Accession Number:

AD0603404

Title:

AN INVESTIGATION OF STRUCTURAL DAMAGE IN METAL-FORMING PROCESSES.

Descriptive Note:

Final rept. for 18 Jun 63-18 Jun 64,

Corporate Author:

GENERAL ELECTRIC CO SCHENECTADY N Y

Report Date:

1964-07-01

Pagination or Media Count:

59.0

Abstract:

A study of structural damage in the sheet-drawing of OFHC copper, tough-pitch copper, and aluminum alloy 6061-T6 was undertaken in an attempt to investigate the role of the stress state occurring during the deformation to the concomitant changes in the microstructure that would influence the resultant mechanical properties. Because of its completeness, the Hill-Tupper slip-line field solution for sheet-drawing was employed, and experimental drawing experiments were conducted matching as closely as possible the assumptions of the theory regarding plane strain, constancy of yield stress, and die geometry. Calculations showed that for light reductions at various die angles, marked gradients in the hydrostatic component of stress developed in the deformation zone, ranging from tension as high as 0.7 of the yield stress along the center line to compressions 2.5 times the yield stress at the surface. Structural damage, as assessed by microscopic examination, and density changes on drawn sheet revealed that central plane void formation developed in those cases where high hydrostatic tensions were produced in the deformation zone under conditions of repeated drawing. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE