Plastic flow and dislocation structures in tantalum carbide: Deformation at low and intermediate homologous temperatures
- Michigan State Univ., East Lansing, MI (United States). Dept. of Materials Science and Mechanics
- RWTH Aachen (Germany). Inst. fuer Metallkunde und Metallphysik
Dislocation structures and plastic flow in TaC[sub 0.99] have been studied in material deformed by microindentation at 20 C, and in specimens crept at temperatures between 0.37 and 0.43 T[sub m] (1300--1500 C). Extensive local plastic deformation occurred during indentation, accomplished mainly by the motion of a/2<011> edge dislocation gliding on [111]. The resulting defect structure consisted primarily of long screw dislocations, suggesting a relatively high mobility for edge segments and a large Peierls stress for screw dislocation motion. This <110>[111] slip system also operated in specimens crept at 0.37-0.43 T[sub m]. Thermal activation apparently increased the mobility of screw segments, resulting in substructures containing mixed dislocations with no preferred orientation. Microstructural observations, and analysis of kinetic data for power-law creep, suggest that intermediate temperature creep deformation of TaC[sub 0.99] occurs mainly by climb-controlled grain boundary sliding with severely limited intergranular accommodation.
- OSTI ID:
- 7174876
- Journal Information:
- Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 42:7; ISSN 0956-7151; ISSN AMATEB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
CARBIDES
CARBON COMPOUNDS
CREEP
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
DEFORMATION
DISLOCATIONS
EXPERIMENTAL DATA
INFORMATION
LINE DEFECTS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NUMERICAL DATA
PLASTICITY
REFRACTORY METAL COMPOUNDS
TANTALUM CARBIDES
TANTALUM COMPOUNDS
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TRANSITION ELEMENT COMPOUNDS