Dislocations. Basic concepts edge dislocation screw dislocation Characteristics of Dislocations lattice strains Slip Systems slip in single crystals polycrystalline deformation Twinning. Edge Dislocation.
PowerPoint Slideshow about 'Dislocations' - Samuel
An Image/Link below is provided (as is) to download presentation
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
as a dislocation moves through a lattice, it creates regions of compressive, tensile and shear stresses in the lattice.
Atoms above an edge dislocation are squeezed together and experience compression while atoms below the dislocation are spread apart abnormally and experience tension. Shear may also occur near the dislocation
Screw dislocations provide pure shear lattice strain only.
As dislocations move through polycrystalline materials, they have to move through grains of different orientations, which requires higher amounts of energy, if the grains are not in the preferred orientation.
As they travel between grains they must be emitted across the grain boundary, usually by one half of a partial dislocation, and then annihilated by the second half at a time slightly after the first one.