Accession Number:

ADA003729

Title:

An Investigation of the Crack Tip Deformation Characteristics of Slowly Growing Fatigue Cracks.

Descriptive Note:

Final technical rept.,

Corporate Author:

SOUTHWEST RESEARCH INST SAN ANTONIO TEX DEPT OF MATERIALS SCIENCES

Report Date:

1974-12-01

Pagination or Media Count:

13.0

Abstract:

The technique of selected area electron channeling has been quantified and used to map the shape and quantitative strain distribution within the plastic zones attending fatigue crack tips in 304 stainless steel, 6061-T6 aluminum, and Fe-3Si steel. Simultaneously, crack tip operning displacement, the mechanisms of yielding and decohesion, and maximum shear strains have been measured using high magnification SEM of replicas. Overload plastic zones and their relation to fatigue crack retardation have been characterized. Observed values of all of these parameters have been compared with predictions of various analytical models.

Subject Categories:

  • Metallurgy and Metallography
  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE