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| MICROMECHANICAL STUDY ON YIELD STRESS AND THE EFFECTS OF TWINNING FOR γ-TiAl-BASED PST CRYSTALS |
| SU Jilong; HU Gengkai |
| Department of Mechanics-Electrics ngineering; Fujian Agriculture and Forestry University; Fuzhou 350002 |
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Cite this article:
SU Jilong; HU Gengkai. MICROMECHANICAL STUDY ON YIELD STRESS AND THE EFFECTS OF TWINNING FOR γ-TiAl-BASED PST CRYSTALS. Acta Metall Sin, 2005, 41(12): 1243-1248 .
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Abstract An analytical micromechanical method, based on the lamellar
microstructure and dislocation slip
and twinning deformation mechanisms of polysynthetically twinning
(PST) crystal, is used to investigate the
variation of the yielding stress as function of angle θ between
the load axis and the lamellar boundaries for a PST
crystal. The sub-domain microstructure of the γ-TiAl-based alloy, PST crystal , slip system
phase in PST
crystal and the difference of CRSS in ordinary
slip and true twinning have been considered in this paper. The results
demonstrated that yielding stress relations on
loading angle with respect to the microstructure and in soft mode of
deformation, which is determined by ordinary
dislocation or superdislocation slip systems in γ phase, shear
deformation is parallel to the lamellar boundaries;
in hard mode of deformation, shear deformation crosses the lamellar
boundaries, which is controlled by twinning
in the γ phase. In addition, the predicted yield stress values of
PST crystals for three loading angles
θ=45°, 0°and 90°have the relation as
σy(45°)<σy(0°)}<σy(90°). Furthermore, the active slip and twinning
systems have also been analyzed systematically.
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Received: 14 March 2005
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[1] Appel F, Wagner R. Mater Sci Eng, 1998; R22: 187
[2] Kim Young-Won. J Met, 1994; 46: 30
[3] Dimiduk D M, Hazzledine P M, Parthasarathy T A. Met- all Mater Trans, 1998; 29A: 37
[4] FujiwaraT, Nakamura A, Hosomi M, Nishitani S R, Shirai Y, Yamaguchi M. Philos Mag, 1990; 61A: 591
[5] Kad B K, Dao M, Asaro J. Philos Mag, 1995; 71A : 567
[6] Kad B K, Dao M, Asaro J. Mater Sci Eng, 1995; A192/193: 97
[7] Brockman R A. Int J Plast, 2003; 19: 1749
[8] Schlogl S M, Fischer F D. Philos Mag, 1997; 75A: 621
[9] Schlogl S M, Fischer F D. Mater Sci Eng, 1997; A239/240: 790
[10] Yoo M H, Fu C L. Metall Mater Trans, 1998; 29A: 49
[11] Yoo M H, Zou J, Fu C L. Mater Sci Eng, 1995; A192/193: 14
[12] Wapole L J. Mech Phys Solids, 1969; 17: 235
[13] Fujiwara T, Nakamura A, Hosomi M H, Nishitani S R, Shirai Y, Yamaguchi M. Philos Mag, 1990; 61A: 591
[14] Inui H, Kishida K, Misaki M, Kobayashi M. Philos Mag, 1995; 72A: 1609 |
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