Institute for Applied Materials – Materials Science and Engineering

Research mission

The Physical Metallurgy group focuses on the development of metallic and intermetallic materials for harsh environments. The investigation and optimization of materials for engines operating at high temperatures is of central interest. Therefore, outstanding high temperature stability (mechanical and microstructural) in conjunction with reasonable toughness at room temperature as well as suitable oxidation resistance are the main objectives of the research. In addition, fundamentals of contact materials for vacuum switches and the deformation behavior of high-entropy alloys under various conditions are studied in detail.

Synthesis of new materials

The synthesis of new materials is based on the following methods that are available in house:

  • melting technologies: arc melter and zone melting
  • powder metallurgy: attritor grinding mill, planetary ball mill, hot uniaxial pressing
  • heat treatments in various atmospheres

Methods of characterization

The characterization of mechanical and thermo-physical properties as well as microstructure of metallic and intermetallic materials is performed by means of:

  • standard metallographic procedures
  • mechanical testing under various loading conditions (tension, compression, cyclic, creep conditions, various atmospheres)
  • thermal analysis: thermogravimetry (TGA) and differential scanning calorimetry (DSC)
  • focused ion beam (FIB) for microscopic preparation
  • analytical scanning electron microscopy: energy-dispersive X-ray spectroscopy (EDX) and electron backscatter diffraction (EBSD)
  • X-ray diffraction (XRD)
  • 3D atom probe tomography (APT)
Microstructure analysis
Microstructure analysis
Microstructure analysis
Scanning electron microscopy
Directional solidification
Materials characterization
Materials synthesis

materials KIT, M. Breig
Materials Development
hea laube
High Entropy Alloys
phm phm
Additive Manufacturing
directional_solidification KIT, M. Breig
Directional Solidification
atome probe tomography KIT, M. Breig
Atom Probe Tomography

Recent Publications

artschellert
Current Status of Research on the Oxidation Behavior of Refractory High Entropy Alloys

In this article prepared in collaboration with IAM-AWP and University of Siegen, we review the current status of research on the oxidation behavior of refractory high entropy alloys (RHEA). RHEA are considered as novel promising high-temperature materials for structural applications at ultrahigh temperatures primarily due to their attractive mechanical properties. By contrast, the oxidation behavior of RHEA has raised concern owing to pest oxidation, significant weight changes, scale spallation, or even complete oxidation at elevated temperatures. Herein, the currently available literature on high-temperature oxidation behavior of RHEA is reviewed with respect to alloy composition, mass changes, corrosion products, and scale constitution. While many RHEA indeed suffer from poor oxidation resistance similar to that of pure refractory metals, some RHEA exhibit very good protectiveness, which is attributed to the formation of either well-known protective scales such as α-Al2O3 or rarely encountered complex oxides such as CrTaO4. Thermodynamic and kinetic aspects of oxide formation and growth are discussed to understand the oxidation mechanisms typical of RHEA. Further research directions with respect to additional in-depth studies elucidating the oxidation mechanisms as well as the further consequent improvement of the oxidation resistance of RHEA are developed from the current intermediate stageof research in the field.

to Advanced Engineering Materials
senkovchen
Influence of Temperature and Plastic Strain on Deformation Mechanisms and Kink Band Formation in Homogenized HfNbTaTiZr

In this joined work of CryoMaK at ITEP and PhM, we address temperature and strain depending deformation mechanisms in the equiatomic HfNbTaTiZr. This so-called Senkov alloy serves as model system for investigating deformation of concentrated, body centered cubic solid solutions. For this purpose, compression tests in a temperature range from 77 up to 1073 K were performed and terminated at varying plastic strains for comparison of plastic deformation behavior. The microstructure and chemical homogeneity of a homogenized HfNbTaTiZr ingot were evaluated on different length scales. The compression tests reveal that test temperature significantly influences yield strength as well as work hardening behavior. Electron backscatter diffraction aids on shedding light on the acting deformation mechanisms at various temperatures and strains. It is revealed that kink band formation contributes to plastic deformation only in a certain temperature range. Additionally, the kink band misorientation angle distribution significantly differs at varying plastic strains.

to Crystals
creepobert
The Creep and Oxidation Behaviour of Pesting-Resistant (Mo,Ti)5Si3-Containing Eutectic-Eutectoid Mo-Si-Ti Alloys

This study presents novel Mo-Si-Ti alloys with the so far best achieved combination of oxidation and creep resistance among Mo-Si-based alloy systems. The dilemma of a high Ti vs. high Mo content and, thus, oxidation vs. creep resistance is resolved by profiting from a high Ti-containing Mo silicide, namely (Mo,Ti)5Si3. During casting, (Mo,Ti)5Si3 particles solidify primarily and are embedded in a fine-scaled eutectic-eutectoid matrix when the solidification is completed. These alloys exhibit a good oxidation resistance in the temperature range of 800 to 1200 °C. Additionally, solidus temperatures higher than 1900 °C provide the best creep resistance among the conventional eutectic-eutectoid Mo-Si-Ti alloys. Besides the as-cast microstructures, the oxide scales formed during oxidation and the microstructures after creep testing are analysed. A comparison with a commercially applied Ni-based superalloy reveals the competitiveness of our novel alloys.

to Metals
artobert
Microstructural and Chemical Constitution of the Oxide Scale formed on a Pesting-Resistant Mo-Si-Ti Alloy

In this publication, we analyse the root causes for the excellent oxidation resistance (pesting stability) of a eutectic Mo-Si-Ti alloy. Therefore, we investigate the microstructural and chemical constitution of the oxide scales formed in the temperature range from 800 to 1200 °C by scanning electron microscopy, grazing incident X-ray diffraction and atom probe tomography. The oxide scales are found to be mainly composed of amorphous SiO2 and rutile TiO2. Analysis of the oxide scale growth kinetics reveals linear kinetics at 800 °C up to 100 h. Thus, the oxidation mechanism is reaction-rate controlled. For longer oxidation times, the kinetics change to cubic. Interestingly, a very low oxidation rate is determined, which leads to the slow oxide scale growth. In contrast, parabolic oxidation kinetics are prevalent at 1200 °C revealing diffusion-rate control.

to Corrosion Science
artkauffmann
Dislocation-based Serrated Plastic Flow of High Entropy Alloys at Cryogenic Temperatures

In the current work, we present a phenomenological model for the occurrence of serrations at near 0 K. Our former work [Tirunilai et al., Journal of Materials Research 33 (2018) 3287-3300] established a connection to a dislocation-based mechanism. Our current research shows this mechanism relies on dislocations piled up at Lomer-Cottrell locks and their relative propensity to cross-slip out of these pile-ups, partially similar to a former hypothesis [A. Seeger in Dislocations and Mechanical Properties of Crystals (1958), John Wiley & Sons, New York, 243-330]. Links were drawn between temperature and cross-slip propensity and a corresponding model was generated. The experiments in the current work were carried out on the HEA CoCrFeMnNi, which showed a higher temperature of cryogenic serrations than any other alloy reported in literature. This wide range of possible investigation invalidated multiple hypotheses including correlation of the serrations to local thermomechanical instability, deformation twinning, martensite transformation, exponential temperature dependence of dislocation/dislocation lock density and direct stacking fault energy correlation.

to Acta Materialia
flexidsgombola
A zone melting device for the in situ observation of directional solidification using high-energy synchrotron x-rays

Together with our colleagues from Otto von Guericke University and the Helmholtz-Zentrum Geesthacht, we introduced the new state-of-the-art FlexiDS device for time-resolved in-situ investigation of directional solidification processes using high-energy synchrotron radiation. The system is a valuable addition to the infrastructure of PETRA III at DESY, being specifically designed for the use at P07 HEMS beamline. The apparatus is capable of investigating liquid-solid regions, transformations, and decompositions in various structural intermetallic materials. Moreover, we could show the wide operation range by means of sample geometry, densities and alloy compositions as well as process parameter like withdrawal rate. Even during experiments which exceed a liquidus temperature of 2000 °C, the device operated stable and satisfactory diffraction pattern were obtained. Trial tests of time-resolved processes of TiAl and FeAl alloys were presented in this work. Further detailed experimental results are published elsewhere.

to Review of Scientific Instruments
articlegombola
Microstructural Investigations of Novel High Temperature Alloys Based on NiAl-(Cr,Mo)

Previous work on calculation and validation by refinement of the thermodynamic description reported a eutectic trough in the quaternary Ni-Al-Cr-Mo system (Peng et al. in Journal of Phase Equilibria and Diffusion 37 (2016) 592-600). We present an experimentally study on NiAl-(Cr,Mo) eutectic alloys from room to liquidus temperature. The evolving morphologies were categorized into four regions with respect to the Mo concentration (I - IV). Based on in-situ X-ray diffraction experiments during solidification, it has been proven that the different compositions form due to segregation especially in region III. The influence of the segregation on the lattice parameter and thus on the lattice mismatch as well as on the orientation relationship is discussed in this study by comparing the region III alloy NiAl-9.6Cr-10.3Mo to NiAl-34Cr (I) and NiAl-10Mo (IV).

to Metals
articlelaube
Controlling crystallographic ordering in Mo-Cr-Ti-Al high entropy alloys to enhance ductility

In this study with our colleagues from Siegen University, we utilized our recently proposed methods to reveal ordering phenomena in HEA (Chen et al. in Acta Materialia 176 (2019) 123-133) to enhance ductility of alloys from within the Mo-Cr-Ti-Al system. The composition-depending transistion to disordered alloys is indeed associated to a drop in yield strength. Nevertheless, ductility at room temperature is significantly enhanced when no ordering is present.

to Journal of Alloys and Compounds
articleast
Comparison of cryogenic deformation of the concentrated solid solutions CoCrFeMnNi, CoCrNi and CoNi

This contribution on cryogenic deformation of face-centered cubic high entropy alloys was performed in collaboration with colleagues from ITEP at KIT, Ruhr-University Bochum and IFW Dresden. CoCrFeMnNi and CoCrNi are complex concentrated alloys which show significant strengthening and ductility at cryogenic temperatures. The chief contribution for the strength is associated with solute dislocation interaction. A comparison of the yield strength variation with temperature down to 8 K shows that CoCrFeMnNi and CoCrNi have a similarly high solid solution strengthening effect contributing temperature dependent strengthening despite a higher absolute yield strength of CoCrNi at all temperatures. CoCrNi has a reportedly lower SFE leading to formation of ε-martensite at cryogenic temperatures, while CoCrFeMnNi does not. Comparison of work-hardening rates at cryogenic temperatures indicates that both alloys strengthen at similar rates despite the TRIP effect being active in CoCrNi and not in CoCrFeMnNi. The ε-martensite in CoCrNi exists as twin-martensite nano-laminates and strengthens the alloy through dislocation-interface interaction.

to Materials Science and Engineering A

Doctoral theses


Creep behavior of lamellar FeAl/FeAl2 alloys. PhD dissertation.
Schmitt, A.
2020, April 6. Verlag Dr. Hut
Gefüge und Eigenschaften von äquiatomaren Legierungen aus dem System Ta-Nb-Mo-Cr-Ti-Al. PhD dissertation.
Chen, H.
2020, April 7. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000118090
Gefügeentwicklung von CuCr-Kontaktwerkstoffen nach Einwirkung eines Lichtbogens im Vakuum. PhD dissertation.
Hauf, U.
2018. Karlsruher Institut für Technologie (KIT)
Der Einfluss von Fe auf Ti-haltige Mo-Si-B Legierungen: Phasenbildung, Gefüge und Kriechverhalten. PhD dissertation.
Schliephake, D.
2017. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000073537
Mechanische und oxidative Eigenschaften eutektischer Nb-Si-Cr - Legierungen. PhD dissertation.
Gang, F.
2016. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000063623
Mechanical properties and oxidation behavior of micro-alloyed iron aluminides. PhD dissertation.
Janda, D.
2015. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000046125

Publications


2021
Vertical continuous compound casting of copper aluminum bilayer rods.
Greß, T.; Glück Nardi, V.; Schmid, S.; Hoyer, J.; Rizaiev, Y.; Boll, T.; Seils, S.; Tonn, B.; Volk, W.
2021. Journal of materials processing technology, 288, Art.-Nr.: 116854. doi:10.1016/j.jmatprotec.2020.116854
Microstructural and Chemical Constitution of the Oxide Scale formed on a Pesting-Resistant Mo-Si-Ti Alloy.
Obert, S.; Kauffmann, A.; Seils, S.; Boll, T.; Kauffmann-Weiss, S.; Chen, H.; Anton, R.; Heilmaier, M.
2021. Corrosion science, 178, Art.-Nr. 109081. doi:10.1016/j.corsci.2020.109081
High temperature strength retention of Cu/Nb nanolaminates through dynamic strain ageing.
Liu, Z.; Snel, J.; Boll, T.; Wang, J. Y.; Monclús, M. A.; Molina-Aldareguía, J. M.; LLorca, J.
2021. Materials science and engineering / A, 799, Article no: 140117. doi:10.1016/j.msea.2020.140117
Temperature Resistance of Mo3Si: Phase Stability, Microhardness, and Creep Properties.
Kauss, O.; Obert, S.; Bogomol, I.; Wablat, T.; Siemensmeyer, N.; Naumenko, K.; Krüger, M.
2021. Metals, 11 (4), Article no: 564. doi:10.3390/met11040564
Microcantilever Fracture Tests on Eutectic NiAl‐Cr(Mo) in‐situ Composites.
Gabel, S.; Giese, S.; Merle, B.; Sprenger, I.; Heilmaier, M.; Neumeier, S.; Bitzek, E.; Göken, M.
2021. Advanced engineering materials, Art.-Nr. 202001464. doi:10.1002/adem.202001464
Current Status of Research on the Oxidation Behavior of Refractory High Entropy Alloys.
Gorr, B.; Schellert, S.; Müller, F.; Christ, H.-J.; Kauffmann, A.; Heilmaier, M.
2021. Advanced engineering materials, Article no: 2001047. doi:10.1002/adem.202001047
Influence of Temperature and Plastic Strain on Deformation Mechanisms and Kink Band Formation in Homogenized HfNbTaTiZr.
Chen, H.; Hanemann, T.; Seils, S.; Schliephake, D.; Tirunilai, A. S.; Heilmaier, M.; Weiss, K.-P.; Kauffmann, A.
2021. Crystals, 11 (2), 81. doi:10.3390/cryst11020081
The Creep and Oxidation Behaviour of Pesting-Resistant -Containing Eutectic-Eutectoid Mo-Si-Ti Alloys.
Obert, S.; Kauffmann, A.; Pretzler, R.; Schliephake, D.; Hinrichs, F.; Heilmaier, M.
2021. Metals, 11 (1), Art.-Nr.: 169. doi:10.3390/met11010169
Superior low-cycle fatigue properties of CoCrNi compared to CoCrFeMnNi.
Lu, K.; Chauhan, A.; Walter, M.; Tirunilai, A. S.; Schneider, M.; Laplanche, G.; Freudenberger, J.; Kauffmann, A.; Heilmaier, M.; Aktaa, J.
2021. Scripta materialia, 194, Art.-Nr.: 113667. doi:10.1016/j.scriptamat.2020.113667
2020
Oxidation behaviour of NiAl intermetallics with embedded Cr and Mo.
Geramifard, G.; Gombola, C.; Franke, P.; Seifert, H. J.
2020. Corrosion science, 177, Art. Nr.: 108956. doi:10.1016/j.corsci.2020.108956
Origins of strength and plasticity in the precious metal based High-Entropy Alloy AuCuNiPdPt.
Thiel, F.; Geissler, D.; Nielsch, K.; Kauffmann, A.; Seils, S.; Heilmaier, M.; Utt, D.; Albe, K.; Motylenko, M.; Rafaja, D.; Freudenberger, J.
2020. Acta materialia, 185, 400–411. doi:10.1016/j.actamat.2019.12.020
Microstructure, mechanical behaviour and strengthening mechanisms in Hastelloy X manufactured by electron beam and laser beam powder bed fusion.
Karapuzha, A. S.; Fraser, D.; Schliephake, D.; Dietrich, S.; Zhu, Y.; Wu, X.; Huang, A.
2020. Journal of alloys and compounds, Art.-Nr.: 158034. doi:10.1016/j.jallcom.2020.158034
Intensive processing optimization for achieving strong and ductile Al-Mn-Mg-Sc-Zr alloy produced by selective laser melting.
Bayoumy, D.; Schliephake, D.; Dietrich, S.; Wu, X. H.; Zhu, Y. M.; Huang, A. J.
2020. Materials and design, 198, Art.Nr. 109317. doi:10.1016/j.matdes.2020.109317
Dislocation-based Serrated Plastic Flow of High Entropy Alloys at Cryogenic Temperatures.
Tirunilai, A. S.; Hanemann, T.; Weiss, K.-P.; Freudenberger, J.; Heilmaier, M.; Kauffmann, A.
2020. Acta materialia, 200, 980–991. doi:10.1016/j.actamat.2020.09.052
A zone melting device for the in situ observation of directional solidification using high-energy synchrotron x rays editors-pick.
Gombola, C.; Hasemann, G.; Kauffmann, A.; Sprenger, I.; Laube, S.; Schmitt, A.; Gang, F.; Bolbut, V.; Oehring, M.; Blankenburg, M.; Schell, N.; Staron, P.; Pyczak, F.; Krüger, M.; Heilmaier, M.
2020. Review of scientific instruments, 91 (9), Art.Nr. 093901. doi:10.1063/5.0019020
Effect of Y Additions on the Oxidation Behaviour of Novel Refractory High-Entropy Alloy NbMoCrTiAl at 1000 °C in Air.
Müller, F.; Gorr, B.; Christ, H.-J.; Chen, H.; Kauffmann, A.; Heilmaier, M.
2020. Oxidation of metals, 94 (1-2), 147–163. doi:10.1007/s11085-020-09983-6
High-temperature low cycle fatigue behavior of an equiatomic CoCrFeMnNi high-entropy alloy.
Lu, K.; Chauhan, A.; Litvinov, D.; Walter, M.; Tirunilai, A. S.; Freudenberger, J.; Kauffmann, A.; Heilmaier, M.; Aktaa, J.
2020. Materials science and engineering / A, 791, Article: 139781. doi:10.1016/j.msea.2020.139781
Formation of complex intermetallic phases in novel refractory high-entropy alloys NbMoCrTiAl and TaMoCrTiAl: Thermodynamic assessment and experimental validation.
Müller, F.; Gorr, B.; Christ, H.-J.; Chen, H.; Kauffmann, A.; Laube, S.; Heilmaier, M.
2020. Journal of alloys and compounds, Article no: 155726. doi:10.1016/j.jallcom.2020.155726
Creep of an oxidation resistant coated Mo-9Si-8B alloy.
Gombola, C.; Schliephake, D.; Heilmaier, M.; Perepezko, J. H.
2020. Intermetallics, 120, 106743. doi:10.1016/j.intermet.2020.106743
Breakdown of Varvenne scaling in (AuNiPdPt) Cu high-entropy alloys.
Thiel, F.; Utt, D.; Kauffmann, A.; Nielsch, K.; Albe, K.; Heilmaier, M.; Freudenberger, J.
2020. Scripta materialia, 181, 15–18. doi:10.1016/j.scriptamat.2020.02.007
Temperature dependent strengthening contributions in austenitic and ferritic ODS steels.
Seils, S.; Kauffmann, A.; Hinrichs, F.; Schliephake, D.; Boll, T.; Heilmaier, M.
2020. Materials science and engineering / A, 786, Article: 139452. doi:10.1016/j.msea.2020.139452
Solid solution strengthening and deformation behavior of single-phase Cu-base alloys under tribological load.
Laube, S.; Kauffmann, A.; Ruebeling, F.; Freudenberger, J.; Heilmaier, M.; Greiner, C.
2020. Acta materialia, 185, 300–308. doi:10.1016/j.actamat.2019.12.005
Characterisation of the oxidation and creep behaviour of novel Mo-Si-Ti alloys.
Obert, S.; Kauffmann, A.; Heilmaier, M.
2020. Acta materialia, 184, 132–142. doi:10.1016/j.actamat.2019.11.045
A new strategy to intrinsically protect refractory metal based alloys at ultra high temperatures.
Gorr, B.; Müller, F.; Schellert, S.; Christ, H.-J.; Chen, H.; Kauffmann, A.; Heilmaier, M.
2020. Corrosion science, 166, Art. Nr.: 108475. doi:10.1016/j.corsci.2020.108475
Controlling crystallographic ordering in Mo–Cr–Ti–Al high entropy alloys to enhance ductility.
Laube, S.; Chen, H.; Kauffmann, A.; Schellert, S.; Müller, F.; Gorr, B.; Müller, J.; Butz, B.; Christ, H.-J.; Heilmaier, M.
2020. Journal of alloys and compounds, 823, Article No.153805. doi:10.1016/j.jallcom.2020.153805
Microstructural properties and peritectic reactions in a binary Co–Sn alloy by means of scanning electron microscopy and atom probe tomography.
Khushaim, M.; Alahmari, F.; Kattan, N.; Chassaing, D.; Boll, T.
2020. Materials Research Express, 7 (8), Art.Nr. 086508. doi:10.1088/2053-1591/abad04
Characterization of the Microstructure After Composite Peening of Aluminum.
Seitz, M.; Dürrschnabel, M.; Kauffmann, A.; Kurpiers, C.; Greiner, C.; Weidenmann, K. A.
2020. Advanced engineering materials, Art.Nr. 2000575. doi:10.1002/adem.202000575
Microstructural Investigations of Novel High Temperature Alloys Based on NiAl-(Cr,Mo).
Gombola, C.; Kauffmann, A.; Geramifard, G.; Blankenburg, M.; Heilmaier, M.
2020. Metals, 10 (7), Art. Nr.: 961. doi:10.3390/met10070961
On the chemical and microstructural requirements for the pesting-resistance of Mo-Si-Ti alloys.
Obert, S.; Kauffmann, A.; Seils, S.; Schellert, S.; Weber, M.; Gorr, B.; Christ, H.-J.; Heilmaier, M.
2020. Journal of materials research and technology, 9 (4), 8556–8567. doi:10.1016/j.jmrt.2020.06.002
Microstructural changes in CoCrFeMnNi under mild tribological load.
Dollmann, A.; Kauffmann, A.; Heilmaier, M.; Haug, C.; Greiner, C.
2020. Journal of materials science, 55 (26), 12353–12372. doi:10.1007/s10853-020-04806-0
Effect of Water Vapor on the Oxidation Behavior of the Eutectic High‐Temperature Alloy Mo‐20Si‐52.8Ti.
Weber, M.; Gorr, B.; Christ, H.-J.; Obert, S.; Kauffmann, A.; Heilmaier, M.
2020. Advanced engineering materials, 22 (7), Art. Nr.: 2000219. doi:10.1002/adem.202000219
Magnetron sputtered silicon coatings as oxidation protection for Mo‐based alloys.
Anton, R.; Laska, N.; Schulz, U.; Obert, S.; Heilmaier, M.
2020. Advanced engineering materials, 22 (7), Article Nr.: 2000218. doi:10.1002/adem.202000218
Comparison of cryogenic deformation of the concentrated solid solutions CoCrFeMnNi, CoCrNi and CoNi.
Tirunilai, A. S.; Hanemann, T.; Reinhart, C.; Tschan, V.; Weiss, K.-P.; Laplanche, G.; Freudenberger, J.; Heilmaier, M.; Kauffmann, A.
2020. Materials science and engineering / A, 783, Art. Nr.: 139290. doi:10.1016/j.msea.2020.139290
2019
On the oxidation mechanism of refractory high entropy alloys.
Müller, F.; Gorr, B.; Christ, H.-J.; Müller, J.; Butz, B.; Chen, H.; Kauffmann, A.; Heilmaier, M.
2019. Corrosion science, 159, Article: 108161. doi:10.1016/j.corsci.2019.108161
Crystallographic ordering in a series of Al-containing refractory high entropy alloys Ta-Nb-Mo-Cr-Ti-Al.
Chen, H.; Kauffmann, A.; Seils, S.; Boll, T.; Liebscher, C. H.; Harding, I.; Kumar, K. S.; Szabo, D. V.; Schlabach, S.; Kauffmann-Weiss, S.; Müller, F.; Gorr, B.; Christ, H.-J.; Heilmaier, M.
2019. Acta materialia. doi:10.1016/j.actamat.2019.07.001
Microstructural evolution during creep of lamellar eutectoid and off-eutectoid FeAl/FeAl2 alloys.
Schmitt, A.; Kumar, K. S.; Kauffmann, A.; Heilmaier, M.
2019. Intermetallics, 107, 116–125. doi:10.1016/j.intermet.2019.01.015
Constitution, oxidation and creep of eutectic and eutectoid Mo-Si-Ti alloys.
Schliephake, D.; Kauffmann, A.; Cong, X.; Gombola, C.; Azim, M.; Gorr, B.; Christ, H.-J.; Heilmaier, M.
2019. Intermetallics, 104, 133–142. doi:10.1016/j.intermet.2018.10.028
Precipitation behaviour and mechanical properties of a novel AlMoTaTi complex concentrated alloy.
Schliephake, D.; Medvedev, A. E.; Imran, M. K.; Obert, S.; Fabijanic, D.; Heilmaier, M.; Molotnikov, A.; Wu, X.
2019. Scripta materialia, 173, 16–20. doi:10.1016/j.scriptamat.2019.07.033
2018
Contribution of Lattice Distortion to Solid Solution Strengthening in a Series of Refractory High Entropy Alloys.
Chen, H.; Kauffmann, A.; Laube, S.; Choi, I.-C.; Schwaiger, R.; Huang, Y.; Lichtenberg, K.; Müller, F.; Gorr, B.; Christ, H.-J.; Heilmaier, M.
2018. Metallurgical and materials transactions / A, 49 (3), 772–781. doi:10.1007/s11661-017-4386-1
Phase Evolution in and Creep Properties of Nb-Rich Nb-Si-Cr Eutectics.
Gang, F.; Kauffmann, A.; Heilmaier, M.
2018. Metallurgical and materials transactions / A, 49 (3), 763–771. doi:10.1007/s11661-017-4367-4
Development of Oxidation Resistant Refractory High Entropy Alloys for High Temperature Applications: Recent Results and Development Strategy.
Gorr, B.; Mueller, F.; Christ, H.-J.; Chen, H.; Kauffmann, A.; Schweiger, R.; Szabo, D. V.; Heilmaier, M.
2018. 147th Annual Meeting & Exhibition Supplemental Proceedings (TMS), Phoenix, Arizona, March 11-15, 2018, 647–659, Springer. doi:10.1007/978-3-319-72526-0_61
Peculiarities of deformation of CoCrFeMnNi at cryogenic temperatures.
Tirunilai, A. S.; Sas, J.; Weiss, K.-P.; Chen, H.; Szabo, D. V.; Schlabach, S.; Haas, S.; Geissler, D.; Freudenberger, J.; Heilmaier, M.; Kauffmann, A.
2018. Journal of materials research, 1–14. doi:10.1557/jmr.2018.252
Influence of work-hardening on fatigue crack growth, effective threshold and crack opening behavior in the nickel-based superalloy Inconel 718.
Klumpp, A.; Maier, S.; Chen, H.; Fotouhi, M.; Schneider, R.; Dietrich, S.; Lang, K.-H.; Schulze, V.
2018. International journal of fatigue, 116, 257–267. doi:10.1016/j.ijfatigue.2018.06.033
2017
Microstructure Formation and Resistivity Change in CuCr during Rapid Solidification.
Hauf, U.; Kauffmann, A.; Kauffmann-Weiss, S.; Feilbach, A.; Boening, M.; Mueller, F. E. H.; Hinrichsen, V.; Heilmaier, M.
2017. Metals, 7 (11), Art.Nr. 478. doi:10.3390/met7110478
Combinatorial exploration of the high entropy alloy system Co-Cr-Fe-Mn-Ni.
Kauffmann, A.; Stüber, M.; Leiste, H.; Ulrich, S.; Schlabach, S.; Szabo, D. V.; Seils, S.; Gorr, B.; Chen, H.; Seifert, H.-J.; Heilmaier, M.
2017. Surface and coatings technology, 325, 174–180. doi:10.1016/j.surfcoat.2017.06.041
Effect of microalloying with silicon on high temperature oxidation resistance of novel refractory high-entropy alloy Ta-Mo-Cr-Ti-Al.
Müller, F.; Gorr, B.; Christ, H.-J.; Chen, H.; Kauffmann, A.; Heilmaier, M.
2017. Materials at high temperatures, 35 (1-3), 168–176. doi:10.1080/09603409.2017.1389115
Effect of Ti content and nitrogen on the high-temperature oxidation behavior of (Mo,Ti)5Si3.
Azim, M. A.; Gorr, B.; Christ, H.-J.; Lenchuk, O.; Albe, K.; Schliephake, D.; Heilmaier, M.
2017. Intermetallics, 90, 103–112. doi:10.1016/j.intermet.2017.05.023
Creep of binary Fe-Al alloys with ultrafine lamellar microstructures.
Schmitt, A.; Kumar, K. S.; Kauffmann, A.; Li, X.; Stein, F.; Heilmaier, M.
2017. Intermetallics, 90, 180–187. doi:10.1016/j.intermet.2017.07.016
Face Centred Cubic Multi-Component Equiatomic Solid Solutions in the Au-Cu-Ni-Pd-Pt System.
Freudenberger, J.; Rafaja, D.; Geissler, D.; Giebeler, L.; Ullrich, C.; Kauffmann, A.; Heilmaier, M.; Nielsch, K.
2017. Metals, 7 (4), Art. Nr.: 135. doi:10.3390/met7040135
Enhanced Oxidation Resistance of Mo-Si-B-Ti Alloys by Pack Cementation.
Schliephake, D.; Gombola, C.; Kauffmann, A.; Heilmaier, M.; Perepezko, J. H.
2017. Oxidation of metals, 88 (SI, 3-4), 267–277. doi:10.1007/s11085-017-9730-8
High-Temperature Oxidation Behavior of Refractory High-Entropy Alloys : Effect of Alloy Composition.
Gorr, B.; Müller, F.; Azim, M.; Christ, H.-J.; Müller, T.; Chen, H.; Kauffmann, A.; Heilmaier, M.
2017. Oxidation of metals, 88 (3-4), 339–349. doi:10.1007/s11085-016-9696-y
2016
Al-Ti Particulate Composite : Processing and Studies on Particle Twinning, Microstructure, and Thermal Stability.
Yadav, D.; Bauri, R.; Kauffmann, A.; Freudenberger, J.
2016. Metallurgical and materials transactions / A, 47 (8), Art.Nr. 4226–4238. doi:10.1007/s11661-016-3597-1
Microstructure and mechanical properties at elevated temperatures of a new Al-containing refractory high-entropy alloy Nb-Mo-Cr-Ti-Al.
Chen, H.; Kauffmann, A.; Gorr, B.; Schliephake, D.; Seemüller, C.; Wagner, J. N.; Christ, H.-J.; Heilmaier, M.
2016. Journal of alloys and compounds, 661, 206–215. doi:10.1016/j.jallcom.2015.11.050
Thermal stability of electrical and mechanical properties of cryo-drawn Cu and CuZr wires.
Kauffmann, A.; Geissler, D.; Freudenberger, J.
2016. Materials Science and Engineering: A, 651, 567–573. doi:10.1016/j.msea.2015.10.119
Investigation of the heat affected volume of CuCr contact material for vacuum interrupters.
Hauf, U.; Feilbach, A.; Böning, M.; Heilmaier, M.; Hinrichsen, V.; Müller, F. E. H.
2016. 27th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV), Suzhou, China, 18-23 Sept. 2016, 1–4, Institute of Electrical and Electronics Engineers (IEEE). doi:10.1109/DEIV.2016.7748695
Microstructure Variations and Creep Properties of Novel High Temperature V-Si-B Materials.
Krüger, M.; Bolbut, V.; Gang, F.; Hasemann, G.
2016. JOM, 68 (11), 2811–2816. doi:10.1007/s11837-016-2096-6
High temperature oxidation behavior of an equimolar refractory metal-based alloy 20Nb-20Mo-20Cr-20Ti-20Al with and without Si addition.
Gorr, B.; Mueller, F.; Christ, H.-J.; Mueller, T.; Chen, H.; Kauffmann, A.; Heilmaier, M.
2016. Journal of alloys and compounds, 688, Part B, 468–477. doi:10.1016/j.jallcom.2016.07.219
Orientation relationship of eutectoid FeAl and FeAl₂.
Scherf, A.; Kauffmann, A.; Kauffmann-Weiss, S.; Scherer, T.; Li, X.; Stein, F.; Heilmaier, M.
2016. Journal of applied crystallography, 49 (2), 442–449. doi:10.1107/S1600576716000911
In Situ Study of the Influence of Nickel on the Phase Transformation Kinetics in Austempered Ductile Iron.
Saal, P.; Meier, L.; Li, X.; Hofmann, M.; Hoelzel, M.; Wagner, J. N.; Volk, W.
2016. Metallurgical and materials transactions / A, 47 (2), 661–671. doi:10.1007/s11661-015-3261-1
In-situ neutron diffraction during biaxial deformation.
Van Petegem, S.; Wagner, J.; Panzner, T.; Upadhyay, M. V.; Trang, T. T. T.; Van Swygenhoven, H.
2016. Acta Materialia, 105, 404–416. doi:10.1016/j.actamat.2015.12.015
Microstructure Evolution in a New Refractory High-Entropy Alloy W-Mo-Cr-Ti-Al.
Gorr, B.; Azim, M.; Christ, H.-J.; Chen, H.; Szabo, D. V.; Kauffmann, A.; Heilmaier, M.
2016. Metallurgical and Materials Transactions A, 47, 961–970. doi:10.1007/s11661-015-3246-0
2015
Early cluster formation during rapid cooling of an Al-Cu-Mg alloy: In situ small-angle X-ray scattering.
Schloth, P.; Menzel, A.; Fife, J. L.; Wagner, J. N.; Van Swygenhoven, H.; J.-M. Drezet.
2015. Scripta Materialia, 108, 56–59. doi:10.1016/j.scriptamat.2015.06.015
An APT investigation of an amorphous Cr-B-C thin film.
Boll, T.; Thuvander, M.; Koch, S.; Wagner, J. N.; Nedfors, N.; Jansson, U.; Stiller, K.
2015. Ultramicroscopy, 159 (2), 217–222. doi:10.1016/j.ultramic.2015.01.001
Microstructure and Phase Transformation Temperatures of Two-Phase FeAl (B2) + FeAl2 Alloys.
Li, X.; Palm, M.; Scherf, A.; Janda, D.; Heilmaier, M.; Stein, F.
2015. Advanced structural and functional intermetallic-based alloys : November 30 - December 5, 2014, Boston, Massachusetts, USA ; [Symposium YY: Advanced Structural and Functional Intermetallic-Based Alloys ; held at the 2014 MRS fall meeting] . Ed.: I. Baker, 55–60, Materials Research Society. doi:10.1557/opl.2014.965
Mechanisms of oxide scale formation on yttrium-alloyed Mo-Si-B containing fine-grained microstructure.
Majumdar, S.; Dönges, B.; Gorr, B.; Christ, H.-J.; Schliephake, D.; Heilmaier, M.
2015. Corrosion science, 90, 76–88. doi:10.1016/j.corsci.2014.09.017
Phase equilibria, microstructure, and high temperature oxidation resistance of novel refractory high-entropy alloys.
Gorr, B.; Azim, M.; Christ, H.-J.; Mueller, T.; Schliephake, D.; Heilmaier, M.
2015. Journal of alloys and compounds, 624, 270–278. doi:10.1016/j.jallcom.2014.11.012
The influence of microstructural features on the electrical conductivity of solid phase sintered CuCr composites.
Klinski-Wetzel, K. von; Kowanda, C.; Heilmaier, M.; Mueller, F. E. H.
2015. Journal of alloys and compounds, 631, 237–247. doi:10.1016/j.jallcom.2014.12.249
Experimental and Numerical Investigation on the Phase Separation Affected by Cooling Rates and Marangoni Convection in Cu-Cr Alloys.
Wang, F.; Klinski-Wetzel, K. von; Mukherjee, R.; Nestler, B.; Heilmaier, M.
2015. Metallurgical and materials transactions / A, 46 (4), 1756–1766. doi:10.1007/s11661-015-2745-3
Oxidation Behavior of Binary Aluminium-Rich Fe-Al Alloys with a Fine-Scaled, Lamellar Microstructure.
Scherf, A.; Janda, D.; Baghaie Yazdi, M.; Li, X.; Stein, F.; Heilmaier, M.
2015. Oxidation of metals, 83 (5-6), 559–574. doi:10.1007/s11085-015-9535-6
Magnetron Sputtered Mo(Six,Al[1-x])2 Oxidation Protection Coatings for Mo-Si-B Alloys.
Lange, A.; Braun, R.; Heilmaier, M.
2015. Oxidation of Metals, 84 (1-2), 91–104. doi:10.1007/s11085-015-9545-4
Creep Resistance and Oxidation Behavior of Novel Mo-Si-B-Ti Alloys.
Azim, M. A.; Schliephake, D.; Hochmuth, C.; Gorr, B.; Christ, H.-J.; Glatzel, U.; Heilmaier, M.
2015. JOM, 67 (11), 2621–2628. doi:10.1007/s11837-015-1560-z
2014
Influence of the processing technique on the properties of Nb-Si intermetallic composites for high temperature applications processed by MIM and HIP.
Mulser, M.; Hartwig, T.; Seemüller, C.; Heilmaier, M.; Adkins, N.; Wickins, M.
2014. Advances in powder metallurgy & particulate Materials - 2014 : proceedings of the 2014 International Conference on Powder Metallurgy & Particulate Materials sponsored by the Metal Powder Industries Federation, May 18 - 22, Orlando, FL. Ed.: R.A. Chernenkoff, 04/8–04/16, Metal Powder Industries Federation
Hall-Petch Breakdown at Elevated Temperatures.
Schneibel, J. H.; Heilmaier, M.
2014. Materials transactions, 55 (1), 44–51. doi:10.2320/matertrans.MA201309
High-Temperature Creep and Oxidation Behavior of Mo-Si-B Alloys with High Ti Contents.
Schliephake, D.; Azim, M.; Klinski-Wetzel, K. von; Gorr, B.; Christ, H.-J.; Bei, H.; George, E. P.; Heilmaier, M.
2014. Metallurgical and materials transactions / A, 45 (3), 1102–1111. doi:10.1007/s11661-013-1944-z
Influence of Powder Metallurgical Processing Routes on Phase Formations in a Multicomponent NbSi-Alloy.
Seemüller, C.; Hartwig, T.; Mulser, M.; Adkins, N.; Wickins, M.; Heilmaier, M.
2014. JOM, 66 (9), 1900–1907. doi:10.1007/s11837-014-1096-7
High-Temperature Creep Behavior of SiOC Glass-Ceramics: Influence of Network Carbon Versus Segregated Carbon.
Ionescu, E.; Balan, C.; Kleebe, H.-J.; Müller, M. M.; Guillon, O.; Schliephake, D.; Heilmaier, M.; Riedel, R.
2014. Journal of the American Ceramic Society, 97 (12), 3935–3942. doi:10.1111/jace.13206
2011
Fatigue resistance of Fe3Al-based alloys.
Gang, F.; Krüger, M.; Laskowsky, A.; Rühe, H.; Schneibel, J. H.; Heilmaier, M.
2011. Intermetallic-based alloys for structural and functional applications : symposium held november 29 - december 3, Boston, Massachussetts, U.S.A.; [Symposium N, "Intermetallic-Based Alloys for Structural and Functional Applications" held ... at the 2010 MRS Fall Meeting]. Ed.: M. Palm, 59–64, Materials Research Society. doi:10.1557/opl.2011.26
Microstructural and mechanical properties of ternary Mo-Si-B alloys resulting from different processing routes.
Krüger, M.; Heilmaier, M.; Shyrska, V.; Loboda, P. I.
2011. Intermetallic-based alloys for structural and functional applications : symposium held november 29 - december 3, Boston, Massachussetts, U.S.A.; [Symposium N, "Intermetallic-Based Alloys for Structural and Functional Applications" held ... at the 2010 MRS Fall Meeting]. Ed.: M. Palm, 361–366, Materials Research Society. doi:10.1557/opl.2011.188
2010
Tracking of RRR value and microstructure in high purity niobium along the production chain from the ingot to the finished cavity.
Janda, D.; Heilmaier, M.; Singer, G. X.; Singer, W.; Simader, W.; Grill, R.
2010. 1st International Particle Accelerator Conference, IPAC 2010; Kyoto; Japan; 23 May 2010 through 28 May 2010, 435–437, ACFA