Evolution of substructures in deformed NiAl single crystals oriented for single slip

1999 ◽  
Vol 79 (7) ◽  
pp. 1555-1566 ◽  
Author(s):  
Xiaoli Shi ◽  
S. Mahajan ◽  
T. M. Pollock ◽  
V. S. Arunachalam
Keyword(s):  
Single Crystals ◽  
Single Slip

The yield strength anomaly of single-slip-oriented Fe–Al single crystals

2007 ◽  
Vol 15 (2) ◽  
pp. 103-107 ◽  
Author(s):  
D. Wu ◽  
I. Baker ◽  
P.R. Munroe ◽  
E.P. George
Keyword(s):  
Yield Strength ◽  
Single Crystals ◽  
Single Slip

Surface film softening of iron single crystals oriented for single slip

1977 ◽  
Vol 39 (2) ◽  
pp. 491-498 ◽  
Author(s):  
K. Kojima ◽  
M. Meshii
Keyword(s):  
Single Crystals ◽  
Surface Film ◽  
Single Slip

The detection of submicroscopic lattice defects in aluminium utilizing a vacancy supersaturation

1969 ◽  
Vol 314 (1516) ◽  
pp. 129-141 ◽  
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Lattice Defects ◽  
Supersaturated Solution ◽  
Dislocation Loops ◽  
Single Slip ◽  
Quench Temperature ◽  
Decoration Technique

The conditions under which submicroscopic defects can be revealed due to decoration by the precipitation of vacant lattice sites from a supersaturated solution have been investigated in aluminium. It is shown that quench temperature, specimen purity and other conditions have to be so chosen that the nucleation of self-sinks is minimized while an adequate vacancy supersaturation is maintained. The conditions for the optimum visibility of defects revealed in this way have been studied primarily by observing the variation in the density of rows of dislocation loops along <110> directions. This decoration technique has been used in quenched single crystals deformed in single slip to show that these rows and also narrow faulted dislocation dipoles with their long axes in the <110> direction form along the specific <110> direction predicted from a hypothesis involving the dragging of a jog by a moving screw dislocation.

Dislocation Structure in Single Crystal L1o Type Ti-Al-V Compound

1990 ◽  
Vol 213 ◽  
Author(s):  
Y.D. Hahn ◽  
Z.X. Li ◽  
S.H. Whang ◽  
T. Kawabata
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
High Temperatures ◽  
Dislocation Structure ◽  
The Other ◽  
Dislocation Loops ◽  
Single Slip ◽  
Pile Up ◽  
Favorable Configuration ◽  
Dipole Form

ABSTRACTSingle Crystals of L1o type Ti44Al54V2 alloy were deformed at high temperatures and various orientations. The dislocations thus produced by single slip were studied by TEM. 1/2<110] dislocations produced at 1073 K consist of dislocation loops and curled dislocations with spiral segments, which is in agreement with those shown in the polycrystalline Ti-Al-V, and -Nb alloys deformed under the same conditions. The normal dislocations produced at 873 K pile up in groups, each of which contains several straight dislocations with a screw character. On the other hand, the majority of superdislocations produced at 873 K were found in a dipole form, indicating that the dipole is a favorable configuration at this temperature.

Micromechanisms of deformation in γ-TiAl

2002 ◽  
Vol 753 ◽  
Author(s):  
Patrick Veyssière ◽  
Yu-Lung Chiu ◽  
Fabienne Grégori
Keyword(s):  
Single Crystals ◽  
Lamellar Structure ◽  
Deformation Mechanisms ◽  
Slip Systems ◽  
Plastic Properties ◽  
Single Slip ◽  
Self Organisation

ABSTRACTInvestigations conducted in our group on plastic properties of a variety of strained TiAl based alloys and resulting microstructures are reviewed. These include oriented single crystals of Al-rich γ-TiAl and semi-oriented polycrystals with γ + α2 lamellar structure. The wealth of micro-mechanisms encountered in this family of alloys is, to large extent, due to the decomposition of <011] dislocations: <011] ↔ 1/2<112] + 1/2<110]. This transformation sometimes introduces serious uncertainties as to which slip systems were actually operating during deformation. Another transformation involving decomposition is the formation of intralamellar networks during deformation. Mechanisms not involving decomposition include the trailing of faulted dipoles by <011] dislocations and the generation of arrays of prismatic loops of ordinary dislocations. The latter maneuver is at the origin of fundamental processes such as self-organisation in single slip in a variety of crystals.

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