K. Vartanov MODELING ELECTROMAGNETIC EFFECT ON DENDRITE GROWTH DURING DIRECTIONAL SOLIDIFICATION OF АLLOYS The proposed Modeling is directed to an investigation, designed to manipulate a structure and as a consequent a material properties of alloys, which form during directional solidification. <...> This is accomplished by using a computer simulation, which is based on a new mathematical approach for describing of a dendrite growth process. <...> If successfully developed, this capability will provide industry with an additional method of forming a directional structure during a casting process. <...> The most of alloys has a solidification temperature range, so during directional solidification ahead of a solidification front, a two-phase zone (liquid - solid) exist, where dendrites are formed. <...> The two-phase zone value depends on a solidification temperature range, a thermal gradient in the liquid at the solidification front and a cooling velocity. <...> A description of directional solidification of alloys on a temperature gradient field is based on the wellknown concept of constitutional supercooling [1]. <...> According to this concept, if a gradient of a liquidus temperature surpasses an actual gradient of temperature, then a zone of the constitutional supercooling is formed. <...> The basic criterion for avoiding supercooling and reaching a flat solidification front is given by G V T T DS / ( L − ) / > , (1) where G is the actual gradient in the liquid zone in front of the solidification front, V is a velocity of a dendrite growth (a movement of is front), (T T− S ) L the solidification temperature range, and D is the liquid diffusivity. <...> The idea of the electromagnetic effect on the directional solidification is based on the concept of constitutional supercooling. <...> On this scheme are indicated: • cbc’b’ is a two-phase zone and bb’ is a solidification front • 1 is a supercooling liquid aba’b’ • 2 is a growth dendrite mnm • 3 is a interdendritec zone n’m’mn and nmm’’n’’ • 4 is a solid phase 78 Проблемы машиностроения и автоматизации, № 3 – 2007 elements in the dendrite and interdendritic zone, respectively, where с2 and j j the solidification Fig. 1. <...> The relation (1) determines the thermal gradient G in the liquid phase on the solidification front bb’ which it is necessary for realizing the directional solidification process. <...> The law <...>