HIRB - the Clarkson University Centrifuge

International Center for Gravity Materials Science and Applications

Construction of the first centrifuge in the world to be dedicated to materials processing research and related flow visualization was completed at this Center in 1993. The centrifuge was named "HIRB," which is an acronym for "High Inertia Rotating Behemoth." HIRB is a novel modification of a 62 inch, variable-speed boring mill.

CENTRIFUGE FEATURES

• Maximum rotation rate of table: 90 rpm
• Diameter of rotating table: 1.6 m
• Radius of arm: 1.5 m
• Maximum acceleration: 14 g at 1.5 m
• Control system: DC-6 Non-regenerative with 6 SCR's
• Accuracy: Speed regulation of <1%
• Centrifuge drive: Mechanical drive via gears

A variety of equipment has been mounted on this centrifuge, with data acquisition and control exercised externally via slip rings mounted on the center post of the centrifuge.  This equipment has included directional solidification furnaces, a diamond film deposition apparatus, flow visualization utilizing laser ilumination with CCD video cameras, the holographic interferometer "REGINA," and a furnace with interferometer to study dissolution of compound semiconductors.

Centrifuge Advantages

• It can run continuously for extended periods of time.
• The rotating table can accommodate extremely large and heavy loads.
• Withstands somewhat off-balance loads.
• Maintains a constant rotation rate without vibration.

RESEARCH

There are two motives for studying materials processing in centrifuges:

1. Such research improves our understanding of the influence of acceleration and convection on materials processing.
2. There are commercial opportunities for production of unique and improved materials that cannot be prepared under normal earth conditions or in space.

Centrifugation has been found to have a large effect on compositional homogeneity, gas bubble incorporation, grain size, infrared absorption of semiconductors, metal alloy solidification, welding, diamond film deposition, protein crystal growth, etc. Under some conditions, crystals have been grown of higher quality than those grown with earth's gravity or in space. For example, crystallization of oxide superconductors during centrifugation resulted in large vertical variations and new records for superconducting transition temperature.

Through a combination of experiments and theory, we are gaining an understanding of the influence of centrifugation on phenomena of importance to materials processing. We find that it is necessary to consider not only acceleration, but also the Coriolis effect and the variation of acceleration with position. As one consequence, the vigor of buoyancy-driven convection is sometimes increased by centrifugation and sometimes decreased. Similarly the tendency of the convection to become unstable or oscillatory may either be increased or decreased by centrifugation.

• Centrifuge after construction
• Photographs of Dr. Yuko Inatomi (The Institute of Space & Aeronautical Science) and Mr. Takao Maki (Olympus Company): 1 2 3
• In operation
• Video

Publications
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Last updated on June 21, 2002.