The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting

efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization

process and microstructure of synthetic hypereutectic alloys: AlSi15 and AlSi19. Casts were made in permanent mold cooled with water

mist stream. The study was conducted for unmodified silumins on the research station allowing the cooling of the special permanent probe

using a program of computer control. Furthermore the study used a thermal imaging camera to analyze the solidification process of

hypereutectic silumins. The study demonstrated that the use of mold cooled with water mist stream allows in wide range the formation of

the microstructure of hypereutectic silumins. It leads to higher homogeneity of microstructure and refinement of crystallizing phases and

also it increases subsequently the mechanical properties of casting.