3D model of T-x-y diagram as a tool of materials science

Alternative principle of the phase diagram (PD) engineering has been offered: 1) a space scheme of 3-phase regions is to be elaborated; 2) contours of the surfaces of unruled nature are to be closed and data of thermodynamic assessment are used on this stage; 3) surfaces should be approximated as the minimal ones (with the minimal area); 4) all geometrical elements are designated, and their “names” contain the meaning (reason) of these designations; 5) after the computer assembling the PD space model becomes a useful tool to solve different fundamental and applied tasks of materials science.