Approximating the liquidus surface of the ZrO2-Y2O3-La2O3 phase equilibrium diagram with reduced polynomials

A mathematical model of the liquidus surface of the ZrO2 - Y2O3 - La2O3 pha se equilibrium diagram was constructed by the rise of reduced polynomials. It tvas established thar the liquidus surface of the ternary system include s five primary solidification fields: solid solutions based on the cubic (C ) and hexagonal (H) modifications of Y2O3, cubic modification of ZrO2 with the fluorite structure (F), high-temperature cubic modification of La2O3 (X ), and ordered phase La2Zr2O7 with a pyrochlor structure (Py). Three four-p hase invariant equilibria of the eutectic and peritecric types exist in the ternary system.