CRACK INITIATION IN METALLIC MATERIALS,
Abstract
The effect of surface structure on the fracture strength has been studied on commercially pure tungsten 2.5A1-16V titanium alloy and LiF specimens. Brittle titanium alloy specimens with piggy back notches, tested at room temperature, showed that the decrease in fracture strength due to small grooves in large notches was less than one would expect from an elastic stress analysis. Similar results were obtained from tensile tests on notched tungsten specimens, tested in the as-received and the recrystallized condition at room and liquid nitrogen temperature. Various surface preparation techniques were used. Microplasticity at the surface seems to influence crack initiation. Bend test on notched LiF specimens at room temperature showed that small cleavage cracks at the surface are not necessarily responsible for crack initiation. The following stages of crack initiation were observed: slip bands were formed near the notch, high stress fields were found where these slip bands intersected and the first microcracks were formed in such areas, probably unconnected with the notch surface. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1964
- Accession Number
- AD0431612
Entities
People
- G. Nash
- K. Schroder
- P. Packman
- V. Weiss
Organizations
- Syracuse University