Numerical Simulation of the Dynamics of Noncongruent Melting of Binary Materials

Numerical simulation of the dynamics of incongruent phase transitions in binary materials under the action of a laser radiation pulse was carried out. A mathematical model proposed earlier was used, which allowed for the possibility of formation of two-phase zones within the condensed phase. Specific calculations were carried out for hyperstoichiometric uranium oxide. The major characteristics of the process were compared with those calculated earlier within the framework of the simpler Stefanov’s model, which assumes the existence of solely solid and/or liquid phases delimited by interfacial areas. In particular, it was demonstrated that the use of different mass transfer models in the condensed phase has virtually no effect on the appearance of the calculated thermogram of the surface, which is one of the major characteristics of the process that is experimentally registered. The model with the two-phased zone, as opposed to Stefanov’s, predicts the formation of an extended region of partial alloying in the material. The character of solidification of this region should be considerably different from solidification of the region of complete alloying.