A5091765226- Solidification and crystal growth phenomena
- nanoparticles nucleation surface interactions
- Metallurgical Processes and Thermodynamics
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Glass properties and applications
- Ferroelectric and Piezoelectric Materials
- Electrohydrodynamics and Fluid Dynamics
- Aluminum Alloy Microstructure Properties
- Microwave Dielectric Ceramics Synthesis
- Material Dynamics and Properties
- Crystallization and Solubility Studies
- Rocket and propulsion systems research
- Acoustic Wave Resonator Technologies
- Dielectric properties of ceramics
- Luminescence Properties of Advanced Materials
- Thermodynamic and Structural Properties of Metals and Alloys
- X-ray Diffraction in Crystallography
- Metallurgical and Alloy Processes
- Spacecraft Design and Technology
- Theoretical and Computational Physics
- Multiferroics and related materials
- Spaceflight effects on biology
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
Japan Aerospace Exploration Agency
2013-2025
Institute of Space and Astronautical Science
2007-2024
IHI Corporation (United States)
2021
Tokyo University of Agriculture and Technology
2021
The Graduate University for Advanced Studies, SOKENDAI
2017
SPring-8
2015
Japan Synchrotron Radiation Research Institute
2006
Tokyo Institute of Technology
2006
Japan Science and Technology Agency
2006
Tsukuba Medical Center Hospital
2002
A 2-mm-diameter glass sphere of ferroelectric BaTi2O5 was fabricated from melt using containerless processing. The structure analyzed by high-energy X-ray diffraction an incident photon energy 113.5 keV, indicating that distorted Ti−O polyhedra, with average coordination number (NTi-O) approximately 5, presented in the glass. Above transition temperature (972 K), three successive phase transitions, to a metastable α at 972 K, then β 1038 and finally stable monoclinic γ above 1100 were...
Viscosities of several refractory metals (titanium, nickel, zirconium, niobium, ruthenium, rhodium, hafnium, iridium and platinum) terbium have been measured by the oscillation drop method with an improved procedure. The data were less scattered than our previous measurements. at their melting temperatures showed good agreement literature values some predicted values.
Electrostatic levitation and multi-beam radiative heating overcame contamination sample position instability problems associated with handling of liquid alumina. This allowed the measurements surface tension viscosity in superheated undercooled states using oscillation drop method. Over 2190–2500 K interval, alumina was measured as σ( T )=0.64–8.2×10 -5 ( - m ) (N/m), where , melting temperature, is 2327 K. Similarly, on same temperature range, determined η( )=3.2exp [43.2×10 3 /( R )]...
Understanding disordered structure is difficult due to insufficient information in experimental data. Here, we overcome this issue by using a combination of diffraction and simulation investigate oxygen packing network topology glassy (g-) liquid (l-) MgO–SiO2 based on comparison with the crystalline topology. We find that atoms Mg2SiO4 larger than MgSiO3, glasses liquids. Moreover, topological analysis suggests similarity between (c)- g-(l-) signature low glass-forming ability (GFA), high...
Rare earth aluminum garnets are important materials in optical, dielectric, and thermal barrier applications. To advance the understanding of their melt processing glass forming ability, we report atomic structure molten Yb3Al5O12 over 1770–2630 K, which spans equilibrium supercooled liquid regimes. The density at Tm = 2283 K is 5.50 g cm−3, measured via silhouette imaging electrostatically levitated drops 1010–2420 K. Four separate measurements were made with aerodynamically melts using...
Abstract The relationships between materials processing and structure can vary terrestrial reduced gravity environments. As one case study, we compare the nonequilibrium melt of a rare-earth titanate, nominally 83TiO 2 -17Nd O 3 , its glassy crystalline products. Density thermal expansion for liquid, supercooled glass are measured over 300–1850 °C using Electrostatic Levitation Furnace (ELF) in microgravity, two replicate density measurements were reproducible to within 0.4%. Cooling rates...
Abstract A new method for quantifying facility performance has been discussed in this study that encompasses uncertainties associated with thermophysical property measurement. Four key properties: density, volumetric thermal expansion coefficient, surface tension, and viscosity of liquid Au have measured microgravity environment using two different levitation facilities. Levitation experiments were conducted the Electrostatic Furnace (ELF) onboard ISS Argon air, TEMPUS Electromagnetic (EML)...
Maintaining deep undercooling melts represents a formidable challenge when dealing with tungsten due to its high vapor pressure, melting temperature (Tm=3695K), and the risk of contamination. Using electrostatic levitation, properties liquid were measured above as well in undercooled phase. Over 3125–3710K interval, density was ρ(T)=1.67×104−1.08(T−Tm)kgm−3. Similarly, surface tension σ(T)=2.478×103−0.31(T−Tm) over 3360–3700K range. At Tm, data agree literature values. The excellent...
Rare earth and barium titanates are useful as ferroelectric, dielectric, optical materials. Measurements of their thermophysical properties in the liquid state can help guide melt processing technologies for manufacture advance understanding fragile liquids' behavior glass formation. Here, we report density, thermal expansion, viscosity, surface tension molten BaTi2O5, BaTi4O9, 83TiO2-17RE2O3 (RE = La or Nd). were made using electrostatic levitation droplet oscillation techniques...
Electrostatic levitation together with multibeam heating and ultraviolet imaging overcame contamination, imaging, sample position stability problems associated handling of liquid tantalum rhenium. Here, the density [ρ(T)] these metals is reported in superheated undercooled states. Over 2760–3580 K interval, was measured as ρ(T)=1.50×104−0.41(T−Tm) kg m−3, where melting temperature Tm, 3290 K. For rhenium, determined (2700–3810 K) ρ(T)=1.84×104−0.91(T−Tm), Tm=3453 From data, respective volume...
Abstract We measured the thermophysical properties of molten gallium oxide (Ga 2 O 3 ) in a contamination-free and microgravity environment by using electrostatic levitation furnace International Space Station. The density Ga was obtained over wide temperature range 2001–2174 K including undercooled state found to be expressed as 5004.8–0.4478( T − m (kg −3 ), where , melting point, is 2066 K. Measurements its viscosity surface tension were also performed drop oscillation method these values...
Thermophysical properties of equilibrium and supercooled liquid platinum were measured using non-contact diagnostic techniques with an electrostatic levitator. Over the 1691 to 2216 K temperature range, density can be expressed as ρ(T)=19.2 ×103-0.96(T-Tm) (kg ·m-3) Tm=2041 K, yielding a volume expansion coefficient 5.0 ×10-5 K-1. In addition, surface tension γ(T)=1.80 ×103-0.14(T-Tm) (10-3 N ·m-1) viscosity η(T)=0.25 exp [4.99 ×104/(RT)] Pa ·s) over 1743 2313 range.
Due to their high melting temperatures and the risk of contamination from crucibles, molten oxides which are above 2000 °C can hardly be processed using conventional methods. This explains that thermophysical properties very scarce. Containerless methods with gas flows have been developed several such as density, surface tension, viscosity reported. However, flow has detrimental side effects deformation sample induction internal in sample, affect accuracy measurements. The electrostatic...
In order to measure the surface tension and viscosity of molten oxides, oscillation drop technique has been applied on a pressurized hybrid electrostatic-aerodynamic levitator. To suppress electrical discharge between top bottom electrodes, excitation method which used with high vacuum electrostatic levitators modified. As demonstration, liquid BaTiO3 were measured using this new method. Over 1500–2000K interval, was as γ(T)=349−0.03 (T−Tm) (10−3N∕m), where Tm=1893K is melting temperature....
Thermophysical properties of high temperature melts are important to better understand material processes such as casting, welding, and crystal growth. Containerless processing techniques combined with non-contact diagnostic methods play significant roles in thermophysical property measurements because these can circumvent problems which arise from a reaction between container melts. The electrostatic levitation method measure density, surface tension, viscosity materials. Most refractory...
Bonding characteristics of liquid boron at 2500 K are studied by using high-resolution Compton scattering. An excellent agreement is found between the measurements and corresponding Car-Parrinello molecular dynamics simulations. Covalent bond pairs clearly shown to dominate in along with coexistence diffuse pairs. Our study reveals complex bonding pattern gives insight into unusual properties this high-temperature liquid.
Validity of the surface tension measurement technique that was proposed by Elleman et al. experimentally verified. The based on Brown and Scriven’s work shape evolution rotating drops. Molten tin aluminum drops were levitated in high vacuum electrostatic levitator rotated applying a magnetic field. This offers an alternative for those liquids where drop oscillation cannot be used. As demonstration, applied to glass-forming alloy (Zr41.2Ti13.8Cu12.5Ni10.0Be22.5) its measured down lower...
Ice crystal growth experiments in heavy water were carried out under microgravity to investigate the morphological transition from a disk dendrite. Surprisingly, however, no was observed, namely, or dendrite maintained its shape throughout experiments, unlike results obtained on ground. Therefore, we introduce model understand growth. The Gibbs-Thomson effect is taken into account as stabilization mechanism. numerically solved by varying both an interfacial tension of prism plane and...
Co-Cr-Mo (CCM) alloys, which are used in biomedical implants, currently produced by additive manufacturing, for accurate modeling of the process is required to attain desired thermophysical properties melts. For purpose modeling, density, surface tension, and viscosity two CCM melts distinct carbon content (0.05 0.25% mass) were measured using an electrostatic levitation technique. The temperature dependence both density tension assumed be linear, whereas that was have Arrhenius form, from...