Accession Number:

AD0436804

Title:

YIELDING IN POLYCRYSTALLINE METALS,

Descriptive Note:

Corporate Author:

IIT RESEARCH INST CHICAGO ILL

Personal Author(s):

Report Date:

1963-06-01

Pagination or Media Count:

36.0

Abstract:

Stress-microstrain studies of Ni, Fe, and Fe-3 Si have been conducted on materials with various grain sizes. The microyield stress 1 microinch plastic strain has been shown to depend on grain size in Ni and Fe-3 Si in the same manner as the macroyield. On the other hand, the microyield stress of Fe seems to be nearly independent of grain size. The stress-strain behavior in the microyield region is verified to follow an exponential rule. The exponent increases above 0.5 as the macroyield range is approached. The proportionality constant contains a dependence on grain size of the form of a simple power function, but the exponent is not consistent with different metals. Etch pit studies of a preliminary nature have shown that, even with the strain sensitivity attained, considerable slip has already occurred and that the true microyield stresses are below those measured. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE