Nonlinear surface processes under nonequilibrium TiNi activation by a pulsed electron beam

Nonlinear processes involved in oxygen diffusion from the adsorption layer into the bulk of an alloy exposed to a low-energy high-current pulsed electron beam are investigated in the framework of a mathematical model accounting for nonequilibrium activation and melting of the irradiated material. An example is a TiNi alloy. The model includes heat, diffusion, and kinetic equations, with initial and boundary conditions corresponding to electron-beam treatment of the alloy. Kinetic parameters are estimated. The time and space distributions of the TiNi temperature and oxygen concentration for a varying maximum pulse power density and pulse duration are calculated. The heating and diffusion depths are determined. The results obtained with and without regard to the activation effect are compared.