Individual Papers

Authors:

Mohammad Ibrahim (Norwegian University of Science and Technology, Norway) Tiziano Trapletti (Norwegian University of Science and Technology, Norway) Ragnhild Elizabeth Aune (Norwegian University of Science and Technology, Norway)

Abstract:

A functionally graded strategy was employed to address brittleness and thermal-expansion mismatches in four nickel-silicon-based alloys—NiSi11.9Co3.4, NiSi10.15V4.85, NiSi11.2Mo1.8, and NiSi10.78Ti1.84B0.1—during Directed Energy Deposition (DED) on S355 steel. Each alloy was deposited atop an Inconel 625 transition layer, producing 30?mm cylinders for structural evaluation. Except for NiSi10.78Ti1.84B0.1, all alloys printed successfully, exhibiting stable builds as they demonstrated minimal hot cracks and low porosity. Microstructural examinations using Optical Microscopy, Scanning Electron Microscopy and Energy-dispersive X-ray spectroscopy mapping showed a uniform distribution of secondary phases and grains, suggesting robust solidification conditions throughout the builds, confirming that Inconel 625 effectively mitigates residual stress and thermal mismatch issues between Nickel Silicide alloys and S355 steel. This functionally graded approach demonstrates the feasibility of DED processing for nickel-silicon-based alloys, providing a versatile solution to compositional and thermal constraints.

DOI:

https://doi.org/10.59499/EP256768149

Authors:

Tim Marter (Element22 GmbH, Germany)

Abstract:

Sinter-based additive manufacturing of Titanium and its alloys faces challenges from deformation and shrinkage during sintering, limiting its adoption for complex geometries and small batch sizes. To address these issues, this presentation explores Finite Element Method (FEM)-based sinter simulations, incorporating sinter stress, gravity load, viscosity, friction, and time-temperature-densification effects. Traditional simulation models require hard-to-measure parameters and fail to match experimental curves, such as dilatometric studies.A phenomenological approach, leveraging real-world data from dilatometer measurements, overcomes these limitations by reducing the need for extensive material-specific investigations. This approach enables accurate simulations using a single temperature-time profile, simplifying data collection and improving predictive accuracy.The talk highlights the integration of these simulations into the Cold Metal Fusion (CMF) process, comparing real-world and simulated results, and discussing potential refinements. This research aims to optimize sinter-based additive manufacturing, minimizing costs in time, labour, and materials while enhancing process efficiency.

DOI:

https://doi.org/10.59499/EP256766761

Authors:

Sunil Raghavendra (1), Sasan Amirabdollahian (2), Matteo Perini (2), Marco Chemello (3), Matteo Benedetti (1)

1- Department of Industrial Engineering, University of Trento, Trento, Italy

2- ProM Facility, Trentino Sviluppo S.p.A, Rovereto, Italy

3- Sicor S.p.A, Rovereto, Italy

Abstract:

With the current development in additive manufacturing (AM) processes, such as Laser directed energy deposition (L-DED), efficient usage of raw materials is possible. With the aid of this L-DED process, we aim to develop an efficient way to reduce the use of bronze in worm gears. Our objective is to fabricate worm gears by applying CuSn10 (bronze) alloy onto a stainless steel tooth created through the L-PBF process. We assess the impact of laser power, feed rate, scanning speed, and scanning strategy on the deposition process. The deposited cross-sections undergo analysis for porosity, hardness, dilution, and microstructure at various locations along the tooth profile.

DOI:

https://doi.org/10.59499/EP246283629

Authors:

G. Walther (1), J. Trapp (1), T. Weißgärber (1,2)

1- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Branch Lab Dresden, Germany

2- Technische Universität Dresden, Faculty of Mechanical Engineering, Institute of Materials Science, Germany

Abstract:

Sintered friction materials are used in particular for high performance applications due to their excellent temperature stability. Increasingly, new regulations regarding sustainability and environmental compatibility require innovative materials. In the USA, only brake pads with less than 0.5 percent may be sold by 2025 due to toxic abrasion. In addition, the new Euro 7 standard also imposes stricter limitations on non-exhaust particulate emissions. In this paper, material solutions for iron-based sintered linings for motorcycle brakes and synchronizer rings are discussed as an example of how to replace copper-based systems without losses in performance. Furthermore, the development of an aluminum composite brake disc is presented. These new brake discs use a particle-reinforced aluminum friction ring, which ensures an almost complete avoidance of the abrasion and, therefore, particle emission. Besides, the aluminum-based brake discs allow for lighter and more sustainable cars, e.g. by a 50 % reduction of the brake system’s weight.

DOI:

https://doi.org/10.59499/EP235764215

Authors:

Tom Andersson (1); Matti Lindroos (2); Abhishek Biswas (1); Tomi Suhonen (1); Supriya Nandy (1); Anssi Laukkanen (1); Juha Lagerbom (2); Tomi Lindroos (2); Pilar Rey Rodriguez (2)

1- VTT Technical Research Centre of Finland, Espoo, Finland

2- VTT Technical Research Centre of Finland, Tampere, Finland

3- AIMEN Centro Tecnológico, Porriño,Spain

Abstract:

We present a workflow and model prediction of a behaviour for an alloy designed for an application, which require high strength materials, with multiscale material modelling method. Material is designed to have suitable phase composition with CALPHAD-method and neural network tool that is taught with the empirical high entropy alloy design criteria. The material is estimated to be two phase (FCC-BCC) structure in as-build condition and after heat treatment gamma-gamma' and BCC-B2 structure. Designed alloy is atomized and test specimens are produced with direct energy deposition method. Specimens are heat-treated to get the desired phase composition. Tensile tests and micromechanical characterization are combined with simulation tools to create a micromechanical model that is used for mechanical property and performance simulations. A workflow to combine the different methods in order to assess the performance of the material.

DOI:

https://doi.org/10.59499/EP235764634

Authors:

Michael Andersson (Höganäs AB, Sweden)

Abstract:

Gears are an interesting application for pressed and sintered applications, and having accurate fatigue data is often a pre-requisite for starting a new gear design. Ideally gear fatigue strength is tested on gears, but that is not always possible. At the same time standard bending fatigue data are often more readily available. Therefore, it’s interesting to have reliable methods for going from, for instance, bending fatigue strength on a test bar to tooth root fatigue strength of a gear. This paper investigates how gear fatigue strength can be calculated from test bar data and the results are compared with pulsator testing of gears.

DOI:

https://doi.org/10.59499/WP225371871

Authors:

Mohammadreza Jandaghi (1,2), Johan Moverare (1,2)

1-Division of Engineering Materials, Department of Management and Engineering (IEI), Linköping University, Sweden

2-Wallenberg Initiative Materials Science for Sustainability, Department of Management and Engineering (IEI), Linköping University, Sweden

Abstract:

The sustainability of Laser Powder Bed Fusion (L-PBF) in metallic component production hinges on effective powder reusing, given the significant unsolidified feedstock residue. This study evaluates the influence of powder reuse on phase evolutions using thermodynamic simulations via Thermo-Calc software. Both virgin and five-time reused powders of austenitic steel 316L (SS316L) were examined alongside printed parts. Results indicate unavoidable Rhodonite (MnSiO3) inclusions due to its high oxidation affinity. Rapid solidification produces ferritic single crystal particles from hot spatters. Sieving inefficiencies allow smaller oxide particles to persist, increasing oxide fractions in printed parts. Scheil diagrams show that while minor oxygen does not impact solidification, increased dissolved oxygen promotes Spinel (MnCr2O4) formation and inclusion clustering, serving as potential nucleation sites for ferrite. Tensile sample analysis reveals that, despite the pinning effect of fine oxide particles, increased inclusion size in reused samples compromises tensile strength.

DOI:

https://doi.org/10.59499/EP246281053

Authors:

Ángel Biedma (Universidad Carlos III de Madrid, Spain) Sandra Gordon (Hilti A.G., Liechtenstein) Olivier Ther (Hyperion Materials & Technologies, Spain) Luis García (Hyperion Materials & Technologies, Spain) Steven Moseley (Hilti A.G., Liechtenstein) Elena Gordo (Universidad Carlos III de Madrid, Spain)

Abstract:

This work investigates the thermodynamic design and experimental validation of Ti(C,N)-based cermets, focusing on the role of different secondary carbides (WC, Mo2C) and Co-free Ni-based metallic binders. A CALPHAD-based approach is used to predict the influence of single and combined phases on carbon activity, liquidus temperature, and secondary phase formation.This step-by-step methodology integrates thermodynamic predictions with experimental validation to guide the design of Co-free Ti(C,N)-based cermets. Experimental methods include differential thermal analysis (DTA) to assess melting temperatures, contact angle measurements to assess wettability, and microstructural characterisation to determine phase distribution. The study aims to systematically investigate each component's effect on sintering behaviour and microstructural evolution, providing insight into their contribution to expanding the carbon equilibrium range and optimising processing conditions.

DOI:

https://doi.org/10.59499/EP256765968

Authors:

Neyder A. Sandoval (1), Edwin A. Murillo (2), Sophia A. Tsipas (1)

1- Materials Science and Engineering Department, IAAB, Universidad Carlos III de Madrid, Spain

2- Chemistry Department, Universidad Francisco de Paula Santander, Cúcuta, Norte de Santander, Colombia

Abstract:

Sinter-based additive manufacturing of metallic materials offers advantages in terms of design and efficiency but poses environmental concerns due to the use of chemicals and the generation of pollutant gases during the elimination of binders which are harmful to the environment. To improve this problem, the study of biopolymeric binders derived from renewable sources is proposed. This work explores composite extrusion modelling of metallic or metal-ceramic alloys using biopolymers to produce environmentally friendly feedstocks. Comprehensive evaluation of biopolymer blends based on poly lactic acid and polyvinyl alcohol were carried out for their use as binders. A study of critical solidity loads, microstructural, rheological characterisation, densification, and homogenisation, studies were performed.

DOI:

https://doi.org/10.59499/EP246282804

Authors:

Ji-Woon Lee (Kongju National University(CAMP2), Korea, Republic of) Soon-jik Hong (Kongju National University(CAMP2), Korea, Republic of) Gian Song (Kongju National University(CAMP2), Korea, Republic of) Jin-Kyu Lee (Kongju National University(CAMP2), Korea, Republic of) Jongun Moon (Kongju National University(CAMP2), Korea, Republic of)

Abstract:

Additive Manufacturing (AM) has garnered significant attention in recent years for the fabrication of metallic components. The processability and quality of AM-produced parts are strongly influenced by the flow behavior of feedstock powders. Therefore, a thorough understanding of powder flowability and its governing characteristics is essential for optimizing AM processes. In this study, spherical, fine metallic powders of IN625, Maraging steel, Hastelloy C-22, and STS316L with a uniform particle size distribution (PSD) were produced via gas atomization. The dynamic flowability of these powders was systematically evaluated as a function of their PSD and material properties. The results highlight the critical role of intrinsic material characteristics in determining flowability and powder performance, providing valuable insights into the selection and optimization of feedstock powders for AM applications.

DOI:

https://doi.org/10.59499/EP256779608

Authors:

Deekshitha Kancharla (1), Moritz Greifzu (1,2), Axel Marquardt (1,2), Joanna Eckardt (1)

1- Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Germany

2- Institut für Werkstoffwissenschaft, TU Dresden, Germany

Abstract:

Metal Binder jetting (BJ) is an additive manufacturing technology that requires a series of post-processing steps to obtain the final product, with sintering being one of the important steps. Multiple coupled phenomena such as densification, coarsening, grain growth, and evolution of microstructure, influence sintering. Grain growth during sintering impacts the final mechanical properties and the densification of a material. The most common method to evaluate the grain growth behaviour is conducting interrupted-sintering analysis followed by microscopy which is a time-consuming process. This work intends to estimate the grain growth during sintering from the shrinkage data obtained from dilatometry. The concept of integrating a master sintering curve (MSC) into the Skorohod-Olevsky-based model is explored to predict grain growth and sintering behaviour. The main aim is to evaluate the adaptability of this approach to BJ.

DOI:

https://doi.org/10.59499/EP235763105

Authors:

Philip Sperling (Volume Graphics GmbH, Germany), Nils Achilles (Yxlon International GmbH, Germany), Torben Kuhnt (Yxlon International GmbH, Germany), Lea Reineke (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany), Bastian Barthel (Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany)

Abstract:

Metal Binder Jetting (MBJ) offers many advantages, as the material variety also includes non-weldable materials and is capable of higher build rates compared to other powder bed-based processes, which makes the process interesting from an economical perspective. In contrast to other powder bed-based processes the binder application is unique. The aim of this work is to characterize and analyse the porosity distribution of the green parts by computed tomography. The parameters binder saturation and layer thickness are varied. These results show that binder application leads to porosity in green and sintered parts due to droplet impact. A higher binder saturation can compact the particle structure in the green part due to capillary forces. This also results in a better inter-layer bonding and leads to a lower anisotropy of the shrinkage. Resulting particle segregation in the powder bed & green part are due to powder application by a counter rotating roller.

DOI:

https://doi.org/10.59499/WP225372057