Non-contact measurement of creep resistance of ultra-high-temperature materials

Lee, J.; Bradshaw, Richard C.; Hyers, R. W.; Rogers, J. R.; Rathz, T. J.; Wall, James A.; Choo, Hahn; Liaw, Peter K.

doi:10.1016/j.msea.2006.07.160

Cited by 17 publications

(20 citation statements)

References 49 publications

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“…Industrial Tectonics Inc. fabricated the calibration spheres to the specifications of American Bearing Manufacturers Association, Grade 3 (tolerances: 75 nm sphericity and 750 nm diameter). A new technique for measuring creep deformation using the MSFC ESL has been developed 10 . This technique is based on electrostatic levitation of a spherical sample, heated to the measurement temperature and rotated at a rate such that the centrifugal acceleration causes creep deformation.…”

Section: Resultsmentioning

confidence: 99%

Containerless Processing Studies in the MSFC Electrostatic Levitator

Rogers

SanSoucie

2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Levitation or containerless processing represents an important tool in materials research. Levitated specimens are free from contact with a container, which permits studies of deeply undercooled melts, and high-temperature, highly reactive materials. Containerless processing provides data for studies of thermophysical properties, phase equilibria, metastable state formation, microstructure formation, undercooling, and nucleation. Levitation techniques include: acoustic, aero-acoustic, electromagnetic, and electrostatic. In microgravity, levitation can be achieved with greatly reduced positioning forces. Microgravity also reduces the effects of buoyancy and sedimentation in melts. The European Space Agency (ESA) and the German Aerospace Center (DLR) jointly developed an electromagnetic levitator facility (MSL-EML) for containerless materials processing in space. The MSL-EML will be accommodated in the European Columbus Facility on the International Space Station (ISS). The electrostatic levitator (ESL) facility at the Marshall Space Flight Center provides support for the development of containerless processing studies for the ISS. The capabilities of the facility and recent results will be discussed.

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Section: Resultsmentioning

confidence: 99%

Containerless Processing Studies in the MSFC Electrostatic Levitator

Rogers

SanSoucie

2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…The rate of mass evaporation of a pure substance in a vacuum condition can be calculated using Langmuir's equation [12].…”

Section: Measurement Of Mass Evaporationmentioning

confidence: 99%

“…The emissivity input of the pyrometer is adjusted until the melt plateau is observed at the correct temperature. Additional capabilities of the MSFC ESL lab include non-contact creep strength measurement [12,13], triggered nucleation [14], and a rapid quench system [15]. …”

mentioning

confidence: 99%

“…Therefore, an accurate calculation of mass evaporation is of critical importance when we are dealing with materials with high vapor pressure. The composition shift must also be incorporated in the analysis for alloys whose constituents have considerably different evaporation behaviors.The rate of mass evaporation of a pure substance in a vacuum condition can be calculated using Langmuir's equation [12].where ̇ is the rate of mass evaporation, is the surface area, is the vapor pressure, is the molecular weight of the material, is the universal gas constant, and is the temperature. The calculation of mass evaporation of a pure substance is easier compared to that of alloys.…”

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confidence: 99%

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Experiments Using a Ground-Based Electrostatic Levitator and Numerical Modeling of Melt Convection for the Iron-Cobalt System in Support of Space Experiments

Lee¹,

SanSoucie

2017

JOM

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Materials research is being conducted using an electromagnetic levitator installed in the International Space Station. Various metallic alloys were tested to elucidate unknown links among the structures, processes, and properties. To accomplish the mission of these space experiments, several ground-based activities have been carried out. This paper presents some of our ground-based supporting experiments and numerical modeling efforts. Mass evaporation of Fe50Co50, one of the flight compositions, was predicted numerically and validated by the tests using an electrostatic levitator (ESL). The density of various compositions within the Fe-Co system was measured with ESL. These results serve as reference data for the space experiments. The convection inside a electromagneticallylevitated droplet was also modeled to predict the flow status, shear rate, and convection velocity under various process parameters, which is essential information for designing and analyzing the space experiments of some flight compositions influenced by convection. INTRODUCTIONSince 2015, several materials experiments have been performed using the materials science laboratory electromagnetic levitator (MSL-EML) aboard the International Space Station (ISS). More than 50 principal investigators from 13 different countries have been participating in this space program. Thermophysical properties, transport phenomena, and glass/quasicrystal formation of various alloys are being studied using MSL-EML. To increase the chance of success in the space experiments, the team has meticulously planned and prepared for their science experiments. The safety aspects, mass evaporation [1] and thermophysical properties [2-4] of each sample have been measured as part of the ground support program.The measurement of mass evaporation is important. Evaporation often causes composition shifts of tested alloys resulting from preferential evaporation of volatile species. Such composition shifts can be reduced by limiting superheating and time for thermal hold during property measurements. On the other hand, evaporated materials may end up as aerosols, which can be hazardous to the health of the astronauts. Otherwise the evaporated materials will deposit on the optics, obscuring measurements, or on the coils. Excessive coil deposition can cause flaking of deposited materials, cross-contamination, short circuiting, and arcing. Each batch has 18 samples, and the amount of mass evaporation of each sample is different depending on the composition and thermal history. After discussion among scientists, the thermal cycles of each samples are adjusted such that the total amount of mass evaporation does not exceed a designated value.For flight samples whose internal convection is of interest, numerical models were developed [5] and used [6]. The developed numerical models have been used to predict the convection status under an anticipated combination of process parameters. The status of convection affects phase selection during solidification of metal alloys which exhibit ...

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“…Precise measurement of properties of high-temperature molten material is of practical importance in many engineering fields [1][2][3]. Material properties of molten mixtures of nuclear fuel are, for instance, indispensable for evaluation of severe accident scenario of nuclear reactors [1].…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of oscillating flow field including a droplet

Watanabe¹

2013

The International Journal of Multiphysics

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Non-contact measurement of creep resistance of ultra-high-temperature materials

Cited by 17 publications

References 49 publications

Containerless Processing Studies in the MSFC Electrostatic Levitator

Containerless Processing Studies in the MSFC Electrostatic Levitator

Experiments Using a Ground-Based Electrostatic Levitator and Numerical Modeling of Melt Convection for the Iron-Cobalt System in Support of Space Experiments

Numerical simulation of oscillating flow field including a droplet

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