Ternary phases in three-dimension

The use of phase diagrams is fundamental to engineering new materials and to process optimization and debugging in the manufacture of well-established materials and products. Although proper interpretation of binary-phase diagrams is generally straightforward, ternary diagrams are, to some, more intimidating. A number of subtle rules must be followed to determine the cooling path of a chosen composition, and composition/temperature correlations require extrapolation between distant isotherms on the diagram. Software has been developed that follows these rules with digital precision, so that greater accuracy can be extracted from the diagrams and misinterpretations can be avoided. The software inputs a data file containing the coordinates of compounds, boundary lines and isotherms, as well as their names and values. Based on this, least-squares polynomial surfaces can be fit to primary phase fields and polynomial curves fit to phase boundaries. A 3-D ternary diagram can then be rendered and phase calculations performed from these curves. The code is written to input a data file representing any ternary system, although presently, only the CaO-Al{sub 2}O{sub 3}-SiO{sub 2} system has been used. This system is plate No. 1 in the 10 large-scale ternary system diagrams published by the American Ceramic Society. This program immediately servesmore » as a useful teaching tool on how to interpret a ternary phase diagram. It is anticipated that the next version of the code will contain all 10 of the large-scale diagram plates. This will require additional algorithms to handle solid solutions and liquid immiscibility.« less