Accession Number:

AD0435021

Title:

FRACTURE OF METALS.

Descriptive Note:

Summary rept., 22 Mar 63-22 Mar 64,

Corporate Author:

IIT RESEARCH INST CHICAGO ILL

Personal Author(s):

• Rostoker,W.

Report Date:

1964-04-02

Pagination or Media Count:

38.0

Abstract:

Delayed failure is shown to occur with highstrength metals wetted by certain embrittling liquid metals. Dispersion-strengthened and coldworked metals are prone to delayed failure but soft, annealed metals are not. Cracking during the period of sustained loading can only be detected in the last few minutes before failure. A mechanism is proposed based on stress-accelerated intergranular penetration. Thus, failure time depends on both stress and temperature. Below a certain stress endurance limit, temperature alone is inadequate, and failure does not occur. Certain preconditioning anneals retard and suppress delayed failure. A method is described for measuring the fracture energy of polycrystalline metals in the presence of a low-melting liquid metal. Author

Descriptors:

• *FAILURE(MECHANICS)
• FRACTURE(MECHANICS)
• METALS
• LIQUID METALS
• MERCURY
• BERYLLIUM ALLOYS
• COPPER ALLOYS
• STRESSES
• TEMPERATURE
• TIME
• METALLOGRAPHY
• GRAIN BOUNDARIES
• HEAT TREATMENT
• BRITTLENESS
• PENETRATION
• ENERGY

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE