Electrostatic Levitation Research and Development at JAXA: Past and Present Activities in Thermophysics

Paradis, Paul‐François; Ishikawa, Takehiko; Yoda, Shinichi

doi:10.1007/s10765-005-6683-y

Cited by 25 publications

(17 citation statements)

References 56 publications

(72 reference statements)

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“…Figure 2 illustrates the specimen-handling mechanism of our vacuum levitator. A single sliding cartridge comprised 10 distinct pedestals [17], which minimized sample jamming problems. Since these pedestals are easy to replace, those made of refractory metals were used for the W, Re and Os.…”

Section: Handling Of Samples With Smaller Diametermentioning

confidence: 99%

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Challenges of Handling, Processing, and Studying Liquid and Supercooled Materials at Temperatures above 3000 K with Electrostatic Levitation

Ishikawa

Paradis

2017

Crystals

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Abstract:Over the last 20 years, great progress has been made in techniques for electrostatic levitation, with innovations such as containerless thermophysical property measurements and combination of levitators with synchrotron radiation source and neutron beams, to name but a few. This review focuses on the technological developments necessary for handling materials whose melting temperatures are above 3000 K. Although the original electrostatic levitator designed by Rhim et al. allowed the handling, processing, and study of most metals with melting points below 2500 K, several issues appeared, in addition to the risk of contamination, when metals such as Os, Re, and W were processed. This paper describes the procedures and the innovations that made successful levitation and the study of refractory metals at extreme temperatures (>3000 K) possible; namely, sample handling, electrode design (shape and material), levitation initiation, laser heating configuration, and UV range imaging. Typical results are also presented, putting emphasis on the measurements of density, surface tension, and viscosity of refractory materials in their liquid and supercooled phases. The data obtained are exemplified by tungsten, which has the highest melting temperature among metals (and is second only to carbon in the periodic table), rhenium and osmium. The remaining technical difficulties such as temperature measurement and evaporation are discussed.

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Section: Handling Of Samples With Smaller Diametermentioning

confidence: 99%

“…[19]. Illustration showing the electrodes and sample-handling system of the JAXA vacuum levitator [17].…”

Section: Laser Heating and Electrode Configurationmentioning

confidence: 99%

Challenges of Handling, Processing, and Studying Liquid and Supercooled Materials at Temperatures above 3000 K with Electrostatic Levitation

Ishikawa

Paradis

2017

Crystals

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“…Subsequently, the electrostatic levitators were also developed in German Aerospace Center (DLR) [9], Bremen University [9] and Japan Aerospace Exploration Agency (JAXA) [10] till 2001. At present, the research work with electrostatic levitators mainly focuses on such subjects as thermophysical properties, liquid structure and rapid solidification of liquid alloys [11][12][13][14][15][16][17]. The study of electrostatic levitation in China was mainly concentrated on the suspended gyroscope and nondestructive examination [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Electrostatic levitation under the single-axis feedback control condition

Wang

Xie

et al. 2010

Sci. China Phys. Mech. Astron.

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An electrostatic levitator with a single-axis feedback control system was developed on the basis of electric field analysis and optimum design for levitation electrodes. In order to realize the stable levitation of various types of materials such as metals, inorganic materials and polymers, we made both experimental and theoretical investigations to solve the four key problems of electric field optimization, sample position detecting, sample charging control and levitation voltage minimization. Under the capacitive induction charging condition, a sample with the size of 2.6-4.5 mm usually bears positive charges amounting to 10 −9 Coulomb. Because the single-axis feedback control system responds quickly, it takes the levitated sample only 0.1 s from leaving the bottom electrode until attaining a stable levitation in the upright direction. The levitated sample displays satisfactory levitation stability in both the upright and the horizontal directions owing to the constraining force produced by spherical electrodes. electrostatic levitation, containerless processing, feedback control, space science PACS: 41.20.Cv, 61.25.Mv, 81.30.Fb

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“…1 Over the last decade, the electrostatic levitation technique was developed robustly and demonstrated great potential in determining the thermophysical properties of molten metals and in fabricating various advanced materials. [2][3][4][5] The sample levitated by electrostatic force under vacuum is isolated from any contact with crucible or substrate and from the contamination from surrounding gas.Coupling with laser heating, electrostatic levitator (ESL) has accurately enabled noncontact measurement of thermophysical properties for many refractory metals, including tungsten, 6 tantalum, 7 rhenium, 7,8 etc. 9,10 However, the measurement of liquid metal with high activity is still a challenge.…”

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confidence: 99%

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Noncontact thermophysical property measurement of liquid cerium by electrostatic levitation

Ishikawa

Okada

et al. 2009

J. Mater. Res.

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The knowledge of thermophysical properties of active metals is critical to understand their metallurgical processes and further industrial applications. However, due to high reactivity and melt contamination from a crucible and gaseous environment, accurate values of the properties are hard to obtain using conventional methods such as the sessiledrop method. In the present study, a vacuum electrostatic levitator was used to circumvent these difficulties and enabled the noncontact determination of thermophysical properties of liquid cerium even in an undercooled state. The data of density, surface tension, and viscosity of molten cerium were reported, as well as their temperature dependence.Active metals (alkali, alkaline earth, rare earth metals, etc.) play critical roles in a large variety of industrial applications. Knowledge of the density, surface, and viscosity of these metals in liquid phase is essential to understand their refining, casting, welding, and other processes. However, accurate measurements of these thermophysical properties are difficult to determine using conventional methods in which crucible (or substrate) and nonvacuum atmosphere are engaged. Contact measurements easily carry contamination to chemically active liquid metals, resulting in experimental data with a large discrepancy and inapplicability. 1 Over the last decade, the electrostatic levitation technique was developed robustly and demonstrated great potential in determining the thermophysical properties of molten metals and in fabricating various advanced materials. [2][3][4][5] The sample levitated by electrostatic force under vacuum is isolated from any contact with crucible or substrate and from the contamination from surrounding gas.Coupling with laser heating, electrostatic levitator (ESL) has accurately enabled noncontact measurement of thermophysical properties for many refractory metals, including tungsten, 6 tantalum, 7 rhenium, 7,8 etc. 9,10 However, the measurement of liquid metal with high activity is still a challenge.In the present work, cerium was selected as an example to identify the feasibility of ESL in measuring thermophysical properties of active metals. One reason for selecting cerium is that cerium possesses extreme activity (only europium ahead within rare earth elements), oxidizes rapidly when exposed to air, and reacts directly with nitrogen and other elements. This process leads to a rare report on the thermophysical properties of liquid cerium. Even the melting point of cerium in the literature was scattered, with temperatures ranging from 1068 to 1081 K. From a practical standpoint, ceriumbased materials are critical in a variety of industrial applications, including production and purification of hydrogen, 11 the purification of exhaust gases in three-way automotive catalytic converters, and other catalytic applications. 12 Cerium metal can be used as getter for refining metallic melts, opacifier and polisher for glasses, and

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Electrostatic Levitation Research and Development at JAXA: Past and Present Activities in Thermophysics

Cited by 25 publications

References 56 publications

Challenges of Handling, Processing, and Studying Liquid and Supercooled Materials at Temperatures above 3000 K with Electrostatic Levitation

Challenges of Handling, Processing, and Studying Liquid and Supercooled Materials at Temperatures above 3000 K with Electrostatic Levitation

Electrostatic levitation under the single-axis feedback control condition

Noncontact thermophysical property measurement of liquid cerium by electrostatic levitation

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