Molecular-dynamics study of the mechanism and kinetics of void growth in ductile metallic thin films

A molecular-dynamics study is presented of the mechanism and kinetics of vo id growth and morphological evolution in ductile metallic thin films subjec t to biaxial tensile strains. The void becomes faceted, grows, and relieves strain by emission from its surface of pairs of screw dislocations with op posite Burgers vectors. Repeated dislocation generation and propagation lea ds to formation of a step pattern on the film's surfaces. A simple phenomen ological kinetic model of void growth is derived. Such kinetic equations ca n be used to formulate constitutive theories of plastic deformation for con tinuum-scale modeling of void evolution. (C) 2000 American Institute of Phy sics. [S0003-6951(00)00729-4].