Phase transitions in grain boundaries with structural multiplicity

1989 ◽  
Vol 23 (7) ◽  
pp. 1037-1042 ◽  
Author(s):  
Craig Rottman
Keyword(s):  
Phase Transitions ◽  
Grain Boundaries

GRAIN BOUNDARIES: PHASE TRANSITIONS AND CRITICAL PHENOMENA

1991 ◽  
Vol 05 (19) ◽  
pp. 2989-3028 ◽  
Author(s):  
E.I. RABKIN ◽  
L.S. SHVINDLERMAN ◽  
B.B. STRAUMAL
Keyword(s):  
Phase Transitions ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Critical Phenomena ◽  
External Surface ◽  
Theoretical Models ◽  
Boundary Structure ◽  
Boundary Phase ◽  
Recent Experimental Data ◽  
Grain Boundary Structure

Recent theories of grain boundary structure have been reviewed briefly. The possibility of existence of the same variety of phase transitions on grain boundaries as that on the crystal external surface has been demonstrated. Recent experimental data and theoretical models concerning grain boundary phase transitions are critically analysed. Grain boundary phase transitions connected with the formation of thin disordered layers on the boundary (prewetting, premelting) are particularly distinguished. Results of recent indirect experiments, which may be treated in terms of prewetting and premelting, have been reviewed. Experimentally observed critical phenomena in the vicinity of the prewetting transition on the tin-germanium interphase boundary have been discussed in terms of the critical exponents theory. Some ideas regarding directions of further research are presented.

On Specific Phase Transitions to the Compound-Like Impurity Nanosegregation Structures at Dislocations and Grain Boundaries in Metals and their Influence on Diffusion-Assisted Processes

2008 ◽  
Vol 138 ◽  
pp. 91-118 ◽  
Author(s):  
Yuriy S. Nechaev
Keyword(s):  
Phase Transitions ◽  
Grain Boundaries ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Nanostructured Metals ◽  
Study Results ◽  
And Diffusion ◽  
Specific Phase Transitions ◽  
Specific Phase

Specific phase transitions to the compound-like impurity nanosegregation structures at dislocations and grain boundaries in metals and their influence on diffusion-assisted processes are considered, mainly, on the basis of the thermodynamic analysis of the related experimental data. The following systems and aspects are in detail considered: (1) the hydride-like nanosegregation of hydrogen at dislocations and grain boundaries in palladium and their influence on the apparent characteristics of hydrogen solubility and diffusivity in palladium; (2) the physics of the anomalous characteristics of diffusion of Fe and other transition impurities in crystalline Al at elevated temperatures, the role of the compound-like nanosegregation (CLNS) of Fe and the others at dislocations and grain boundaries in Al, analysis of the Mössbauer and diffusion data on CLNS of Fe at grain boundaries and dislocations in Al; (3) some new physical aspects of internal oxidation and nitridation of metals (for Cu-0.3%Fe alloy/Cu2O surface layer, and for (Ni-5%Cr) alloy / N2 gas), the role of the compound-like impurity nanosegregation at dislocations and grain boundaries, study results on the deviations from the classical theories predictions and their interpretation. The possibility is considered of nanotechnology applications of the study results for creation of nanostructured metals with compound-like nanosegregation structures at grain boundaries, in order to obtain specific physical and mechanical properties of such a cellural-type nanocomposites. In particular, it can be complex hydride-like, carbide-like, nitride-like, carbide-nitride-like, oxide-like or intermetallide-like nanosegregation structures at grain boundaries of nanostructured metals.

Pseudopartial Grain Boundary Wetting: Key to the Thin Intergranular Layers

2013 ◽  
Vol 333 ◽  
pp. 175-192 ◽  
Author(s):  
Boris B. Straumal ◽  
Alexey Rodin ◽  
A.E. Shotanov ◽  
Alexander B. Straumal ◽  
Olga A. Kogtenkova ◽  
...  
Keyword(s):  
Contact Angle ◽  
Phase Transitions ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Thin Layers ◽  
Second Phase ◽  
Triple Junctions ◽  
Complete Wetting ◽  
Grain Boundary Wetting

The thin layers of a second phase (also called complexions) in grain boundaries (GB) and triple junctions (TJs) are more and more frequently observed in polycrystals. The prewetting (or premelting) phase transitions were the first phenomena proposed to explain their existence. The deficit of the wetting phase in case of complete wetting can also lead to the formation of thin GB and TJ phases. However, only the phenomenon of pseudopartial (or pseudoincomplete, or constrained complete) wetting permitted to explain, how the thin GB film can exist in the equilibrium with GB lenses of a second phase with non-zero contact angle.

Segregation and Phase Transitions in Grain Boundaries

2019 ◽  
Vol 22 ◽  
pp. 160-169
Author(s):  
Boris Bokstein ◽  
Alexey Rodin ◽  
Aleksei Itckovich ◽  
Leonid Klinger
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Computer Modeling ◽  
Boundary Segregation ◽  
Short Description ◽  
Grain Boundary Segregation ◽  
Atomic Interactions

The paper is devoted to some properties of grain boundaries: Segregation and concentration phase transitions – two important consequences of atomic interactions in grain boundaries. Except of a short description the Gibbs method of surface excesses and grain boundary segregation isotherms with the limited number of segregation sites in grain boundary, the paper concentrates on the effects of complexes formation, including thermodynamic and computer modeling, and concentration phase transition in the grain boundaries in systems with restricted solubility and intermediate compounds.

scholarly journals Sculpted grain boundaries in soft crystals

2019 ◽  
Vol 5 (11) ◽  
pp. eaax9112 ◽  
Author(s):  
Xiao Li ◽  
José A. Martínez-González ◽  
Orlando Guzmán ◽  
Xuedan Ma ◽  
Kangho Park ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Grain Boundaries ◽  
Liquid Crystalline ◽  
Three Dimensional ◽  
Soft Materials ◽  
Lattice Orientation ◽  
Liquid Interfaces ◽  
Crystalline Materials ◽  
Precise Control ◽  
Adsorption Processes

Engineering the grain boundaries of crystalline materials represents an enduring challenge, particularly in the case of soft materials. Grain boundaries, however, can provide preferential sites for chemical reactions, adsorption processes, nucleation of phase transitions, and mechanical transformations. In this work, “soft heteroepitaxy” is used to exert precise control over the lattice orientation of three-dimensional liquid crystalline soft crystals, thereby granting the ability to sculpt the grain boundaries between them. Since these soft crystals are liquid-like in nature, the heteroepitaxy approach introduced here provides a clear strategy to accurately mold liquid-liquid interfaces in structured liquids with a hitherto unavailable level of precision.

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