9634657 Beltz This award is made in order to fund research that models material behavior on various length scales from the atomistic to the macroscopic levels. In particular cleavage in the presence of plastic flow, in circumstances which do not involve strong viscoplastic retardation of dislocation motion, will be studied. An outstanding issue will be the role of nanoscale blunting of a sharp crack when propagating through dislocation-free zones. It is expected that methods for reducing brittle failure of structural metallic alloys will emerge from this research. ***