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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:

Tim Marter (Element22 GmbH, Germany)

Abstract:

This study explores the challenges of sinter-based additive manufacturing for reactive materials, focusing on titanium. Thermal debinding and sintering, crucial steps in shaping, are analyzed with emphasis on polymer binder removal and control of interstitial elements like C and O to meet ASTM F2885-17 standards. While prior research emphasized simpler materials like 316L and 17-4-PH, titanium introduces complexities requiring meticulous process adjustments.The research examines shaping requirements such as green part strength, flexibility (filaments), flowability (Metal Injection Moulding), and crosslinking (Stereolithography). Lithography-Based Metal Manufacturing (LMM) and Cold Metal Fusion (CMF) are highlighted as cost-effective, sustainable alternatives to Metal Injection Moulding for small to medium titanium batches, enabling efficient reuse of feedstock.A detailed comparison of LMM and CMF evaluates mechanical properties, surface finishes, and costs. This study aims to optimize shaping technologies based on mechanical performance, density, interstitial acceptance, complexity, and structural features like wall thickness and overhangs.

DOI:

https://doi.org/10.59499/EP256767043

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:

Mark Hash (Ervin Industries, USA) Florian Götz (Ervin Germany, Germany) Paul Abram (Ervin Germany, Germany) Alexander Stawenow (SLV Mecklenburg-Vorpommern GmbH, Germany)

Abstract:

Fine, Type 17-4PH powders made by centrifugal were employed in both Laser Powder Bed Fusion (LPBF) and Directed Energy Deposition (DED) applications. Powders at a nominal, particle size ranges of 15-53 or 53-106 micron were used to print LPBF and DED test specimens comparing print quality and speed. Finished parts were characterized for final density, porosity, feature resolution, print consistency, and mechanical properties. Comparable specimens made using commercial, gas atomized powders were printed in parallel to provide baseline levels of performance for comparison. Resulting data and microscopy are presented and discussed with respect to powder manufacturing method describing benefits and limitations of these powders.

DOI:

https://doi.org/10.59499/EP256767926

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 Berger (1), Johannes Pötschke (1), Uwe Scheithauer (1)

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

Abstract:

Binder-jetting (BJT), a sinter and powder-based additive manufacturing technology, is becoming more and more established on the market due to its high productivity and the wide variety of materials it can process. The production of WC-Co based hardmetals is being promoted by well-known hardmetal and powder manufacturers using the BJT technology. Within this study, five different binder jetting printers from four different manufacturers were tested and compared for their suitability to produce hardmetals. In addition to hardmetal properties, printing performance and green part handling are compared and the investigated differences discussed. The study shows, that all tested BJT printers show the principle feasibility of producing hardmetal green parts which can after sintering yield dense samples.

DOI:

https://doi.org/10.59499/EP246281340

Authors:

Maxime Stephan (1), Guilhem Roux (1), Carine Ablitzer (2), Jean-Paul Garandet (1), Alexis Burr (1)

1- Univ. Grenoble Alpes, CEA, LITEN, DTNM, L3M, Grenoble 38000, France

2- CEA, DES, IRESNE, DEC, Cadarache, Saint-Paul-lez-Durance 13108, France

Abstract:

The powder spreadability partly drives the robustness of powder-bed-based additive manufacturing processes as well as material performances of the printed parts. The full comprehension of the mechanisms involved during powder spreading is therefore paramount. Literature showed that the impact of friction between the powder and previous layers is significant on powder bed quality. Thus, this work presents an experimental test bench that captures the heap profile during spreading in real time. Indeed, it is found that the heap profile and recoating angle are sensitive to the platform surface roughness and powder properties. Improving the interaction of the powder with the platform results in a larger recoating angle, and improves the powder bed density. This is done by increasing the friction through cleverly oriented ridges or by reducing powder rolling friction through sphericity. Our test bench is relevant for understanding powder deposition experimentally, and has interest for further spreadability optimizations.

DOI:

https://doi.org/10.59499/EP246276968

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:

Malte Becker (Fraunhofer IAPT, Germany), Ina Ludwig (Fraunhofer IAPT, Germany)

Abstract:

Additive Manufacturing (AM) stands out in lightweight construction, material efficiency and geometric freedom. But as it is still a relatively young technology only a small number of alloys has been developed and thus there is a lack of material diversity especially for highly stressed AM components.One way to increase mechanical properties is using composite alloys that are reinforced by ceramic particles.Subject of this investigation are the effects of reinforcing AlSi10Mg with different volume fractions of silicon carbide (SiC), by either mixing or milling and the processability of the reinforced powder in a LPBF process.The used powders are characterized including optical inspection, particle size distribution, particle morphology and flowability. The manufactured parts analyzed regarding the density and tested for their mechanical properties. Based on the results correlations between the powder manufacturing process, alloy composition and mechanical properties are evaluated.

DOI:

https://doi.org/10.59499/WP225371733

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:

Anatolii Laptiev (Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine, Ukraine) Dmytro Verbylo (Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine, Ukraine) Victor Novichenko (Technical Center NAS of Ukraine, Ukraine) Oleksandr Myslyvchenko (Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine, Ukraine) Anatolii Laptiev (Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine, Ukraine)

Abstract:

Titanium is one of the most important materials for aviation and space industry. High-strength parts can be obtained by powder metallurgy methods from fine-grained powder. However, pressureless sintering of titanium powders requires high temperature (1200-1300 °C) and long holding (2-4 hours). To obtain high-density samples at lower temperatures, of interest is the method of a vacuum compaction of a porous briquette under the action of an impact load, at which the pressure reaches values of 1100-1300 MPa, and the compaction process lasts 0.003-0.005 s. In this study, titanium samples were obtained using two technologies: pressureless sintering of porous briquettes at a temperature of 1300 °C with an isothermal holding time of 80 min, and impact compaction at temperatures of 750, 850 and 950 °C with an isothermal holding time of 30 min before impact. The density, mechanical properties and microstructure of samples after their compaction by different methods were studied.

DOI:

https://doi.org/10.59499/EP256717003