Glide on {111} planes in NaCl

The stress relaxation method is used to obtain the internal and effective stresses, and, also, an average dislocation velocity in deformed NaCl polycrystals. The grain size reduction and increasing stress result in the fact that the dragging role of grain boundaries increases and the dislocation interaction gets strong. Owing to this, the effective stress increases and an average dislocation velocity does not coincide with the velocity of individual dislocations as different from the case for NaCl single crystals. An activation volume decrease with deformation caused by point formation during plastic deformation is observed.

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Dislocation structure of plastically deformed NaCl polycrystals

Nadgornyi

Strunk

1987

Phys. Stat. Sol. (a)

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NaCl polycrystals, produced by press forging of single crystals at 275°C, are deformed in compression at room temperature. The dislocation structure is analysed by transmission electron microscopy as a function of the flow stress. Macroscopic yield of the polycrystals occurs at a stress that is equivalent to the flow stress of single crystals deforming in single glide at a comparable dislocation density. During deformation, a three‐dimensional dislocation structure is observed to form within the grains. This structure bears strong resemblance with that observed in [111]‐ orientated NaCl single crystals. Consistently, the high flow stress of the polycrystals arises due to the activation of considerable glide in subsidiary glide systems. This activation is necessary to accomodate the plastic incompatibilities that occur at the grain boundaries of the polycrystals.

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Glide on {111} planes in NaCl

Abstract: The investigation of plastically deformed [111]‐orientated NaCl single crystals by etching and X‐ray topography reveals that glide starts on {111} planes. Additional glide on other planes, including {100}, initiates only at a higher shear stress level.

Cited by 9 publications

References 9 publications

Evidence for glide of charged dislocations on {111} planes in NaCl crystals

Evidence for glide of charged dislocations on {111} planes in NaCl crystals

Effect of the Polycrystalline Structure on the Relaxation Processes and Dislocation Motion in NaCl Crystals

Dislocation structure of plastically deformed NaCl polycrystals

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