9301102 Vitek This U.S.-Argentina Cooperative Science Program award will support the collaboration of Vaclav Vitek of the University of Pennsylvania and Ana Maria Monti and Roberto Pasianot of the National Atomic Energy Commission (CNEA) in Buenos Aires, Argentina. The project aims to conduct atomistic studies of grain boundaries and interphases and interaction of these interfaces with point defects. The researchers will carry out calculations for model hcp, bcc, and hcp/bcc systems using empirical many-body potentials of the EAM type. The construction of these potentials is an integral part of the proposed research. The principal goal is to analyze differences between grain and interphase boundaries, particularly with respect to the atomic transport in these interfaces. The interphases studied will be chosen so that they emulate as closely as possible the interphases in Zr/Zr-Nb systems which have been extensively studied at CNEA. The Argentine group will conduct the computer simulations and develop or select of the interatomic potentials. The U.S. side will provide the computer codes for the atomistic modelling of grain boundaries and the graphical programs necessary to interpret atomistic calculations. Both sides will benefit from collaboration on the interpretation and analysis of data, encompassing the construction of interatomic potentials and their testing and the computer modeling of interfaces. ***
