Determination of the kinetic parameters of crystallization thermograms

S. A. Frolova, O. V. Sobol, N. V. Shchebetovskaya, A. Yu. Sobolev, O. A. Pokyntelytsia. 

ABSTRACT

Using thermograms of bismuth, obtained by the method of cyclic thermal analysis (CTA), melting processes and various types of crystallization (quasi-equilibrium) (QRC) and nonequilibrium-explosive (NRVC) are investigated. Thermocinetic parameters (melting τ_L⁰  and crystallization τ_S⁰ times, heating υ_heat and cooling υ_cool rates, etc.), which were used to calculate the parameters of nucleation and crystallization, were found directly from the heating- cooling curves. A difference in the parameters of crystallization of the (QRC) and (NRVC) type was noted, associated with the absence of stages of nucleation and coagulation of nuclei during nonequilibrium explosive crystallization.

KEY WORDS:

bismuth, thermal analysis, quasi-equilibrium and nonequilibrium-explosive crystallization, supercooling, nucleation, coagulation, recrystallization.

DOI: 10.31857/S0235010621050030