000004708 001__ 4708
000004708 005__ 20141119144546.0
000004708 04107 $$aeng
000004708 046__ $$k2002-06-02
000004708 100__ $$aKysar, Jeffrey W.
000004708 24500 $$aCRACK TIP DEFORMATION FIELDS IN ALUMINUM SINGLE CRYSTALS

000004708 24630 $$n15.$$pProceedings of the 15th ASCE Engineering Mechanics Division Conference
000004708 260__ $$bColumbia University in the City of New York
000004708 506__ $$arestricted
000004708 520__ $$2eng$$aThe deformation fields near the tip of a crack in ductile single crystal media are studied experimentally. The crack, located between two single crystals of aluminum joined by a thin ductile interlayer of tin, is introduced via selective chemical etching and can be considered “sharp”; the material surrounding the tip is fully annealed. The crack is oriented in the crystal such that a state of plane deformation is attained in the plane normal to the crack front; this effectively renders the deformation state to be two-dimensional. A Mode I loading is applied after which the specimen is sectioned along its center plane and the in-plane rotation field under plane strain conditions is mapped using Electron Backscatter Diffraction (EBSD) in a scanning electron microscope (SEM). In essence, this measures the in-plane component of the rotation field of the displacement gradient tensor. The observations provide evidence of the main features of the deformation fields predicted by continuum single crystal plasticity, especially the existence of kink shear sector boundaries which had not been unambiguously identified in previous studies. However in order to explain the measured change in lattice rotation at the kink shear sector boundary, a dislocation structure is deduced which is different than that traditionally thought to form the kink shear sector boundary. The results have implications for analytic and numerical simulations of plastic deformation in ductile single crystal media, from the length scale of microns to the macroscopic length scale.

000004708 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000004708 653__ $$aFracture, Ductility, Toughness, EBSD, Scanning Electron Microscope

000004708 7112_ $$a15th ASCE Engineering Mechanics Division Conference$$cNew York (US)$$d2002-06-02 / 2002-06-05$$gEM2002
000004708 720__ $$aKysar, Jeffrey W.
000004708 8560_ $$ffischerc@itam.cas.cz
000004708 8564_ $$s512748$$uhttp://invenio.itam.cas.cz/record/4708/files/206.pdf$$yOriginal version of the author's contribution as presented on CD, .
000004708 962__ $$r4594
000004708 980__ $$aPAPER