scholarly journals Secondary Recrystallization Goss Texture Development in a Binary Fe81Ga19 Sheet Induced by Inherent Grain Boundary Mobility

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1254
Author(s):  
Zhenghua He ◽  
Yuhui Sha ◽  
Ning Shan ◽  
Yongkuang Gao ◽  
Fan Lei ◽  
...  

Secondary recrystallization Goss texture was efficiently achieved in rolled, binary Fe81Ga19 alloy sheets without the traditional dependence on inhibitors and the surface energy effect. The development of abnormal grain growth (AGG) of Goss grains was analyzed by quasi-situ electron backscatter diffraction (EBSD). The special primary recrystallization texture with strong {112}–{111}<110> and weak Goss texture provides the inherent pinning effect for normal grain growth by a large number of low angle grain boundaries (<15°) and very high angle grain boundaries (>45°) according to the calculation of misorientation angle distribution. The evolution of grain orientation and grain boundary characteristic indicates that the higher fraction of high energy grain boundaries (20–45°) around primary Goss grains supplies a relative advantage in grain boundary mobility from 950 °C to 1000 °C. The secondary recrystallization in binary Fe81Ga19 alloy is realized in terms of the controllable grain boundary mobility difference between Goss and matrix grains, coupled with the orientation and misorientation angle distribution of adjacent matrix grains.

2013 ◽  
Vol 753 ◽  
pp. 107-112 ◽  
Author(s):  
Christoph Günster ◽  
Dmitri A. Molodov ◽  
Günter Gottstein

The motion of grain boundaries in zinc bicrystals (99.995%) driven by the “magnetic” driving force was investigated. Planar symmetrical and asymmetrical tilt grain boundaries with rotation angles in the range between 60° and 90° were examined. At a given temperature the boundary migration rate was found to increase linearly with an applied driving force. The absolute grain boundary mobility was determined. The boundary mobility and its temperature dependence were found to depend on the misorientation angle and the inclination of the boundary plane. An application of a magnetic field during the annealing of cold rolled (90%) Zn-1.1%Al sheet specimens resulted in an asymmetry of the two major texture components. This is interpreted in terms of magnetically affected grain growth kinetics.


2004 ◽  
Vol 467-470 ◽  
pp. 1045-1050 ◽  
Author(s):  
Koenraad G.F. Janssens ◽  
Elizabeth A. Holm ◽  
Stephen M. Foiles

In this paper we discuss the principles of a combined approach to solve the problem of solute drag as it occurs in microstructure evolution processes such as grain growth, recrystallization and phase transformation. A recently developed irregular grid cellular automaton is used to simulate normal grain growth, in which the energy of the grain boundaries is the driving force. A new, discrete diffusion model is used to simulate solute segregation to the grain boundaries. The local concentration of the solute is then taken into account in the calculation of the local grain boundary mobility and/or grain boundary energy, thereby constituting a drag force. The relation between solute concentration and grain boundary mobility/energy is derived from molecular dynamics simulations.


2005 ◽  
Vol 495-497 ◽  
pp. 1231-1236
Author(s):  
Vera G. Sursaeva

Texture formation during secondary recrystallization depends on the nature of secondary recrystallization process itself. So microstructure evolution and texture development during secondary recrystallization should be discussed concurrently. The main goal of the paper is studying of the effect of internal stresses on grain boundary motion or, more generally, the interaction of grain boundaries with stress fields and the effect of deformation inhomogeniety on grain boundary mobility during secondary recrystallization. Considering transformation from normal grain growth to secondary recrystallization, the attempt was made to characterize the microstructure and to relate it to the processes of nucleation and growth of new rains. The nucleation process is heterogeneous. The data allow us to assume that the nuclei are strain free grains.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 370
Author(s):  
Chih-Ting Lai ◽  
Hsuan-Hao Lai ◽  
Yen-Hao Su ◽  
Fei-Ya Huang ◽  
Chi-Kang Lin ◽  
...  

In this study, the effects of the addition of Mg to the grain growth of austenite and the magnesium-based inclusions to mobility were investigated in SS400 steel at high temperatures. A high-temperature confocal scanning laser microscope (HT-CSLM) was employed to directly observe, in situ, the grain structure of austenite under 25 torr Ar at high temperatures. The grain size distribution of austenite showed the log-normal distribution. The results of the grain growth curves using 3D surface fitting showed that the n and Q values of the growth equation parameters ranged from 0.2 to 0.26 and from 405 kJ/mole to 752 kJ/mole, respectively, when adding 5.6–22 ppm of Mg. Increasing the temperature from 1150 to 1250 °C for 20 min and increasing the addition of Mg by 5.6, 11, and 22 ppm resulted in increases in the grain boundary velocity. The effects of solute drag and Zener pinning on grain boundary mobility were also calculated in this study.


2007 ◽  
Vol 558-559 ◽  
pp. 747-750 ◽  
Author(s):  
Kyu Seok Han ◽  
Jong Tae Park ◽  
Jae Kwan Kim ◽  
Jerzy A. Szpunar

Recrystallization texture in grain oriented silicon steel at different annealing temperature is investigated. Normalized x-ray intensities of various orientation components observed in Orientation Distribution Function are used for comparison. The computed CSL boundary distributions about Goss component with annealing condition were calculated. The misorientation angle distribution is also measured in order to find the importance of high-energy boundary with misorientation 20~45° range for the secondary recrystallization of Goss grain. From the analysis of CSL boundary distribution and misorienation angle distribution, the distribution of CSL boundaries does not evidently show any preferred difference between Goss and other texture components. Whereas, the misorientation angle analysis shows that the number of 20°~45° misoriented boundaries is higher around the Goss grains than around other texture components.


2004 ◽  
Vol 467-470 ◽  
pp. 745-750 ◽  
Author(s):  
Nong Moon Hwang

Although it has been generally believed that the advantage of the grain boundary mobility induces abnormal grain growth (AGG), it is suggested that the advantage of the low grain boundary energy, which favors the growth by solid-state wetting, induces AGG. Analyses based on Monte Carlo (MC) simulation show that the approach by solid-state wetting could explain AGG much better than that by grain boundary mobility. AGG by solid-state wetting is supported not only by MC simulations but also by the experimental observation of microstructure evolution near or at the growth front of abnormally growing grain. The microstructure shows island grains and solid-state wetting along grain boundary and triple junction.


Electron microscope observations on some polycrystalline metals suggest that after small to moderate deformation, recrystallization occurs by the migration of the original grain boundaries. A theory based on this mechanism can account for the known form of the recrystallization kinetics without necessarily introducing any anisotropy of grain boundary mobility. For this mechanism the so-called recrystallization activation energy is identical to the activation energy for grain boundary migration.


2012 ◽  
Vol 715-716 ◽  
pp. 191-196
Author(s):  
Myrjam Winning ◽  
Dierk Raabe

The paper introduces first investigations on how low angle grain boundaries can influence the recrystallisation behaviour of crystalline metallic materials. For this purpose a three-dimensional cellular automaton model was used. The approach in this study is to allow even low angle grain boundaries to move during recrystallisation. The effect of this non-zero mobility of low angle grain boundaries will be analysed for the recrystallisation of deformed Al single crystals with Cube orientation. It will be shown that low angle grain boundaries indeed influence the kinetics as well as the texture evolution of metallic materials during recrystallisation.


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