ANISOTROPY OF ANTIPHASE BOUNDARY FORMATION ENERGY IN L12 ALLOYS

Analytical expressions that determine the formation energy of antiphas e boundaries (APBs) by an approximation taking into account interatomi c bonds in seven coordination spheres for a large number of boundary o rientations are derived. For thermal-type APBs the energy constants ar e found for defects completing each other to a stoichiometric ratio. T he anisotropy of antiphase boundary formation energies is calculated u sing an approximation taking into account atomic interactions for Cu3A u, Ni3Al, Ni3Fe alloys by sets of Morse potentials. Models of defect t ransformation contributing to strain hardening of materials are sugges ted.