ON THE THEORY OF NONISOTHERMAL COALESCENCE (COARSENING) IN THE DECOMPOSITION OF SUPERSATURATED SOLID-SOLUTIONS

In this paper the effect of the heat of atom interphase transfer on the decomposition kinetics of supersaturated solid solutions at the coarsening stage is studied. The system in which the decomposition proceeds is assumed to be heat-insulated. A set of equations describing this process is derived. The asymptotic solution of the equations allows the size distribution function of the new-phase nuclei to be established, as well as the dependences of their density and mean size on the coarsening time. These dependences proved to be of the same form as those for isothermal coalescence. Only the parameters involving temperature vary. These are to be estimated at a temperature different from the initial one. An equation for the determination of this temperature is derived. It is shown how one can estimate the temperature dependence of the equilibrium concentration of atoms dissolved in a solid solution.