Thomas Kresse

Dr. Thomas Kresse

Materials Research Institute, Hochschule Aalen, Aalen, Baden-Württemberg, Germany
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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 January 2019 in Physical Review B
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BSB. Schönfeld
B. Schönfeld
CSC. R. Sax
C. R. Sax
JZJ. Zemp
J. Zemp
MEM. Engelke
M. Engelke
PBP. Boesecke
P. Boesecke
ARA. V. Ruban
A. V. Ruban
A quenched-in state of thermal equilibrium (at 723 K) in a single crystal of Cr-Fe-Co-Ni close to equal atomic percent was studied. Atom probe tomography revealed a single-phase state with no signs of long-range order. The presence of short-range order (SRO) was established by diffuse x-ray scattering exploiting the variation in scattering contrast close to the absorption edges of the constituents: At the incoming photon energies of 5969, 7092, and 8313 eV, SRO maxima that result from the linear superposition of the six partial SRO scattering patterns, were always found at X position. Electronic structure calculations showed that this type of maximum stems from the strong Cr-Ni and Cr-Co pair correlations, that are furthermore connected with the largest scattering contrast at 5969 eV. The calculated effective pair interaction parameters revealed an order-disorder transition at approximately 500 K to a L12-type (Fe,Co,Ni)3Cr structure. The calculated magnetic exchange interactions were dominantly of the antiferromagnetic type between Cr and any other alloy component and ferromagnetic between Fe, Co, and Ni. They yielded a Curie temperature (TC) of 120 K, close to experimental findings. Despite the low value of TC, the global magnetic state strongly affects chemical and elastic interactions in this system. In particular, it significantly increases the ordering tendency in the ferromagnetic state compared to the paramagnetic one.

1 November 2013 in Scripta Materialia
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Journal Article
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Thomas KresseThomas Kresse
Thomas Kresse
CBC. Borchers
C. Borchers
RKR. Kirchheim
R. Kirchheim

1 September 2013 in Scripta Materialia
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Journal Article
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Thomas KresseThomas Kresse
Thomas Kresse
YLY.J. Li
Y.J. Li
TBT. Boll
T. Boll
CBC. Borchers
C. Borchers
PCP. Choi
P. Choi
RKR. Kirchheim
R. Kirchheim

3 November 2022 in Metals
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Thomas KresseThomas Kresse
Thomas Kresse
JSJulian Schurr
Julian Schurr
MLMaximilian Lanz
Maximilian Lanz
TKTorsten Kunert
Torsten Kunert
Martin SchmidMartin Schmid
Martin Schmid
DGDagmar Goll
Dagmar Goll
Laser powder bed fusion (L-PBF) was used to produce stator half-shells of a transverse flux machine from pure iron (99.9% Fe). In order to reduce iron losses in the bulk components, radially extending slits with a nominal width of 150 and 300 µm, respectively, were integrated during manufacturing. The components were subjected to a suitable heat treatment. In addition to a microscopic examination of the slit quality, the iron losses were also measured using both a commercial and a self-developed measurement setup. The investigations showed the iron losses can be reduced by up to 49% due to the integrated slits and the heat treatment.

2 January 2024 in Materials
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Thomas KresseThomas Kresse
Thomas Kresse
GMGerhard Martinek
Gerhard Martinek
GSGerhard Schneider
Gerhard Schneider
DGDagmar Goll
Dagmar Goll
The time-dependent decrease of the magnetic polarization of magnet materials in the presence of an opposing field is well known as the magnetic viscosity or magnetic aftereffect. In previous studies, magnetic viscosity was usually measured in fields when in the vicinity of coercivity HcJ, and this was conducted in order to understand the coercivity mechanism in magnetic materials. In this study, the magnetic viscosity of commercial FeNdB magnets is determined at opposing fields weaker than HcJ and at different temperatures in the range from 303 to 433 K (i.e., from 30 to 160 °C) by means of a vibrating sample magnetometer (VSM). As a result, the parameter Sv, which describes the magnetic viscosity in the material, was found to increase with increases in the opposing field. Furthermore, both the parameter Sv and its dependence on the temperature were found to correlate with the coercivity HcJ of the material. Also, a difference with regard to the parameter Sv for the materials measured in this study with similar magnetic properties, but which had undergone different types of processing, could not be found. Knowledge of the field- and temperature-dependent behavior of the magnetic viscosity of FeNdB magnets allows for better estimations over the lifetime of a component under operating conditions with respect to the magnetic losses in FeNdB magnets that are used in electric components.

23 June 2020 in Physica Status Solidi (a)
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DGDagmar Goll
Dagmar Goll
Thomas KresseThomas Kresse
Thomas Kresse
DSDavid Schuller
David Schuller
AKArif Kazi
Arif Kazi
GSGerhard Schneider
Gerhard Schneider
Ferritic steel has the potential to act as a medium for magnetic storage of certain information, for example, to document the history of parts. The material is expected to play a role in supporting intelligent production processes and logistics routines for industrial internet applications. For writing and reading stable magnetic codes into steel, it is necessary to investigate and understand the corresponding requirements of the material. Both sensitively depend on characteristic microstructural details and related magnetic properties. They are either already present in the material or may be locally achieved in the code area by supplementary hardening methods.