scholarly journals Solute Drag and Dynamic Phase Transformations in Moving Grain Boundaries

2019 ◽  
Author(s):  
Y. Mishin
Keyword(s):  
Phase Transformations ◽  
Grain Boundaries ◽  
Solute Drag ◽  
Dynamic Phase

scholarly journals Internal melt figures in ice by rapid adiabatic compression

1994 ◽  
Vol 40 (134) ◽  
pp. 132-134
Author(s):  
R.E. Gagnon ◽  
C. Tulk ◽  
H. Kiefte
Keyword(s):  
Phase Transformations ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Adiabatic Compression ◽  
Air Bubbles ◽  
Water Ice ◽  
Deep Focus ◽  
And Behavior ◽  
First Time

AbstractSingle crystals and bicrystals of water ice have been adiabatically pressurized to produce, and clearly illustrate, two types of internal melt figures: (1) dendritic figures that grow from nucleation imperfections on the specimen’s surface, or from air bubbles at grain boundaries, into the ice as pressure is elevated; and (2) compression melt fractures, flat liquid-filled disks, that nucleate at imperfections in the crystal and grow with the application of pressure eventually to sprout dendritic fingers at the periphery. The transparency of the ice permitted visualization of the growth and behavior of the figures, and this could be an important tool in understanding the role of phase transformations in deep-focus earthquakes. Correlation between figure size and pressure is noted for the first time.

scholarly journals Dynamic phase transformations in additively manufactured Ti-6Al-4V during thermo-mechanical gyrations

Materialia ◽  
2020 ◽  
Vol 14 ◽  
pp. 100883
Author(s):  
Sabina Kumar ◽  
Rakesh Kamath ◽  
Peeyush Nandwana ◽  
Yan Chen ◽  
Suresh Babu
Keyword(s):  
Phase Transformations ◽  
Dynamic Phase

scholarly journals Bicrystallography and Beyond: Example of Group–Subgroup Phase Transformations

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 560
Author(s):  
Denis Gratias ◽  
Marianne Quiquandon
Keyword(s):  
Phase Transformations ◽  
Grain Boundaries ◽  
The Other ◽  
Permutation Groups ◽  
Global Symmetry ◽  
Simple Link

This paper presents the basic elementary tools for describing the global symmetry obtained by overlapping two or more crystal variants of the same structure, differently oriented and displaced one with respect to the other. It gives an explicit simple link between the concepts used in the symmetry studies on grain boundaries on one side and group–subgroup transformations on the other side. These questions are essentially of the same nature and boil down to the resolution of the same problem: identifying the permutation groups that are images of the corresponding applications. Examples are given from both domains, classical grain boundaries with coincidence lattices and group–subgroup phase transformations that illustrate the profound similarities between the two approaches.

scholarly journals Dynamic Phase Transformation Behavior of a Nb-microalloyed Steel during Roughing Passes at Temperatures above the Ae3

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 334 ◽  
Author(s):  
Samuel Rodrigues ◽  
Fulvio Siciliano ◽  
Clodualdo Aranas ◽  
Eden Silva ◽  
Gedeon Reis ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Driving Forces ◽  
Microalloyed Steel ◽  
Solute Drag ◽  
Energy Difference ◽  
Delta Ferrite ◽  
Dynamic Phase ◽  
Plate Rolling ◽  
Nb Microalloyed Steel ◽  
Critical Strains

A five-pass torsion simulation of the roughing passes applied during hot plate rolling was performed in the single-phase austenite region of a Nb-microalloyed steel under continuous cooling conditions. The deformation temperatures were approximately half-way between the Ae3 and the delta ferrite formation temperature (i.e., 250 °C above the Ae3) in which the free energy difference of austenite and ferrite is at maximum. The microstructures in-between passes were analyzed to characterize and quantify the occurrence of deformation-induced dynamic phase transformation. It was observed that about 7% of austenite transforms into ferrite right after the final pass. The results are consistent with the calculated critical strains and driving forces which indicate that dynamic transformation (DT) can take place at any temperature above the Ae3. This mechanism occurs even with the presence of high Nb in the material, which is known to retard and hinder the occurrence of DT by means of pinning and solute drag effects. The calculated cooling rate during quenching and the time–temperature–transformation curves of the present material further verified the existence of dynamically transformed ferrite.

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