Undercooled rapidly solidified titanium-rare earth alloys
- Vanderbilt Univ., Nashville, TN (United States). Dept. of Applied and Engineering Sciences
The microstructural effects of undercooling on eight titanium-rare earth alloys were investigated. Electromagnetic levitation allowed cooling of the liquid well below the liquidus prior to nucleation/solidification. For each alloy, a series of samples was splat quenched with systematically varied undercoolings. The resulting materials were characterized by scanning and transmission electron microscopy in the as-quenched and annealed states. Typically, rapid solidification of titanium-rare earth alloys results in supersaturation of {alpha} Ti and precipitation occurs during annealing treatments. In these experiments, evidence of precipitation during cooling through the {beta}/{alpha} transus was observed and has been attributed to an interphase boundary precipitation mechanism. The results of undercooling/splat quench experiments were utilized to select materials for undercool/rapid quench technology (URQT) processing. This novel technique combines electromagnetic levitation, an ultrahigh (10{sup {minus}8} torr) vacuum system and a three meter drop tube with melt spinning via a variable speed copper wheel. Materials processed by this method exhibited homogeneous solidification microstructures uncharacteristic of conventional melt spinning, and small (1 nm) interphase boundary precipitates in the as-quenched state.
- OSTI ID:
- 186732
- Report Number(s):
- CONF-950201--; ISBN 0-87339-316-3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANNEALING
CERIUM ALLOYS
ERBIUM ALLOYS
HELIUM
LANTHANUM ALLOYS
LEVITATION
LIQUID METALS
MELTING
MICROSTRUCTURE
MORPHOLOGY
OPTICAL MICROSCOPY
OPTICAL PYROMETERS
PRECIPITATION
QUENCHING
SCANNING ELECTRON MICROSCOPY
SOLIDIFICATION
TITANIUM ALLOYS
TRANSMISSION ELECTRON MICROSCOPY
ULTRAHIGH VACUUM
YTTRIUM ALLOYS