A5038822875- Additive Manufacturing Materials and Processes
- High Entropy Alloys Studies
- Additive Manufacturing and 3D Printing Technologies
- Advanced Materials Characterization Techniques
- Welding Techniques and Residual Stresses
- Manufacturing Process and Optimization
- Aluminum Alloy Microstructure Properties
- Hydrogen embrittlement and corrosion behaviors in metals
- Microstructure and mechanical properties
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Microstructure and Mechanical Properties of Steels
- Aluminum Alloys Composites Properties
- Titanium Alloys Microstructure and Properties
- Laser and Thermal Forming Techniques
- Intermetallics and Advanced Alloy Properties
- Metallurgy and Material Forming
- High-Temperature Coating Behaviors
- Laser Material Processing Techniques
- Metallic Glasses and Amorphous Alloys
- Metallurgical Processes and Thermodynamics
- Metal Alloys Wear and Properties
- Solidification and crystal growth phenomena
- High Temperature Alloys and Creep
- Fusion materials and technologies
Max-Planck-Institut für Nachhaltige Materialien
2015-2024
Universität der Bundeswehr München
2019-2024
Technical University of Munich
2023
Max Planck Society
2011-2020
Max Planck Institute for Intelligent Systems
2010-2012
Maraging steels are used to produce tools by Additive Manufacturing (AM) methods such as Laser Metal Deposition (LMD) and Selective Melting (SLM). Although it is well established that dense parts can be produced AM, the influence of AM process on microstructure—in particular content retained reversed austenite nanostructure, especially precipitate density chemistry, not yet explored. Here, we study these features using microhardness measurements, Optical Microscopy, Electron Backscatter...
Abstract This is a viewpoint paper on recent progress in the understanding of microstructure–property relations advanced high-strength steels (AHSS). These alloys constitute class high-strength, formable that are designed mainly as sheet products for transportation sector. AHSS have often very complex and hierarchical microstructures consisting ferrite, austenite, bainite, or martensite matrix duplex even multiphase mixtures these constituents, sometimes enriched with precipitates....
In conventional processing, metals go through multiple manufacturing steps including casting, plastic deformation, and heat treatment to achieve the desired property. additive (AM) same target must be reached in one fabrication process, involving solidification cyclic remelting. The thermodynamic kinetic differences between solid liquid phases lead constitutional undercooling, local variations interval, unexpected precipitation of secondary phases. These features may cause many undesired...
We describe and study the thermal profiles experienced by various age-hardenable alloys during laser additive manufacturing (LAM), employing two different techniques: selective melting metal deposition. Using scanning electron microscopy atom probe tomography, we reveal at which stages process desired undesired precipitation reactions can occur in alloys. examples from a maraging steel, nickel-base superalloy scandium-containing aluminium alloy, demonstrate that already production of powders...
Deformation of ductile crystalline-amorphous nanolaminates is not well understood due to the complex interplay interface mechanics, shear banding, and deformation-driven chemical mixing. Here we present indentation experiments on 10 nm nanocrystalline Cu-100 amorphous CuZr model multilayers study these mechanisms down atomic scale. By using correlative atom probe tomography transmission electron microscopy find that crystallographic slip bands in Cu layers coincide with noncrystallographic...
A vital issue during selective laser melting of nonweldable polycrystalline nickel-base superalloys is the formation microcracks. These are cracks occurring last stage solidification and only at high angle grain boundaries (HAGBs). Solute enrichment to remaining interdendritic liquid its partial back-diffusion into solid contributes crack nucleation mechanism. Here we use atom probe tomography coupled with transmission Kikuchi diffraction determine misorientation chemical composition...
Abstract The allotropic, martensitic phase transformation (hcp → fcc) in cobalt was investigated by differential scanning calorimetry (DSC) upon isochronal annealing at heating rates the range from 10 K min−1 to 40 min−1. microstructural evolution traced optical microscopy and X-ray diffractometry. kinetics of hcp fcc Co described on basis a modular model. Appropriate model descriptions for athermal nucleation thermally activated, anisotropic interface controlled growth tailored were...
There is growing interest in Laser Powder Bed Fusion (L-PBF) or Selective Melting (SLM) manufacturing of high conductivity metals such as copper and refractory metals. SLM thermal particularly difficult. In case metals, the difficulty amplified because their melting point brittle behaviour. Rapid process development strategies are essential to identify suitable parameters for achieving minimum porosities these alloys, yet current suffer from several limitations. We propose a simple approach...
The authors uses laser additive manufacturing (LAM) as a combinatorial method for synthesizing microstructurally and compositionally piecewise graded bulk alloys. Authors fabricate blocks consisting of sequence ≈500 μm thick tool steel layers, each with different chemical composition, by metal deposition where alloy powders are deposited layer-wise on substrate. reference materials Cr–Mo–V hot working Ni-based maraging steel. layers between them consist corresponding blends the two varying...
Grain structure control is essential in metal additive manufacturing. It used to avoid anisotropic mechanical properties, hot cracking and increase the strength via Hall-Petch effect. Here we demonstrate use of grain refining particles for ferritic alloys, specifically Fe-Ti model alloys. We introduce three different ways, namely (i) by using oxygen-rich raw powders, (ii) reaction molten material with process gas atmosphere (iii) direct addition ceramic phase powder form. Samples are...