Accession Number:

ADA504368

Title:

Dislocation Mechanics of Copper and Iron in High Rate Deformation Tests

Descriptive Note:

Journal article

Corporate Author:

MARYLAND UNIV COLLEGE PARK

Report Date:

2009-01-01

Pagination or Media Count:

8.0

Abstract:

Different dislocation processes are shown to be operative under high rate loading by impact-induced shock tests as compared with shockless isentropic compression experiments ICEs. Under shock loading, the plastic deformation rate dependence of the flow stress of copper is attributed to dislocation generation at the propagating shock front, while in shockless ICEs, the rate dependence is attributed to drag-controlled mobile dislocation movement from within the originally resident dislocation density. In contrast with shock loading, shockless isentropic compression can lead to flow stress levels approaching the theoretical yield stress and dislocation velocities approaching the speed of sound. In iron, extensive shock measurements reported for plate impact tests are explained in terms of plasticity-control via the nucleation of deformation twins at the propagating shock front.

Subject Categories:

  • Inorganic Chemistry
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE