A rheological view of high-strain-rate superplasticity in alloys and metal-matrix composites

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(92)90423-C· OSTI ID:5429350

Nieh, T G; Wadsworth, J; Imai, T ^[1]

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1. Lockheed Missiles and Space Co., Inc., Research and Development Div., Palo Alto, CA (United States) Government Industrial Research Institute, Nagoya, (Japan)

Recent studies have indicated that superplasticity can occur at extremely high strain rates, yielding tensile elongations of the order of 1250 percent at a strain rate of 1/s. This phenomenon, presently designated 'high strain rate superplasticity' (HSRS), has been reported in alloys, metal-matrix composites (MMCs), and mechanically-alloyed materials; all materials exhibiting HSRS have extremely fine, about 1-micron grain size, and the phenomenon is observed at high homologous matrix temperatures that are in some cases higher than the matrix solidus temperature. Attention is presently given to the rheological factor in HSRS. It is suggested that the presence of a liquid phase or a low melting point region due to solute segregation, as at the whisker-matrix interface of an MMC, is responsible for HSRS. 24 refs.

• OSTI ID: 5429350
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 26; ISSN SCRME; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360603 -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
GRAIN SIZE
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PLASTICITY
RHEOLOGY
SILICON CARBIDES
SILICON COMPOUNDS
SIZE
STRAIN RATE
TENSILE PROPERTIES