Zugl.: Erlangen, Nürnberg, Univ., Diss., 2005

Die Implementierung von Laser Powder Bed Fusion bei Aluminiumoxidkeramiken ist aufgrund einer geringen Temperaturwechselbeständigkeit, Bauteilverdichtung, Pulverfließfähigkeit und Lichtabsorption eine große Herausforderung. In dieser Arbeit wurden diese Prob-leme mit unterschiedlichen Ansätzen adressiert. Sprühgetrocknete Aluminiumoxid Granulate wurde zur Verbesserung der Laserabsorption (über 80 % Verbesserung) mit farbigen Nano-Oxidpartikeln dotiert. Es wurden verschiedene Partikelpackungstheorien und Pulverbehand-lungen getestet, um die Pulverbettdichte und damit die Dichte des endgültigen Bauteils (Dichten bis zu 98,6 %) zu erhöhen. Die Pulverqualität wurde durch Schütt und Rütteldichte, Feuchtigkeitsgehalt, Partikelgrößenverteilung, Hausner-Verhältnis, Lawinenwinkel und Oberflächenfraktal charakterisiert. Des Weiteren wurde der Zusatz geeigneter Stoffe zur Verringerung der Rissbildung durch thermische Spannungen getestet. Die In-situ-Bildung von Phasen mit geringer und negativer Wärmeausdehnung reduzierte die Rissbildung in den lasergefertigten Oxidkeramiken stark.:1 Introduction 1 1.1 Motivation 1 1.2 State of the art . 2 1.3 Aim of the project 2 2 Literature review 5 2.1 Additive manufacturing by laser powder bed fusion 5 2.1.1 Classification and process description 5 2.1.2 Advantages against other AM processes 9 2.1.3 Challenges of laser powder bed fusion 12 2.1.4 State of the art of laser powder bed fusion of aluminum oxide based ceramics 13 2.1.4.1 Powder bed preparation and impact on the process 13 2.1.4.2 Critical rating of the powder bed preparation techniques 17 2.1.4.3 Processing methods and properties 19 2.1.4.4 Part properties 26 2.2 Theoretical and experimental considerations for powder bed preparation 35 2.2.1 Spray granulation 35 2.2.2 Particle packing theories 39 2.3 Mechanisms for particle dispersing 41 2.3.1 DLVO-theory 41 2.3.2 Surface charge and electrical double layer 43 2.4 Conceptualization of new ideas for laser powder bed fusion of aluminum oxide 45 2.4.1 Densification, powder flowability and absorption issue 46 2.4.2 Reduction of crack formation 47 3 Doped spray-dried granules to solve densification and absorption issue in laser powder bed fusion of alumina 55 3.1 Dispersing of aluminum oxide, iron oxide and manganese oxide 55 3.1.1 Experimental 55 3.1.2 Particle characterization 57 3.1.3 Saturation amount evaluation of dispersant 59 3.1.4 Particle size distributions after dispersing 62 3.1.4.1 Particle size distributions of alumina powders 62 3.1.4.2 Particle size distribution of dopant 67 3.2 Packing density increase of spray-dried granules 76 3.2.1 Experimental 77 3.2.2 Influence of solid load and particle ratio on granules 83 3.2.3 Influence of dopant shape and multimodal distributions on granules 84 3.2.4 Evolution of pH-value during slurry preparation and slurry stability after mixing of all components 85 3.2.5 Influence of slurry viscosity on yield of granules 88 3.2.6 Addition of coarse alumina to spray-dried granules 89 3.2.7 Application of Andreasen model on mixtures of ceramic particles with spray-dried granules 94 3.2.8 Thermal pre-treatment of granules 98 3.2.9 Influence of surface tension of slurry on granule size and density 110 3.3 Investigation of laser manufactured parts 114 3.3.1 Experimental 115 3.3.2 Influence of different iron oxide dopants and multimodal particle distributions within granules 118 3.3.3 Influence of coarse alumina variation 121 3.3.4 Influence of thermal pre-treatment of powders 127 3.3.5 Grain structure of laser additive manufactured parts 135 3.3.6 Thermal expansion of laser processed parts 137 3.3.7 Influence of thermal pre-treatment and laser processing on manganese amount within granules and laser additive manufactured parts 138 4 Additives to reduce crack formation in selective laser melting and sintering of alumina 143 4.1 Experimental 144 4.2 Additives to reduce thermal stresses 150 4.2.1 Selective laser melting with mullite additives 150 4.2.2 Amorphous alumina formation by rare earth oxide doping 160 4.2.3 Formation of aluminum titanate by use of reduced titanium oxide 169 4.2.3.1 Dispersing of titanium oxide nanoparticles in water 170 4.2.3.2 Thermal treatment of Al2O3/TiO2 granules under argon/hydrogen atmosphere 172 4.2.3.3 Laser manufacturing of parts 178 4.2.4 In-situ formation of negative thermal expansion materials 187 4.2.4.1 Dispersing of zirconia and tungsten oxide nanoparticles 187 4.2.4.2 Influence of spray drying process parameters 191 4.2.4.3 Preparation of final powders for laser powder bed fusion 197 4.2.4.4 Laser manufacturing of layers and parts 200 4.3 Mechanical properties of laser processed parts 205 5 Flowability and inner structure of customized granules 209 5.1 Experimental 209 5.2 Comparison of flowability in terms of Hausner ratio, Avalanche angle and surface fractal measurements 211 5.2.1 Influence of coarse alumina AA18 variation 211 5.2.2 Influence of thermal pre-treatment of powders 213 5.2.3 Influence of dopant content within granules 216 5.2.4 Flowability of zirconia-tungsten oxide granules and alumina granules with mullite or rare earth oxide addition 219 5.2.5 Flowability of titanium oxide doped alumina powders 221 5.3 Cross sections of customized granules to image inner structure 224 6 Summary, conclusions and outlook 233 6.1 Summary and conclusions 233 6.2 Outlook 241 References 245 List of Figures 260 List of Tables 269 / The implementation of laser powder bed fusion of aluminum oxide ceramics is challenging due to a low thermal shock resistance, part densification, powder flowability and light absorptance. In this work, these challenges have been addressed by different approaches. Spray-dried alumina granules were doped with colored oxide nanoparticles to improve the laser absorption (improvement by over 80%). Different particle packing theories and powder treatments were tested to increase the powder bed density and therefore, the final part density (densities up to 98.6%). The powder quality was characterized by apparent and tapped density, moisture content, particle size distribution, Hausner ratio, avalanche angle and sur-face fractal. Furthermore, the addition of suitable was tested to reduce crack formation caused by thermal stresses. The in-situ formation of low and negative thermal expansion phases strongly reduced the crack formation in the laser manufactured oxide ceramic parts.:1 Introduction 1 1.1 Motivation 1 1.2 State of the art . 2 1.3 Aim of the project 2 2 Literature review 5 2.1 Additive manufacturing by laser powder bed fusion 5 2.1.1 Classification and process description 5 2.1.2 Advantages against other AM processes 9 2.1.3 Challenges of laser powder bed fusion 12 2.1.4 State of the art of laser powder bed fusion of aluminum oxide based ceramics 13 2.1.4.1 Powder bed preparation and impact on the process 13 2.1.4.2 Critical rating of the powder bed preparation techniques 17 2.1.4.3 Processing methods and properties 19 2.1.4.4 Part properties 26 2.2 Theoretical and experimental considerations for powder bed preparation 35 2.2.1 Spray granulation 35 2.2.2 Particle packing theories 39 2.3 Mechanisms for particle dispersing 41 2.3.1 DLVO-theory 41 2.3.2 Surface charge and electrical double layer 43 2.4 Conceptualization of new ideas for laser powder bed fusion of aluminum oxide 45 2.4.1 Densification, powder flowability and absorption issue 46 2.4.2 Reduction of crack formation 47 3 Doped spray-dried granules to solve densification and absorption issue in laser powder bed fusion of alumina 55 3.1 Dispersing of aluminum oxide, iron oxide and manganese oxide 55 3.1.1 Experimental 55 3.1.2 Particle characterization 57 3.1.3 Saturation amount evaluation of dispersant 59 3.1.4 Particle size distributions after dispersing 62 3.1.4.1 Particle size distributions of alumina powders 62 3.1.4.2 Particle size distribution of dopant 67 3.2 Packing density increase of spray-dried granules 76 3.2.1 Experimental 77 3.2.2 Influence of solid load and particle ratio on granules 83 3.2.3 Influence of dopant shape and multimodal distributions on granules 84 3.2.4 Evolution of pH-value during slurry preparation and slurry stability after mixing of all components 85 3.2.5 Influence of slurry viscosity on yield of granules 88 3.2.6 Addition of coarse alumina to spray-dried granules 89 3.2.7 Application of Andreasen model on mixtures of ceramic particles with spray-dried granules 94 3.2.8 Thermal pre-treatment of granules 98 3.2.9 Influence of surface tension of slurry on granule size and density 110 3.3 Investigation of laser manufactured parts 114 3.3.1 Experimental 115 3.3.2 Influence of different iron oxide dopants and multimodal particle distributions within granules 118 3.3.3 Influence of coarse alumina variation 121 3.3.4 Influence of thermal pre-treatment of powders 127 3.3.5 Grain structure of laser additive manufactured parts 135 3.3.6 Thermal expansion of laser processed parts 137 3.3.7 Influence of thermal pre-treatment and laser processing on manganese amount within granules and laser additive manufactured parts 138 4 Additives to reduce crack formation in selective laser melting and sintering of alumina 143 4.1 Experimental 144 4.2 Additives to reduce thermal stresses 150 4.2.1 Selective laser melting with mullite additives 150 4.2.2 Amorphous alumina formation by rare earth oxide doping 160 4.2.3 Formation of aluminum titanate by use of reduced titanium oxide 169 4.2.3.1 Dispersing of titanium oxide nanoparticles in water 170 4.2.3.2 Thermal treatment of Al2O3/TiO2 granules under argon/hydrogen atmosphere 172 4.2.3.3 Laser manufacturing of parts 178 4.2.4 In-situ formation of negative thermal expansion materials 187 4.2.4.1 Dispersing of zirconia and tungsten oxide nanoparticles 187 4.2.4.2 Influence of spray drying process parameters 191 4.2.4.3 Preparation of final powders for laser powder bed fusion 197 4.2.4.4 Laser manufacturing of layers and parts 200 4.3 Mechanical properties of laser processed parts 205 5 Flowability and inner structure of customized granules 209 5.1 Experimental 209 5.2 Comparison of flowability in terms of Hausner ratio, Avalanche angle and surface fractal measurements 211 5.2.1 Influence of coarse alumina AA18 variation 211 5.2.2 Influence of thermal pre-treatment of powders 213 5.2.3 Influence of dopant content within granules 216 5.2.4 Flowability of zirconia-tungsten oxide granules and alumina granules with mullite or rare earth oxide addition 219 5.2.5 Flowability of titanium oxide doped alumina powders 221 5.3 Cross sections of customized granules to image inner structure 224 6 Summary, conclusions and outlook 233 6.1 Summary and conclusions 233 6.2 Outlook 241 References 245 List of Figures 260 List of Tables 269

Doping allows us to modify semiconductor materials for desired properties such as conductivity, bandgap, and / or lattice parameter. A small portion replacement of the highly mismatched isoelectronic dopants with the host atoms of a semiconductor can result in drastic variation of its structural, optical, and / or electronic properties. Here, the term "mismatch" describes the properties of atom size, ionicity, and / or electronegativity. This thesis presents the fabrication of two kinds of highly mismatched semiconductor alloys, i.e., Ge(1-x)Sn(x) and GaAs(1-x)N(x). The structural and optical properties of the prepared Ge(1-x)Sn(x) and GaAs(1-x)N(x) have been investigated. The results suggest an efficient above-solubility doping induced by non-equilibrium methods of ion implantation and ultrashort annealing. Pulsed laser melting promotes the regrowth of monocrystalline Ge(1-x)Sn(x), whereas flash lamp annealing brings about the formation of high quality GaAs(1-x)N(x) with room temperature photoluminescence. The bandgap modification of Ge(1-x)Sn(x) and GaAs(1-x)N(x) has been verified by optical measurements of spectroscopic ellipsometry and photoluminescence, respectively. In addition, effective defect engineering in GaAs has been achieved by flash lamp annealing, by which a quasi-temperature-stable photoluminescence at 1.3 µm has been obtained. / Dotierung ermöglicht es, die Eigenschaften von Halbleitermaterialien, wie Leitfähigkeit, aber auch Bandabstand und / oder Gitterkonstanten gezielt zu verändern. Wenn ein Halbleiter mit einer kleinen Menge unterschiedliche Fremdatome dotiert wird, kann dies in einer drastischen Modifikation der strukturellen, optischen und / oder elektronischen Eigenschaften resultieren. Der Begriff "unterschiedlich" bedeutet hier die Eigenschaften von Atomgröße, Ioniztät und / oder Elektronegativität. Diese Doktorarbeit beschreibt die Herstellung von zwei Arten von stark fehlangepassten Halbleiterlegierungen: Ge(1-x)Sn(x) und GaAs(1-x)N(x). Die strukturellen und optischen Eigenschaften von Ge(1-x)Sn(x) und GaAs(1-x)N(x) wurden untersucht. Die Ergebnisse deuten auf eine effiziente Dotierung oberhalb der Löslichkeit, induziert durch die Nicht-Gleichgewichtsverfahren Ionenimplantation und Ultrakurzzeit-Ausheilung. Gepulstes Laserschmelzen ermöglicht das Nachwachsen von monokristallinem Ge(1-x)Sn(x), während die Blitzlampenausheilung in der Bildung von GaAs(1-x)N(x) hoher Qualität mit Photolumineszenz bei Raumtemperatur resultiert. Die Änderung der Bandlücke von Ge(1-x)Sn(x) und GaAs(1-x)N(x) wurde durch die optischen Methoden der spektroskopischen Ellipsometrie und Photolumineszenz verifiziert. Darüber hinaus konnte in ausgeheiltem GaAs eine quasi-temperaturstabile Photolumineszenz bei 1,3 µm beobachtet werden.

Das selektive Laserschmelzen (SLM) erlaubt komplexe Geometrien zu fertigen, die, z. B. in Form von integrierten Kühlkanälen, bei Werkzeugen von großer Bedeutung sind. Aktuell werden in der Industrie hauptsächlich Aluminium-, Stahl-, Titan-, Nickel- und Kobaltchromlegierungen mit SLM verarbeitet. Für die additive Fertigung sind Stähle interessant, die besondere Eigenschaften aufweisen. So wird für Konstruktionsbauteile größtenteils korrosionsbeständiger Stahl verwendet. Ein weiteres Anwendungsfeld ist die Herstellung von Werkzeugen. Die besonderen Ansprüche an die mechanischen Eigenschaften, die für Werkzeuge benötigt werden, erfüllen die Werkzeugstähle. Durch die Neigung zu Rissbildung und Verzug resultiert eine herausfordernde Verarbeitbarkeit im SLM-Prozess. Werkzeugstähle wurden bisher auf Grund dieser Herausforderungen selten mit SLM prozessiert. Es besteht daher ein großer Bedarf die Zusammenhänge zwischen dem Prozess, der Verarbeitbarkeit, dem entstehenden Gefüge und den resultierenden Eigenschaften aufzuklären. In dieser Arbeit werden die Mikrostruktur und die mechanischen Eigenschaften dreier hochfester Stahllegierungen, verarbeitet im SLM-Prozess, untersucht. Eine Legierungsentwicklung, speziell auf die Anforderungen des SLM-Prozesses zugeschnitten, ermöglicht, das volle Potenzial des SLM-Prozesses auszuschöpfen. Die Verarbeitbarkeit der neu entwickelten Legierung im SLM-Prozess konnte erfolgreich gegenüber den Ausgangslegierungen verbessert werden.

The effect of annealing on the tribological and corrosion properties of Al–12Si samples produced by selective laser melting (SLM) is evaluated via sliding and fretting wear tests and weight loss experiments and compared to the corresponding material processed by conventional casting. Sliding wear shows that the as-prepared SLM material has the least wear rate compared to the cast and heat-treated SLM samples with abrasive wear as the major wear mechanism along with oxidation. Similar trend has also been observed for the fretting wear experiments, where the as-prepared SLM sample displays the minimum wear loss. On the other hand, the acidic corrosion behavior of the as-prepared SLM material as well as of the cast samples is similar and the corrosion rate is accelerated by increasing the heat treatment temperature. This behavior is due to the microstructural changes induced by the heat treatment, where the continuous network of Si characterizing the as-prepared SLM sample transforms to isolated Si particles in the heat-treated SLM specimens. This shows that both the wear and corrosion behaviors are strongly associated with the change in microstructure of the SLM samples due to the heat-treatment process, where the size of the hard Si particles increases, and their density decreases with increasing annealing temperature.

Doping allows us to modify semiconductor materials for desired properties such as conductivity, bandgap, and / or lattice parameter. A small portion replacement of the highly mismatched isoelectronic dopants with the host atoms of a semiconductor can result in drastic variation of its structural, optical, and / or electronic properties. Here, the term "mismatch" describes the properties of atom size, ionicity, and / or electronegativity. This thesis presents the fabrication of two kinds of highly mismatched semiconductor alloys, i.e., Ge(1-x)Sn(x) and GaAs(1-x)N(x). The structural and optical properties of the prepared Ge(1-x)Sn(x) and GaAs(1-x)N(x) have been investigated. The results suggest an efficient above-solubility doping induced by non-equilibrium methods of ion implantation and ultrashort annealing. Pulsed laser melting promotes the regrowth of monocrystalline Ge(1-x)Sn(x), whereas flash lamp annealing brings about the formation of high quality GaAs(1-x)N(x) with room temperature photoluminescence. The bandgap modification of Ge(1-x)Sn(x) and GaAs(1-x)N(x) has been verified by optical measurements of spectroscopic ellipsometry and photoluminescence, respectively. In addition, effective defect engineering in GaAs has been achieved by flash lamp annealing, by which a quasi-temperature-stable photoluminescence at 1.3 µm has been obtained. / Dotierung ermöglicht es, die Eigenschaften von Halbleitermaterialien, wie Leitfähigkeit, aber auch Bandabstand und / oder Gitterkonstanten gezielt zu verändern. Wenn ein Halbleiter mit einer kleinen Menge unterschiedliche Fremdatome dotiert wird, kann dies in einer drastischen Modifikation der strukturellen, optischen und / oder elektronischen Eigenschaften resultieren. Der Begriff "unterschiedlich" bedeutet hier die Eigenschaften von Atomgröße, Ioniztät und / oder Elektronegativität. Diese Doktorarbeit beschreibt die Herstellung von zwei Arten von stark fehlangepassten Halbleiterlegierungen: Ge(1-x)Sn(x) und GaAs(1-x)N(x). Die strukturellen und optischen Eigenschaften von Ge(1-x)Sn(x) und GaAs(1-x)N(x) wurden untersucht. Die Ergebnisse deuten auf eine effiziente Dotierung oberhalb der Löslichkeit, induziert durch die Nicht-Gleichgewichtsverfahren Ionenimplantation und Ultrakurzzeit-Ausheilung. Gepulstes Laserschmelzen ermöglicht das Nachwachsen von monokristallinem Ge(1-x)Sn(x), während die Blitzlampenausheilung in der Bildung von GaAs(1-x)N(x) hoher Qualität mit Photolumineszenz bei Raumtemperatur resultiert. Die Änderung der Bandlücke von Ge(1-x)Sn(x) und GaAs(1-x)N(x) wurde durch die optischen Methoden der spektroskopischen Ellipsometrie und Photolumineszenz verifiziert. Darüber hinaus konnte in ausgeheiltem GaAs eine quasi-temperaturstabile Photolumineszenz bei 1,3 µm beobachtet werden.

Das selektive Laserschmelzen (SLM) erlaubt komplexe Geometrien zu fertigen, die, z. B. in Form von integrierten Kühlkanälen, bei Werkzeugen von großer Bedeutung sind. Aktuell werden in der Industrie hauptsächlich Aluminium-, Stahl-, Titan-, Nickel- und Kobaltchromlegierungen mit SLM verarbeitet. Für die additive Fertigung sind Stähle interessant, die besondere Eigenschaften aufweisen. So wird für Konstruktionsbauteile größtenteils korrosionsbeständiger Stahl verwendet. Ein weiteres Anwendungsfeld ist die Herstellung von Werkzeugen. Die besonderen Ansprüche an die mechanischen Eigenschaften, die für Werkzeuge benötigt werden, erfüllen die Werkzeugstähle. Durch die Neigung zu Rissbildung und Verzug resultiert eine herausfordernde Verarbeitbarkeit im SLM-Prozess. Werkzeugstähle wurden bisher auf Grund dieser Herausforderungen selten mit SLM prozessiert. Es besteht daher ein großer Bedarf die Zusammenhänge zwischen dem Prozess, der Verarbeitbarkeit, dem entstehenden Gefüge und den resultierenden Eigenschaften aufzuklären. In dieser Arbeit werden die Mikrostruktur und die mechanischen Eigenschaften dreier hochfester Stahllegierungen, verarbeitet im SLM-Prozess, untersucht. Eine Legierungsentwicklung, speziell auf die Anforderungen des SLM-Prozesses zugeschnitten, ermöglicht, das volle Potenzial des SLM-Prozesses auszuschöpfen. Die Verarbeitbarkeit der neu entwickelten Legierung im SLM-Prozess konnte erfolgreich gegenüber den Ausgangslegierungen verbessert werden.

Selective laser melting (SLM), is a type of additive manufacturing, which selectively melts a pre-spread layer of metal powders and produce a part by a layer-on-layer manner. SLM has demonstrated a great potential to reduce size and weight in hydraulic manifolds. However, a theoretical base is lacking since friction loss is unclear in a SLMed fluid passage. In this study, various fluid passages without supports, from diameters from 4 mm to 16 mm, were produced horizontally using SLM. The profile was measured using a 3D scanner and surface roughness was measured using a confocal laser scanning microscope. Friction factor was studied using simulation, experiments, and classical theory. The hydraulic diameter of the SLMed passages is smaller than the design diameter. Surface roughness is extremely high on the top part of the inner wall while the rest part is around 10 μm. Such trends are irrelevant of passage diameters. Friction factors in SLMed passage is much larger than those predicted using Moody theory, particularly in laminar flow. The transition from laminar flow to turbulent flow appears at a smaller Reynolds number with increased passage diameter. The influence of the profile overweighs that of the surface roughness on friction factor.

Selective laser melting (SLM), one type of metal additive manufacturing (AM) technology, uses a highintensity laser to selectively melt pre-spread metal powders by a layer-on-layer manner. The technology does not only provide a new way of manufacturing but also innovates product design methodology. In this study, a hydraulic block manifold is designed and manufactured using SLM. In this paper, we present an AM-driven design approach of hydraulic manifolds based on a case study. The target is not only to reduce weight but also to enhance fluid flow by optimizing fluid path to reduce pressure drop. The novelty of the research includes developing a design approach of hydraulic manifolds using SLM with a particular focus on fluid flow. Compared to the traditional hydraulic manifold, the weight of the new SLMed hydraulic manifold was reduced by more than 80%, size by half. Pressure loss of the main functional oil circuit was reduced by 31%, illustrating that the new hydraulic manifold design simultaneously achieves lightweight and high performance. This study contributes to providing theoretical guidance to the design of additively manufactured hydraulic components with high performance.

Selective laser melting (SLM) is an additive manufacturing technology. In this thesis, a heat-treatable Al-3.5Cu-1.5Mg-1Si alloy and related materials (composites and hybrid materials) have been successfully fabricated by selective laser melting and characterized in terms of densification, microstructure, heat treatment, mechanical properties as well as tribological and corrosion behavior. Firstly, the fully dense SLM Al-Cu-Mg-Si alloy was fabricated by SLM successfully. The alloy shows a higher yield strength than SLM Al-12Si alloy, and lower wear resistance and corrosion rate than commercial 2024 alloy before and after T6 heat treatment. Secondly, with the aim of designing new alloy compositions and to examine the phases and microstructures of SLM Al-Cu alloys and to correlate their microstructures with the observed mechanical properties, Al-xCu (x = 4.5, 6, 20, 33 and 40 wt. %) alloys have been synthesized in-situ by SLM from mixtures of Al-4.5Cu and Cu powders. The results indicate that the insufficient Cu solute diffusion during the layer-by-layer processing results in an inhomogeneous microstructure around the introduced Cu powders. With increasing Cu content, the Al2Cu phase in the alloys increases improving the strength of the material. These results show that powder mixtures can be used for the synthesis of SLM composites but the reaction between the matrix and the second-phase should be considered carefully. Thirdly, the TiB2/Al-Cu-Mg-Si composite was also designed and fabricated successfully by SLM and it shows a higher strength than the unreinforced SLM alloy before and after T6 heat treatment. Finally, an Al-12Si/Al-3.5Cu-1.5Mg-1Si hybrid with a good interface was fabricated successfully. This hybrid alloy shows a good yield strength and elongation at room temperature, indicating an effective potential of selective laser melting in the field of hybrid manufacturing.