About
43
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585
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Citations since 2017
Introduction
Additional affiliations
September 2021 - present
Position
- Group Leader
Description
- Sustainable Synthesis of Materials The aim of this group is to increase the direct sustainability of structural metals in areas such as reduced carbon dioxide-intensive primary production, low-energy metallurgical synthesis, recycling, scrap-compatible alloy design, pollutant tolerance of alloys and improved longevity of alloys. The focus lies on the study of the basic physical and chemical foundations for improving the direct sustainability of structural metals.
January 2020 - September 2021
October 2017 - August 2018
Education
January 2016 - October 2019
August 2013 - August 2015
February 2008 - July 2013
Publications
Publications (43)
Austenite (g) reversion in a cold-rolled 17.6 wt.% Mn steel was tracked by means of dilatometry and in-situ magnetic measurements during slow continuous annealing. A splitting of the g-reversion into two stages was observed to be a result of strong elemental partitioning between g and a 0-martensite during the low temperature stage between 390 and...
Strain partitioning and localization were investigated in a high-Mn steel (17.1 wt.% Mn) during tensile testing by a correlative probing approach including in-situ synchrotron X-ray diffraction, micro- digital image correlation (μ-DIC) and electron microscopy. By combining Warren's theory with the μ-DIC analysis, we monitored the formation of plana...
Steel is the most important material class in terms of volume and environmental impact. While it is a sustainability enabler, for instance through lightweight design, magnetic devices, and efficient turbines, its primary production is not. Iron is reduced from ores by carbon, causing 30% of the global CO2 emissions in manufacturing, qualifying it a...
Iron- and steelmaking is the largest single industrial CO2 emitter, accounting for 6.5% of all CO2 emissions on the planet. This fact challenges the current technologies to achieve carbon-lean steel production and to align with the requirement of a drastic reduction of 80% in all CO2 emissions by around 2050. Thus, alternative reduction technologie...
Iron- and steelmaking cause ∼7% of the global CO2 emissions, due to the use of carbon for the reduction of iron ores. Replacing carbon by hydrogen as the reductant offers a pathway to massively reduce these emissions. However, the production of hydrogen using renewable energy will remain as one of the bottlenecks at least during the next two decade...
To counteract the rising greenhouse gas emissions, mainly CO2, the European steel industry needs to restructure the current process route for steel production. Globally, the blast furnace and the subsequent basic oxygen furnace are used in 73% of crude steel production, with a CO2 footprint of roughly 1.8 t CO2 per ton of produced steel. Hydrogen P...
Soft magnetic materials (SMMs) serve in electrical applications and sustainable energy supply, allowing magnetic flux variation in response to changes in applied magnetic field, at low energy loss 1. The electrification of transport, households and manufacturing leads to an increase in energy consumption due to hysteresis losses 2. Therefore, minim...
Fe- and steelmaking is the largest single industrial CO2 emitter, accounting for 6.5% of all CO2 emissions on the planet. This fact challenges the current technologies to achieve carbon-lean steel production and to align with the requirement of a drastic reduction of 80% in all CO2 emissions by around 2050. Thus, alternative reduction technologies...
To successfully transition from fossil-fuel to sustainable carbon-free energy carriers, a safe, stable and high-density energy storage technology is required. The combustion of iron powders seems very promising in this regard. Yet, little is known about their in-process morphological and microstructural evolution, which are critical features for th...
Soft magnetic materials (SMMs) serve in electrical applications and sustainable energy supply, allowing magnetic flux variation in response to changes in applied magnetic field, at low energy loss1. The electrification of transport, households and manufacturing leads to an increase in energy consumption due to hysteresis losses2. Therefore, minimiz...
Alloys processed by laser powder-bed fusion show distinct microstructures composed of dislocation cells, dispersed nanoparticles, and columnar grains. Upon post-build annealing, such alloys show sluggish recrystallization kinetics compared to the conventionally processed counterpart. To understand this behavior, AISI 316L stainless steel samples we...
The enormous magnitude of 2 billion tons of alloys produced per year demands a change in design philosophy to make materials environmentally, economically, and socially more sustainable. This disqualifies the use of critical elements that are rare or have questionable origin. Amongst the major alloy strengthening mechanisms, a high-dispersion of se...
Mining tailings are becoming more and more abundant and consequently it has been shown to be a material of great concern, especially after the dam failures in Brazil, Bento Rodrigues, 2015 and Brumadinho, 2019. In this work, iron ore tailings (IOT) were used as an aggregate in the production of geopolymers based on metakaolin used as a precursor an...
Steel production causes a third of all industrial CO2 emissions due to the use of carbon-based substances as reductants for iron ores, making it a key driver of global warming. Therefore, research efforts aim at replacing these reductants with sustainably produced hydrogen. Hydrogen-based direct reduction (HyDR) is an attractive processing technolo...
Fossil-free ironmaking is indispensable for reducing massive anthropogenic CO2 emissions in the steel industry. Hydrogen-based direct reduction (HyDR) is among the most attractive solutions for green ironmaking, with high technology readiness. The underlying mechanisms governing this process are characterized by a complex interaction of several che...
The ultimate goal for structural materials is achieving both high strength and ductility. However, increasing one of these properties can usually decrease the other, resulting in the so-called strength-ductility trade-off. According to the Considère criterion, increased strain hardening rates are demanded at higher strains to prevent necking and st...
Iron- and steelmaking cause ~7% of the global CO2 emissions, due to the use of carbon for the reduction of iron ores. Replacing carbon by hydrogen as the reductant offers a pathway to reduce emissions. However, production of hydrogen using renewable energy will remain a bottlenecks, because making the annual crude steel production of 1.8 billion to...
Fossil-free ironmaking is indispensable for reducing massive anthropogenic CO2 emissions in the steel industry. Hydrogen-based direct reduction (HyDR) is among the most attractive solutions for green ironmaking, with high technology readiness. The underlying mechanisms governing this process are characterized by a complex interaction of several che...
Soft magnetic materials (SMMs) are indispensable components in electrified applications and sustainable energy supply, allowing permanent magnetic flux variations in response to high frequency changes of the applied magnetic field, at lowest possible energy loss1. The global trend towards electrification of transport, households and manufacturing l...
The lack of strength and damage tolerance can limit the applications of conventional soft magnetic materials (SMMs), particularly in mechanically loaded functional devices. Therefore, strengthening and toughening of SMMs is critically important. However, conventional strengthening concepts usually significantly deteriorate soft magnetic properties,...
Steel is the most important material class in terms of volume and environmental impact. While it is a sustainability enabler, for instance through lightweight design, magnetic devices, and efficient turbines, its primary production is not. Iron is reduced from ores by carbon, causing 30% of the global CO 2 emissions in manufacturing , qualifying it...
With 1.85 billion tons produced per year, steel is the most important material class in terms of volume and environmental impact. While steel is a sustainability enabler, for instance through lightweight design, magnetic devices, and efficient turbines, its primary production is not. For 3000 years, iron has been reduced from ores using carbon. Tod...
A R T I C L E I N F O Keywords: Lean duplex steel Strain-induced martensite Austenite reversion Magnetic properties Microstructural evolution A B S T R A C T Strain-induced α′-martensite and austenite reversion in a cold rolled UNS S32304 lean duplex steel were tracked by means of magnetic measurements, with emphasis on both M s (saturation magneti...
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...
The presence of δ-ferrite in 316L stainless steel powder reused several times contributes to structural defect formation in selective laser melted parts built using the pin support structure. The virgin 316L stainless steel powder is fully austenitic. After several powder reuse cycles, reused powder has a finer particle size and about 6 vol. % of δ...
In situ synchrotron X-ray diffraction was used to track real-time austenite reversion in AISI 201 austenitic stainless steel deformed to a true strain of 0.34 under tensile testing. The deformed material was continuously annealed from 100 °C up to 800 °C at a heating rate of 0.05 °C s −1. Phase changes and microstrain partitioning were evaluated by...
The formation of submicron structural defects within austenite (γ), ε-and α′-martensite during cold rolling was followed in a 17.6 wt.% Mn steel. Several probes, including XRD, EBSD, and ECCI-imaging, were used to reveal the complex superposition of the strain hardening mechanisms of these phases. The maximum amount of ε-martensite is observed at a...
Austenite (g) reversion in a cold-rolled 17.6 wt.% Mn steel was tracked by means of dilatometry and in-situ magnetic measurements during slow continuous annealing. A splitting of the g-reversion into two stages was observed to be a result of strong elemental partitioning between g and a 0-martensite during the low temperature stage between 390 and...
Strain-induced martensite (SIM) formation was evaluated upon cold-rolling of a 17.6 wt.%Mn-TRIP steel by means of magnetic measurements, X-ray diffraction, and high-resolution electron backscatter diffraction (EBSD). α′-martensite formation was observed to be dependent on the presence of prior ε-martensite. Upon deformation, the coercivity of the f...
A systematic study of the superconducting properties in a series of arc-melted Nb-B samples close to the 1:1 composition was carried out. Powder X-ray diffraction (XRD) shows that all samples are both non-stoichiometric, and comprising of two crystal phases: a majority orthorhombic NbB-type phase, and traces of a minor body-centered cubic Nb-rich p...
Strain partitioning and texture evolution of AISI 201 austenitic stainless steel were investigated upon cold rolling up to a true strain of ε = 0.92. ε-martensite formation is the main work hardening mechanism at low strains (ε = 0.11). With increasing strain, the volume fraction of α’-martensite increases with a sigmoidal-like behavior. Remaining...
The AISI 317L stainless steel is an austenitic grade with at least 3%Mo. Recently, this steel has replaced AISI 316L in many applications in chemical and petrochemical industries, due to its higher pitting corrosion resistance. The microstructure of the hot rolled and annealed material studied in this work consists of austenitic grains and 4.0% of...
Oxide-dispersion strengthened (ODS) Eurofer steel is targeted for structural applications in future fusion nuclear reactors. Samples were cold rolled down to 80% reduction in thickness and annealed at 1350 C up to 8 h. The microstructural characterization was performed using Vickers microhardness testing, electron backscatter diffraction, scanning...
In this work the recrystallization of the ABNT 1015 steel deformed by equal channel angular extrusion (ECAP) was reported. The corresponding von Mises equivalent strain (?vM) of the material, after one unique ECAP pass was 0.67. After deformation the material was annealed (under vacuum) at several temperatures up to 800°C. The microstructural chara...
Projects
Projects (2)
The goal of this project is to understand and improve the sustainability of metallic materials and the products made from it. Metals which have enabled progress over thousands of years, are now facing limits set by sustainability. Accelerated demand for structural alloys in key areas such as energy, construction, safety and transportation creates huge growth rates. Yet, most of these materials are energy, greenhouse gas and pollution intense when extracted and manufactured. This project will develop the scientific foundations and approaches to improve the sustainability of and through metallic materials.
The State Scholarship Fund of Chinese Scholarship Council (CSC) (No. 201506080070)
From 1st October 2015 to 30th September 2016: working in the Max-Planck-Institut für Eisenforschung GmbH (Department of Microstructure Physics and Alloy Design), as a visiting PhD student on a project dealing with microstructure/property relationships in advanced TRIP-assisted steels.
