research and Technology Alliance (BRTA), Spain.

2- Universidad de Navarra, Tecnun, Spain.

3- HILTI CORPORATION, Liechtenstein

4- EURICE – European Research and Project Office GmbH, Germany

Abstract:

WB4-B-TaB2 based materials with hardness values over 42 GPa have been obtained by glass encapsulated HIPing. Sintering of WB4-B-TaB2 powders is significantly activated by Ni additions. Porosity removal is achieved at 1100ºC-150 MPa- 1hour, that is, 250ºC below the temperature needed without nickel. However, there is strong chemical reactivity between Ni and WB4-B-TaB2 powders leading to the formation of W2B5, NiB, Ni4B3 and M2B5 phases. Since no metallic nickel remains after sintering, these ceramic composites are very brittle. Strength and toughness of WB4-B-TaB2-Ni alloys are notably improved by TiAl3 and Zr additions. Although Ni containing borides are still present in these materials, there are also Ni-rich regions free of boron after sintering, which provide a significant strengthening effect, reaching fracture strength values near 1 GPa. However, when Zr is added to the mixtures, WB4 grains are fully decomposed into a combination of mixed borides.

DOI:

https://doi.org/10.59499/EP246281649

Authors:

Dmitri Riabov (1), Karin Frisk (2), Sven Bengtsson (1)

1- Höganäs AB, Sweden

2- Innomat AB, Sweden

Abstract:

This work presents the alloy TS-CF1, a new cobalt-free stainless maraging steel designed specifically for laser-based powder bed fusion using a computer-based alloy design approach. The aim was to create a material that easily prints, while performing similarly to the common maraging variant 18Ni-300. After exploring various compositions, we settled on Fe-13.2Cr-9.1Ni-1.1Al-0.6Mo-0.5Nb-0.23Ti-0.5Mn-0.5Si (wt.%). This composition exhibited excellent printability at 40, and 80 µm layer thicknesses with minimal porosity. The precipitation response was assessed by aging at 500 °C, in both as-built and solutioned conditions. A balanced set of properties was reached after aging between 3 and 6 hours, reaching 530 HV5. Different conditions were microstructurally characterized using EBSD and XRD, showing a mostly martensitic structure with some retained austenite. The tensile strength was between 1560 and 1700 MPa, where higher strength was reached by performing a solutioning heat-treatment. Long-term high temperature exposure tests showed good resilience against precipitate coarsening.

DOI:

https://doi.org/10.59499/EP246281567

Authors:

Oliver Schenk (1), Ali Rajaei (1), Christoph Broeckmann (1)

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

Abstract:

Powder compaction and sintering offer the efficient and sustainable production of net shape components. As the inherent porosity affects the strength and durability, secondary operations such as cold rolling or shot peening may be applied to reduce the porosity. A combination with subsequent case hardening contributes to a further increase of fatigue strength. Numerous experimental studies examined the effect of various parameters of such processes on the fatigue behaviour. However, a numerical approach that accounts for the interaction between individual processes has rarely been reported. In this work, a computational approach is developed, which integrates the numerical modelling of surface densification, case hardening and loading condition to obtain information on the increase of fatigue strength of Astaloy 85Mo. The validity of the model is shown by comparison to available experimental findings on fatigue test bars. The potential of the approach is shown by its application to a sintered gear.

DOI:

https://doi.org/10.59499/EP246281733

Authors:

Baraa QADDAH (1,2), Pierre CHAPELLE (2), Bernard DUSSOUBS (2), Nicolas RIMBERT (3), Alexandre PIAGET (4), Alireza ARBAB (4), Pascal LAMESLE (1)

1- IRT M2P, Metz, France

2- Institut Jean Lamour, Université de Lorraine, France

3- LEMTA, Vandœuvre-les-Nancy, France

4- Constellium, Voreppe, France

Abstract:

Gas atomization is currently the main method of powder production for metal additive manufacturing. The Vacuum Induction Melting Gas Atomization (VIGA) is a close-coupled process used to produce spherical powders for all non-reactive materials melted by induction in a crucible. In this process, a supersonic gas jet impinges on a stream of molten metal, atomizing it into small droplets forming powders once solidification has taken place. A numerical model is developed to simulate gas flow patterns through and downstream of the VIGA nozzle. The influence of the type of gas (argon or nitrogen) on gas flow behaviour in the atomization chamber is investigated. The results show that nitrogen provides a higher velocity than argon, reduces gas consumption in the system and could be beneficial for the production of smaller droplets. The underlying mechanisms and implications for operation of the atomizer will be discussed.

DOI:

https://doi.org/10.59499/EP246287353

Authors:

Dr. Erik J. Cox (1)

1- Gencoa Ltd, United Kingdom

Abstract:

Although time consuming, degassing of HIP canisters is a critical step in the manufacture of powder hot isostatic pressed components. Carried out effectively, this stage of the process enables high quality components to be produced by preventing the retention of atmospheric contaminants such as oxygen, nitrogen, hydrogen and argon which are responsible for defects leading to poor material performance. Gencoa Optix is a gas sensing instrument that can be utilised to monitor the level of contaminant gases such as water vapour, nitrogen, oxygen etc. Optix requires no additional pumping or sampling equipment, And can operate throughout the entire degassing process. Use of a pioneering technique developed by Gencoa - Remote plasma optical emission spectroscopy, provides useful data allowing degas end point to be determined.

DOI:

https://doi.org/10.59499/EP246281542

Authors:

Ángel Sota Munoz (1,2) Nerea Burgos (1,2), Valentina Zhukova (3), Julián González (3), Mikel Osinalde (4), Jose Manuel Martín (1,2)

1- CEIT-Basque Research and Technology Alliance (BRTA), Donostia/San Sebastián, Spain

2- Universidad de Navarra, Tecnun, Donostia/San Sebastián, Spain

3- Department of Advanced Polymers and Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country, UPV/EHU, Donostia/San Sebastián, Spain

4- Elesa, Zarautz, Spain

Abstract:

Amorphous soft magnetic composites (SMCs) are characterised by low-volume fraction of magnetic material and therefore, poor magnetic permeability and saturation magnetisation. In this work, amorphous powder (Fe0.425 Co0.30 Si0.125 B0.15)96.5Nb3Cu0.5) is coated with 10 and 15 vol.% of resin and consolidated at high pressures (up to 2 GPa). Maximisation of particles packaging is obtained by mixing fractions of 0-10 µm and 20-45 µm in a volume ratio of 27:73 vol.%, respectively. Magnetic properties and power losses of SMCs made from 0-10 µm fraction and from the mixed fractions are compared. SMCs made from mixed fractions result in higher permeability but increased power losses. Low power losses (Pcv = 5850 mW/cm3 at f = 1 MHz, B = 50 mT), highest permeability (µ’ = 43.4) and highest saturation magnetisation (Ms = 0.82 T) are obtained with the SMC made from the mixed fractions after annealing and subsequent resin infiltration.

DOI:

https://doi.org/10.59499/EP246281383

Authors:

S. Fooladi Mahani (1), C. Liu (2), G. Ramírez (1,3), B.L. Liu (2), L. Lin (2), L. Llanes (1,3)

1- CIEFMA, Department of Materials Science and Engineering, Universitat Politècnica de Catalunya, Spain

2- Xiamen Tungsten Co., Ltd., China

3- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Spain

Abstract:

Laser ablation is a proven method for post-processing fabrication, surface texturing, and micromachining hardmetal tools. In this regard, dimensional accuracy and surface integrity of shaped features are expected to depend on both processing parameters and microstructural assemblage. However, detailed information about such correlations is limited, especially concerning practical and cost-effective methods like short-pulse laser ablation. This study addresses this gap by shaping microfeatures on cemented carbide surfaces with different microstructures. In doing so, distinct laser processing parameters are optimized to accurately shape microdimples and through-thickness microgrooves. Advanced characterization techniques, including scanning electron microscopy and digital image correlation, are employed to investigate the surface integrity of these features. Results revealed that laser parameter alterations affect the geometry and dimensions of induced flaws more than a difference in microstructural characteristics. By elevating the input energy level on the surface through an increase in the number of passes and fluence, the depth of laser-formed defects can be significantly rised.

DOI:

https://doi.org/10.59499/EP246280715

Authors:

Sven Bengtsson (1), Dmitri Riabov (1)

1- Höganäs AB, Sweden

Abstract:

Additive manufacturing by powder bed fusion – laser beam process can produce parts with complex geometry and good mechanical strength. However, most conventional alloys with higher strength are not very well suited for the AM process, which has led to the development of new alloy systems. The newly developed Al-Mn-Cr-Zr alloy requires an aging process step after printing where several types of precipitates are formed. This is the main contributor to the strength of this alloy system. It is demonstrated that mechanical strength vs ductility of this alloy system produced via laser powder bed process route can be tailored by changing heat treatment parameters. In the present work tensile test bars were aged at 375 oC for different lengths of time. The response in terms of tensile test data, fracture surface appearance and microstructure are discussed in the paper.

DOI:

https://doi.org/10.59499/EP246281344

Authors:

Lars Wimbert (1), René Lindenau (1), Bettina Neumann (1), Edwin Schnaider (1)

1- GKN Powder Metallurgy Engineering GmbH, D-53177 Bonn, Germany

Abstract:

Permanent magnets and especially NdFeB (Neodymium Iron Boron) magnets are one of the most critical components in the global manufacture of modern electric motors. The production process of NdFeB magnets contains a large number of different procedures, all of which can have an influence on the properties of the end product. Although at first glance, relatively similar to the classic PM process, the manufacturing route involves some special challenges that will be examined in more detail in this paper. Starting with the optimization of the hydrogen decrepitation of the base material, this contribution will additionally describe the effect of different milling parameters on microstructure and magnetic properties, the procedure of dimensionally precise compaction and sintering of magnet preforms and the magnetic testing of finished magnets.

DOI:

https://doi.org/10.59499/EP246277035

Authors:

Ahmed Fardan (1), Johannes Gårdstam (2), Håkan Brodin (1,3), Eduard Hryha (1)

1- Department of Industrial and Materials Science, Chalmers University of Technology, Göteborg, Sweden

2- Quintus Technologies AB, Västerås, Sweden

3- Siemens Energy AB, Finspång, Sweden

Abstract:

Powder bed fusion – laser beam (PBF-LB) is an additive manufacturing technique that can produce near-net shape components. However, PBF-LB of high γ’ Ni-base superalloys is limited due to their increased strain age cracking (SAC) susceptibility in post-processing heat treatment. This work proposes tailored hot isostatic pressing (HIP) to minimize SAC, in addition to studying the impact of solution temperatures above the γ’ solvus on the microstructure. Results indicated that the Pre-pressurisation strategy where the target pressure was first achieved, and then the ramp up to the target temperature effectively minimized SAC. The microstructure study showed that there was recrystallization for temperatures as low as 1250°C, however, there was no significant change in the grain size (equivalent circle diameter was 80 to 90 μm) up to 1280 °C. These findings indicate that SAC can be minimized with HIP and with additional optimization can enable fully heat-treated crack-free components.

DOI:

https://doi.org/10.59499/EP246281533