Numerical simulation of modifying material distribution during the impulse induction heating of metal surface

Method of improvement of operational properties of surfaces is considered. Under study is the applicability of high- frequency electromagnetic field for metal heating and melting with a view to its subsequent modification. 2D numerical modeling of the processes during the modification of the substrate surface metal layer is carried out. The substrate surface is covered with a layer of specially prepared nano-size particles of refractory compounds, which are active crystallization centers after the penetration into the melt. The distribution of the electromagnetic energy in the metal is described by empirical formulas. The proposed mathematical model is used to consider the processes including heat- ing, phase transition and heat transfer in the molten metal, the nucleation and growth of the solid phase in the presence of a modifier material in the melt. Melting of the metal is considered at the Stephan’s approximation, and during solidi- fication all nano-size particles are assumed to be centers of volume-consecutive crystallization. The flow in the liquid is described by the Navier-Stokes equations in the Boussinesq approximation. The movement of the markers models the distribution of nano-size particles in the melt. According to the results of numerical experiments, the flow structure in the melt was evaluated versus the characteristics of induction heating and the amount of surface-active impurities in the metal. The modes of the induction-pulse action are detected: they promote creating the flows for the homogeneous dis- tribution of modifying particles in the melt. Found that the application of high frequency electromagnetic field for heat- ing and melting of metals allows to modify the metal deeper in comparison with the use of a laser.