Accession Number : AD0436804


Title :   YIELDING IN POLYCRYSTALLINE METALS,


Corporate Author : IIT RESEARCH INST CHICAGO ILL


Personal Author(s) : Rostoker,William


Report Date : Jun 1963


Pagination or Media Count : 36


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)


Descriptors :   *METAL CRYSTALS , *NICKEL , *IRON , *IRON ALLOYS , SILICON ALLOYS , DEFORMATION , GRAIN STRUCTURES(METALLURGY) , EXTENSOMETERS , PARTICLE SIZE


Distribution Statement : APPROVED FOR PUBLIC RELEASE