Uta Kühn

Dr. Uta Kühn

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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27 April 2015 in Metals
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Journal Article
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HSHolger Schwab
Holger Schwab
Prashanth Konda GokuldossPrashanth Konda Gokuldoss
Prashanth Konda Gokuldoss
LLLukas Löber
Lukas Löber
UKUta Kühn
Uta Kühn
JEJürgen Eckert
Jürgen Eckert
Ti-45Nb is one of the potential alloys that can be applied for biomedical applications as implants due to its low Young’s modulus. Ti-45Nb (wt.%) gas atomized powders were used to produce bulk samples by selective laser melting with three different parameter sets (energy inputs). A β-phase microstructure consisting of elliptical grains with an enriched edge of titanium was observed by scanning electron microscopy and X-ray diffraction studies. The mechanical properties of these samples were evaluated using hardness and compression tests, which suggested that the strength of the samples increases with increasing energy input within the range considered.

8 October 2016 in Technologies
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Prashanth Konda GokuldossPrashanth Konda Gokuldoss
Prashanth Konda Gokuldoss
LLLukas Löber
Lukas Löber
HKHans-Jörg Klauss
Hans-Jörg Klauss
UKUta Kühn
Uta Kühn
JEJürgen Eckert
Jürgen Eckert
The compression behavior of different 316L steel cellular dodecahedron structures with different density values were studied. The 316L steel structures produced using the selective laser melting process has four different geometries: single unit cells with and without the addition of base plates beneath and on top, and sandwich structures with multiple unit cells with different unit cell sizes. The relation between the relative compressive strength and the relative density was compared using different Gibson-Ashby models and with other published reports. The different aspects of the deformation and the mechanical properties were evaluated and the deformation at distinct loading levels was recorded. Finite element method (FEM) simulations were carried out with the defined structures and the mechanical testing results were compared. The calculated theory, simulation estimation, and the observed experimental results are in good agreement.

20 December 2011 in Materials
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JSJoan Torrens Serra
Joan Torrens Serra
SVShankar Venkataraman
Shankar Venkataraman
MSMihai Stoica
Mihai Stoica
UKUta Kühn
Uta Kühn
SRStefan Roth
Stefan Roth
JEJürgen Eckert
Jürgen Eckert
The non-isothermal transformation rate curves of metallic glasses are analyzed with the Master Curve method grounded in the Kolmogorov-Johnson-Mehl-Avrami theory. The method is applied to the study of two different metallic glasses determining the activation energy of the transformation and the experimental kinetic function that is analyzed using Avrami kinetics. The analysis of the crystallization of Cu47Ti33Zr11Ni8Si1 metallic glassy powders gives Ea = 3.8 eV, in good agreement with the calculation by other methods, and a transformation initiated by an accelerating nucleation and diffusion-controlled growth. The other studied alloy is a Nanoperm-type Fe77Nb7B15Cu1 metallic glass with a primary crystallization of bcc-Fe. An activation energy of Ea = 5.7 eV is obtained from the Master Curve analysis. It is shown that the use of Avrami kinetics is not able to explain the crystallization mechanisms in this alloy giving an Avrami exponent of n = 1.

15 May 2012 in Metals
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JKJin Young Kim
Jin Young Kim
SSSergio Scudino
Sergio Scudino
UKUta Kühn
Uta Kühn
BKBum Sung Kim
Bum Sung Kim
MLMIN HA LEE
MIN HA LEE
JEJürgen Eckert
Jürgen Eckert
Brass-matrix composites reinforced with 40 and 60 vol.% of Ni59Zr20Ti16Si2Sn3 glassy particles were produced by powder metallurgy. The crystallization behavior and the temperature dependence of the viscosity of the glass reinforcement were studied in detail to select the proper sintering parameters in order to avoid crystallization of the glassy phase during consolidation. The brass-glass powder mixtures were prepared through manual blending as well as by ball milling to analyze the effect of the matrix ligament size on the mechanical properties of the composites. The powder mixtures were then consolidated into highly-dense bulk specimens at temperatures within the supercooled liquid region by hot pressing followed by hot extrusion. The preparation of the powder mixtures has a strong influence on the mechanical behavior of the composites. The strength increases from 500 MPa for pure brass to 740 and 925 MPa for the blended composites with 40 and 60vol.% of glass reinforcement, while the strength increases to 1,240 and 1,640 MPa for the corresponding composites produced by ball milling. Modeling of the mechanical properties indicates that this behavior is related to the reduced matrix ligament size characterizing the milled composites.

1 September 2005 in Journal of Applied Physics
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UKUta Kühn
Uta Kühn
NMN. Mattern
N. Mattern
GAGebert Annett
Gebert Annett
MKMartin Kusy
Martin Kusy
MBM. Boström
M. Boström
LSL. Schultz
L. Schultz
Multicomponent composite materials with the compositions Zr66Nb13Cu8Ni6.8Al6.2 and Ti66Nb13Cu8Ni6.8Al6.2 were produced by copper mold casting, and their microstructure and their room-temperature mechanical properties were investigated. The specific alloys were developed to circumvent the limited ductility of Zr- and Ti-based bulk metallic glasses by the formation of a heterogeneous microstructure consisting of a nanocrystalline matrix and ductile dendritic bcc precipitates. Comparing the microstructure of both alloys, two significant differences were observed. The volume fraction of the dendritic bcc phase is higher for the Ti-based alloy and the formed interdendritic matrix phase(s) have a different structure. The two alloys show an excellent combination of strength and plastic strain. Especially the Ti-based alloy exhibits exceptional mechanical properties, such as high fracture stress of more than 2000MPa and a plastic elongation to failure of almost 30%.

1 February 2014 in Intermetallics
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Journal Article
Open access
LZL.-F. Zhu
L.-F. Zhu
Martin FriákMartin Friák
Martin Friák
AUA. Udyansky
A. Udyansky
DMD. Ma
D. Ma
ASA. Schlieter
A. Schlieter
JNJörg Neugebauer
Jörg Neugebauer