Accession Number : ADA018136

Title :   Deformation Substructure of Copper Single Crystals After Explosive Loading as Disclosed by Electron-Optical and X-Ray methods,

Corporate Author : BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Personal Author(s) : Greenhut,V. A. ; Kingman,P. W. ; Weissmann,S. ; Chen,M.

Report Date : OCT 1975

Pagination or Media Count : 30

Abstract : Compressively shock-loaded copper single crystals were examined employing complementary methods of X-ray diffraction, X-ray topography (XRT), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The defect structures induced depended on the crystal orientation relative to the direction of shock propagation and also upon the existence or absence of a reflected tensile wave. TEM disclosed that the defect structure induced by compressive shock loading consisted of clusters of microtwins alternating with a tangled dislocation substructure. Failure zones did not occur. The induced defect structure exhibited a low net macroscopic misorientation which amounted to less than two degrees of arc and the misorientation of the twinned regions with respect to the adjacent dislocation substructure was less than 1/2 degree of arc. By contrast specimens subjected to a reflected tensile pulse exhibited a failure zone and the defect structure in its vicinity showed a substantial macroscopic misorientation. In addition, a high incidence of porosity was observed by SEM. The pores had octahedral shape with facets corresponding to close-packed planes. Structural details observed within the pores were identified as twinned regions. (Author)

Descriptors :   *COPPER, *SINGLE CRYSTALS, *DEFORMATION, *SHOCK WAVES, EXPLOSION EFFECTS, DEFECTS(MATERIALS), EXPLOSIONS, IMPULSE LOADING, LOADS(FORCES), ELECTRON MICROSCOPY, MICROSCOPY, ELECTRONIC SCANNERS, RADIOGRAPHY, CRYSTALS, ORIENTATION(DIRECTION), WAVE PROPAGATION

Subject Categories : Metallurgy and Metallography
      Explosions
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE