Euro PM2024 Proceedings

Authors:

Arnaud Fregeac (1), Méyane Hurtault (1), Céline Larignon (1), Yannick Beynet (1), Romain Epherre (1)

1- Norimat, Labège, France

Abstract:

Sinter Based Additive Manufacturing (SBAM) processes are receiving much attention as an alternative to LPBF processes for the rapid production of metal and ceramic components with reduced cost and environmental impact. On the other hand, the sintering step is sometimes difficult to perform for green parts from SBAM process resulting in high residual porosity. This paper proposes a versatile alternative with FAST/SPS hybridisation. The FAST/SPS process is recognised as an R&D method capable of producing high performance parts from a wide range of materials. In recent years, significant progress has been made in overcoming the two main limitations of the technology: production capacity and geometric constraints. An important industrial breakthrough is presented here, with the development of a unique hybrid process that enables the consolidation of 3D SBAM parts by FAST/SPS. It allows green parts to be fully densified (porosity <1%) immediately after printing in a single step and with less than 2 hours of thermal treatment.

DOI:

https://doi.org/10.59499/EP246281550

Authors:

Tugce Tekin (1,2), Francesco Naclerio (3), Rasim Ipek (2), Alberto Molinari (1), Matteo Benedetti (1)

1- University of Trento, Trento, Italy

2- Ege University, Izmir, Turkey

3- Pontillo Officine Meccaniche & C., Scafati (SA), Italy

Abstract:

The axial fatigue strength of maraging steel produced by Laser Powder Bed Fusion (L-PBF) was investigated for different heat and surface treatments The following treatments were considered: Direct Aging of the as-built material and a duplex surface treatment consisting in a plasma nitriding followed by a PVD coating. The surface treatment increases the fatigue strength by 40% at 107 cycles, but the improvement decreases with increasing stress amplitude. The improvement is due to the hard diffusion layer, which causes a transition from a surface-initiating failure to an interior-initiating failure at low stress amplitude.

DOI:

https://doi.org/10.59499/EP246281494

Authors:

Asier Lores (1), Naiara Azurmendi (1), Iñigo Agote (1), Xabier Gomez (1)

1- TECNALIA, Basque Research and Technology Alliance (BRTA) Donostia/San Sebastian, Spain

2- TÉCNICAS REUNIDAS, Madrid, Spain

Abstract:

In response to the recent demand for innovation in new sustainable energy sources, nuclear fusion emerges as a highly relevant and significant process. Given the international effort invested in manufacturing functional reactors, Additive Manufacturing (AM) stands out as a technology that can contribute to meeting the challenges and objectives of applications requiring advanced designs. This study explores the manufacturability of P91 alloy using Binder Jetting (BJ) for high-pressure applications, including those within prospective fusion reactor systems. Following the optimization of the AM process, subsequent adjustments in sintering, Hot Isostatic Pressing (HIP), and various required heat treatments have resulted in excellent material quality in terms of microstructure. Therefore, this study validates the successful use of BJ technology for employing P91 alloy.

DOI:

https://doi.org/10.59499/EP246283206

Authors:

Markus Schneider (1), Dennis Wawoczny (1), Kevin Haffke (1)

1- GKN Powder Metallurgy Engineering GmbH, Radevormwald, Germany

Abstract:

The critical grain depth of cut hcu, crit. is a grinding metric which controls the transition from a ductile grinding regime to a brittle grinding regime and it can be correlated with several material parameters. A ductile grinding regime is preferred because it does not damage the bulk material. Intermetallic compounds, e.g. sintered Nd2Fe14B hard magnets, are very brittle and therefore prone for chipping defects. The fracture toughness KIc is a relevant factor – with a quadratic effect – in the equation of the critical grain depth of cut hcu, crit. and controls the required grinding process parameters. Anyhow, the conventional plane-strain fracture toughness derivation method with chevron notched 3-point bending specimens is very expensive due to the needed electro discharge machining (EDM) procedure to wire erode the chevron-shaped notch. As an alternative the indentation based Palmqvist toughness method was applied with good results. The derived fracture toughness KIc values are very low but in a reasonable range.

DOI:

https://doi.org/10.59499/EP246319981

Authors:

Zhenghua Yan (1), Yan Liu (1), Zhoujin Lv (2), Jiawei Li (2), Chang Gao (2), Wen Qi (2), Anders Eklund (2)

1- Simtec Soft Sweden AB, Sweden

2- CISRI-HIPEX TECHNOLOGY CO., LTD, China

Abstract:

Hot Isostatic Pressing (HIP) is an increasingly used heat treatment process for densifying and enhancing the material properties of components in the aerospace, energy, medical, and additive manufacturing industries. Optimizing HIP cycles and designing efficient HIP furnaces are critical to determine hot-spots, and the computer simulation of the furnace’s processes is indispensable. In this study, which addresses the common convergence and the time-consuming issues of traditional simulations, a novel, fully coupled, and highly efficient Computational Fluid Dynamics (CFD) simulation method was employed. This method was utilized to model a complete 25-hour HIP cycle for a three-dimensional, full-scale furnace, including heating, holding, and cooling phases, based on the given furnace power. The advanced approach enables detailed, fully coupled and full-scale 3D computations of all critical processes, such as gas flow, pressure build-up, thermal radiative heat transfer, convective heat transfer, and conjugate heat conduction in solids. The simulation delivers results in a good agreement with the measurement. By avoiding the common pitfalls of error-prone simplifications, this method lays the groundwork for optimizing HIP furnace design and operations.

DOI:

https://doi.org/10.59499/EP246206006

Authors:

Sandra Tedeschi (1), Fransisca Pirone (1), Mattia Garabelli (1), Domenico Ruggiero (1), Gian Pietro De Gaudenzi (1)

1- F.I.L.M.S. S.p.A. – OMCD Group, Anzola d’Ossola (Italy)

Abstract:

The application of the Functionally Graded Materials concept to cubic carbide-free hardmetals is commonly associated with achieving optimized mechanical properties in different regions of an article. In this work, special attention is given to maximize the corrosion and wear resistance of an outer layer while keeping the toughness values of the bulk material. This involves a detailed examination of gradients in the alloying of the metallic binder. A Ni-based outer layer, featuring a composition known for corrosion resistance, is sintered over a Co-based bulk with a medium WC grain size distribution. The concentration gradients of Ni and Co, along with the influence on mechanical properties and corrosion resistance, are thoroughly assessed. This analysis extends to the effects of additives such as chromium, molybdenum, with copper considered as an additional additive. The results reveal a promising path for the development of innovative hardmetal solutions in demanding applications.

DOI:

https://doi.org/10.59499/EP246278565

Authors:

Soundariya Ravi (1), Mária Fáberová (1), Radovan Bureš (1), Vladyslav Kostiuk (1), Vasily Milyutin (1), Róbert Džunda (1), Zuzana Birčáková (1)

1- Institute of Materials Research, Slovak Academy of Sciences, Košice, Slovakia

Abstract:

Soft magnetic composites are materials based on ferromagnetic particles surrounded by secondary electrical insulating components. The geometric size&shape of the ferromagnetic particles are crucial for the functional properties of consolidated SMC materials. Modern electronic and engineering applications create pressure for the development of materials applicable at increasingly higher frequencies of alternating magnetization. An increase in the frequency stability of the magnetic properties can be achieved by reducing the size of the ferromagnetic particles and/or by increasing the thickness of the electrical insulation layer. In any case, permeability and magnetic flux density decrease. The subject of this research is the preparation of FeSiAl particles realized by several methods of resonant acoustic and ball milling. Spherical and flake-like ferromagnetic particles with different distributions of Si and Al were prepared. Coercivity as well as changes in density and compressibility were studied depending on the structural and geometrical characteristics of the powders.

DOI:

https://doi.org/10.59499/EP246281454

Authors:

Ricardo Chávez-Vásconez (1,2), Nicolás Acevedo (1), Cristina Arévalo (2), Sergio Sauceda-Martínez (2,3), Eva Pérez-Soriano (2), Yadir Torres (2), Sheila Lascano Farak (1)

1- Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Santiago, Chile

2- Departamento de Ingeniería y Ciencia de los Materiales y del Transporte, Escuela Politécnica Superior, Universidad de Sevilla, Sevilla, Spain

3- Departamento de Ingeniería de Materiales, Universidad de Concepción, Concepción, Chile

Abstract:

High entropy alloys (HEAs) are potential materials for biomedical applications due to their unique properties. Also, the use of functionally graded porous materials (FGPM) presents an interesting approach that could help to decrease the Young’s modulus while simultaneously mimicking highly hierarchical porosity of the bone structure. In this study, Field Assisted Sintering Technology/Spark Plasma Sintering (FAST/SPS) and space-holder techniques were used to determine the viability of its use for produce HEAs which exhibit radially graded porous structures from Ti, Nb, Ta, Hf and Mo powders, using NH4HCO3 as space-holder. Results have shown that the radially porous gradient was formed when sintering at 1450°C and 10 min, but the sintering necks were not sufficient to provide adequate mechanical properties and achieve the desired porosity levels. Hence, future studies have to be carried out to determine the adequate sintering parameters to achieve good diffusion between particles.

DOI:

https://doi.org/10.59499/EP246283678

Authors:

Karl Burkamp (1), Tobias Hajeck (1), Paul Beiss (1), Alexander Bezold (1), Christoph Broeckmann (1)

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

Abstract:

This short study tackles macro hardness conversion challenges in sintered steels, underscoring the inadequacies of standard methods suited for fully dense steels. By examining a range of sintered steel samples across Rockwell, Vickers, and Brinell hardness scales, it reveals significant measurement discrepancies. In response, the study introduces bespoke conversion functions for sintered steels, aimed at ensuring precise and dependable hardness scale translations. This approach not only illuminates the distinct hardness characteristics of sintered steels but also offers vital tools for enhancing data interpretability and industry-wide comparability. This short study stands out for its practical implications, promising to improve material evaluation reliability through better hardness data comparisons, benefiting engineers, metallurgists, and researchers focused on sintered steels.

DOI:

https://doi.org/10.59499/EP246281408

Authors:

Yasin M. El Sayed (1), Alessandro Colaneri (1), Stefano Lionetti (1), Leonardo Fransesini (1), Chiara Guerrera (1), Oriana Tassa (1)

1- RINA Consulting – Centro Sviluppo Materiali, Italy

Abstract:

The purpose of this work was to develop a heat treatment to be performed on Additive Manufacturing (AM) 3D printed samples made of M300 steel to improve their mechanical properties, tailoring the as-built microstructure with the minimization of material defects like voids, porosity, micro-cracks, and variations in material structure. Different solution and ageing heat treatments were performed on samples printed via the Selective Laser Melting (SLM) technique, testing different durations, temperatures, and trends in the heating and cooling phases. The samples were microscopically analysed and mechanically tested with tensile tests and hardness (HV10). The results were compared with as-is samples showing improved mechanical properties, meaning an effective heat treatment was applied.

DOI:

https://doi.org/10.59499/EP246281343

Authors:

Srinivasan Suresh (1), Gillham Joe (1), Marshall M. Jessica (1)

1- University of Warwick, Coventry, United Kingdom

Abstract:

Development of high-density radiation shielding is one of the key aspects in deploying new nuclear reactors (Gen IV fission and fusion) to decarbonize global energy production. The current candidate materials based on refractory metals and tungsten (W)-based alloys do not yet meet the engineering requirements of a practical power generating compact spherical tokamak (cST) reactor. Radiation shielding materials must fulfil not only the materials challenges and radiological safety requirements, but also the regulatory requirements in the case of accidents. Cemented tungsten carbide (cWC)-reactive sintered boride (RSB) composites are promising candidate for compact radiation-dense nuclear armour. This review presents the synthesis and characterization of cWC-RSB materials under various processing conditions for nuclear radiation shielding. This includes simulation of compositions and synthesis parameters of cWC-RSB composites using the CALPHAD method. The radiation attenuation capabilities, radiation damage and mechanical properties of cWC-RSP composites under various scenario, simulations and conditions are discussed.

DOI:

https://doi.org/10.59499/EP246283660

Authors:

A. Meza (1), A. Alonso (1,2), J.M. Torralba (1,2), L. García de la Cruz (2)

1- IMDEA Materials Institute, Spain

2- Universidad Carlos III de Madrid, Spain

Abstract:

High entropy alloys (HEAs) are researched due to their distinct microstructures and impressive mechanical performance, which are achieved by combining multiple principal elements in nearly equal ratios. However, the inclusion of multiple elements poses challenges in HEAs fabrication by PM routes due to the high cost of pure elemental powders and the absence of readily available prealloyed HEAs compositions. Employing commodity powders such as Ni625, CoCrF75, or 316L has emerged as a viable approach, reducing manufacturing expenses and facilitating HEAs development. In this study, a fixed fraction of the aforementioned powders was used to produce HEAs using metal injection moulding (MIM). The main goal is to achieve a single FCC HEA phase exhibiting exceptional mechanical properties. To this aim, the metallic powder was mixed with high-density polyethylene and paraffin wax as binder system, and the optimal powder loading was investigated. After injection, debinding and sintering stages were optimised while microstructural and mechanical assessments were conducted on the final samples.

DOI:

https://doi.org/10.59499/EP246278267