Accession Number : AD0696855

Title :   DEFORMATION STRUCTURES IN ROLLED 70/30 BRASS,

Corporate Author : DEFENCE STANDARDS LABS MARIBYRNONG (AUSTRALIA)

Personal Author(s) : Turley,D. M.

Report Date : 14 APR 1969

Pagination or Media Count : 7

Abstract : Strain etch markings observed by optical microscopy after deformation by cold rolling were correlated with dislocation substructures observed by electron microscopy using thin-film techniques. The nature of the strain etch markings depends upon the amount of reduction. Slip-line etch markings, which are readily developed up to 20% reduction, are associated with the movement of dislocations on (111) planes. Slip-band etch markings, initially formed at grain boundaries, develop at regions of faulted material. When more profusely developed at 40% reduction, they form at bands of parallel deformation twins. Deformation-band etch markings and fragmentation of grains at 70-80% reduction correspond with the beginning of the breakdown of deformation twins and the development of regions of high deformation. These regions of high deformation, which are characterized in the electron-microscope image by a high density of tangled extinction contours, have a small subgrain structure. At higher reductions (90-99%) the grains become increasingly more fragmented and the proportion of high-deformation regions increases. (Author)

Descriptors :   (*BRASS, GRAIN STRUCTURES(METALLURGY)), DEFORMATION, MICROSTRUCTURE, DISLOCATIONS, AUSTRALIA

Subject Categories : Properties of Metals and Alloys
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE