Accession Number : AD0465243


Title :   FATIGUE OF METAL CRYSTALS.


Descriptive Note : Final rept., 1 Mar 63-31 Jan 65,


Corporate Author : RUTGERS - THE STATE UNIV NEW BRUNSWICK NJ BUREAU OF ENGINEERING RESEARCH


Personal Author(s) : Shrier, A ; Yamamoto, H ; Weissman, S


Report Date : Apr 1965


Pagination or Media Count : 23


Abstract : Structure changes caused by fatigue in silver and aluminum crystals were studied by X-ray and electron microscope techniques at various distances from the crystal boundaries. It was observed that the fatigue life is drastically reduced in the presence of transverse boundaries, while longitudinal boundaries have a much smaller effect. The dislocation arrangements produced by fatigue depend on the distribution of strains. In the highly strained regions near the grain boundary the study revealed formation of lattice domains of small size bounded by very complex dislocation arrangements. In the less strained regions a led to a formation of a coarser and simpler substructure. The observed differences in dislocation structure between the high and low strain regions were ascribed to differences in the rate of generation of disclocations relative to their ability to cross-slip. (Author)


Descriptors :   *SILVER , *ALUMINUM , FATIGUE(MECHANICS) , METAL CRYSTALS , GRAIN BOUNDARIES , GRAIN STRUCTURES(METALLURGY) , CRYSTAL DEFECTS , ELECTRON MICROSCOPY , X RAY DIFFRACTION , CRYSTAL SUBSTRUCTURE


Distribution Statement : APPROVED FOR PUBLIC RELEASE