Undercooled rapidly solidified titanium-rare earth alloys

Conference · Sun Dec 31 00:00:00 EST 1995

OSTI ID:186732

Kral, M V; Hofmeister, W H; Wittig, J E ^[1]

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1. 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; TRN: 96:007143
• Resource Relation: Conference: Annual meeting and exhibition of the Minerals, Metals and Materials Society (TMS), Las Vegas, NV (United States), 12-16 Feb 1995; Other Information: PBD: 1995; Related Information: Is Part Of Synthesis/processing of lightweight metallic materials. Proceedings; Froes, F.H.; Suryanarayana, C. [eds.] [Univ. of Idaho, Moscow, ID (United States). Inst. for Materials and Advanced Processes]; Ward-Close, C.M. [ed.] [Defence Research Agency, Farnborough (United Kingdom)]; PB: 380 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TITANIUM ALLOYS
MELTING
SOLIDIFICATION
MICROSTRUCTURE
CERIUM ALLOYS
ERBIUM ALLOYS
LANTHANUM ALLOYS
YTTRIUM ALLOYS
LEVITATION
QUENCHING
LIQUID METALS
HELIUM
ULTRAHIGH VACUUM
OPTICAL PYROMETERS
ANNEALING
SCANNING ELECTRON MICROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
OPTICAL MICROSCOPY
PRECIPITATION
MORPHOLOGY