Accession Number : AD0706434

Title :   MICROSTRUCTURAL DAMAGE ADJACENT TO BULLET HOLES IN 70-30 BRASS,

Corporate Author : DEFENCE STANDARDS LABS MARIBYRNONG (AUSTRALIA)

Personal Author(s) : Craig,J. V. ; Stock,T. A. C.

Report Date : 1970

Pagination or Media Count : 5

Abstract : Severely deformed surface layers and bands of intense shear are associated with the bullet holes. Surface layers of similar depth and disposition are associated with slowly punched holes. The structure of the deformed layers and bands adjacent to the bullet holes consists of small cells or grains (approximately equals 0.2 micrometers grain dia.); there is considerable misorientation between the grains and there are distinctive cell or grain boundaries. On the other hand, the structure of the deformed layers associated with slowly punched holes consists of tangles of dislocations and extinction contours; although there is no distinct cell structure visible, selected area diffraction indicates that many small subgrains or cells are present. It is concluded that polygonization of this type of structure has produced the structures associated with the bullet holes, the necessary heat being generated during adiabatic shear. (Author)

Descriptors :   (*SMALL ARMS AMMUNITION, TERMINAL BALLISTICS), (*BRASS, DAMAGE ASSESSMENT), DEFORMATION, MICROSTRUCTURE, STRUCTURAL PROPERTIES, SHEAR STRESSES, PROPAGATION, IMPACT, FRAGMENTATION, ELECTRON MICROSCOPY, AUSTRALIA

Subject Categories : Properties of Metals and Alloys
      Ballistics

Distribution Statement : APPROVED FOR PUBLIC RELEASE