Accession Number:

ADA011368

Title:

Detection of Vacancy Concentration and Defects in Aluminum, Titanium and their Alloys and Nickel Base Superalloys by Positron Annihilation.

Descriptive Note:

Final rept. Dec 73-Nov 74,

Corporate Author:

NEW ENGLAND INST RIDGEFIELD CONN

Personal Author(s):

Report Date:

1975-03-01

Pagination or Media Count:

53.0

Abstract:

Positron annihilation has been used as a tool to study the effects of defects in crystalline solids in the realm of fundamental research for a long time. This paper reports an initial effort to evaluate the usefulness and the future development of positron annihilation as a tool in non-destructive evaluation, NDE. The metals studied included Al 99.99, Al-1100, Al-2024, Ti-35A, Ti-6Al-4V, and nickel based superalloys, U-700 and M-200. The processes studied involve temperature change, work-hardening, stress-strain, creep and cyclic fatigue. The conclusion is that the process of positron annihilation is very sensitive to many kinds of defects in metals and that its potential as a tool of NDE is high. Certainly, more work is required to explore its full potential. A brief review describing the method of positron annihilation and its interaction with defects in metals is attached as an appendix.

Subject Categories:

  • Metallurgy and Metallography
  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE