Dislocation mobility in potassium and iron single crystals

AbstractDislocation velocities have been measured in both lightly and heavily HCl-doped ice single crystals using synchrotron-based, monochromatic X-ray topography. In the temperature range −10°C to −30°C, a concentration of ˜1 × 10−6M was found not to affect the mobility of either 60° or screw basal dislocations, confirming the earlier observations of C. Shearwood and R. W. Whitworth [Philosophical Magazine A65, 1992, 85]. However, heavier doping (˜1.9 × 10−4M) increased the basal dislocation velocity, compared to pure ice, by a factor of 2.6 at −16.4°C.

Download Full-text

Dislocation Mobility and Yield Stress in Silver and Silver-Tin Dilute Alloy Single Crystals

Japanese Journal of Applied Physics ◽

10.1143/jjap.12.751 ◽

1973 ◽

Vol 12 (5) ◽

pp. 751-752 ◽

Cited By ~ 5

Author(s):

Hisaaki Suga ◽

Toru Imura

Keyword(s):

Single Crystals ◽

Yield Stress ◽

Dislocation Mobility ◽

Dilute Alloy

Download Full-text

Influence of Dislocation Mobility on Room and High Temperature Ductility of -Oriented Nial Single Crystals

MRS Proceedings ◽

10.1557/proc-364-413 ◽

1994 ◽

Vol 364 ◽

Cited By ~ 1

Author(s):

M. A. Morris ◽

J. P. Perez ◽

R. Darolia

Keyword(s):

High Temperature ◽

Single Crystals ◽

Room Temperature ◽

Tensile Tests ◽

Slip Systems ◽

Dislocation Mobility ◽

Screw Dislocations ◽

Large Density ◽

Thin Foils

AbstractThe dislocation configurations produced by room and high temperature compression of <100> oriented single crystals of binary NiAl and in those containing iron and hafnium additions have been analysed and compared to those obtained by hardness indentation and TEM insitu tensile tests. Kinking occurs during room temperature compression such that <100> dislocations are activated in all cases but the iron-containing alloy also exhibited a large density of <111> screw dislocations. The latter however, appear immobile when they are created by hardness indentations of thin foils, while only pile-ups of <100> segments can propagate. Similarly, although different slip systems are present after high temperature compression, only <100> dislocation segments have been confirmed to be mobile after room temperature hardness indentation of these predeformed thin foils. The improvement in ductility observed at room temperature in the predeformed specimens of the binary and the iron containing alloys has been attributed to the increased production of these mobile <100> dislocations.

Download Full-text