SOME ASPECTS OF THE ORIGIN OF DISLOCATIONS IN METAL CRYSTALS
Abstract
Single crystals of 99.999% pure and zone-refined Al were grown by the Czochralski method at rates of speed that varied from 0.4 to 5 mm/min. The axes of most of the crystals were parallel to a (110) direction. The crystals were carrot-shaped,ABOUT 4 CM LONG, TAPERING FROM A DIAMETER OF ABOUT 3MM AT THE TOP TO ABOUT 0.1 MM AT THE BOTTOM. X-ray diffraction micrographs were taken of the crystals by means of Lang's technique, which is capable of revealing the dislocation structure in the interior of a crystal. It was found that the density of dislocations present in an asgrown crystal increases with both increasing diameter and rate of growth. In some cases dislocations were only found on the surface of the crystals; these dislocations could be removed by careful electropolishing, thus producing crystals free of detectable dislocations. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1961
- Accession Number
- AD0252237
Entities
People
- Charles Elbaum
- Stephen Howe
Organizations
- Brown University