scholarly journals The Structure Effect on Selective Growth in Recrystallization

Texture ◽  
1975 ◽  
Vol 2 (1) ◽  
pp. 35-44 ◽  
Author(s):  
V. Ju. Novikov
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Secondary Recrystallization ◽  
Primary Recrystallization ◽  
Grain Boundary Mobility ◽  
Effective Mobility ◽  
The Matrix ◽  
The Difference ◽  
Grain Misorientation ◽  
Misorientation Angles

The effect of the dependence of grain boundary mobility on misorientation angle and that of structure of the matrix on the growth selectivity during primary and secondary recrystallization are discussed. It was found that the longer is the distance travelled by the growing grain boundaries and the wider the range of the misorientation angles between the new grains and the matrix, the less is the difference between the grain boundary mobilities of the growing grains, necessary for the manifestation of growth selectivity. So during secondary recrystallization the latter is more manifest. In primary recrystallization after moderate deformations, the growth selectivity will be the least obvious when the deformed matrix consists of small differently oriented areas at whose borders new grains nucleate simultaneously. The secondary grain boundaries should be characterized by “effective” mobility, which depends on the number of the adjacent grains and their dimensions, as well as on the growing grain misorientation in relation to these grains. In the small grained material without a texture, the effective boundary mobilities of any grains are equal, and so the growth selectivity in such a material is non-existing.

Observation of Growth Front on the Initial Stage of Goss Abnormally-Growing Grain in Fe-3%Si Steel

2013 ◽  
Vol 753 ◽  
pp. 307-310
Author(s):  
Kyung Jun Ko ◽  
Jong Tae Park ◽  
Chan Hee Han
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Three Dimensional ◽  
Secondary Recrystallization ◽  
Growth Front ◽  
Very High Frequency ◽  
Grain Boundary Mobility ◽  
Initial Stage ◽  
The Matrix

During abnormal grain growth, a few Goss grains grow exclusively fast and consume the matrix grains. The Goss abnormally-growing grain (AGG) has peculiar features which are irregular grain boundaries and very high frequency of peninsular grains nearby the growth front of AGG and island grains trapped inside AGG. These features might provide a clue for clarifying the mechanism of Goss AGG. The experimentally-observed microstructural feature and grain boundary characterization of Goss were approached by the solid-state wetting mechanism. In this study, observing the three-dimensional wetting morphology in serial section images of Goss AGG by EBSD, we report some direct microstrucrual evidence supporting solid-state wetting mechanism for Goss AGG. The solid-state wetting mechanism for the evolution of the Goss AGG in Fe-3%Si steel explains the microstructural features evolved during secondary recrystallization, which cannot be approached by the conventional theories based on the grain boundary mobility.

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 ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Misorientation Angle ◽  
Secondary Recrystallization ◽  
Angle Distribution ◽  
Boundary Mobility ◽  
Goss Texture ◽  
Grain Boundary Mobility ◽  
Misorientation Angle Distribution

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.

Effect of Hexagonal Crystal Structure Anisotropy on the Selective Grain Boundary Mobility during Texture Formation and Secondary Recrystallization in Zn

2005 ◽  
Vol 495-497 ◽  
pp. 1231-1236
Author(s):  
Vera G. Sursaeva
Keyword(s):  
Grain Boundary ◽  
Secondary Recrystallization ◽  
Stress Fields ◽  
Internal Stresses ◽  
Recrystallization Process ◽  
Boundary Mobility ◽  
Texture Formation ◽  
Hexagonal Crystal ◽  
Grain Boundary Mobility ◽  
Grain Boundary Motion

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.

Grain Boundary Diffusion and Segregation in the Solid State Phase Transformations

1998 ◽  
Vol 527 ◽  
Author(s):  
E. Rabkin ◽  
W. Gust
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Solute Diffusion ◽  
Apparent Difference ◽  
Impurity Drag ◽  
The Difference ◽  
Boundary Width ◽  
Dynamic Segregation

ABSTRACTWe consider the problem of solute diffusion and segregation in the grain boundaries moving during a phase transformation in the framework of Cahn's impurity drag model. The concept of a dynamic segregation factor for the diffusion along moving grain boundaries is introduced. The difference between static and dynamic segregation factors may cause the apparent difference of the triple product of the segregation factor, grain boundary width and grain boundary diffusion coefficient for stationary and moving grain boundaries. The difference between static and dynamic segregation is experimentally verified for the Cu(In)-Bi system, for which the parameters of static segregation are well-known. It is shown that the complications associated with the dynamic segregation may be avoided during the study of the discontinuous ordering reaction. From the kinetics of this reaction, the activation energy of the grain boundary self-diffusion can be determined.

Characterization of Zinalco Alloy Superplastically Deformed Using Orientation Imaging Microscopy

2009 ◽  
Vol 1242 ◽  
Author(s):  
Ramos A. Mitsuo ◽  
Martínez F. Elizabeth ◽  
Negrete S. Jesús ◽  
Torres-Villaseñor G.
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Superplastic Deformation ◽  
Orientation Imaging Microscopy ◽  
Grain Boundary Sliding ◽  
Boundary Misorientation ◽  
Average Grain Size ◽  
Grain Boundary Misorientation ◽  
Misorientation Angles

ABSTRACTZinalco alloy (Zn-21mass%Al-2mass%Cu) specimens were deformed superplastically with a strain rate (ε) of 1×10-3 s-1 at homologous temperature (TH) of 0.68 (5 ). It was observed neck formation that indicate nonhomegeneus deformation. Grain size and grain boundaries misorientation changes, due superplastic deformation, were characterized by Orientation Imagining Microscopy (OIM) technique. It was studied three regions in deformed specimens and the results were compared with the results for a specimen without deformation. Average grain size of 1 mm was observed in non-deformed specimen and a fraction of 82% for grain boundary misorientation angles with a grain boundaries angles between 15° and 55° was found. For deformed specimen, the fraction of angles between 15° and 55° was decreced to average value of 75% and fractions of low angle (<5°) and high angle (>55°) misorientations were 10% and 15% respectively. The grain size and high fraction of grain boundary misorientation angles between 15° and 55° observed in the alloy without deformation, are favorable for grain rotation and grain boundary sliding (GBS) procces. The changes observed in the fraction of favorable grain boundary angles during superplastic deformation, shown that the superplastic capacity of Zinalco was reduced with the deformation.

The recrystallization process in some polycrystalline metals

1962 ◽  
Vol 267 (1328) ◽  
pp. 11-30 ◽  
Keyword(s):  
Activation Energy ◽  
Electron Microscope ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Recrystallization Process ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Polycrystalline Metals

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.

Simulation of Primary Recrystallization in Automotive Steels by Consideration of Particle Pinning

2007 ◽  
Vol 558-559 ◽  
pp. 171-176
Author(s):  
Shi Hoon Choi ◽  
B.J. Kim ◽  
S.I. Kim ◽  
Jin Won Choi ◽  
Kwang Geun Chin
Keyword(s):  
Grain Boundary ◽  
Fine Particles ◽  
Boundary Energy ◽  
Sheet Steel ◽  
Primary Recrystallization ◽  
Subgrain Structure ◽  
Interstitial Free ◽  
Stored Energy ◽  
Boundary Misorientation ◽  
Grain Boundary Mobility

A modified two dimensional (2-D) Monte Carlo (MC) technique was used to simulate primary recrystallization in automotive steels containing fine particles. In order to consider anisotropic properties of grain boundary energy and grain boundary mobility, functions of boundary misorientation were introduced. Orientation-dependent stored energy developed in 80% cold-rolled interstitial free (IF) sheet steel was evaluated by reconstructing of data measured using electron back-scattered diffraction (EBSD) analysis. A subgrain method based on subgrain structure is used for quantitative analysis of the stored energy. The simulation reveals that particles affect evolution of microstructure during recrystallization. The simulation provided a theoretical foundation for understanding effect of particles on the final microstructures and crystallographic textures.

Influence of Grain Boundary Mobility on Microstructure Evolution during Recrystallisation

2012 ◽  
Vol 715-716 ◽  
pp. 191-196
Author(s):  
Myrjam Winning ◽  
Dierk Raabe
Keyword(s):  
Grain Boundary ◽  
Cellular Automaton ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Microstructure Evolution ◽  
Texture Evolution ◽  
Three Dimensional ◽  
Boundary Mobility ◽  
Metallic Materials ◽  
Grain Boundary Mobility

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.

Study of Bonding of Grain Boundaries in Steels Using EELS

2005 ◽  
Vol 475-479 ◽  
pp. 4063-4066
Author(s):  
X. Zhang ◽  
Lina Zhang ◽  
Jun Jie Qi ◽  
Yue Ma
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Intergranular Fracture ◽  
Fracture Mode ◽  
Fracture Property ◽  
Transgranular Fracture ◽  
The Difference ◽  
Relationship Of ◽  
The Relationship

A novel EELS technique was developed to study bonding of grain boundary in many kinds of steels. We measured the normalized intensities of Fe white lines and calculated the occupancies of 3d states of iron, and then analyzed the relationship of the occupancies of 3d states of iron and the fracture property of the steels. We found that if the grain boundary has a different occupancy of 3d state of iron from that of the bulk, the steel tends to have an intergranular fracture, whereas if the grain boundary has almost the same occupancy of 3d state as the bulk, the steel tends to have a transgranular fracture. Our result shows that the difference in the occupancy of 3d state between bulk and grain boundary can be used to study the fracture mode at grain boundary in steel.

Study on Creep Properties of SiCp/AZ61 Composites

2011 ◽  
Vol 189-193 ◽  
pp. 4227-4230
Author(s):  
Hong Yan ◽  
Zhi Min Huang
Keyword(s):  
Thermal Analysis ◽  
High Temperature ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Dynamic Mechanical Thermal Analysis ◽  
Creep Properties ◽  
Casting Technique ◽  
Sic Particles ◽  
The Matrix ◽  
Semi Solid

SiCp/AZ61 composites reinforced with SiC particles were fabricated by semi-solid stirring-melt casting technique. The creep properties of the composites have been studied by dynamic mechanical thermal analysis, micro-structural and XRD observation. The results show that the matrix grains were refined obviously at high temperature with SiC particles introducing and the creep properties of SiCp/AZ61 composites were improved comparing with AZ61 alloy. SiC particles were substituted for Mg17Al12 phase that was easily intenerated at high temperature on grain boundaries. The pinning of SiC particles prevents dislocation and slip of grain boundary at high temperature.

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