Materials Research in Reduced Gravity: Programmatics and Facility Status; Thermophysical Properties I
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Process Technology and Modeling Committee
Program Organizers: Robert Hyers, Worcester Polytechnic Institute; Douglas Matson, Tufts University; Michael Sansoucie, Nasa Marshall Space Flight Center; Shaun McFadden, Ulster University; Jonghyun Lee, Iowa State University; Wilhelmus Sillekens, European Space Agency; Takehiko Ishikawa, Japan Aerospace Exploration Agency
Wednesday 8:30 AM
February 26, 2020
Room: 18
Location: San Diego Convention Ctr
Session Chair: Michael SanSoucie, NASA MSFC; Takehiko Ishikawa, JAXA
8:30 AM
Space for Science: ESA’s Microgravity Research Programme on Materials Science: Wilhelmus Sillekens1; 1European Space Agency
Over the past decades, the European Space Agency has developed and employed a suite of microgravity platforms that enables scientific and industrial communities to conduct space-relevant investigations for the physical as well as for the life sciences. These platforms include drop towers, parabolic flights, sounding rockets, and the International Space Station (ISS), each with their particular features and hence application areas. This paper gives an overview of the research programme on materials science using these platforms, thereby drawing from the various projects that are conducted by (European) research teams in this domain. Examples are on solidification studies by amongst others the use of X-ray imaging equipment, and the study of solidification kinetics and the measurement of thermo-physical property data by means of an electromagnetic levitator. Results from these investigations provide for unique benchmark data for the testing and validation of fundamental theories and for modelling and simulation of (solidification) processes.
8:55 AM
Current and Future Experiment Capabilities On-board the ISS for Materials Sciences: Douglas Matson1; 1Tufts University
The decadal survey effort is a report by the National Academies and commissioned by Congress and NASA to guide the discussion on establishing research priorities, commitment of mission and fiscal resources and developing a comprehensive strategy for space exploration over the next decade. It is prepared by a steering committee of leaders in the community of scientists conducting planetary and exploration research. The initial phase is developing white papers that summarize the needs and future direction of specific elements which will make up the portfolio of research topics that will be addressed over the next ten years. It is thus important that researchers in Materials Science actively work to support the efforts of the National Academies to promote Physical Science research activities. This presentation is a summary of the existing facilities currently used by Material Scientists to conduct research in Low-Earth Orbit. Future research supporting colonization of the Moon and then on to Mars will be discussed in terms of identifying upcoming needs and experiment capabilities.
9:20 AM
Experiment Preparation and Operation of the Electromagnetic Levitator EML on the ISS: Stephan Schneider1; Mitja Beckers1; Angelika Diefenbach2; 1DLR Institut für Materialphysik im Weltraum; 2DLR MUSC
EML is an electromagnetic levitation facility of the European Space Agency (ESA) for the ISS aiming at processing liquid metals or semiconductors under microgravity conditions. Its diagnostics and processing methods allow to measure thermophysical properties in the liquid state and to investigate solidification phenomena. The on-orbit experiment performance is embedded in an extensive ground support program at DLR Cologne. Pre-mission, the sample characterization, experiment planning, parameter development and finally experiment validation with the EML ground model are performed. After the ground preparation steps the experiment parameters are uploaded to the facility and the experiments are performed on orbit. The scientific data are provided to the involved scientists for analysis and are archived at MUSC.An overview of the status of EML operations and the scientific experiments of the first two sample batches will be provided with the necessary preparation steps to run experiments in the EML.
9:45 AM
Measurement of Diffusion Coefficients of Dopants in Ge and Si Melts: Aleksandar Ostrogorsky1; Martin Volz2; Arne Croell3; 1Illinois Institute of Technology; 2NASA Marshall Space Flight Center; 3University of Alabama Huntsville
The values of diffusion coefficients of dopants in semiconductor melts (“D values”) are so low, that even a minute level of convection will disturb a measurement. On Earth, this is true even for measurements conducted in fine capillaries and shear cells. The unavoidable buoyancy-driven convection inflates the D values. Thus, microgravity presents an ideal environment for experiments intended to yield the diffusion coefficients. For example, the crystal growth experiment conducted during the Apollo-Soyuz mission gave the diffusion coefficient of Ga in molten germanium, obtained by fitting the Tiller’s equation to the Ga redistribution profile. For silicon melts, all D values reported so far were obtained on Earth. Turovskii (1962), and Kodera (1963) fitted the BPS equation to the dopant redistribution profiles, in crystals grown by the Czochralski (CZ) process. Shaskov and Gurevich (1967) used the capillary-reservoir method and obtained drastically different values. Acknowledgements: This project is supported by the NASA Research Announcement “Research Opportunities in Materials Science – MaterialsLab Open Science Campaigns for Experiments on the International Space Station,” NNH15ZTT002N.
10:10 AM Break
10:40 AM Cancelled
Surface Oscillation of Molten Oxides Under Microgravity Using Electrostatic Levitation Furnace in ISS: Masahito Watanabe1; 1Gakushuin University
Microgravity conditions have advantages of measurement of surface tension and viscosity of high-temperature liquids by the oscillating drop method using a levitation device. The levitated droplet under microgravity is the completely spherical shape without the effect of gravitational force. Moreover, under microgravity the damping time of surface oscillation is correctly obtained because without large levitation force. We investigate the surface oscillation of levitated molten oxide droplets using the electrostatic levitation furnace (ELF) in the International Space Station (ISS). We succeeded to obtain the surface oscillation of complete spherical shape molten oxide droplet under microgravity. The surface oscillation data were good agreement with the damping sine function with single damping time constant and therefore we obtained surface tension and viscosity of molten oxides.
11:00 AM
Effects of Oxygen Partial Pressure on the Surface Tension of Liquid Aerospace Alloys: Michael Sansoucie1; Gwendolyn Bracker2; Elizabeth Hodges2; Madeline Scott2; Robert Hyers2; 1NASA MSFC; 2University of Massachusetts
Oxygen partial pressure can considerably influence the surface tension of liquid metals. The NASA Marshall Space Flight Center’s electrostatic levitation (ESL) laboratory has an oxygen partial pressure control system that allows the oxygen partial pressure within the vacuum chamber to be measured and controlled in the range from 10-28 to 10-9 bar. The MSFC ESL lab's oxygen control system consists of an oxygen sensor, oxygen pump, and a control unit. The oxygen sensor is a potentiometric device that determines the difference in oxygen activity in two gas compartments separated by an yttria-stabilized zirconia electrolyte. The pump utilizes coulometric titration to either add or remove oxygen.The effects of oxygen partial pressure on the surface tension of molten aerospace alloys were determined, and the results will be presented. The surface tension was measured at several different oxygen partial pressures using the oscillating drop method.
11:20 AM
Thermophysical Properties of Bulk Metallic Glasses Measured in the Liquid Phase on Board the International Space Station: Markus Mohr1; Rainer Wunderlich1; Hans Fecht1; 1Ulm University
Bulk metallic glasses are a new development of metallic materials with superior properties, such as high elastic limits and high hardness. This makes the materials interesting for applications, e. g. in space exploration. Study of glass formation is also the study of the opposite, crystal nucleation – which is influenced by kinetic and thermodynamic driving forces. As such, thermophysical properties (viscosity, specific heat capacity) and the derived thermodynamic functions are important in understanding of glass formation. Within the last few years, several BMG materials were investigated in the ISS-EML. The two Zr-based glasses Vit106a (Zr58.5Cu15.6Ni12.8Al10.3Nb2.8) and LM105 (Zr52.5Cu17.9Ni14.6Ti5Al10) as well as a Fe-based glass former (Fe57.75Ni19.25Mo10.0C5.0B8.0) were processed successfully in the Material Science Laboratory Electromagnetic Levitator (ISS-EML) on board the European Space Laboratory Columbus in the international space station (ISS). We will present an overview over the thermophysical properties of these bulk metallic glasses.
11:40 AM
Modelling Liquid Droplet Oscillation and Laminar Damping in Reduced Gravity Conditions: Valdis Bojarevics1; 1University of Greenwich
Electromagnetic levitation of liquid droplets for a noncontact liquid material properties measurements are investigated in detail using the high accuracy spectral method numerical modelling techniques and comparing to the experimental observations at the ISS. The long term nonlinear simulation results give a deeper insight to the mechanics and dynamic regimes of the interacting surface oscillation and the internal circulation generated by the AC electromagnetic forces. The example of the nickel based alloy LEK94 provides experimental results which are replicated closely by the numerical predictions. The results indicate that the flow stays completely laminar with internal recirculation velocities reaching 0.40 m/s, the oscillation frequencies experience predictable small shifts from the Rayleigh analytical predictions, the damping rate leads to an accurate laminar viscosity comparable to the measured value. New ideas for the EML technique using high strength permanent magnets are discussed, which could be implemented in the future space experiments.