OPTIMIZATION OF THE AMOUNT OF MAGNESIUM AND COPPER IN SILUMINS OF THEAK7 TYPE

In order to optimize the concentrations of the basic alloying elements in standard low-copper silumins of the AK7 and AK9 types the effect o f copper and magnesium on structure and the phase composition of these alloys is analyzed and phase diagrams are constructed for the conditi ons of actual crystallization. The method of simplex design is used to construct mathematical models of the dependences of the main mechanic al properties of silumins on the concentration of the alloying element s in the cast state and alter conventional forms of heat treatment. Th is has made it possible to determine the possibility of widening the r ange of copper and magnesium concentrations without worsening the mech anical properties of silumins.