Physical Metallurgy
Group Leader
Group Members
Dr.-Ing. Daniel Schliephake (Head of the Materialography Lab)
Dr. rer. nat. Sandipan Sen
Raja Jothi Vikram, PhD (Fellow of the AvH Foundation)
M.Sc. Georg Winkens
M.Sc. Marcel Münch (LGF scholar)
M.Sc. Liu Yang (CSC scholar)
M.Sc. Gabriely Falcão
M.Eng. Jan Lars Riedel (joint member with Fatigue)
M.Sc. Sri Rathinamani Ramdoss
M.Sc. Amin Radi
We get support by our APT experts at KNMF:
M.Sc. Michael Eusterholz
Dr. Pamela M. Pineda Dominguez
Research Mission
The Physical Metallurgy group focuses on the development of metallic and intermetallic materials for extreme application conditions. The identification of suitable alloy compositions and tailoring of the microstructures is particular aim of our work.
The investigation and optimization of materials for engines operating at high temperatures is of central interest. 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 in this case. Furthermore, other extreme application conditions became relevant over time, for example deformation at cryogenic temperatures close to 0 K. The research activities all have the identification of fundamental mechanisms of the important phenomena, their relationship to materials properties and application to materials tailoring in common. In order to address these objectives, we routinely apply various materials synthesis techniques and scale-bridging characterization methods.
Synthesis of New Materials
The synthesis of new materials is based on the following methods that are available in house:
- cast metallurgy: arc melter and zone melting
- powder metallurgy: attritor grinding mill, planetary ball mill, hot uniaxial pressing
- heat treatments in various atmospheres
Characterization Methods
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)
During this year's MSE conference organized by Deutsche Gesellschaft für Materialkunde e.V. (DGM) and held in Darmstadt, the Physical Metallurgy group will present our recent research results in various presentations and posters, Michael Eusterholz, Gabriely Falcão, Sri Rathinamani Ramdoss, Jan Lars Riedel, R. J. Vikram, Liu Yang, Sandipan Sen.
to the programDuring the award ceremony in the framework of the DGM-Tag on Sept. 23rd, Alexander Kauffmann was awarded the Masing-Gedächtnispreis for his research contributions to refractory high entropy alloys and high temperature candidate materials. We appreciate the selection by DGM for this prestigious award and look forward to fruitful contributions to the field.
Alex expresses his special thanks to all group members over the years which made and make the successful unit that it is. We are proud about your constant and strong commitment to our work.
As the specific work on refractory high entropy alloys and Cr-Mo-Si alloys are particularly noted in the laudatio, special thanks are due to Hans Chen, Stephan Laube, Daniel Schliephake, Liu Yang, Sandipan Sen, R. J. Vikram as well as Frauke Hinrichs, Georg Winkens, Gabriely Falcão, Sri Rathinamani Ramdoss!
In this study, our collabroative partners from IISc Bangalore and us explore the influence of off-eutectic microstructures on the mechanical properties of ternary Mo-Si-Ti alloys, with a particular focus on Ti-rich compositions in both as-cast and directionally solidified specimens. Our findings reveal the formation of nanoprecipitates of silicide and carbides due to intrinsic heat treatment during directional solidification. The nanoscale precipitates lead to strength enhancement, counterbalancing the typical reduction associated with increased microstructural length scales. In fact, the strength of the directionally solidified specimen was higher than the as cast specimen. Additionally, we observed that this increase in microstructural length scale results in improved indentation fracture toughness, offering simultaneous benefits between the trade-off mechanical properties.
This research provides valuable insights into optimizing mechanical properties in Mo-Si-Ti systems and demonstrates the significance of strategic alloy design and processing for next-generation high-temperature materials with enhanced performance.
ti Scripta MaterialiaDigitalization and Research Data Management
In order to address the increasing complexity of materials development and to increase the efficiency of materials characterization, our entire research activity is digitally documented in kadi4mat. We focus on documentation of complex synthesis from various raw materials and using several processing steps. Also materials characterization is recorded in detail. By contributions of Daniel Schliephake, Georg Winkens, Marcel Münch and Stephan Laube, we established the following framework:
- Research Structure
- Synthesis
- Processing
- Preparation
- Analysis
- Mechanical Testing
- Calibration
Furthermore, we make our research data publicly available along with our journal articles. In case, this did not take place, please do not hesitate to contact us for exchange of the research data.