Accession Number : AD0726742

Title :   Measurement of Surface Stress via the Moessbauer Effect.

Descriptive Note : Final rept. 15 Jun 69-15 Jun 71,

Corporate Author : AUSTIN SCIENCE ASSOCIATES INC TEX

Personal Author(s) : Collins,R. L. ; Beasley,M. L. ; Gilchrist,J. L. ; Spijkerman,J. J. ; Yagnik,C. M.

Report Date : 15 JUN 1971

Pagination or Media Count : 31

Abstract : The feasibility of applying Mossbauer spectroscopy to non-destructive measurement of surface stresses in ferrous metals was examined. The concept is based on the small changes in Mossbauer spectra of ferrous metals under stress. The concept was first proved using the well-developed transmission geometry technique. The transition to back-scatter, which is essential for general use of the technique, called for a major effort for detector development. The effort finally paid off, with signal/noise per unit time fully 90% as good as is obtained in transmission. Further hard-ware development is required for a fully operational instrument, and there remain theoretical problems bearing on changes of steel alloy composition, the effects of surface roughness, and the stress distribution vs. depth. (Author)

Descriptors :   (*NONDESTRUCTIVE TESTING, STRESSES), (*STRESSES, MOSSBAUER EFFECT), METALS, SURFACES, FEASIBILITY STUDIES, SPECTROSCOPY

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE