Eric A. Jägle

Eric A. Jägle
Universität der Bundeswehr München · Fakultät für Luft- und Raumfahrttechnik

Professor

About

101
Publications
35,936
Reads
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2,923
Citations
Citations since 2017
70 Research Items
2756 Citations
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Additional affiliations
January 2020 - present
Universität der Bundeswehr München
Position
  • Chair
April 2015 - December 2019
Max Planck Institute for Iron Research GmbH
Position
  • Group Leader
November 2012 - March 2015
Max Planck Institute for Iron Research GmbH
Position
  • Atom probe tomography study of deformation-induced mixing
Education
October 2006 - September 2007
University of Cambridge
Field of study
  • Materials Modelling
October 2001 - August 2006
Universität Stuttgart
Field of study
  • Materials Science

Publications

Publications (101)
Article
A non weldable nickel-based superalloy was fabricated by powder bed-based selective electron beam melting (S-EBM). The as-built samples exhibit a heterogeneous microstructure along the build direction. A gradient of columnar grain size as well as a significant gradient in the g0 precipitate size were found along the build direction. Microstructural...
Article
Full-text available
Laser additive manufacturing is attractive for the production of complex, three-dimensional parts from metallic powder using a computer-aided design model1,2,3. The approach enables the digital control of the processing parameters and thus the resulting alloy’s microstructure, for example, by using high cooling rates and cyclic re-heating4,5,6,7,8,...
Article
Grain structure control is essential in metal additive manufacturing. It is used to avoid anisotropic mechanical properties, hot cracking and to increase the strength via the Hall-Petch effect. Here we demonstrate the use of grain refining particles for grain control in ferritic alloys, specifically FeTi model alloys. We introduce the particles in...
Article
In the development of high-strength aluminium alloys tailored specifically to additive manufacturing (AM), L12-Al3X-forming elements have been proven to be particularly effective alloying additions, reducing the susceptibility of aluminium alloys to solidification cracking by grain refinement and increasing the strength by forming secondary nanosca...
Article
Today, a large number of different steels are being processed by Additive Manufacturing (AM) methods. The different matrix microstructure components and phases (austenite, ferrite, martensite) and the various precipitation phases (intermetallic precipitates, carbides) lend a huge variability in microstructure and properties to this class of alloys....
Article
Full-text available
Metal powders in laser-powder-bed-fusion (L-PBF) often exhibit cohesive flow resulting from interparticle adhesion. Nanoparticle dry-coating can improve powder flowability and promote powder layer densification. A Co25Cr25Fe25Ni25 metal powder (20-90 µm) is dry-coated with TiN particles with a diameter of 16 nm at low concentrations of up to 69 ppm...
Conference Paper
Full-text available
The identification of material properties at high strain rates is of considerable technical interest, e.g., in applications for passenger safety-related parts which are expected to absorb energy in case of collisions. To additionally meet the requirements of a rapid and resource-efficient materials characterization, a novel high-speed hardness test...
Article
The present work investigates the effect of the coupled thermo-mechanical phenomena that occur when applying differential cooling technology by heated and cooled forming tool segments established in functional gradation by press hardening of high strength steel to precipitation-hardenable aluminum alloy AA7075. This application aims at creating gra...
Article
Full-text available
Disadvantageous complex residual stress distributions are common in parts manufactured by laser-based powder bed fusion metals (PBF-LB/M). Thus, the residual stress state determination is essential for understanding the part’s limitations. One residual stress measurement technique applicable to PBF-LB/M parts is the slitting method. This destructiv...
Article
Full-text available
Laser-based additive manufacturing (LAM) in all its variations is now being established as a technique for manufacturing components from various material types and alloys [...]
Article
Full-text available
In conventional processing, metals go through multiple manufacturing steps including casting, plastic deformation, and heat treatment to achieve the desired property. In additive manufacturing (AM) the same target must be reached in one fabrication process, involving solidification and cyclic remelting. The thermodynamic and kinetic differences bet...
Article
The temperature distribution, geometry and size of the melt pool, and solidification parameters were computed using the heat transfer and material flow model for the directed energy deposition process. The thermal cycle and melt pool size were computed for different process parameters such as laser power, deposition speed, and laser beam radius acr...
Article
The significant strengthening of selectively laser melted (SLM) 304L stainless steel that occurs due to high-pressure torsion (HPT) is examined by recourse to detailed nanomechanical and microstructural characterization. In the as-built alloy, dislocation hardening is the main strengthening mechanism. After HPT, however, the synergistic combination...
Article
The influence of hydrogen on the mechanical behavior of Inconel 718 fabricated by laser powder-bed-fusion was investigated through a series of tensile experiments. Samples subjected to two different post-fabrication heat treatments, viz. direct aging (DA) and homogenization plus aging (HA), were tested. Detailed microstructural characterization sho...
Article
Full-text available
The development of strong-scaling computational tools for high-throughput methods with an open-source code and transparent metadata standards has successfully transformed many computational materials science communities. While such tools are mature already in the condensed-matter physics community, the situation is still very different for many exp...
Article
Designing a metastable microstructure with a coherent nano-sized precipitation phase in the matrix is an effective strategy in improving the strength of materials. Recently, the rapid fusion and solidification cycle associated with laser-based additive manufacturing (AM) has emerged as a promising strategy to design unique microstructures with latt...
Article
The 15-5PH (UNS S 15500) stainless steel combines high mechanical strength, ductility, and good corrosion resistance for aircraft and aerospace applications. This set of properties and its high added-value applications make it an excellent choice for additive manufacturing processes such as laser powder-bed fusion (LPBF). However, there is a need t...
Article
Alloys manufactured by laser powder-bed fusion have intrinsic and hierarchical microstructural features inherited from fast solidification (up to 10⁴ K/s) and subsequent thermal cycles. This creates epitaxial grains, dislocation cell structures, and second-phase oxide nanoparticles. Epitaxial grains follow a pattern where finer grains are found in...
Article
The development of a composite microstructure with hard aluminum nitrides (AlN) dispersed in a soft ferritic iron-based solid has been achieved in this work through the powder metallurgy route. Fe-4.6at.% Al alloy powders subjected to two different thermo-chemical treatments viz. nitriding and nitriding followed by hydrogen reduction have been cons...
Article
By using laser powder bed fusion (LPBF) in the tooling industry, tools with complex geometries and integrated functions, such as adapted cooling channels, can be manufactured with high potential in terms of product lifetimes or cycle times. When processing tool steels with a carbon content > 0.6 wt.-% by means of LPBF, hard and brittle phases are f...
Article
Many alloys produced by Laser Powder Bed Fusion (LPBF) suffer from coarse grains and anisotropic mechanical properties. Here, we investigate how the addition of Ti can cause significant strengthening via grain refinement in a model ferritic stainless steel. We perform LPBF experiments using elemental Fe, Cr, and Ti powders (with significant O impur...
Article
Inspired by steel forming strategies, this study focuses on the effect of differential cooling on mechanical properties and precipitation kinetics during hot stamping of high strength AA7075 alloy. For this aim, different forming strategies were performed using segmented and differentially heated forming tools to provide locally tailored microstruc...
Article
Laser surface remelting can be used to manipulate the microstructure of cast materials. Here, we present a detailed analysis of Fe2VAl following laser surface remelting. Within the melt pool, elongated grains grow nearly epitaxially from the heat-affected zone. These grains are separated by low-angle grain boundaries with 1°–5° misorientations. Seg...
Article
Grain refinement tendency of pure Fe and Fe-X (X=5~10at%Al, 2~10at%Ti) alloys produced by laser powder bed fusion (LPBF) process was investigated. Pure Fe, Al, and Ti powders were dry mixed and cubic samples were built from the mixtures. The microstructure analysis revealed that (1) the microstructure of pure Fe consisted of equiaxed grains having...
Article
Full-text available
One major hindrance that alloy design for additive manufacturing (AM) faces nowadays is hot tearing. Contrary to the previous works which either try to reduce solidification range or introduce grain refinement , the current work presents a new approach of employing segregation engineering to alter the residual stress states at the interdendritic an...
Article
Hydrogen embrittlement in 304L austenitic stainless steel fabricated by laser powder-bed-fusion (LPBF) was investigated and compared to conventionally produced 304L samples with two different processing histories; casting plus annealing (CA) and CA plus thermomechanical treatment (CA-TMT). Interestingly, no significant difference in the amount of d...
Article
Additive manufacturing processes, such as laser powder bed fusion, require steady powder processing but often exhibit poor flowability and low powder bed densities. Reducing the attractive Van-der-Waals force through nanoparticle coating can enhance initially poor flowability. We investigated the effect of dry-coating nanosized SiO2 on gas-atomized...
Preprint
Laser surface remelting can be used to manipulate the microstructure of cast material. Here, we present a detailed analysis of the microstructure of Fe$_2$VAl following laser surface remelting. Within the melt pool, elongated grains grow nearly epitaxially from the heat-affected zone. These grains are separated by low-angle grain boundaries with 1{...
Article
Full-text available
open access links: https://link.springer.com/article/10.1007%2Fs11661-020-05947-2 https://rdcu.be/b6P8O https://doi.org/10.1007/s11661-020-05947-2 This is a viewpoint paper on recent progress in the understanding of the microstructure–property relations of advanced high-strength steels (AHSS). These alloys constitute a class of high-strength, for...
Article
Full-text available
The design of advanced alloys specifically tailored to additive manufacturing processes is a research field that is attracting ever-increasing attention. Laser powder-bed fusion (LPBF) commonly uses pre-alloyed, fine powders (diameter usually 15–45 µm) to produce fully dense metallic parts. The availability of such fine, pre-alloyed powders reduces...
Article
Conductive and yet strong copper alloys are essential materials in highly mechanically loaded electrical devices. We demonstrate a novel in-situ synthesis approach via laser metal deposition (LMD) in a lean copper alloy, Cu-3.4Cr-0.6Nb (at.%). Strengthening in the lean alloy comes from chromium nano-scale precipitates formed in-situ (4 nm diameter;...
Article
In this work an unexplored method of utilization of gaseous nitriding of Fe-2.3 wt% Al alloy powders was employed to realize a dispersion of nanosized AlN particles in the ferritic matrix. The nitriding treatment was carried out at 580 °C in ammonia atmosphere and the resulting microstructures were characterized by employing light microscopy, scann...
Preprint
Full-text available
Advanced characterisation techniques were used on LPBF Ti-6Al-4V samples produced on a heated base plate. When the substrate temperature is 100{\deg}C the elongation is 6\%, which increases and peaks at 10\% at 570{\deg}C, then sharply decreases to zero ductility at 770{\deg}C. At 100{\deg}C, a heavily strained and twinned microstructure, primarily...
Article
Advanced characterisation techniques were used on LPBF Ti-6Al-4V samples produced on a heated base plate. When the substrate temperature is 100°C the elongation is 6\%, which increases and peaks at 10\% at 570°C, then sharply decreases to zero ductility at 770°C. At 100°C, a heavily strained and twinned microstructure, primarily composed of {\alpha...
Preprint
Full-text available
High entropy alloys are generally considered to be single phase material. This state is, however, typically a non-equilibrium state after fabrication at high cooling rates. Phase constitution after fabrication or heat treatment is mostly known for isothermal annealing only and for casts as well as rapidly quenched alloys. Knowledge on early phase s...
Article
We report the synthesis of a bulk nanostructured alloy using laser-powder bed fusion. The equiatomic AlCoCrFeMnNi chemically complex alloy forms a nanoscale modulated structure, which is homogeneously distributed in the as-built condition. The nanostructure consists of Al & Ni-rich ordered and Cr & Fe-rich disordered BCC phases. The two phases form...
Chapter
Full-text available
Empfehlungen zur Anpassung der Arbeitswelt an die Anforderungen der Additiven Fertigung: Weitreichende Veränderungen im Zuge der künftigen Erschließung neuer Anwendungsfelder für die Additive Fertigung sind insbesondere für die Arbeitswelt zu erwarten. Neue Technologien beeinflussen die Arbeitswelt in mehrfacher Hinsicht. Sie erfordern entsprechen...
Preprint
We report the synthesis of a bulk nanostructured alloy using the laser-powder bed fusion process. The equiatomic AlCoCrFeMnNi chemically complex alloy forms a nanoscale modulated structure, which is homogeneously distributed in the as-built condition. The nanostructure consisted of Al & Ni-rich ordered (B2) and Cr & Fe-rich disordered (A2) BCC phas...
Article
Full-text available
High entropy alloys are generally considered to be single phase material. This state is, however, typically a non-equilibrium state after fabrication at high cooling rates. Phase constitution after fabrication or heat treatment is mostly known for isothermal annealing only and for casts as well as rapidly quenched alloys. Knowledge on early phase s...
Preprint
Hydrogen embrittlement in 304L (18wt.% Cr, 8-10wt.% Ni) austenitic stainless steel (ASS) fabricated by laser powder-bed-fusion (LPBF) was investigated by tensile testing after electrochemical hydrogen pre-charging and compared to conventionally available 304L ASSs with two different processing histories, (i) casting plus annealing (CA) and (ii) CA...
Article
Traditionally, reactive gases such as oxygen (O2) and carbon dioxide (CO2) have been avoided during laser powder bed fusion (L-PBF) of metals and alloys based on the notion that it may lead to defect formation and poor properties. Here we show that instead, these gases can be used to form sub-µm-sized oxide particles in-situ during the L-PBF proces...
Article
Full-text available
A vital issue during selective laser melting of nonweldable polycrystalline nickel-base superalloys is the formation of microcracks. These are cracks occurring during the last stage of solidification and only at high angle grain boundaries (HAGBs). Solute enrichment to the remaining interdendritic liquid and its partial back-diffusion into the soli...
Article
Laser Additive Manufacturing (LAM) of light metals such as high-strength Al-based alloys offers tremendous potential for e.g. weight reduction and associated reduced fuel consumptions for the transportation industry. Typically, commercial Sc-containing alloys, such as Scalmalloy®, rely on precipitation hardening to increase their strength. Conventi...
Article
On Strong Scaling Open Source Tools for Mining Atom Probe Tomography Data - Volume 25 Supplement - Markus Kühbach, Priyanshu Bajaj, Andrew Breen, Eric A. Jägle, Baptiste Gault
Article
Application of Atom Probe Tomography to Complex Microstructures of Laser Additively Manufactured Samples - Volume 25 Supplement - Philipp Kürnsteiner, Avinash Hariharan, Hyo Yun Jung, Nicolas Peter, Markus Benjamin Wilms, Andreas Weisheit, Pere Barriobero-Vila, Baptiste Gault, Dierk Raabe, Eric Aimé Jägle
Article
The microstructure and phase composition in selective laser melted (SLM) Ti-6Al-4V plays a key role for its mechanical performance. The microstructure evolution in SLM Ti-6Al-4V was studied in the as-built condition and after sub-transus heat treatments between 400 °C and 800 °C focusing on elemental partitioning and the role of lattice defects on...
Conference Paper
Additive Fertigung (Additive Manufacturing - AM) ist eine Technologie mit enormem Potenzial, jedoch auch hoher Komplexität. Im Gegensatz zu herkömmlichen Fertigungsansätzen ist AM sehr interdisziplinär und erfordert eine zusammenhängende Betrachtung der AM-Prozesse, des AM-konformen Designs und Engineerings, von Baustrategien, Nachbehandlungen und...
Conference Paper
Introduction Additive manufacturing (AM) is a technology of enormous potential, yet also of high complexity. Understanding and exploiting AM requires very interdisciplinary research efforts since material, processing, AM-design and engineering, build strategies, post-treatments and surface finishing are all interdependent. Particularly for class-on...
Article
Full-text available
There is growing interest in Laser Powder Bed Fusion (L-PBF) or Selective Laser Melting (SLM) manufacturing of high conductivity metals such as copper and refractory metals. SLM manufacturing of high thermal conductivity metals is particularly difficult. In case of refractory metals, the difficulty is amplified because of their high melting point a...
Article
Full-text available
Atom probe tomography (APT) is rising in influence across many parts of materials science and engineering thanks to its unique combination of highly sensitive composition measurement and three-dimensional microstructural characterization. In this invited article, we have selected a few recent applications that showcase the unique capacity of APT to...
Poster
Additive manufacturing (AM) is a technology of enormous potential, yet also of enormous complexity. Unlike “conventional” manufacturing approaches, understanding and exploiting AM requires very interdisciplinary research efforts since material, processing, AM-conformal design & engineering, build strategies, post-treatments and surface finishing ar...
Article
Mo-Si-B alloys are potential creep resistant materials for accessing harsh loading scenarios beyond Ni-based superalloys due to their excellent mechanical performance at ultra-high temperatures (> 1200 °C). Here, we report on the fabrication through laser additive manufacturing of a Mo rich Mo-Si-B alloy with and without dispersion of oxide (La2O3)...
Article
Ti and its alloys have a high affinity for hydrogen and are typical hydride formers. Ti-hydride are brittle phases which probably cause premature failure of Ti-alloys. Here, we used atom probe tomography and electron microscopy to investigate the hydrogen distribution in a set of specimens of commercially pure Ti, model and commercial Ti-alloys. Al...
Article
Additive manufacturing is considered a disruptive technology that is expected to revolutionize production technology and affect value chains on a global scale. The scope of accessible materials ranges from polymers to metals and ceramics as well as composites. The keynote will provide an overview of available manufacturing processes for the various...
Article
Atom probe tomography (APT) is rising in influence across many parts of materials science and engineering thanks to its unique combination of highly sensitive composition measurement and three-dimensional microstructural characterization. In this invited article, we have selected a few recent applications that showcase the unique capacity of APT to...
Article
In-process Precipitation During Laser Additive Manufacturing Investigated by Atom Probe Tomography - Volume 23 Issue S1 - Philipp Kürnsteiner, Markus Benjamin Wilms, Andreas Weisheit, Pere Barriobero-Vila, Baptiste Gault, Eric Aimé Jägle, Dierk Raabe
Article
Due to the layer-by-layer build-up of additively manufactured parts, the deposited material experiences a cyclic re-heating in the form of a sequence of temperature pulses. In the current work, this “intrinsic heat treatment (IHT)” was exploited to induce the precipitation of NiAl nanoparticles in an Fe-19Ni-xAl (at%) model maraging steel, a system...
Article
Maraging steels are used to produce tools by Additive Manufacturing (AM) methods such as Laser Metal Deposition (LMD) and Selective Laser Melting (SLM). Although it is well established that dense parts can be produced by AM, the influence of the AM process on the microstructure—in particular the content of retained and reversed austenite as well as...
Article
Maraging steels are used to produce tools by Additive Manufacturing (AM) methods such as Laser Metal Deposition (LMD) and Selective Laser Melting (SLM). Although it is well established that dense parts can be produced by AM, the influence of the AM process on the microstructure—in particular the content of retained and reversed austenite as well as...
Article
Atom-probe tomography is a materials characterization method ideally suited for the investigation of clustering and precipitation phenomena. To distinguish the clusters from the surrounding matrix, the maximum separation algorithm is widely employed. However, the results of the cluster analysis strongly depend on the parameters used in the algorith...
Article
We used laser additive manufacturing as a combinatorial method for synthesizing microstructurally and compositionally piecewise graded bulk alloys. We fabricated blocks consisting of a sequence of ~500 µm thick tool steel layers, each with different chemical composition, by laser metal deposition where alloy powders were deposited layer-wise on a s...
Article
Full-text available
The effect of the initial microstructure (recrystallized or cold-rolled) on the nitride precipitation process upon gaseous nitriding of ternary Fe-4.3 at. pct Cr-8.1 at. pct Al alloy was investigated at 723 K (450 °C) employing X-ray diffraction (XRD) analyses, transmission electron microscopy (TEM), atom probe tomography (APT), and electron probe...
Article
We describe and study the thermal profiles experienced by various age-hardenable alloys during laser additive manufacturing (LAM), employing two different manufacturing techniques: selective laser melting and laser metal deposition. Using scanning electron microscopy and atom probe tomography, we reveal at which stages during the manufacturing proc...
Article
Gaseous nitriding of Ni-4 wt pct Ti alloy plates led to the development of double expanded austenite (γ N1 and γ N2) at the surface of the nitride plates. Grazing-incidence X-ray diffraction analysis demonstrated that the component γ N1 is located close to the surface and the component γ N2 is located at a certain depth below the specimen surface,...
Article
Full-text available
div class="title">Co-deformation of crystalline-amorphous nanolaminates - Volume 21 Issue S3 - Wei Guo, Jiahao Yao, Eric A. Jagle, Pyuck-Pa Choi, Dierk Raabe