bluuebunny/crossref_metadata_2025 huggingface dataset:
Binder Jetting - Reusability Of 17-4 PH Stainless Steel Powder
Authors: Zissel Kai , Quejido Elena Bernardo , Deckers Tobias , Forêt Pierre , Hryha Eduard
Published: November 2024

Binder Jetting (BJT) is a binder-based Additive Manufacturing technology, where only a small fraction of the processed powder is bonded inside the green parts after printing. Unbound powder, which is recovered during the BJT process, is reused for printing. For powder reuse, the resulting changes in the physical and chemical powder properties along with the powder surface conditions strongly affect the reproducibility of the BJT process and its final part properties. In this study, the powder degradation and its impact on the reusability of 17-4 PH stainless steel powder are evaluated for the BJT process. Powder characteristics are analyzed after multiple reuse cycles after different process steps, namely drying, sieving, printing and curing. The influence of reused powder on print quality and green densities is investigated and compared to virgin powder. Furthermore, the effect of inert and reducing atmospheres on the powder reusability during curing is examined.
A Novel Approach To The Development Of Multifunctional Insulating Layers For Soft Magnetic Composites
Authors: Poskovic Emir , Ceroni Marta , Carosio Federico , Franchini Fausto , Ferraris Luca , Actis Grande Marco
Published: November 2024

Soft Magnetic Composites (SMC) comprise magnetic grains held together by an insulating layer. The widespread diffusion in the market for such materials, conventionally employed in electrical machines, is currently held back by limitations associated with material properties and processing constraints. These drawbacks are mostly related to the insulating layer employed. This contribution aims at overcoming such limitations by means of a novel surface approach. The proposed surface modification allows to coat of each particle with a nanostructured layer providing electrical insulation while also conferring additional features such as improved mechanical properties and withstanding higher treatment temperatures. In addition, the use of the proposed technology makes the layer feasible with a wide range of materials. The layer materials can be organic, inorganic or a combination of both. SMCs encompassing the developed innovative multi-functional layers have been prepared and characterized by means of surface morphology, magnetic and mechanical properties.
Challenges Of Water Based Hard Metal Extrusion
Authors: Müller-Köhn Axel , Werner David , Pötschke Johannes , Aleksandrov Fabijanić Tamara , Jeren Ivan
Published: November 2024

Water and cellulose-ether-based extrusion of hardmetals give the opportunity of an environmentally friendly processing. Furthermore, water as a solvent significantly reduces the demands in occupational safety and also costs in suction systems and drying processes.Use of water requires specific binders and additives to achieve the desired processing behavior of extrusion feedstocks as well as the necessary hardmetal properties after sintering. Additionally, water removal during drying of extruded parts demands well controlled conditions to ensure shape retention and defect free green parts.In this presentation necessary organics and processes for a successful feedstock preparation and extrusion will be shown. As an example, it was possible to apply submicron (d50 less than 1 µm) WC-10 Co and binder free, nano scaled WC powders. Finally, resulting material properties of extruded and sintered parts will be demonstrated.
Field Assisted Sintering Technique|Spark Plasma Sintering (FAST|SPS) Of Self-passivating Tungsten Alloys For Future Fusion Power Plants
Authors: Bram Martin , Gonzalez-Julian Jesus , Linsmeier Christian , Coenen Jan W. , Litnovsky Andrey
Published: November 2024

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.
Developement And Optimisation Of A PLA Bio-based Feedstock For PIM-like Extrusion-based Additive Manufacturing Of Steel Tool Alloy
Authors: Charpentier Nicolas , Barrière Thierry , Frederic Bernard , Boudeau Nathalie , Vikner Peter
Published: November 2024

Bio-based binder alleviate the important carbon footprint that is created during PIM-like process with a carbon cycle for the binder. Moreover, some bio-based polymer are more suited to EAM, like PLA.This work presents the different steps in developing a suitable pellets feedstock for PIM-like EAM and its optimisation to minimize porosity by tomographic observation in the final part. The work is focused in the use of a steel-tool alloy powder but using the same method other materials can broaden the field of application.
Influence Of Oxygen In The Production Chain Of Metallic Glasses Via Laser Powder Bed Fusion
Authors: Soares Barreto Erika , Soares Barreto Erika , Wegner Jan , Frey Maximilian , Kleszczynski Stefan , Busch Ralf , Uhlenwinkel Volker , Uhlenwinkel Volker , Mädler Lutz , Mädler Lutz , Ellendt Nils , Ellendt Nils
Published: November 2024

Laser powder bed fusion of metals (PBF-LB|M) is advantageous for manufacturing bulk metallic glasses with size and geometrical freedom. However, the oxygen uptake along the production chain can negatively impact the generation of high-quality, amorphous parts. In this context, Cu-Ti-based alloys were gas-atomized and additively manufactured using commercial and high purity feedstocks. The oxygen absorption in each processing step was tracked and related to the amorphous phase formation and glass-forming ability (GFA) of alloys. Results show an increasing oxygen absorption, considerably influenced by the starting feedstock, especially for commercial purity. In high purity material, the most contribution is inherent from the powder oxygen content. Findings reveal the lack of influence of the oxygen content in the GFA. TEM analysis of commercial powder and PBF-LB|M sample show uniform and featureless micrographs, displaying the absence of oxygen-induced nucleation. The present contribution enhances the qualification and economic processability of amorphous metals by PBF-LB|M.
Additive Manufacturing For Tungsten Heavy Alloys With High Mechanical Characteristics
Authors: Cury Rafael , Mahot Pascal , Handtrack Dirk , Kestler Heinrich
Published: November 2024

Amour Piercing fin-stabilized discarding sabot is a type of a non-explosive kinetic energy penetrator ammunition used on anti-tank weapons. It requires material showing remarkable characteristics such as high density, high mechanical and impact resistance in order to provide the best penetration possible against targets. Tungsten Heavy Alloys are commonly used for this type of penetrators. Recently, with the increasing interest on Tungsten Heavy Alloy additive manufactured parts, it became mandatory to investigate the influence of this process on material properties. Thus, additive manufacturing was used to obtain bars, which were submitted to solid-liquid sintering under hydrogen and processed under vacuum to avoid embrittlement. These alloys were fully characterized with respect to their microstructure and mechanical characteristics. Results shown that additive manufacturing is a viable process for this type of alloys.
A Microstructural Analysis Of The Bonding Layer In The Manufacturing Of Co Alloy | Ti Alloy Bimetallic Components By Directed Energy Deposition
Authors: De Bortoli Lucia , Amirabdollahian Sasan , Facchini Luca , Rappo Stefano , Perini Matteo , Fabrizi Alberto , Molinari Alberto
Published: November 2024

In the production of Co alloy | Ti alloy bimetallic components by Laser Directed Energy Deposition (L-DED), one critical issue is the microstructure of the metallurgical bonding layer produced by the melting of the substrate. This layer has a complex microstructure resulting from the mixing of the two alloys in liquid state and solidification. To investigate such a microstructure, specimens with a different content of the two alloys were produced by SPS and melted by laser, with the working parameters typical of the L-DED process. The solidified microstructure is quite complex. The SEM-EDXS and EBDS analyses show the partitioning of Ti, Co and the alloying elements in different compounds and phases depending on the relative amount of the two alloys. The tendency to cracking shows a dependence on the microstructure.
Binder Jetting Of Hard Metals: A Comparative Study Of Microstructure And Properties Of Different Commercial Powder Grades
Authors: Azurmendi Naiara , Agote Iñigo , Lores Asier , Fernandes Cristina , Figueiredo Daniel
Published: November 2024

Additive manufacturing of hardmetals is gaining attention due to the possibility of fabricating complex shaped parts and new functional designs. Comparing to laser-based AM processes, binder jetting appears to be more promising technology due to its low-cost, fast manufacturing process that produces stress and crack-free parts with isotropic properties. In the present work, properties of two different plasma spherodized commercial powders (AMWC701 and AMWC702 grades), have been characterized and printed with binder jetting technology. In addition, final properties of the printed parts sintered in a Sinter-HIP furnace at two different temperatures (1455°C and 1480°C) have been evaluated. Density, shrinkages, microstructure and hardness have been analysed. Best results were obtained with AMWC702 grade sintered at 1455°C, where near full density was obtained (>99%). Measured Vickers hardness was 1227 HV30, which is coherent with the microstructural analysis and close to medium grained commercial products.
Production Of Dense Ti-6Al-4V Parts By Composite Extrusion Modeling (CEM) With Excellent Mechanical Properties Identical To MIM
Authors: Limberg Wolfgang , Ebel Thomas
Published: November 2024

In this study, Ti-6Al-4V tensile test specimens were produced by Metal Injection Moulding (MIM) using fine powder less than 20 µm and 10 wt.% binder. Specimens of the same shape and size were printed by Composite Extrusion Modeling (CEM), using the same MIM-feedstock on an AIM3D-printer with modified extrusion unit. The specimens were printed with different infill directions (longitudinal and cross diagonal). Residual porosity after sintering for one hour at 1300 °C was only 1.6% for the MIM-specimens and 1.9% for the CEM-specimens. No geometrical distortion was observed during processing. X-ray tomography of the CEM-parts showed only few larger pores of less than 100 µm. The MIM- as well as the CEM-specimens achieved the same ultimate tensile strength of 945 MPa independent of the infill print direction. The plastic elongation to fracture was 15.3% for MIM, 14.5% for CEM with cross diagonal infill and 16.5% for CEM with longitudinal infill.
Stereolithography Of Copper For 5G, 6G And Beyond
Authors: Studnitzky Thomas , Weißgärber Thomas , Reuter Kay , Strauss Alexander , Altmann Marc , Häßlich Florian , Scheibler Jakob
Published: November 2024

New mobile communication standards such as 5G, 6G and beyond require further miniaturisation of complex components such as waveguides or filters made of pure copper. Previous manufacturing methods for 3D components have reached their limits in terms of precision and productivity. As a new sinter-based additive process, lithography-based metal manufacturing (LMM) enables the economical and high-precision production of such components with structure widths of around 100 µm. Since only steels have been available in LMM so far, the material copper was developed for LMM for the first time in this work. The entire process chain from powder selection, paste formulation and printing process parameters to debinding and sintering was investigated. Special emphasis was focused on the achievable geometries and the material properties in order to achieve high purity, excellent debindering quality and maximum sintering density .
Manufacturing Silver Coated Copper Particles Dedicated For Production Of Conductive Layers On The Elements Of Power Contacts By The Thermal Silvering Method
Authors: Hryniszyn Alicja , Wrona Adriana , Czechowska Kinga , Mazur Jacek , Janoszka Anna , Osadnik Małgorzata , Pecak Krzysztof , Sobik Piotr , Pawlowski Radoslaw , Jeremiasz Olgierd , Blazyca Hanna , Pawlowski Bartłomiej
Published: November 2024

The aim of the research conducted as part of the project was to develop a composite for the production of conductive layers on elements of electric power contacts by thermal silvering with the addition of ultrafine copper particles, copper oxide or copper particles coated with silver. The document will focus on the production of silver coated copper powder. First the copper powder with the assumed parameters such as: particle size distribution, shape, purity was produced using chemical method. Then, the silvering of copper particles was carried out by means of a chemical method, using silver nitrate as the silver precursor. The following silver | copper molar ratios were used during the process: 0.1 | 1M; 0.6 | 1M; 1|1 M. The produced powders were analysed for specific surface area, phase composition, particle size distribution, morphology, layer appearance, chemical composition.
High-coercivity NdFeB Printed Magnets With Laser Powder Bed Fusion Method
Authors: Tosoni Olivier , Borges Mendonça Elisa , Reijonen Joni , Antikainen Atte , Schäfer Lukas , Riegg Stefan
Published: November 2024

NdFeB permanent magnets are key components for the energy transition and the electrification of transportation, which causes their demand to grow at high pace. Yet, the supply risk for rare earth metals motivates the industry to look for an efficient use of magnets. Designing systems with complex-shaped magnets can help reducing the magnet use if accompanied by the development of net-shape processes. Powder Bed Fusion using Laser Beam of NdFeB has been studied since 2016 as a way to produce complex-shaped dense parts without any binder; most of the works are based on a commercial Nd-lean spherical powder. In the present work, a close-to-industrial process route was developed in order to produce a narrow-distributed 40-µm Nd-Fe-B powder with a composition close to the usual sintered magnet grades. This powder was used to additively manufacture parts and study the impact of changing the laser scanning strategy on the magnetic properties.
Effect Of Alloy Composition On The Atomization By EIGA Process
Authors: Deborde Agathe , Franceschini Aurélie , Delfosse Jérôme , Hans Stéphane
Published: November 2024

Powder metallurgy is used in various industries such as aerospace, medical, defence, etc. For high cleanliness materials, metal powders can be produced using the EIGA process (Electrode Induction melting Gas Atomization). The EIGA process involves the crucible-free melting of an ingot followed by atomization using high-pressure argon. A full-scale EIGA is installed at MetaFensch|IRT M2P for R&D purposes (alloy development, numerical simulation, upscaling, etc.).Process parameters such as electrode size and gas parameters have a predominant influence on powder size and yields. On the other hand, chemical composition of the alloy and the associated thermophysical properties have a significant impact on the atomization process, and therefore on the quality of the powders. To better understand the effect of the composition, several alloys were selected (Ti64, titanium aluminide, nickel-based alloys, etc.) and atomized using the EIGA process. The properties of the powders, especially particle size distribution and morphology, are compared.
Organic Contamination During The PIM Process Of High Performance NdFeB Magnets: Mechanims And Solutions
Authors: Bioud Thomas , Ollivier Maëlig , Favergeon Loïc , Luca Sorana , Rolère Sébastien
Published: November 2024

NdFeB permanents magnets are key components for green transition technologies that require high energy|volume ratio. The conventional powder metallurgy process (alloying, powdering, compression and sintering) allow obtaining high magnetic performances however it does not allow the manufacturing of complex shapes and machining produces critical and expensive material waste.The Powder Injection Molding (PIM) process, involving the manufacturing of a feedstock that can be shaped using the conventional injection molding equipment, would solve these issues. Nevertheless, the use of organic binders for injection moulding, and the post-injection debinding steps during the PIM procedure, are sources of carbon and oxygen contaminations that reduce the magnetic properties. In this work, we investigated the organic contamination mechanism in magnets produced by PIM using polyolefin-based feedstocks. The control of the debinding parameters combined with specific feedstock and particle coating engineering steps, allowed us to produce magnets with excellent magnetic properties.
Determination And Evaluation Of The Maximum Surface Densification Of Cold Rolled Powder Metal Gears
Authors: Hellenbrand Gerrit , Klee Lukas , Mevissen Dieter , Brimmers Jens , Brecher Christian , Bergs Thomas
Published: November 2024

Due to the remaining porosity of powder metallurgical (PM) gears, the highly stressed surface is post-densified in a cold rolling process to increase the wear resistance. In this report, an approach to determine the maximum possible surface densification of a demonstrator gear is presented. To realise a high degree of deformation and simultaneously avoid spalling damages at the tip area, an adaption of the process kinematic is used. Metallographic microsections are analysed to detect subsurface damages resulting from the cold rolling process. Additionally, the machine traces concerning the upcoming rolling forces over the feed-rate and number of over-rollings are evaluated. Finally, the realised densification profile is evaluated using an image-processing tool, based on the metallographic microsections and a core-density measurement. This profile can serve as an input for an FE-based tooth contact analysis with consideration of the local density profile.
A Study Of The Binder Jet 3D Printed 440C+Nb Stainless Steel: Process Development Towards High Density And Hardness Level
Authors: Sainz Shandra , Ruiz Odei , Guruceaga Idoia , Iturriza Iñigo , Kernan Brian , Morishige Ashley , Hudelson Steve , Dary Francois
Published: November 2024

Single Pass JettingTM technology was explored using the Desktop Metal’s Production SystemTM P-1 to develop a 440C stainless steel with Nb addition. A MIM powder grade was used as the raw material and the complete process towards its densification has been defined, from the selection of the appropriate powder conditioning and printing parameters to the identification of the sintering and heat-treating cycles considering metallurgical criteria. On those grounds, C and Nb content as well as the sintering atmosphere play a critical role. Chemical analysis and metallographic characterization were performed to analyse the evolution of the porosity and the microstructure. The steps of the heat treatment were selected based on retained austenite monitoring and a target hardness of 58±1 HRC. Testing samples were printed to evaluate the tensile and impact properties of the alloy against Standard MPIF35 .
Influence Of Air Humidity On Water Content And Flowability Of Different Metallic Powders
Authors: Weck Christian , Schinderling Andrea , Hein Sebastian Boris
Published: November 2024

The flowability of metal powders is crucial for all powder bed-based Additive Manufacturing processes. To ensure a defined and reproducible flowability of powders and therefore a robust AM process, a good understanding of the influence of the air humidity on the flowability is important. The flowability of powders is a result of the complex interaction of intrinsic powder properties (e.g. particle size distribution, particle morphology, chemical composition) and the water content.To investigate the influence of the particle size as well as the chemical composition, four different metal powders (316L, Ti6Al4V, AlSi10Mg) were selected. The powders were exposed to different air humidifies between 30% and 80% for different times between 1 hour and 4 hours. All powders were characterized regarding their particle size and morpholopy, their flowability and their water content. Based on the results the influence of the exposition parameters and the powder properties on the flowability was investigated.
Data Analysis And Design Criteria For Computational Alloy Design Of Metal Powders
Authors: Frisk Karin
Published: November 2024

Computational alloy design based on the CALPHAD approach involves physically based models and therefore successfully predicts properties of complex multicomponent metallic materials. When remelting metal powder by laser the effect of rapid solidification on microstructures often requires adjustments of composition, as compared to those of conventionally produced material, to reach adequate properties and avoid cracks. Searching for new compositions outside the common ranges of alloying elements, can benefit from using design criteria and data analysis. The design criteria can for example be hardenability, solidification ranges, corrosion resistance, precipitation hardening. The calculations provide the dataset to be analysed. A few examples of what is possible for Fe- and Al-based alloys, are given. The models, but also the background data, used for the calculations is critical, and this will be illustrated and discussed.
Evaluation Of Porosity In Metal Binder Jetting Due To Binder Application By Using X-ray CT
Authors: Sperling Philip , Achilles Nils , Kuhnt Torben , Reineke Lea , Barthel Bastian
Published: November 2024

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.
Post-heat Treatment Of NbC-M2 High-speed Steel Cemented Carbides: The Effect On Microstructure And Mechanical Properties
Authors: Hadian Amir , Hosseini Nia Mir Mohammad Reza , Zamani Cyrus , Salimi Mahdiar , Hadian Ali Mohammad , Clemens Frank
Published: November 2024

In this work, the effect of post-heat treatment on microstructure and mechanical properties of M2 high-speed steel (HSS) bonded NbC cemented carbides was studied. Heat treatment cycles consisting of austenitizing and tempering steps were performed under inert atmosphere on as-sintered NbC-M2 HSS specimens. While Vickers hardness remained almost stable, the fracture resistance could be improved compared to untreated cemented carbides. An optimal combination of hardness and fracture resistance was achieved by double tempering at 600 °C. Based on microstructural analysis using scanning electron microscope (SEM), the transformation of retained austenite to martensite and martensite to tempered martensite within the M2 HSS metallic binder during multiple tempering process were found to be responsible for improved fracture resistance toughness of NbC-M2 HSS cemented carbides.
High-nitrogen PM Tool Steel: A Comparison Of Microstructure And Mechanical Properties Of As-HIPed And HIPed Followed By Hot Working
Authors: Javadzadeh Kalahroudi Faezeh , Chantziara Katerina , Sadek Mohamed , Lin Fengxiang , Maistro Giulio , Anantha Krishnan hariramabad , Bergström Jens , Grehk Thomas Mikael
Published: November 2024

High-nitrogen-chromium alloyed powder metallurgy (PM) tool steels offer many attractive features including high strength and corrosion resistance. The PM route offers various advantages such as advanced alloy composition, high homogeneity, and well-defined size distribution of hard phase particles. This study presents microstructure and mechanical properties of a PM Cr-Mo-V-N alloy. The conventional manufacturing route for this alloy is hot isostatic pressing (HIP) followed by hot working. To investigate the possibility of near-net-shape manufacturing, a comprehensive comparison of the performance was made between steels produced by as-HIPed and HIPed followed by hot working. Both steel types were heat treated in the same way to obtain martensitic matrix with limited retained austenite. In the present investigation, microstructure and phase analyses were performed by X-ray diffraction and scanning electron microscopy. Mechanical tests were carried out by hardness measurements and tensile fatigue tests in the very high cycle fatigue regime using ultrasonic fatigue testing.
New Model And Adjustment Protocol For The Viscoplastic Stage Of Densification During Load Assisted Sintering : Application To Hot Isostatic Pressing Of A 316L Steel Powder
Authors: Chateau-Cornu Jean-Philippe , Chaaban Khalil , Ariane Mostapha , Bernard Frédéric , Ardigo-Besnard Maria-Rosa , Genevès Thomas , Perrin Gilles , Gyss Olivier
Published: November 2024

Due to lacks of final shape prediction after HIP by the Abouaf-Chenot model used in previous collaborative projects, we implement a new model initially developed for stage III creep (with reversed stress). The so-called LPS model (viscoplastic) meets the Gurson model (plastic) when the Norton exponent tends to infinity and provides the exact solution for a hollow sphere. The complex mathematical definition of the gauge surface was first numerically approached to simplify the numerical implementation of the model. The creep law of the bulk material is determined by Hot Uniaxial Pressing tests using a SPS device. The model is then fitted on the densification curve obtained by a simple diameter measurement of a spherical container after interrupted HIP tests. The model is finally implemented in a finite element simulation and confronted to the 3D reconstruction of the external shape of a large 316L steel part elaborated by HIP.
Mechanical Activation And SPS Sintering A Pertinent Combination To Produce Advanced Materials
Authors: Bernard Frédéric , Bolsonella Arnaud , Bussiere Florian , Moser Mathias , Couque Hervé
Published: November 2024

The work engaged for many years between the ICB laboratory and the Nexter Munitions company has clearly shown the interest of combining a high-energy mechanical milling of the metallic powders followed by a SPS sintering. Indeed, commercial powders are mechanically activated (i.e. successive actions of fracture | cold welding of the powder particles) by the use of high-energy planetary ball mill, which leads (i) to increase the agglomerate sizes, (ii) to reduce the crystallite sizes and (iii) to induce structural defects. Thus, these so-called mechanically activated agglomerates allow a densification at a lower temperature while avoiding the formation of undesirable phases and limiting the grain growth. The second interest of mechanical milling is to stabilize sometimes out-of-equilibrium phases. Several examples (nickel, maraging steels, ...) will exhibit the existence of a relationship between the powder microstructure and sintered microstructure and consequently on the tensile properties.
Stainless Steel X15TN For Laser Based Powder Bed Fusion: Material Properties For Tooling Applications
Authors: Langer Lukas , Vickner Peter , Schmitt Matthias , Schröder Timo , Schlick Georg
Published: November 2024

The X15TN steel (Euro number 1.4123) in wrought form has broad applications such as fuel injection components, pollution control systems in abrasive or corrosive environments, cutting blades with high requirements on corrosion resistance, surgical instruments and mold components. A previous study has shown that gas atomized X15TN by Aubert&Duval is possible to be processed in powder bed fusion via laser beam (PBF-LB|M) in spite of its relatively high carbon content. Being both Cobalt free and with an excellent corrosion resistance combined with a hardness of up to 59 HRC makes it of high interest for additive manufacturing. In this study, process parameters for PBF-LB|M will be presented. The material properties for different heat treatments will be presented and compared to the wrought form of the material.
Characterization Of Nickel Silicide Deposited On Steel And Nickel Substrate
Authors: Ibrahim Mohammad , Saetre Tor Oskar , Grasmo Geir , Elizabeth Aune Ragnhild
Published: November 2024

In general, silicide-based materials offer efficient improvement of turbines and offshore systems due to their exceptional oxidation, corrosion, and wear resistance. The standard requirement of materials used in these systems is the ability to withstand high temperatures. Nickel silicide (NiSi) is commonly known to possess these abilities, however, its inherent brittleness makes large scale production difficult using standard metal forming techniques. Laser Metal Deposition (LMD) is an Additive Manufacturing (AM) technique similar to cladding that allows pore-free microstructure formation of the metal with refined grains, enabling excellent mechanical properties. In the present study, NiSi16 is deposited on structural steel and nickel substrates, and microstructural development is observed in both cases. The deposited beads are characterised using conventional analytical techniques, i.e., LVFESEM, EDX and XRD, and the results are discussed in the context of changes in chemical composition.
Plasma Metal Deposition (PMD) Of Al-Cu Wire Obtained By Powder Metallurgy (PM)
Authors: Rodríguez González Paula , Gordo Oderiz Elena , Neubauer Erich , Ruiz Navas Elisa María , Ariza-Galván Enrique , Bielik Martin , Petrovic Stanka
Published: November 2024

Wires of AlCuLi alloys belonging to the family 2060 have been produced by powder pressing and extrusion of the green compacts, obtaining bars. The bars were drawn to obtain the wire, which was deposited on a 5083 substrate by PMD. Previously, the parameters were optimized with commercial wire of 2319 alloy. The parameters studied were: current (120 -240A), travel speed (100 -180 mm|min), wire feed speed (0.8 -1 m|min), plasma gas flow (0.8 – 1 m|min) and different atmospheres (Ar, Ar|He15, ArHeN-70|0.015). The optimum parameters were applied to deposit the wires obtained by PM. The results obtained have been compared to typical porosity in Al alloys, which is reduced by pre-heating (> 200 ºC) the substrate prior to welding. Li content losses have been observed in the drawing stage about 60 %wt. However, the Li amount remains during plasma welding process in quantities closed to the 72 %wt.
Influence Of Process Parameters On Laser Metal Deposition (LMD) Of Inductively Coupled Plasma Spheroidized (ICPS) NiSi32 Powder
Authors: Tareq Foysal Kabir , Aune Ragnhild Elizabeth , Sætre Tor Oskar , Ibrahim Mohammad
Published: November 2024

The laser metal deposition (LMD) process is a promising additive manufacturing (AM) technology that enables to build high precision near-net-shape metal components from metal powders. The quality of the LMD parts is highly dependent on the powder properties and processing parameters which need to be optimized to obtain accurate geometry with favorable properties. In the present study, spherical NiSi32 powder was prepared by an inductively coupled plasma spheroidization (ICPS) and later used during LMD to deposit beads on a steel substrate. Spherical NiSi32 power properties and the influence of laser power, deposition speed, and powder mass flow rate on the properties of the LMD deposited beads were investigated using different techniques such as X-ray diffractometer, scanning electron microscope, and energy dispersive spectroscopy to evaluate the phases, microstructure, elemental composition, and surface roughness. The results showed that the process parameters of LMD significantly influenced the properties of LMD deposited beads.
Effect Of Heat Treatment On Strength, Toughness And Fatigue Properties Of Cobalt-free Martensitic Stainless Steels Manufactured By Laser Powder Bed Fusion
Authors: Saby Quentin , Buffière Jean-Yves , Maire Eric , Joffre Thomas , Vikner Peter , Boulnat Xavier
Published: November 2024

Laser Powder Bed Fusion (LPBF) is an additive manufacturing process used to produce conformal cooling injection molds with complex internal channels, mainly using cobalt-rich 18Ni300 maraging steel. Yet, built parts with this steel powder still demand improved toughness and fatigue strength. As an alternative, this work describes the manufacturibility of two alternative cobalt-free martensitic stainless steels by LPBF. After a quantitative characterisation of the microstructure, defects and mechanical properties of as-built parts, different heat treatments were performed to (i) age the precipitation-hardenable low-carbon maraging steel (CX) or (ii) temper the high-carbon martensitic steel (PM420). The hardness, tensile strength, ductility, impact energy and fatigue behavior of as-built and treated parts were compared. The influence of the microstructure and the critical defects on the mechanical behavior is discussed, with an emphasis on the fatigue life. Finally, the manufacturing of complex injection molds using PM420 powder was assessed.
Cold Compacted Green Parts: A Focus On The Role Of The Structural Activity On Sintering Shrinkage
Authors: Baselli Silvia , Molinari Alberto
Published: November 2024

The thermodynamic driving force of sintering is the decrease of the Gibbs free energy related to the excess of specific surface area of the powder. Nevertheless, for cold compacted green parts, the mass transport mechanisms which allow atoms to move to form the neck are promoted by the deformation in compaction that acts as a mechanical driving force expressed through the geometrical and structural activity. The powder particles are in contact over a surface, condition that affects the geometrical relationships in the neck region. The material is strain hardened, the concentration of structural defects is higher than that in the starting powder (enhanced diffusivity). The effect on sintering shrinkage of the geometrical activity has been explained in previous works and a theoretical model is available. To highlight how structural activity acts, a dilatometry study has been carried out on ferrous materials (plain iron and AISI 316L) and different powder morphology.
Influence Of NbC And TaNbC Additions On WC-Ni Based Nanostructured Hardmetals
Authors: Aleksandrov Fabijanić Tamara , Pötschke Johannes , Mayer Markus , Snajdar Musa Mateja
Published: November 2024

The need for Co replacement with alternative binders is imperative in hardmetal research due to environmental and health issues, high cost, and inferior corrosion properties. In combination with nano WC powder, alternative binders could approach the properties of WC-Co hardmetals with improved corrosion resistance. Nickel as a binder is one of the best cobalt alternatives due to its similar properties and enhanced electrochemical corrosion resistance. Previous studies indicated that adding niobium carbide to WC-Co hardmetals significantly refines grain size and limits grain growth. Depending on the amount of NbC in hardmetals, transverse rupture strength, hardness, and wear resistance can be improved. In contrast, TaNbC significantly improves oxidation, thermal and wear resistance, and hot-hardness. In this work, microstructural characteristics and mechanical properties were investigated by observing the influence of adding NbC and TaNbC to starting mixtures with Ni content of 9 wt.% and WC particle size of approximately 150 nm.
Optimizing Metal Powders For Cold Isostatic Pressing: Correlating Composition, Morphology And Microstructure With End-use Performance
Authors: Duffy John , Norberg Nicholas , Dawes Jason , Taylor Mark
Published: November 2024

Isostatic pressing has several benefits over the commonly used press and sinter method, including equal compaction in all directions and a more uniform final component density. Nevertheless, as with other powder metallurgy processes, manufacturers must carefully characterize the metal powder’s properties for the process to be successful. Commonly characterized physical properties include powder flow, density, hardness, particle size, and particle shape of the respective powders.Other key characteristics include chemistry and microstructure. Chemistry is paramount as the powder needs to comply with the alloy composition of the material specified, while phase composition and grain size can affect powder hardness and melt behavior which can affect the forming and sintering process.In this study we are focusing on the complementary use of X-ray powder diffraction (XRPD), X-ray fluorescence (XRF), and Automated Imaging to evaluate the performance of various iron-based alloys for use in a Cold Isostatic Pressing (CIP) manufacturing process.
Iron-based Powder Solutions For Soft Magnetic Composite Applications
Authors: Lindsley Bruce , Kraus Neal , McQuaig Kylan
Published: November 2024

The recent acceleration in interest and market demand in hybrid and fully electric vehicle systems has brought new opportunities to the PM market for use of Soft Magnetic Composite (SMC) materials. As greater acceptance of these materials in both the industrial and automotive market continues, products which serve specific industry needs are being developed and standardized for use. The success of SMC powders for these specific applications is based on three important inputs – base iron, insulating coating and lubricant. Thermal processing of the SMC compact also plays a critical role, as material deformation behavior has a direct impact on magnetic properties. These factors and their influence on final properties will be discussed.
Influence Of Carbon On The Microstructure Of Carbon Steels Produced By L-PBF
Authors: Hearn William , Hryha Eduard
Published: November 2024

The recent development of carbon steel for laser powder bed fusion (L-PBF) has shown that these alloys can be produced using the process. However, knowledge regarding their as-built microstructure remains limited. This work explores the microstructure of carbon steels (0.06-1.1 wt.% C) produced by L-PBF to examine the effect of carbon on phase formation and grain structure. Analysis found that the microstructure of these alloys was primarily composed of tempered martensite that contained nano-sized carbides. Retained austenite was also observed at elevated carbon contents (=0.75 wt.%) due to the suppression of the martensite transformation temperature. With increasing carbon content noticeable changes in the parent austenite grains was not observed, however, the fineness of individual martensite grains did increase. Additionally, a transition from lath to plate martensite was observed at 1.1 wt.% C. These findings establish an understanding of carbon steels that can further their development for L-PBF.
Investigation Of Printing, Sintering, And HIP-processing Of A Nickel Free Stainless Steel For Binder Jetting
Authors: Hecker Lennart , Höges Simon , Schaak Christopher , Koehnen Patrick
Published: November 2024

Beside using Binder Jetting in industrial or automotive applications, it is also an appropriate process for the series production of wearables, jewelry or medical products. Products with constant skin contact have high requirements regarding corrosion resistance and furthermore, the material should not cause any health issues. Common stainless steels do not fit into the second requirement due to a high Nickel amount. Sweat and other fluids can cause a Nickel release from the product surface. This released Nickel can cause allergic reactions since a Nickel-sensitivity for a relevant number of people within the population is present. To offer products without any risk of Nickel release, GKN Additive developed a nickel free austenitic stainless steel material for binder jetting. To achieve an austenitic structure, Nitrogen is used as austenite stabilizer. The present paper gives an insight into the printing, sintering, and HIP process of this new material.
Towards The Additive Manufacturing Of Biocompatible Zr-based Metallic Glasses Using Liquid Phase Sintering: Study Of The Reactivity With Zn-based Additives
Authors: Pontoreau Maël , Boulnat Xavier , Steyer Philippe , Pelletier Jean-Marc , Cardinal Sandrine , Gremillard Laurent , Dezellus Olivier
Published: November 2024

Metallic glasses (MG) are a kind of advanced metallic materials which present attractive mechanical properties and corrosion resistance. The on-going development of powder additive manufacturing techniques offers the opportunity to produce rather large parts composed of MG. As part of the Direct Ink Writing (DIW) technique, the liquid phase sintering of a Zr-based MG (AMZ4, Zr59,3Cu28.8Al10.4Nb1,5) using Zn-based additives has been identified as promising. Indeed, Zn alloys have a melting point (Tf,Zn=420°C) lower than the crystallization temperature of the MG (Tx˜470°C).Here, the study focuses on the understanding of the reactivity between AMZ4 and Zn as a function of temperature and time. A powder mixture and a model interface, systems have been studied combining post-mortem characterizations (SEM, EDX, XRD, micro-hardness…) with in situ characterizations (DSC, XRD-HT). The results will permit to determine the best conditions to manufacture designed MG structures by 3D printing.
Analysis of Swamp Buffalo Tourism Potential to Improve Community Welfare in Paharangan Village, South Kalimantan
Authors: Huda Isra Ul , Karsudjono Anthonius Junianto , Sugiarto Sugiarto
Published: November 2024

This study explores the potential of swamp buffalo tourism in Paharangan Village, South Kalimantan, as a means to improve community welfare. By examining the cultural and economic value of swamp buffalo, the study highlights how community-based tourism could enhance local livelihoods and support sustainable development. Using interviews, observations, and SWOT analysis, findings reveal that swamp buffalo tourism has strong potential due to the cultural uniqueness of the buffalo and the village’s natural setting, despite challenges such as limited infrastructure and marketing support. Opportunities lie in the growing interest in eco-tourism and cultural experiences, which could position Paharangan as a distinctive destination. The study recommends a community-based model for tourism development, involving locals directly in planning, training, and promotional activities, thus enabling economic benefits and preserving cultural heritage. This research underscores the role of community-driven tourism in enhancing rural welfare and sustaining traditional practices in alignment with environmental conservation goals.
Armenia’s Constitutional Catch-22
Authors: Huseynov Tabib
Published: November 2024

In October 2024, the presidents of Armenia and Azerbaijan simultaneously approved a Protocol regulating the joint work of their respective border delimitation commissions. The protocol’s enactment in both countries became possible after Armenia’s Constitutional Court issued a landmark Decision No. 1749 on 26 September 2024, confirming that the border delimitation agreement complied with Armenia’s Constitution. However, the Court’s Decision traps Armenia in a legal and political Catch-22.
From Firewall to AI: Strengthening Linux Server Security
Authors: Atanasov Ivaylo
Published: November 2024

Nowadays, cybersecurity issues are constantly increasing. Some of the main challenges are the rapidly evolving threat landscape, the lack of skilled cybersecurity professionals, complexity of IT environments and emerging technologies, Zero-Day vulnerabilities, lack of international cooperation, user behavior and social engineering. The selection of an operating system can significantly influence the establishment of robust defenses against cyber threats. Now, many strategies are known for defense-in-depth of critical server infrastructure, but the ever-increasing sophistication of cyber-attacks must also be considered. When a previously unknown attack occurs, a defense system must be able to recognize it and act. The current development of Artificial Intelligence (AI) makes it possible to create this type of intelligent protection. This paper aims to provide an overview of some of the most renowned traditional practices and explores the potential of leveraging a neural network model to enhance cybersecurity used to protect Linux servers against cyber-attacks.
Simulation Modelling of Multi-Agent Logistics Model in AnyLogistix Environment
Authors: Dimitrov Radoslav
Published: November 2024

This paper presents the supply chain as a complex logistics system analyzed in the AnyLogistix environment, which includes production centers, warehouses, distribution centers, suppliers, retailers or trade chains. Simulation modelling within scientific research, economic and social processes is presented as one method for creating an agent-based simulation model. The assigned software agents operate in the simulation context, according to a prescribed flowchart of a typical agent-based model. An analysis was made of the elements of the supply chain management system and their interaction according to the assigned agents, namely: supply acquisition agent, logistics agent, transport agent, planning agent, supply agent, dispatcher agent, etc.
Voltage Equalizer for Two Batteries with Buck/ Boost Converters
Authors: Antchev Hristo
Published: November 2024

In this article is presented a complete schematic circuit of the power section and the control system for a voltage equalizer of two batteries. The equalizer consists of two buck/boost inverting DC-DC converters with common inductance. The operation of the circuit is described, and the computer investigation results, and practical use are presented. The shown and implemented device can findapplication in systems with energy conversion from renewable sources and in electric vehicles.
Green and Digital Technologies in Design
Authors: Aralova Galya Dimitrova
Published: November 2024

The goal of the study is to develop conceptual projects and products with an experimental nature within the module “Green Technologies in Design” of the innovative integrative module “Innovative Design”. This module is studied in the extended professional training program at PGD “Elisaveta Vazova,” Sofia, over a two-year period from 2021 to 2023. Project-based learning for students in theeleventh and twelfth grades, specializing in “Computer-Aided Design and Drawing of Textile Flat Products,” is implemented through the application of digital, green, ecological, sustainable, waste-free, and low-waste technologies, techniques, and materials in design. It has led to the creation of original designer projects and environmentally friendly ecological products. The project developssustainable practical skills and emotional-aesthetic competencies for creative ecological thinking, ecological education, culture and behaviour, solving ecological problems, practical application of the interdisciplinary and competence approach, and transforming “green” skills into a “green” way of life.Keywords: green and digital technologies in design, innovative design, product design.