Nanocontact between BCC tungsten and FCC nickel using the quasicontinuum method

The nanocontact between BCC tungsten and FCC nickel is investigated by using the multiscale simulation method (quasicontinuum method). The new proposed interatomic potential – Extended Finnis-Sinclair potential is adopted and compared with the conventional Ackland Finnis-Sinclair potential in the nanoindentation model. A series of multiscale simulations of contact formation, indentation, subsequent pulling, and separation between a tungsten indenter and a nickel substrate are performed by means of the quasicontinuum method. Different plastic mechanisms are observed for different crystal directions and indenter shapes. Besides the adherence between the tungsten indenter and the nickel substrate, the geometrical shape, which is formed by the slip planes inside the substrate, plays a vital role in the material transfer between the indenter and the substrate. The formation and evolution of necking and cracking in the nanocontact model are also discussed.