scholarly journals Molecular Dynamics Calculations of Grain Boundary Mobility in CdTe

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 552 ◽  
Author(s):  
Rodolfo Aguirre ◽  
Sharmin Abdullah ◽  
Xiaowang Zhou ◽  
David Zubia
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Driving Forces ◽  
Md Simulations ◽  
Face Centered Cubic ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Different Temperatures ◽  
Lower Mobility

Molecular dynamics (MD) simulations have been applied to study mobilities of Σ3, Σ7 and Σ11 grain boundaries in CdTe. First, an existing MD approach to drive the motion of grain boundaries in face-centered-cubic and body-centered-cubic crystals was generalized for arbitrary crystals. MD simulations were next performed to calculate grain boundary velocities in CdTe crystals at different temperatures, driving forces, and grain boundary terminations. Here a grain boundary is said to be Te-terminated if its migration encounters sequentially C d · T e − C d · T e … planes, where “·” and “−” represent short and long spacing respectively. Likewise, a grain boundary is said to be Cd-terminated if its migration encounters sequentially T e · C d − T e · C d … planes. Grain boundary mobility laws, suitable for engineering time and length scales, were then obtained by fitting the MD results to Arrhenius equation. These studies indicated that the Σ3 grain boundary has significantly lower mobility than the Σ7 and Σ11 grain boundaries. The Σ7 Te-terminated grain boundary has lower mobility than the Σ7 Cd-terminated grain boundary, and that the Σ11 Cd-terminated grain boundary has lower mobility than the Σ11 Te-terminated grain boundary.

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.

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.

The interaction between basal-twin boundaries and a glassy phase in α-Alumina compacts

1988 ◽  
Vol 46 ◽  
pp. 570-571
Author(s):  
Yonn Kouh Simpson ◽  
C. Barry Carter
Keyword(s):  
Liquid Phase ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Glassy Phase ◽  
Liquid Phase Sintering ◽  
Boundary Mobility ◽  
Scientific Interest ◽  
Strong Anisotropy ◽  
Grain Boundary Mobility ◽  
Polycrystalline Ceramics

Understanding the nature of glass/crystalline interfaces is not only of fundamental scientific interest but is directly relevant to the liquid-phase sintering of polycrystalline ceramics such as α-alumina. Faceting behavior of alumina in the presence of SiO2 glass has been of much interest in the field of sintering with respect to the grain growth and the grain boundary mobility during sintering. The study of grain boundaries containing a glassy phase in alumina compacts is difficult however, since many of the TEM techniques presently available for the identification of a glassy phase at grain boundaries can give ambiguous results due to grain boundary grooving. A method for systematically studying glassy / crystalline interfaces without such ambiguity is therefore needed. Part of this study of the interaction of grain boundaries in alumina with an anorthite-based glassy phase is presented here.Previous systematic studies4 of different low-index surfaces of single crystal alumina showed that there is strong anisotropy in the faceting behavior of alumina and in the mobility of these facets in the presence of an anorthite-based glassy phase.

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.

Simulation of Recrystallization Using Molecular Dynamics; Effects of the Interatomic Potential

2007 ◽  
Vol 558-559 ◽  
pp. 1081-1086 ◽  
Author(s):  
Rasmus B. Godiksen ◽  
Zachary T. Trautt ◽  
Moneesh Upmanyu ◽  
Søren Schmidt ◽  
Dorte Juul Jensen
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Interatomic Potential ◽  
Driving Forces ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
High Angle ◽  
Embedded Atom ◽  
Atomic Interactions

Recrystallization is governed by the migration of high angle grain boundaries traveling through a deformed material driven by the excess energy located primarily in dislocation structures. A method for investigating the interaction between a migrating grain boundary and dislocation boundaries using molecular dynamics (MD) was recently developed. During simulations migrating high angle grain boundaries interact with dislocation boundaries, and individual dislocations from the dislocation boundaries are absorbed into the grain boundaries. Results obtained previously, using a simple Lennard-Jones (LJ) potential, showed surprisingly irregular grain boundary migration compared to simulations of grain boundary migration applying other types of driving forces. Inhomogeneous boundary-dislocation interactions were also observed in which the grain boundaries locally acquired significant cusps during dislocation absorption events. The study presented here makes comparisons between simulations performed using a LJ- and an embedded atom method (EAM) aluminum potential. The results show similarities which indicate that it is the crystallographic features rather than the atomic interactions that determine the details of the migration process.

Sign in / Sign up

Export Citation Format

Share Document