Accession Number:

AD0272074

Title:

ON THE DEBRIS MECHANISM OF STRAIN-HARDENING

Descriptive Note:

Corporate Author:

BROWN UNIV PROVIDENCE R I

Personal Author(s):

• GILMAN,J.J.

Report Date:

1962-01-01

Pagination or Media Count:

1.0

Abstract:

A hypothesis is presented regarding a mechanism of strain-hardening. This mechanism concerns strain-hardening caused by debris left in the wake of a moving screw dislocation. The debris consists of edge dislocation dipoles which inhibit the motions of subsequent dislocations on the same or nearby glide planes. The hypothesis resulted from direct observations of the velocities of dislocations as they moved through strained regions in LiF crystals, when it was found that the behavior did not conform to theories. In less exact form than what will be discussed here, however, the debris idea is quite old. One can consider it to be a detscendant of the amorphous metal theory discussed long ago. The debris mechanism is attractive because it provides a natural and satisfying explanation of a wide variety of well-known phenomena without additional ad hoc assumptions. This hypothesis views strain-hardening as a direct consequence of the fact that screw dislocations move in three, rather than two dimensions. No special geometrical arrangements of dislocations or reactions between dislocations are required. Author

Descriptors:

• *DEFORMATION
• *HARDENING
• *SHEAR STRESSES
• *SINGLE CRYSTALS
• CRYSTAL STRUCTURE
• ELECTRON MICROSCOPY
• FATIGUE(MECHANICS)
• FLUORIDES
• FRACTURE(MECHANICS)
• IRON
• LITHIUM COMPOUNDS
• PHOTOGRAPHIC ANALYSIS
• SILICON
• SOLID STATE PHYSICS
• TENSILE PROPERTIES

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE