Materials in harsh environments

International researcher team develops scalable aluminium alloys for the hydrogen economy more

The project HyWay aims to promote the design of advanced materials that maintain outstanding mechanical properties while mitigating the impact of hydrogen by developing flexible, efficient tools for multiscale material modelling and characterization. These efficient material assessment suites integrate data-driven approaches, advanced characterization, multiscale modelling, and ontology-based knowledge management seamlessly, revealing hydrogen-material interactions in storage and transport conditions. more

In this project, the effects of scratch-induced deformation on the hydrogen embrittlement susceptibility in pearlite is investigated by in-situ nanoscratch test during hydrogen charging, and atomic scale characterization. This project aims at revealing the interaction mechanism between hydrogen and scratch-induced deformation in pearlite. more

This project aims to develop a micromechanical metrology technique based on thin film deposition and dewetting to rapidly assess the dynamic thermomechanical behavior of multicomponent alloys. This technique can guide the alloy design process faster than the traditional approach of fabrication of small-scale test samples using FIB milling and subsequent mechanical testing. As a case study for validation, B2-FeAl intermetallic particles are tested at a variety of strain rates and are planned to be tested at high temperatures. more

The aim of the current study is to investigate electrochemical corrosion mechanisms by examining the metal-liquid nanointerfaces. To achieve this, corrosive fluids will be strategically trapped within metal structures using novel additive micro fabrication techniques. Subsequently, the nanointerfaces will be analyzed using cryo-atom probe tomography. more

“Smaller is stronger” is well known in micromechanics, but the properties far from the quasi-static regime and the nominal temperatures remain unexplored. This research will bridge this gap on how materials behave under the extreme conditions of strain rate and temperature, to enhance fundamental understanding of their deformation mechanisms. The mechanical behavior of different material systems is investigated in a statistically relevant manner using dewetted microparticles as the test-beds. more

Biological materials in nature have a lot to teach us when in comes to creating tough bio-inspired designs. This project aims to explore the unknown impact mitigation mechanisms of the muskox head (ovibus moschatus) at several length scales and use this gained knowledge to develop a novel mesoscale (10 µm to 1000 µm) metamaterial that can mimic the high energy absorption characteristics of the muskox head without failure between strain rates of 0.001/s and 1000/s. more

This project aims to investigate the influence of grain boundaries on mechanical behavior at ultra-high strain rates and low temperatures. For this micropillar compressions on copper bi-crystals containing different grain boundaries will be performed. more

New video explains strategies to counteract crack propagation in aluminum more

Nickel-based alloys are a particularly interesting class of materials due to their specific properties such as high-temperature strength, low-temperature ductility and toughness, oxidation resistance, hot-corrosion resistance, and weldability, becoming potential candidates for high-performance components that require corrosion resistance and good mechanical properties. This unparalleled combination of properties is achieved by adding alloying elements and changes in microstructure. This research project blended Ni-based metal welds produced by in situ alloying using the tandem GMAW process in a previous research project developed by the Welding Research and Technology Laboratory team at the Federal University of Ceará, in Brazil.
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Within this project, we will investigate the micromechanical properties of STO materials with low and higher content of dislocations at a wide range of strain rates (0.001/s-1000/s). Oxide ceramics have increasing importance as superconductors and their dislocation-based electrical functionalities that will affect these electrical properties. Hence it is fundamental to understand the deformation limits to introduce dislocations for both the fabrication process and in-use performance.
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Statistical significance in materials science is a challenge that has been trying to overcome by miniaturization. However, this process is still limited to 4-5 tests per parameter variance, i.e. Size, orientation, grain size, composition, etc. as the process of fabricating pillars and testing has to be done one by one. With this project, we aim to fabricate arrays of well-defined and located particles that can be tested in an automated manner. With a statistically significant amount of samples tested per parameter variance, we expect to apply more complex statistical models and implement machine learning techniques to analyze this complex problem. more

Hydrogen in aluminium can cause embrittlement and critical failure. However, the behaviour of hydrogen in aluminium was not yet understood. Scientists at the Max-Planck-Institut für Eisenforschung were able to locate hydrogen inside aluminium’s microstructure and designed strategies to trap the hydrogen atoms inside the microstructure. This can reduce failure due to hydrogen embrittlement.  
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Grain boundaries (GBs) are regions connecting adjacent crystals with different crystallographic orientations. GBs are a type of lattice imperfection, with their own structure and composition, and as such impact a material’s mechanical and functional properties. Structural motifs and phases formed at chemically decorated GBs can be of a transient nature or are local thermodynamic structural-chemical equilibrium states. more

Recently developed dual-phase high entropy alloys (HEAs) exhibit both an increase in strength and ductility upon grain refinement, overcoming the strength-ductility trade-off in conventional alloys [1]. Metastability engineering through compositional tuning in non-equimolar Fe-Mn-Co-Cr HEAs enabled the design of a dual-phase alloy composed of metastable face centered cubic (fcc) and hexagonal closed packed (hcp) phases. more

To design novel alloys with tailored properties and microstructure, two materials science approaches have proven immensely successful: Firstly, thermodynamic and kinetic descriptions for tailoring and processing alloys to achieve a desired microstructure. Secondly, crystal defect manipulation to control strength, formability and corrosion resistance. more

Project C3 of the SFB/TR103 investigates high-temperature dislocation-dislocation and dislocation-precipitate interactions in the gamma/gamma-prime microstructure of Ni-base superalloys. more

New research group on “Microstructure and Mechanics” starts at the MPIE more

The goal of this project is to develop an environmental chamber for mechanical testing setups, which will enable mechanical metrology of different microarchitectures such as micropillars and microlattices, as a function of temperature, humidity and gaseous environment. more

Within this project, we will use a green laser beam source based selective melting to fabricate full dense copper architectures. The focus will be on identifying the process parameter-microstructure-mechanical property relationships in 3-dimensional copper lattice architectures, under both quasi-static and dynamic loading conditions. more