Core structure and mobility of [a{l_angle}101] dislocations in L1{sub 0} TiAl
- UES, Inc. Dayton, OH (United States)
- Wright Lab., Wright-Patterson AFB, OH (United States)
An empirical atomistic potential, fit to the structural and elastic properties of L1{sub 0} TiAl within the embedded atom method (EAM), is used to simulate the mobility of two possible planar forms of a{l_angle}101] dislocations in a model L1{sub 0} compound. The two configurations examined were: the planar SISF-APB-CSF coupled (P core) and the decomposed 1/2{l_angle}110]-SISF-SESF coupled (D core). Six different line orientations are considered for the P core: 0{degree} (screw), 30{degree}, 60{degree}, 90{degree} (edge), 120 and 150{degree}. The `ideal` friction stress at 0 K of a{l_angle}101] dislocations in the P form is found to be a function of line orientation, with the close packed line directions, {l_angle}101] (screw) and {l_angle}110] (60{degree}), having friction stresses ranging from 0.001--0.002{mu}. Previously calculated results on the friction stress of a/2{l_angle}110] dislocations, using an identical potential are consistently higher than the friction stress of a{l_angle}101] dislocations. Simulations of the interaction of glide strains with the D core for the 60{degree} (line directions {l_angle}110]) and 120{degree} (line directions {l_angle}011]) orientations show that the Shockley partial trailing the SESF in the D core is strongly pinned. The dislocation moves by extension of SESF when glide stresses are applied with SESF as the trailing fault.
- OSTI ID:
- 79758
- Report Number(s):
- CONF-941144-; ISBN 1-55899-265-0; TRN: IM9531%%364
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 28 Nov - 9 Dec 1994; Other Information: PBD: 1995; Related Information: Is Part Of High-temperature ordered intermetallic alloys VI: Part 1. Materials Research Society symposium proceedings Volume 364; Horton, J. [ed.] [Oak Ridge National Lab., Oak Ridge, TN (United States)]; Baker, I. [ed.] [Dartmouth College, Hanover, NH (United States)]; Hanada, Shuji [ed.] [Tohoku Univ., Sendai (Japan)]; Noebe, R.D. [ed.] [NASA Lewis Research Center, Cleveland, OH (United States)]; Schwartz, D.S. [ed.] [McDonnell Douglas Aerospace, St. Louis, MO (United States)]; PB: 713 p.
- Country of Publication:
- United States
- Language:
- English
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