Metal Additive Manufacturing Conference - MAMC 2020Virtual Conference

Additive Manufacturing, especially 3D metal printing is becoming more and more essential to manufacturing: it allows to create, quickly, fully functioning parts with high mechanical properties, and sometimes geometries that would be impossible to make with traditional manufacturing techniques. Consequently, most of the world’s top companies have taken notice and are making ambitious moves to capture their share of its potentially huge value. GE’s fuel nozzle, BMW’s roof top bracket, Siemens’ burner tips are only the tip of the iceberg. There are still many undiscovered secrets (and hurdles) of AM in the context of material development, Industrie 4.0 and especially design which will boost the adoption of AM in the future. This presentation will share insight in the current status of Metal AM and the expected development within the above mentioned domains.

Austria was and still is an excellent breeding ground for additive manufacturing. The combination of innovation, world class science and excellent engineers has led to Austria not only being a pioneer and trailblazer in this field, but also being world market leader in some areas. Various clusters and thematic focuses have formed and various initiatives have also been launched. Thus, not only a roadmap has been developed, but also an association (www.am-austria.com) has been founded, which aims to develop Austria into one of the world's most innovative pioneers in the field of additive manufacturing, in order to leverage the enormous potential of this technology for the Austrian economy.

The speech will also focus on the production of Metal Powders and Powder Metallurgical Steels and especially its associated production technologies like HIP, MIM and AM. As they are and will become key future core technologies for a number of demanding products and thus for the usage in different associated industries. The presentation will also highlight the actual supply and demand situation of metal powders and the manufactured metal powder steels, will introduce leading manufacturers of both powders and steels, and summarizes installed capacity and new capacity that are on the way as well as new players that eneter this high value industry. The presentation will also highlight the recent developments in the world of Forged Special Steels and remelted steels (nickel alloys, stainless steel, alloy tool steel and alloy steel) as well as will give an overview about end-user demand and structures of these special steels and also summarize the actual status of installations on a global scale

Additive manufacturing of production tools through laser-based powder bed fusion is at the focus of this presentation. Design and manufacturing of production tools & dies for stamping of sheet metal parts, cores (inserts) for injection moulding of plastic components and other types of production tools are addressed. Solid and topology optimized tools are tested, compared with the conventionally designed and manufactured version of the same tools, and certified. The current possibilities and constraints are addressed from the material, technological and business perspectives. The current manufacturing readiness level and the industrialization status of metal additive manufacturing through laser-based powder bed fusion are evaluated.

Laser Powder Bed Fusion (LPBF) provides advantages compared to conventional manufacturing methods, such as forging or casting, in terms of design freedom. New opportunities regarding tool geometries are introduced. Due to the layered build-up of parts, internal cooling channels can be manufactured in tools enhancing cutting speed and consequently productivity for special applications. Since tool steels exhibit high carbon equivalents, certain problems may occur during LPBF. Besides pore formation, which is mainly a function of the applied laser energy, severe cracking due to a combination of susceptible materials and thermal stresses caused by a high process-related thermal gradient is very likely. This work aims to shed light on the evolution of defect structure and microstructure of an additively manufactured powder metallurgical cold-work tool steel in dependence of the applied volumetric energy density. Investigations were performed on so-called step experiments in which a varying number of welding bead layers were manufactured. Defect surfaces, such as cracks and different types of porosity, were characterized by means of light optical and scanning electron microscopy. Additionally, the microstructure as well as the solidification structure, especially in the immediate vicinity of cracks or within pores, were analyzed in order to determine possible correlations to defect formation mechanisms. The results show that with increasing energy input porosity changes from lack-of-fusion to so-called keyhole porosity. Irrespective of the chosen energy input, crack surfaces exhibit freely solidified dendritic structures and thus hot-cracking can be assigned as dominating fracture mechanism. The microstructure in the as-built condition revealed a martensitic matrix with retained austenite. In contrast to conventionally manufactured and hardened cold-work tool steel, no primary carbides are formed and the material exhibits a very fine solidification structure with a dendritic carbide network.

Joint project of Pankl and MAGNA regarding 3D printing in the automotive industry. The aim is to use additive manufacturing for prototype production (structural components) in the automotive industry. These prototypes must already meet the characteristics of series production in the automotive industry. Currently, they are mainly produced using the die casting process. The 3D printed prototypes must therefore have the same mechanical, joining and crash properties as the series components. It is generally known that the mechanical properties of 3D printed components are higher than those of die-cast parts. Therefore, an adjustment of the mechanical properties of 3D printed parts by heat treatment is investigated.

Additive manufacturing allows the redesign of machine elements with concepts previously underexplored, due to limitations of conventional manufacturing processes. For automotive gears, these new concepts have the potential to provide performance benefits in terms of efficiency, noise and vibration. However, the surface integrity induced by additive manufacturing may be associated to challenges of fatigue resistance. The objective of the study is to analyse microstructural, surface and dimensional aspects of carburizing steel gears manufactured by Selective Laser Melting (SLM). Microstructure and hardness heterogeneities are investigated after SLM and subsequent heat treatments. It is then discussed the potential impacts of the additive manufacturing chains surface integrity on the fatigue behavior of gears.

3D printed components and tools operate under severe conditions that often require additional surface protection and functionality. In order to increase the lifetime and endurance of 3D printed components used for forming of metal parts in the automotive sector, the present paper proposes their functionalization using multifunctional coatings with increased wear resistance and friction control. The 3D printed tools are made of Maraging Steel (EOS MS1, 1.2709) by Laser Beam Melting technology, an additive manufacturing process in which 3D parts are created by consolidating pre-spread powders in a layer-by-layer way. Afterwards, multifunctional coatings are applied by means of laser cladding using a high-power direct diode laser. The resulting claddings provide wear resistance, self-lubrication and oxidation resistance, thus increasing the life span of metal tools and reducing expensive maintenance costs. The functionalized 3D printed tools are investigated for prospective forming of aluminium sheets at high temperatures (300-400°C). To this end, a forming tribometer is utilized paying special attention to the use of realistic forming parameters and short times for having mostly fresh workpiece in contact with the tool, in analogy with forming processes. Prior to the experiments, solid lubricant (graphite-based) is applied to the claddings in order to reduce adhesion with the aluminium counterpart. With the aim of online monitoring of the process conditions, the work also focusses on the integration of sensors in such 3D printed multifunctional tools. As an example, conductivity sensors for determination of tribological relevant parameters (like tension, pressure, acceleration) signalizing for e.g. high friction forces can be listed. The online monitoring assured by the sensors is expected to open doors to new fields of application. Vibration sensors indicating local defects of lubrication are a major focus of development to allow integrated “end of life” or service/maintenance indication.

Additive manufacturing (AM), in contrast to conventional manufacturing technologies, can produce functionally customized metal components of complex shape and geometry directly from 3D computer model, joining materials layer upon layer. Representative additive manufacturing technique, Selective Laser Melting (SLM) based on the complete-melting energy density for titanium alloy was investigated in this study. Due to their good mechanical properties and biocompatibility, titanium and titanium alloys are most commonly used in biomedical engineering, e.g. production of custom medical implants and prostheses. Titanium-Aluminum-Niobium (Ti6Al7Nb), shorter Ti67 alloy is a part of new generation of Ti-alloys that have improved biotolerance properties. In fact, so far the most widely used Ti-alloy in biomedicine, Titanium-Aluminum-Vanadium (Ti6Al4V), contains vanadium ions, which current scientific studies show are harmful. In order to start using selectively laser-melted Ti67 alloy for biomedical purposes, the effects of energy density (ED) and further process parameters on density, porosity and microstructure of cuboid Ti67 samples were examined. Laser power, scanning speed, hatch distance and powder layer thickness as process parameters were set corresponding to the thermodynamically calculated ED. Additionally, some of the samples were printed in three different orientations in order to study the effect of the building orientation on the microstructure. The density of printed samples was measured using Archimedes principle. Light and scanning electron microscopic investigations were used for determination of microstructure, more specifically to see the effect of pore formation on the parts density. Study with wide range of process parameters lead to an optimized process for this Ti-alloy with high density up to 99,36% and a fine grained and porous-free microstructure. Keywords: additive manufacturing, biomedical engineering, selective laser melting, Ti6Al7Nb

An introduction into L-DED (also often known as Laser Metal Deposition - LMD) will be given by discussing the principles and a few applications. Emphasis is laid on the use of the Siemens NX Additive Manufacturing Add-on, which was formerly developed exclusively for DMG Mori and is openly sold for any systems since end of 2019. This software package for path-planning was then immediately installed at JOANNEUM RESEARCH on two different machines, and our experience (advantages and limitations) with this software will be presented. If possible, also preliminary results from a new project starting in March 2020 regarding online monitoring of serveral L-DED process parameters will be shown.

Light weight alloys, but also super alloys are widely used in aerospace industries for large parts. On the one hand the market e.g. for titanium is growing 3.8 % per year to $5.4 Billion in 2030, on the other hand high buy-to-fly ratios of typically 70% due to machining produces incredible amounts of expensive waste. Metal additive manufacturing processes as powder bed fusion give the chance to reduce waste and the amount of parts per assembly, but most technologies are limited in the build area. Plasma Metal Deposition (PMD®) can be used for the manufacturing of large structural parts (0.2 to 2 m) from Ti 6Al 4V, but also Inconel 718/625 or aluminium alloys in a cost-efficient way. Mechanical properties like in standard wrought materials can be achieved. As an outstanding example, the development, manufacturing and material properties of an optical bench demonstrator for the ESA Athena mission is shown. Further results from ongoing R&D are presented.

While already widespread for cladding, the Laser Blown Powder process is also becoming a major tool for 3D printing, with applications such as engine turbine repair. Some of them include deposition of thin-walled structure over a substrate with highly variable topography. Resulting deposition angles can affect the final wall geometry and could be detrimental for thin structures with tight tolerances. This investigation aims to understand how those angles can change the deposition mechanism of such features. Considering a toolpath between two points on a randomly oriented surface, two angles can be defined with regard to the longitudinal and traverse slopes. A design of experiment was created by varying both angles from 0º to ±15º to look at the evolution of the build for straight walls of four layers.

As all technical production processes, every additive manufacturing technology offer advantages and drawbacks. While laser powder bed fusion (L-PBF) offers high precision and fine details, Direct Energy Deposition (DED) offers the possibility of creating large parts with high build rates. Aim of this study is to investigate material properties of hybrid parts made from Ti6Al4V by these two additive manufacturing processes. In comparison to already tried materials like Steels [1] and Nickel superalloys Ti64 bring new challenges concerning microstructure and oxidation. Therefore, samples in varying orientation are build on an L-PBF machine and afterwards completed with a DED system. Further on they are machined according to standard and heat threatened. Test include static and dynamic characterization as well as investigation of the microstructure and adaptation of heat treatment to reach satisfying properties for hybrid parts. [1] Advanced manufacturing approach via the combination of selective laser melting and laser metal deposition; J. Schneider, A. Seidel, J. Gumpinger, M. Riede, E. López, F. Brueckner, and C. Leyens, J. Laser Appl. 31, 022317 (2019);

Due to the continuously growing variety of products in response to the increasing customer demand for individuality, strict time and cost targets must be achieved in toolmaking. New manufacturing techniques are being researched and integrated into the production process to reduce tool manufacturing costs. The Laser Metal Deposition process (LMD) has already established itself as a flexible additive manufacturing process for geometry changes and repairs in tool making. A new approach is the hybrid-additive manufacturing of entire tool components using LMD. Potential here lies in the reduction of variants of semi-finished products and material savings through topology-optimized component design. For the example of a cutting tool, powder with low hardness is used for the base unit and powder with high hardness for the active element. In this regard, the mechanical properties of the used powder materials, and the connection strength to the substrate material need to be investigated. Therefore cylindrical specimens for tensile tests are manufactured. Furthermore, samples are analyzed metallographically to establish suitable process parameter windows for materials with different carbon contents.

Moisture is often claimed to be one of the main reasons for poor processability of powders when using L-PBF processes. To determine the influence of moisture on the processability, gas atomized superalloy powder IN718 has been printed in two parallel runs: once in the as-received and dry condition and once after four weeks of storage in an atmosphere containing a relative humidity of 75 %. Thereby different specimens have been prepared for notched impact tests, tensile tests, roughness and metallographic analysis. Furthermore, the chemical composition of the powder before and after the build job as well as that of the printed parts have been analyzed. The results of the differently conditioned powders have been compared in the end to determine the influence of humidity on the processability on IN718 powder.

The development and manufacturing of space hardware is strongly based on “heritage”, a concept that favours well known and tested components that ideally have flown on board space missions before. The advent of additive manufacturing (AM) opened new opportunities for the space industry, which typically produces parts in low quantities and places high value on mass reduction and design freedom. Within the European Space Agency (ESA) AM was adopted as an “enabling technology”, first through the funding of small exploratory projects and more recently through larger activities that are encompassed by ESA’s advanced manufacturing road map. While earlier studies were rather focused on intrinsic aspects of the AM process, the more recent framework of studies also includes all stages of the so-called end-to-end AM process (e.g. design and part conception, raw material procurement and quality control, post-processing steps, part verification, etc.) as well as alloy development and process maturation in the context of developing space hardware. A particular emphasis is also placed on strengthening the metal powder supply chain and identifying the key powder characteristics that may help to predict the final part properties. This presentation will highlight the lessons learned from selected projects and how they fed into the current portfolio of ESA activities, which are designed to address the challenges faced by the space community to develop the next generations of space hardware having the required quality and performance levels whilst reducing cost and lead-time.

The requirements regarding the materials in use are steadily increasing in the AM market. As part of a GER-CAN research project (HiPTSLAM), the development of high-performance tool steels for AM is a promising topic regarding the acceptance of LPBF technology for functionally optimized die, forming and cutting tools. Therefore, a holistic development process to efficiently qualify new materials is introduced and its advantages are shown based on a case study with a maraging tool steel. The chemical composition of the steel was particularly developed for the use in the LPBF process to achieve beneficial performance properties. In the case study, effects of the LPBF parameters are evaluated on the material properties. Based on initial microstructure analysis, a promising set of parameters is used to build samples for heat treatment studies and mechanical characterization. The overall material porosity down to 0.06 % with a high tolerance for varying LPBF parameters showing a good processability of the new martensitic tool steel alloy. The hardness of the LPBF samples could be increased by different heat treatment procedures. The highest hardness of 59 HRC was only achieved by a combination of solution annealing, quenching and tempering. By means of further investigations on the process interfaces, it will be possible to optimize the interaction of the whole LPBF process chain to increase the number of qualified materials with better performance properties.

Additive Manufacturing (AM) technologies are providing exciting opportunities for repair and remanufacture of industrial components. Laser Metal Deposition with powder (LMD-p) is an ideal candidate process for selective remanufacture of high value tools and dies exhibiting wear, particularly on complex geometries found in hot forging applications. When used in combination with a multi-axis CNC machining centre and a suitable metal powder metallurgy, LMD-p can produce hybrid (additive/ subtractive) remanufacturing operations which exceed the original wear characteristics of production die sets. DigiTool, a consortium funded project by Innovate UK, consisting of the Advanced Forming Research Centre (AFRC) and 5 industrial partners, developed a remanufacturing process for complex closed die tooling geometry. After careful consideration of commercially available metal powders in the range 40 to 120 µm for use with LMD-p, Metcoclad 21, a cobalt based hard-facing alloy, was selected as the metal powder repair medium due to its superior sliding wear resistance, galling and machinability. Experimental trials determined the optimum LMD-p process parameters, and worn H13 tool steel hot forging dies were successfully remanufactured along the complex flash land areas, and pocket features in the cavity. The selective die repairs were subsequently verified in a production environment at consortium partner Mills Forgings Limited, resulting in die life increase of 170%, whilst maintaining all dimensional and customer quality standards. The die life increase has allowed Mills Forging to reduce the piece-part cost, and win the business back from a competitor

The great acceptance of additive manufacturing in tool making business was to a significant extent spurred by the opportunities to create complex shaped, 3D oriented internal cooling channels in tool inserts. These benefits were mainly achieved with Powder-bed technologies, providing reduced cycle times in e.g. injection moulding. Further achievements were made in post-treatment of 3D-printed parts; the ability to remove sintered-on particles and support structures and to smooth internal surfaces of metal parts in automated processes increased the freedom of design on the one hand, but also raised the quality of the cooling channels on the other hand. Recent R&D is now offering novel methods of creating hollows in large parts, which are produced rather with Direct Energy Deposition processes than with Powder-bed processes. Two new solutions are presented which are using filling material for channels and cavities. These fillers are placeholders in course of the further AM processing which will be removed afterwards. Both solutions differ from HERMLE’s state-of-the-art technology, using water soluble metallic materials, flushed out at the end of the manufacturing process to expose the inner channels. The current status of this twofold development streams will be shown, presenting chosen material combinations and achievements in freedom of design of inner geometries using WAAM at least as the main technology building metal parts.

The increasing demands on metal powders for additive manufacturing applications go hand in hand with an increasing energy consumption for producing these powders. For example, finer powders can be produced by increasing atomization gas pressure and temperature, or also by increasing melt superheat. More spherical particles (or particles with a lower oxygen content) can be produced by using Nitrogen, Argon or even Helium as atomization gas instead of compressed air. This study is a contribution to understand the impact of these parameters on the carbon footprint of the powder. The energy efficiency of a metal powder production process can be defined by relating the theoretical energy to overcome surface tension forces of the melt material to the actual energy consumption to produce this material. Furthermore, a theoretical melt breakup model is used to estimate the impact of the most important production parameters (gas and melt temperature, gas pressure, necessary product yield) on the energy consumption of the process. These theoretical results will be compared to actual powder production data, and methods to improve the carbon footprint of the atomization process are suggested.

The influence of additive manufacturing in various industries like automotive, aerospace, medicine and aviation is increasing constantly. Especially steel grades gain a lot of attention at this new and fast developing market. However, the weldability of a material defines and limits the processability for the Laser-Powder-Bed fusion technique. Therefore, case hardening steels, characterized by a low carbon content, like the Böhler E185 AMPO, attract much interest, due to their easy printability without powder bed-preheating. This material is ready to use in the as-built condition with a well balanced property relationship of strength, ductility and impact toughness. Furthermore, heat- and additional surface treatments improve the hardness and wear resistance. These unique characteristics open the fields for many light weight constructions, several plastic mould-, as well as transmission-, and engineering- applications. In this study, the technological and mechanical properties of the Böhler E185 AMPO are analyzed in detail. By combining microstructural characterizations with tensile and fatigue testing the structure property relationship of this new developed case hardening steel is presented.

In order to create a dense printed part of the right shape and dimensions, it is vital to have both a good understanding of the optimum printing process and powder that exhibits the right behaviour. Many studies have investigated the former, but relatively few have focused on the latter. Furthermore, there is no agreed method for spreading powder for testing or for how that layer should be measured to assess its quality. This presentation will introduce a method by which powder can be spread into a layer of similar thickness and size as is needed for powder bed processes, using similar spreading conditions and commercial, bench-top equipment. A straightforward and repeatable method for quantifying the quality of the layer will also be presented. The metric will then be compared to flowability measurements of the same powders and parts printed from the powders.

One of the main qualitative risks related to powder metallurgy is contamination of metal powders: the mixing between different alloys, in fact, could cause anomalous segregation and possible undesired precipitation of secondary phases that might act as failure initiation. MIMETE is very careful about this aspect and applies strict rules all along the production process to avoid that different powders come into contact. Nevertheless, as additional care, a detailed study was conducted to define the detectability of contamination by means of different techniques: EDS mapping by SEM, ICP chemical analysis, high energy tomography. In order to compare the sensitivity of these methods some controlled artificial blendings were prepared and tested, showing that at the moment only statistical control is possible and relatively high contamination is measurable. Further testing would be necessary to evaluate the real critical limit for application, for instance on additive manufactured samples produced by voluntarily contaminated powders.

Particle Size Distribution (PSD) is usually the first requirement of metal powders users and is considered extremely critical in Additive Manufacturing. Unfortunately this subject is not yet sufficiently standardized and it is difficult to define unambiguous technical specifications for all powders. MIMETE laboratory is equipped with mechanical sieves, laser diffraction, image analysis and SEM: an internal R&R was implemented to compare results from different methods on powders characterized by different PSD and morphology. Experimental results show some interesting evidences, such as: - larger is the PSD, larger is the deviation between laser diffraction results obtained by wet and dry dispersion - SEM is the most detailed method to understand if powder is affected by anomalies as satellites and clusters, but it is time consuming and just qualitative - image analysis is the only technique able to give complete information regarding “real” particle dimensions, but it is not commonly accepted.

Creativity has no limits with 3D-printing of metals allowing the realisation of new geometries that cannot be provided by any other production method. Nevertheless, it is a long way from an innovative idea to a 3D-printing based production process. This presentation will introduce a successful user case, systematically from the first draft to an industrially useable part. Supported by the national research initiative “AM 4 Industry - quality assurance and cost models supporting the widespread use of additive manufacturing” (lead by EcoPlus, FOTEC Research GmbH) - the two industrial partners Franz Haas Waffelmaschinen and RENA Technologies Austria developed an industrial applicable part including sophisticated design features that can be realised by 3D-printing only. The part included complex inner channels with a high requirement on the surface quality. The aim was to create a production tool enabling a new product idea in food industry. Hirtisation® was chosen as post processing technology, since no mechanical or other classical post-treatment can remove inner support structures or reduce the high roughness of inner surfaces after printing. The two industrial partners analysed and adjusted each step of the process chain from the initial design to the finished and applicable part, starting from prototyping scale. The different steps of the production chain had to be fully understood and adjusted to the each other in order to guarantee a constant and reproducible quality of the final products at industrial scale. Among the different process steps, the post-processing of AM metal parts played a crucial part enabling the production of the freely designed product. The holistic approach within this project finally led to a successful implementation of a 3D-Printed part, leading to a product innovation in food industry.

This paper presents correlative microscopy studies performed for the characterization of powders and additive manufactured parts. Starting from µm scale down to atomic resolution, micrographs and chemical analyses provide important information about the micro- and nano-structure as well as about mechanisms that can influence the properties of the final parts. Different investigation techniques such as scanning electron microscopy coupled with Rahman spectroscopy and scanning TEM microscopy coupled with X-ray (EDX) and electron energy-loss spectrometry (EELS) have been used to characterize the surface oxidation and microstructure of the powder grains as well as the microstructure of the as-built or thermal treated parts. Stable and metastable phases have been identified by chemical and crystal structure analysis. Moreover, in-situ measurements provided information regarding the evolution of the powder surfaces, the evolution of the microstructure and diffusion of alloying elements at different temperatures.

An optimized powder atomization plant for the production of high-quality metal powder for Additive Manufacturing (AM) was developed at SMS group and set up at their 3D Competence Center in Mönchengladbach, Germany. To ensure the high quality of the powder produced, the implementation of adequate powder characterization is essential. The definition of AM process- and component-related powder characteristics and the measurement of these properties by using appropriate measuring methods is part of the powder characterization. Most measuring methods have been adopted from previous powder applications and have not been proven to be best suited for AM powders. Research at SMS shows different suitability of the measuring methods commonly used for fine LPBF powders. The results of hall flowmeter do not show correlation with the results of other methods for measuring flowability. The main disadvantage of hall flow measurement is the upper limitation of the measuring scale. It has been shown that powder with no flow in the hall flowmeter can be processed in LPBF without problems. A strict distinction between plant-related flowability and powder-bed-related flowability (spreadability) should be made since the different measuring methods do not seem to measure the same property. Comparisons of measuring methods were also made for other powder properties in order to show advantages and disadvantages of these methods. It is of great importance to better understand the powder properties, measuring methods and property limits to improve powder characterization.

Moisture can potentially affect any production process that use metal powder, both the processing itself and the material that is produced. Here we study laser powder bed fusion (L-PBF) and the effect of moisture on built nickel-base material. We also present research on how humidity, and in turn moisture content, can affect processability including spreadability. In the first part, one lot of nickel-base powder was split into two equal batches. One batch was moisturized using a C1000-40 climate chamber, the other was untreated. We built bars with both batches for mechanical testing in an EOS M100 with a cold build plate. The moisture content of the two powder batches, before and after the build-jobs, were determined using Karl Fischer (KF) titration. Moisturization resulted in a content of 56 µg/g while the untreated powder contained 29 µg/g. These levels were only slightly reduced during the 14 h build jobs. This is notable, and means that the built material should reflect any impact that the moisture has. Still, the impact toughness was only marginally affect while the O and H content of the built material increased significantly. In the second part, we present research on how spreadability can be evaluated with commercially existing devices and how humidity can affect spreadability.

The contribution describes the investigation carried out on novel steel powders based on the Fe-0,3C-1Cr-Mo alloy system to be processed by Laser-Powder Bed Fusion. Two powder batches have been studied in this respect, considering a reference gas atomized version and a variant of it produced by water atomization and post- treatment, with a modified chemistry. The materials have been characterized after L-PBF processing to define their best response to heat treatments, their mechanical behavior and to characterize the degradation of the two powder when subjected to repeated recycling. Results allowed to show that the water atomized variant of the steel powder feature good processability and performances comparable to the gas atomized alloy steel.

Additive manufacturing technologies is considered as a disruptive technology that will not only to create new opportunities but also threats to disrupt existing traditional industries. This new way of manufacturing will also require companies to not only revise but also consider new business models. Organizations using traditional manufacturing methods should start to explore how additive manufacturing will impact their manufacture, value proposition, collaboration with other firms and how they operate. There is still a gap to explore and understand how new manufacturing technologies might affect existing firms and business models and might also provide opportunities for new business models. In this research we used business model canvas framework (A. Osterwalder, 2004; Alexander Osterwalder & Pigneur, 2010) and Lean Canvas (Maurya, 2012) to provide a structural discussion that would lead to a blueprint and explore impact of additive manufacturing in business models. The business model canvas framework divides the business model of a company in four areas (the Product, Customer Interface, Infrastructure Management and Financial Aspects) and nine building blocks (value proposition, target customer, distribution channel, relationship, value configuration, capability, partnership, cost structure and revenue model. The lean canvas implements four new building block elements (problems, solutions, key metrics and unique value proposition) and removes four building block elements of business model canvas (key partners, key activities, key resources and customer relationships (Maurya, 2012). While business model canvas framework works well for established companies, the lean canvas framework was especially designed for entrepreneurs or firms that want to act as entrepreneurial focused to help them to navigate from ideation to a successful business (Maurya, 2012). In this research we combine these building blocks and provide a blueprint of how each of these building blocks could be affected additive manufacturing technologies and illustrate our propositions with examples. In order to present impact of additive manufacturing in business model innovation, we followed theoretical sampling recommended by Glaser and Strauss (1967). As a result, we collected data and examples from additive manufacturing startups, firms and projects in Europe, North and South America and Africa. We used publicly available information at firms’ websites, news, press releases and reports. Maurya, A. (2012). Lean Canvas. Running Lean Plan That Works. Osterwalder, A. (2004). The business model ontology a proposition in a design science approach. Doctoral Dissertation, Université de Lausanne, Faculté Des Hautes Études Commerciales. Osterwalder, Alexander, & Pigneur, Y. (2010). Business Model Generation - Canvas. Wiley.

In the last few years, Fused Filament Fabrication (FFF) gained increasing interest as a production method for metal and ceramic parts. Fused Filament Fabrication (FFF) is a type of material extrusion additive manufacturing (MEAM) and it is one of the most commonly used polymer-based additive manufacturing techniques. FFF could also be used to produce green parts with complex geometry out of feedstocks and after debinding and sintering a full metal or ceramic part is obtained. One advantage of this method is the possibility to combine different materials in one part within one production step. Thus, different properties can be combined within one part, such as electrically conductive/insulating, magnetic/non-magnetic, which can be used in many areas like electronics or sensors. In polymers, the combination of different materials is a relatively easy operation. However, for the production of ceramic and/or metal parts consisting of different materials this is a challenging task. First, the materials to be combined have to show a similar thermal expansion coefficient; secondly, their powders have to sinter similarly. Additionally both feedstocks have to be printable in the same machine and must show a comparable debinding behaviour. Here, the processing route for multimaterial components will be shown with emphasis on the critical steps arising from the joint processing of different materials. Several methods to adjust the behaviour of the different materials during processing are discussed.

Lithography-based methods for additive manufacturing of polymers, ceramics and metals enable the fabrication of precise, complex-shaped parts with excellent surface quality in applications like biomedical engineering, automotive and consumer products. Photopolymers contributed 33% to the worldwide materials sales in 2019, thus making lithography-based AM (L-AM) the most widely used AM technology. Although polymers are the dominating material class for L-AM, it is also possible to manufacture composite, ceramic and metallic materials using L-AM. Challenges with the fabrication of advanced materials using L-AM are frequently related to (interlaminar) defects which are incorporated into the parts during processing in the 3D-printer. In order to understand the influence of processing conditions on the finally observed mechanical properties, a fracture mechanical approach will be used. Since AM not only allows to define the shape of a part, but also enables the variation of material properties within the part (gradient materials, digital materials, …), new routes for a detailed scientific investigation of 3D-printable materials are available. Additionally, an overview of recently developed 3D-printable materials (metallic high-performance alloys, strong and tough photopolymers, high-strength ceramics) will be given, allowing to put L-AM in a context with other AM technologies like powder bed fusion and fused deposition modelling.

Ti-6Al-4V is used since years for additive manufacturing. The alpha-beta titanium alloy shows an excellent strength-to-weight ratio in combination with superb corrosion resistance. It is one of the most commonly used titanium alloys and is applied in a wide range of applications where low density and excellent protection against gradual destruction by chemical and/or electrochemical reaction with their environment is necessary, like in aerospace industry and biomechanical applications, especially implants and prostheses. To improve the biomechanical interaction there are reflections to replace Ti-6Al-4V by Ti-6Al-7Nb. Since laser melting produced workpieces are brittle a post-process heat treatment is required. Appropriate investigations were done for Ti-6Al-4V manufactured by Laser Powder Bed Fusion (L-PBF) to study the evolution of the microstructure during the heat treatment. We tackle the issue to analyze the modification of the microstructure for the Ti-6Al-7Nb alloy during heat treatment by using a Phase Field Method Based Software

Innovative solutions in AM tools are already able to contribute to decarbonization. Examples from the areas of aluminium die casting and plastic injection moulding are used to clearly show us the possible potentials. Thermal management is the focus of the entire process chain. Particularly in an energy-intensive process such as aluminum die casting, the reduction of throughput time and the reject rate has a considerable influence on the CO2 savings potential. The use of conformal cooling and innovative material combinations can reduce the cycle time of forming tools and increase the tool life. This means that not only the component quality in functional areas increases, but also the overall process quality. Additive manufacturing using plastic injection molding has an equally positive effect on component design. Here, thin-walled components can only be produced reliably with an adapted cooling system for the tools. All the innovative solutions mentioned here can only be realized if the restrictions of the different additive manufacturing processes are understood. Only then can the potential be exploited to develop new tool concepts from a holistic understanding of the component and process requirements.

The market of powder bed fusion systems is still characterized by machines that are basically designed 10 to 20 years ago. A completely new technique (SLEDM) has been developed and patented at the Institute of Production Engineering at Graz University of Technology. The unique system works with high-power LED energy sources and a very low amount of powder. The build direction is from the top to the bottom. The paper presents the benefits of the new system and gives a detailled description of the new machine. First test objects and their structural compositions are presented. Because of the variable melting spot diameter the cooling rates are not so high comparable to the laser based powder bed fusion systems. Finally some applications and modifications of the SLEDM-machine are explained that make the machine convenient for mass production of fuel cell bipolar plates.

Laser metal deposition (LMD) is a preferred process for metal additive manufacturing due to its unique advantages in terms of build speed, flexibility, its capability to use multiple materials and its ability to deposit metal on non-flat surfaces. However, true 3D process on free-form surfaces require time-consuming programming or teach-in procedures. To overcome this, we have developed a technology which eliminates most of the conventional programming. Using laser profile scanners, free-form parts can be scanned inside the LMD machine. Software algorithms generate digital 3D models of the parts which are used for a subsequent, automated toolpath generation procedure. Depending on the application, different process chains may be used. For LMD coating processes, the 3D models are displayed on a PC screen and the user defines deposition areas and layer thicknesses with some mouse clicks. The software will then calculate all required LMD toolpaths automatically. For the generation of 3D structures on top of existing 3D parts, 3D CAD models can be loaded into the software. After merging them with the scan-based model of the initial part, again all toolpaths will be calculated to generate the required 3D volumes. Finally, a post processor generates the CNC code or robot control code. A built-in simulation visualizes the planned deposition process, allowing final checking of the process. After that, the processes can be immediately executed. Besides the time saving, this technology also improves the build quality significantly as human errors can be eliminated almost completely. We will present not only details regarding the processes, but also real applications examples such as LMD coating of excavator teeth, laser metal deposition on 3D cast parts or LMD on extrusion screws.

Additively manufactured (AM) components have to be post processed in order to achieve the required component properties. This contribution presents methods and approaches to meet the challenges of implementing an additive-subtractive process chain. Additive manufacturing processes are no longer used only for prototypes but also to build production parts. Laser powder bed fusion (LPBF) technology enables metal components to be manufactured in small quantities with high productivity and material efficiency, which cannot be achieved with conventional manufacturing methods or only at considerable expense. However, post-processing of these components is usually unavoidable in order to obtain an optimal final product. Therefore, knowledge of the additively produced raw part and the processing mechanisms is required. In particular, machining processes such as milling, drilling and grinding are used for post processing. The entire process chain of manufacturing additive-subtractive components and maintaining the required form and position tolerances, surface roughness and edge zone properties is therefore relatively complex. Therefore, the properties of the resulting components and the quality characteristics within the individual manufacturing steps as well as in the interaction of successive machining processes must be considered. The implementation of such process chains therefore requires a high degree of expert knowledge. If the properties of the specified components are to be achieved in a targeted manner, in most cases a complex and iterative process qualification must be carried out, which requires a high expenditure of personnel and time. Based on these challenges, the European research project "Ad-Proc-Add" investigates additive-subtractive manufacturing chains in order to obtain a detailed understanding of the dependencies and interactions of material and component properties of additively manufactured workpieces with respect to process parameters, manufacturing strategies and boundary conditions. The aim is to be able to consciously adapt geometry, surface and boundary zone properties via additive-subtractive production chains in order to be able to meet predefined requirements. This enables the targeted design and implementation of additive-subtractive production chains in various industrial applications. This contribution uses practical examples to demonstrate the complex interrelationships of the various technologies within the additive-subtractive process chain. At the same time, the contribution presents methods and approaches to solutions that can be used to meet the challenges of implementing additive-subtractive process chains. This starts with the simulation of the component state during additive manufacturing and ends with process monitoring during post-processing. University of Stuttgart, Institute for Machine Tools (IfW)

Laser Powder Bed Fusion (L-PBF) is an additive manufacturing process for the production of complex high quality metal parts. The surface roughness has an important impact on the mechanical behavior like crack initiation or fatigue life. Especially for complex geometries with its large amount of internal surfaces it is not possible to improve all surfaces by post-processing or even to determine the surface roughness non-destructively. In this study, a non-destructive testing method is presented to determine the as-built surface roughness independent of size or geometry of the part. A fast-curing thixotropic 2-component-silicone was used to produce replicates of the surfaces of as-built Ti-6Al-4V samples. These replicates represent a negative print of the original surface so that the surface roughness can be measured indirectly with a confocal laser scanning microscope. This method was validated using a set of additive manufactured samples with different surface roughness generated by different angles to the build platform where the original surface was compared to the replica. The results show that differences in surface roughness can be measured and the limits of this method are determined.

Moisture is often regarded as one of the main reasons for poor processability of powders using L-PBF processes. To determine the influence of moisture on the spreadability a superalloy powder IN718 commonly used for SLM has been conditioned in two different states: once in the as-received and dry condition and once in a moist condition achieving by storing the powder four weeks in an atmosphere containing a relative humidity of 75 %. Using a self built machine and a subsequent analysis method specially developed for testing the spreadability of a powder, the differently conditioned IN718 powder batches have been investigated regarding the surface roughness and flatness of the powder layers. Additionally, the formation of empty spots between the powder particles in the first layer has been studied.

At the National Institute for Nuclear Physics – Padova Division, the main research of the Development and Innovation on Additive Manufacturing Group is focused on developing new materials for the Laser Powder Bed Fusion (LPBF) technology. One of the major benefits of this technology is the possibility of fabrication of complex geometries and features in only one-step of production. In particular, for the realization of the heat exchangers, this is very convenient for the realization of conformal cooling channels that can improve the performance of the heat transfer capability. In the context of nuclear fusion, this technology could be applied for the manufacturing of the copper acceleration grids of the Neutral Beam Injector. However, obtaining dense copper parts printed via LPBF presents two major problems: the high reflectivity of 1 μm (the wavelength of commonly used laser sources) and the high thermal conductivity of copper that limits the maximum local temperature that can be attained. This lead to the formation of porous parts. Currently, the major solutions for printing pure copper with high density is to use high laser power (>1 kW), use different laser wavelength (green or blue laser) or divert to copper alloys. However, in literature, there is a lack of research on the influence of the powder size distribution on the printability of pure copper. In this work, the influence of the particle size distribution of the powder on the physical and mechanical properties of parts produced via LPBF is studied. Copper powders purchased from three different companies with three different particle size distributions are used in this study. For the manufacturing of the samples, an EOS INT M280 printer with a maximum laser power of 370 W was used and research was carried out to find the optimal process parameters (laser speed, hatching distance, scanning strategy, etc ..) for obtaining dense parts. Subsequently, samples manufactured with the optimal process parameter were analyzed for thermal conductivity and mechanical properties through tensile and surface hardness tests

Refractory metals belong to the group of transition metals and they are also called “ultra-high temperature materials”. In addition to the high melting temperatures, they have properties that make them suitable for many applications. Tungsten, Molybdenum, and Tantalum produced by laser powder bed fusion process are the subjects of this study. Production of refractory metals by Additive Manufacturing (AM) gives many advantages. The possibility of recycling the unmelted particles is one of the most important aspects for high expensive powders like Ta. Since their high melting point, the energy required to melt a volume of material is given by the focused energy of the laser beam which locally raises the temperature up to the melting point. In addition, thanks to the low percentage of oxygen present in the chamber during the process (≈0,1 %), because of the continuous argon flux, the metal does not oxidize during the process. AM is the only process that allows the production of complex geometry and lightweight refractory metals components, two important features for these kinds of materials, according to their high density and their possible applications in the aerospace field, and for biomedical or future nuclear fusion devices. However, selective laser melting of Ta, Mo, and W faces some challenges due to their main properties: high melting point, heat conductivity and susceptibility to cracks. The purpose of this study is to optimize the process parameters in order to produce high-density refractory metals part by SLM on an EOS M100 (maximum power of 170 W). Characterization is performed through physical properties measurements, microstructural analysis, and evaluation of mechanical and thermal performances. Single Scan Tracks (SSTs) are produced on the top surfaces of the blocks in order to evaluate the process parameters that give regular shape continuous melt-pool . The integrity of the material as a function of the thickness is studied in order to define the production parameters of components with thin wall or complex geometry as lattice structures. Complex benchmarks are produced in order to optimize beam offset for the productions of precise components of refractory metals studied and the angle at which the part is self-sustaining. Surface roughness and surface treatments methodologies suitable for components produced by AM will be studied. The purpose is to verify the influence on the performances during the exercise of the part in a specific application field, such as high energy physics (working temperature range 2000-2200°C) as well as prosthetic systems for biomedical applications (lattice structures for implants).

Over the last years, additive manufacturing (AM) has transitioned from a system and materials to a complete end-to-end solution business. Printing cost becomes then a major factor to reduce in order to achieve the business goals. There are continuous attempts from additive manufacturing players to reduce material costs and increase process productivity such that AM becomes a key driver of digital manufacturing on a cost per part level. In this context, our paper describes a methodology to optimally choose the most economical support structure design for metal printing in terms of material by guarantying a minimal and acceptable thermal deformations of the printed parts. This methodology consists of three steps: (1) design support structures with different parameters using an available design tool, (2) simulate the thermal deformations and residual stresses using these different support structures , (3) derive a lumped model that generates a pareto front highlighting the optimal design. In order to demonstrate and validate this methodology, two designs of metal parts are made with an increasing complexity of the design. The first design is relatively simple in geometry and allows to cover large thermal variations due to a broad variations of the printing process parameters. The second design is more complex (derived from an industrial part) and allows to cover thermal variations due to complex geometry while maintaining the printing process parameters close to nominal values. Both designs are printed many times using a selective laser printing process where layer per layer variations on printing parameters are performed. The thermal deformations of these different prints are experimentally measured using a 3d scanner and compared to the simulation results. The validation proves a very good predictive power of the simulation to accurately predict the thermal deformations of the printed parts using more economical support structures. This methodology allows the designers to rely into the simulation in order to choose the optimal support structure design without having to perform expensive trial and errors experiments. The method has the potential to predict layer per layer thermal deformations of printed parts allowing thus to adapt the process parameters during the print and avoid scraps due to thermal stresses.