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Title: Grain boundary phase equilibria in metallic systems: Progress report, December 1, 1986--April 30, 1989

Abstract

A method for growing high purity aluminum bicrystals with controlled misorientation and grain boundary (GB) plane inclination has been successfully implemented. Computer simulations of a ..sigma.. = 5 (001) symmetric tilt GB in aluminum does not undergo premelting but exhibit a second-order transition associated with an increase in atomic mobility in the GB plane. A GB rotation transition in a ..sigma.. = 5 bicrystal from a (210) inclination to a (38 19 1) orientation has been characterized as a first order phase transition. It takes place by differential shear of the grains across the interface. The driving force for rotation is related to the amount of torque the interface may sustain. The elastic energy contribution to segregation of point defects to planar defects is short range. This elastic contribution is long range if the GB is stresses with points of dilatation. Segregation may result in the complete filling of the interface with solute atoms or the formation of regions of high solute concentration along the interface. High resolution electron microscopy images of a near twin boundary in aluminum shows relaxation of secondary grain boundary dislocation cores when the burgers vectors are parallel to the interface plane. The relaxation leads tomore » a local change in translation state of the GB. 8 figs.« less

Authors:
Publication Date:
Research Org.:
Univ. of Arizona, Tucson, AZ (United States)
OSTI Identifier:
6295548
Report Number(s):
DOE/ER/45285-3
ON: DE89011787
DOE Contract Number:  
FG02-87ER45285
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM; FABRICATION; BICRYSTALS; COMPUTERIZED SIMULATION; EQUILIBRIUM; GRAIN BOUNDARIES; GRAIN ORIENTATION; INTERFACES; MICROSTRUCTURE; PHASE TRANSFORMATIONS; PROGRESS REPORT; SEGREGATION; TEMPERATURE DEPENDENCE; TORQUE; TWINNING; CRYSTAL STRUCTURE; CRYSTALS; DOCUMENT TYPES; ELEMENTS; METALS; ORIENTATION; POLYCRYSTALS; SIMULATION; 360101* - Metals & Alloys- Preparation & Fabrication; 360102 - Metals & Alloys- Structure & Phase Studies

Citation Formats

Deymier, P. A. Grain boundary phase equilibria in metallic systems: Progress report, December 1, 1986--April 30, 1989. United States: N. p., 1989. Web. doi:10.2172/6295548.
Deymier, P. A. Grain boundary phase equilibria in metallic systems: Progress report, December 1, 1986--April 30, 1989. United States. https://doi.org/10.2172/6295548
Deymier, P. A. 1989. "Grain boundary phase equilibria in metallic systems: Progress report, December 1, 1986--April 30, 1989". United States. https://doi.org/10.2172/6295548. https://www.osti.gov/servlets/purl/6295548.
@article{osti_6295548,
title = {Grain boundary phase equilibria in metallic systems: Progress report, December 1, 1986--April 30, 1989},
author = {Deymier, P. A.},
abstractNote = {A method for growing high purity aluminum bicrystals with controlled misorientation and grain boundary (GB) plane inclination has been successfully implemented. Computer simulations of a ..sigma.. = 5 (001) symmetric tilt GB in aluminum does not undergo premelting but exhibit a second-order transition associated with an increase in atomic mobility in the GB plane. A GB rotation transition in a ..sigma.. = 5 bicrystal from a (210) inclination to a (38 19 1) orientation has been characterized as a first order phase transition. It takes place by differential shear of the grains across the interface. The driving force for rotation is related to the amount of torque the interface may sustain. The elastic energy contribution to segregation of point defects to planar defects is short range. This elastic contribution is long range if the GB is stresses with points of dilatation. Segregation may result in the complete filling of the interface with solute atoms or the formation of regions of high solute concentration along the interface. High resolution electron microscopy images of a near twin boundary in aluminum shows relaxation of secondary grain boundary dislocation cores when the burgers vectors are parallel to the interface plane. The relaxation leads to a local change in translation state of the GB. 8 figs.},
doi = {10.2172/6295548},
url = {https://www.osti.gov/biblio/6295548}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Apr 01 00:00:00 EST 1989},
month = {Sat Apr 01 00:00:00 EST 1989}
}