The nanometer coherent structure evolution of spinodal decomposition and ordering coexistence phase
transformation in Fe-24Al alloys is investigated by the microscopic phase field kinetic model. The results show that
the concentration and long-range order parameters all continuously change towards to their equilibrium values
during phase transformation. With the increase of elastic interaction energy, the anisotropy along [01] or [10]
elastic soft direction is more obvious and the time reaching equilibrium state is also shortened. According to the
results, the formation of nanometer coherent structures during phase transformation is composed of the initial
decreasing stage of order degree stage, the incubation stage, the continuous increasing stage of concentration order
parameter and long-range order parameter, and the later stable stage. The spinodal decomposition and ordering
is interaction; the initial ordering stage is a necessary condition of the coexistence phase transformation. The
nanometer coherent structures are not found to grow during the whole phase transformation. The simulation
results are in accordance with the results in experiment obtained by the aging treatment in Fe-24Al alloys.
ZHAO Rong-da1,2 (赵荣达), ZHU Jing-chuan2 (朱景川), LAI Zhong-hong2 (来忠红), LIU Yong2 (刘勇)
. Formation of Nanometer Coherent Structures During Spinodal
Decomposition and Ordering Coexistence Phase
Transformation in Fe-24Al Alloys[J]. Journal of Shanghai Jiaotong University(Science), 2012
, 17(4)
: 461
-464
.
DOI: 10.1007/s12204-012-1306-9
[1] Soffa W A, Laughlin D E. Recent experimental studies of continuous transformations in alloys: An
overview [C]//Proceedings of an International Conference on Solid-Solid Phase Transformations. Warrandale Pa: AIME, 1982: 159-183.
[2] Samuel M A, John W C. Mechanisms of phase transformations with the miscibility gap of Fe-rich Fe-Al alloys [J]. Acta Metallurgica, 1975, 24(2): 425-437.
[3] Ino H. A pairwise interaction model for decomposition and ordering processes in B.C.C binary alloys and its
application to the Fe-Be system [J]. Acta Metallurgica, 1978, 26(3): 827-834.
[4] Ren Xiao-bing, Wang Xiao-tian, Tadki T, et al. Theory investigation of ordering and spinodal decomposition coexistence phenomenon [J]. Science in China
(Series E), 1996, 26(3): 193-200 (in Chinese).
[5] Ni Y, Khachaturyan A G. From chessboard tweed to chessboard nanowire structure during pseudospinodal
decomposition [J]. Nature Materials, 2009, 8(2): 410-414.
[6] Chen L Q, Khachaturyan A G. Dynamic of simultaneous ordering and phase separation and effect of
long-range coulomb interactions [J]. Physical Review Letters, 1993, 70(10): 1477-1480.
[7] Chen L Q, Khachaturyan A G. Computer simulation of structural transformations during precipitation
of an ordered intermetallic phase [J]. Acta Metallurgica, 1991, 39(11): 2533-2551.
[8] Chen L Q, Khachaturyan A G. Formation of virtual ordered states along a phase-decomposition path [J].Physical Review, 1991, 44(9): 4681-4684.
[9] Wang Y, Chen L Q, Khachaturyan A G. Kinetics of strain-induced morphological transformation in cubic alloys with a miscibility gap [J]. Acta Metallurgica,1993, 41(1): 279-296.
[10] Chen L Q, Simmons J A. Microscopic master equation approach to diffusional transformation in inhomogenous systems-single-size approximation and direct
exchange mechanism [J]. Acta Metallurgica, 1994,42(9): 2943-2954.
