THE BINARY 50 % METALLIC MELTS’ MICRO CRYSTALLIZATION PECULIARITIES IN DIPHASE TRANSITIONAL ZONE MODEL (DTZ) WITHIN A DIFFUSIVE-RELAXATION PROCEDURE

Abstract

Purpose. Consider in the diffusion-relaxation procedure micro crystallization of binary 50 % of metallic melts. Earlier in the well-known experimental works there has been established the Ag–Au alloy disordering when crystallizing from the proper metallic melt. It confi rmed the possibility of binary metallic crystal disordering presented in given article. Methods and methodology. When using so-called the diphase transitional zone there have been estimated some thermodynamic parameters at which a completely disordered binary crystalline phase characterized by simple cubic lattice and stoichiometric composition could be expected. Results. In the vicinity of disordering point given binary crystalline phase has been studied. There has been established a physical law according to which some far order parameter tended to zero in a continuous way. A thermodynamic parameter describing the binary crystalline phase disordering has been estimated. There have been analyzed some crystalline phase kinetic peculiarities in the vicinity of disordering point. The completely disordered binary crystalline phase reconstruction law has been analyzed as the time function. The disorder-order process relaxation periods have been established in the case of simple cubic lattice binary crystalline phase investigated. Moreover, there have been analyzed some kinetic peculiarities connected with completely ordered and disordered binary crystals. Conclusions. It was known within the temperature interval Tk < T < Te, where Tk – crystalline phase disordering temperature, Te – the melt-crystal kinetic equilibrium one usually the completely ordered binary crystalline phase was observed. This effect can be realized only in the diffusive-relaxation procedure.

Keywords

• diphase transitional zone
• a growth monomer concentration
• a far-order parameter in binary cubic simple lattice
• the metallic melts’ crystallization rate.