YIELDING IN POLYCRYSTALLINE METALS.
Abstract
Microyield, as revealed by etch pit techniques, shows slip activity well below strains of .000001. The grain size dependencies of microyield as defined by microextensometer measurements and by etch pit studies are essentially the same for the two methods as applied to Ni, Fe, and Fe-3% Si. The microyield of Fe is independent of grain size; it is shown that this is probably due to generation of active dislocations at inclusions which were very populous in this material. The microyield of Fe-3% Si and Ni are very much dependent on grain size, following the d to the (-1/2) power function as at higher strain levels. Slip in Fe does not reveal itself as well defined slip lines, but in an apparently uncoordinated multiplication of dislocations. Slip in Fe-3% Si and in Ni appears as welldefined slip lines and bands. Evidence is presented to show that dislocation sources in Fe-3% Si are primarily at grain surfaces. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1964
- Accession Number
- AD0608450
Entities
People
- W. Brentnall
- W. Rostoker
Organizations
- IIT Research Institute