EVALUATION OF BRITTLE-FRACTURE SURFACE ENERGY IN CUBIC METALS BY LATTICE DYNAMICAL METHOD

Using the method of linear response theory in lattice dynamics on the basis of Tyson's model, the response displacements of atoms on cleavage plane at the incipience of brittle fracture was derived and an expression for evaluating brittle fracture surface energy of metals was found. The brittle fracture surface energy for a number of bcc and fcc metals has been calculated and the results coincide with order of magnitude in experimental measurements.