Dislocations in Lithium Fluoride Crystals

Micromechanics of shear banding

“…In the latter case the distances were exactly twice as long (Gilman and Johnston, 1962). This proved that the motion is steady.…”

“…The theory of plastic yielding that was developed using these expressions generates both upper and lower yield-points without adjustable parameters (Gilman and Johnston, 1962). The upper yield-point is determined by a balance between the displacement-rate created by the applied tractions (as modified by the elastic response of the macroscopic loading system), and the displacement-rate response of the specimen.…”

“…As long as they can do this without interfering with one another there is little macroscopic strainhardening, but when a specimen becomes filled with the initially operative shear bands, the macroscopic stress begins to rise (Stokes, 1964) as illustrated by Another general feature of the multiplication process is that the rate is very stress (or velocity) dependent (Gilman and Johnston, 1962). Thus it was…”

Dislocations and Plastic Deformation in MgO Crystals: A Review

“…Since MgO and relatives such as LiF or KCl are brittle at room temperature, micro-indentation test was used early in the 1950s to introduce local plasticity [140,141]. The first analyses of the dislocation structure around the indent were carried out by Keh [142] and Newey [143].…”

Geschwindigkeiten von Schrauben- und 60° -Versetzungen in Germanium

“…Eine Beobachtung der Versetzungen kann durch Anatzen der DurchstoBpunkte dieser Versetzungen durch die Oberflache des Halbleiterkristalls erfolgen. Die Bewegung solcher Versetzungen wird nach Anwendung des r r Mehrfachatzverfahrens " (Gilman und Johnston 1962) sichtbar : Die Ausgangslage der Versetzung wird durch Anatzen markiert. Wird in einem darauffolgenden Experiment die Versetzung bewegt und erneut angeiitzt, dann erscheint die neue Lage der Versetzung wieder als Atzgriibchen, wahrend sicli das alte Atzgriibchen weiter vergroBert und von dem neuen deutlich unterscheidet.…”