Research Projects
International
Center for Gravity Materials Science and Applications
Following are brief descriptions of recent research projects carried out at the International Center for Gravity Materials Science and Applications, Clarkson University, Potsdam, NY 13699-5814, USA. For additional information, contact the Center Director.
Growth of Crystalline Diamond
Objective: To study,
develop and commercialize a new technique for growing polycrystalline diamond
films and single-crystal diamond at low pressure and temperature.
Methods: Experiments are performed in a
closed chamber containing graphite and hydrogen at low pressure and
temperatures down to 150oC, both at earth's gravity and with centrifugation,
on a wide variety of substrates including graphite, glass, metals, carbon felt,
polymers and device structures.
Theoretical modeling of heat transfer, convection and chemical reactions
using FLUENT. Diamond verified
by micro-Raman spectroscopy. (This is not
diamond-like carbon.)
Sponsors: Corning Corporation,
Eastman Kodak Corporation, The New York State Center for Advanced Materials
Processing (CAMP) at Clarkson University, and the U.S. National Science
Foundation (NSF).
Selective
deposition on copper pattern on oxidized silicon, with submicron resolution
Presentation at 1999
International Astronautical Congress
Selective patterned
deposition plus cover
photo
Deposition on graphite
and carbon felt plus cover
photo
2001 paper
2006 patent for
low-temperature & low-pressure deposition
Pending patent for use to
fabricate polymer LEDs
Influence of Centrifugation on Buoyancy-Driven
Convection and Materials Processing
Objective: To determine
the influence of centrifugation on materials processing and on buoyancy-driven
convection.
Methods:
Use the large Clarkson centrifuge HIRB for studies of
solidification of eutectic and off-eutectic aluminum alloys (see below), CdTe solidification, Teflon agglomeration, interferometric observation of dissolution and growth of InP, deposition of diamond films (see above), and flow
visualization. Numerical modeling using FLUENT.
Sponsors: NSF, CRDF
Representative publication
Flow cell on centrifuge
Bottom view of
experimentally observed flow field on centrifuge
Theoretical flow field
with centrifugation at 40 rpm
Experimental values of
maximum and average velocity
The Microstructure of Eutectics
Objective: To
understand the influence of freezing rate oscillations, convection,
centrifugation and levitation on the microstructure of eutectics.
Methods: Directional
solidification of the MnBi-Bi eutectic with
application or periodic current pulses. Directional solidification of the
Al-Si eutectic with application of the accelerated crucible rotation technique
(ACRT). Solidification of Al-Si, Al-Ge, and Al-Ge,Si
eutectics during levitation and centrifugation.
Numerical modeling using the phase-field method.
Sponsors: The U.S. National Aeronautics
and Space Administration (NASA) and the U.S. Civilian Research and Development
Foundation (CRDF).
Video of
phase-field simulation with varying freezing rate (a large zip file)
Influence of electric
current pulses on MnBi-Bi microstructure
Phase-field simulation
of steady eutectic growth
Evolution of
microstructure when the freezing rate is increased 6X
Presentation at
International Astronautical Congress
Detached solidification
Objectives:
To increase our understanding of detached solidification, which has produced
vastly superior crystals in space. To achieve detached solidification on
earth.
Methods: Directional solidification of
transparent materials such as water and naphthalene, which contain dissolved
gas. Directional solidification of InSb in BN-coated ampoules.
Numerical and approximate analytical solutions for our Moving Meniscus Model.
Measurement of the oxygen-dependence of the surface tension and contact
angle of molten InSb.
Sponsor: NASA
Review of literature on
detached solidification in microgravity
Schematic diagram of
Moving Meniscus Model
Modeling results for
InSb and water
Can propagation of gas
bubbles lead to detachment?
Approximate material
balance solution to the Moving Meniscus Model
Detached solidification of
InSb on earth in BN-coated ampoules
Student researchers since 1999
Ms. Fengcui Li, former Ph.D.
student in Chemical Engineering
Dr. Dimitri Popov, former Ph.D. student in interdisciplinary
Engineering Science
Mr. Ram Ramanathan,
former M.S. student in Chemical Engineering
Dr. Peter Skudarnov, former Ph.D. student in interdisciplinary
Engineering Science
Ms. Yazhen
Wang, former Ph.D. student in Chemical Engineering
Mr. Jeffrey Chung, former
M.Eng. in Chemical Engineering & MBA student
Mr. Francis Olajide, former B.S. student in Chemical Engineering
Ms. Katie Flow, former
B.S. honors student in Chemical Engineering
Mr. Suresh Ramakrishnan, former M.S. student in Chemical Engineering
Mr. Jianbin
Wang, former M.S. student in Chemical Engineering
Ms. Siliu
Tan, former M.S. student in interdisciplinary Engineering Science
Mr. Thomas Adsit, former M.S. student in Chemical Engineering
Mr. Arun Kumar Kota,
former M.S. student in Chemical Engineering
Mr. Karthik
Jayaraman, former M.S. student in Chemical
Engineering
Mr. Craig Burkhard,
former M.S. student in Chemical Engineering
Mr. Gaurav Anan, former M.S.
student in Chemical Engineering
Mr. Hasan
Shodiev, former Ph.D. student in interdisciplinary
Engineering Science
Visiting scientists since 1999
· August 1999: Dr. Yuko Inatomi (The Institute of Space & Aeronautical Science) and Mr. Takao Maki (Olympus Company), Japan. Photos: 1 2 3 Centrifuge in operation Video
·
Spring 2000: Professor
Gamaleldin Ata Gadelkarim,
South Valley University, Qena, Egypt
·
Summers 2002, 2003: Drs. Stanislav
Nikanorov, Mikhail P. Volkov
and Vladimir N. Gurin, Ioffe
Physical-Technical Institute, St. Petersburg, Russia
Additional information
International Center for
Gravity Materials Science and Applications
The Center's unique
large centrifuge
Recent publications
MS and PhD theses
Professor Liya L. Regel
Professor William R. Wilcox
Last updated November 22, 2006