Correction of T-x-y Diagrams for Lead-Free Solders

Possibilities of T-x-y diagrams three-dimensional (3D) computer models to search and to correct mistakes of thermodynamic calculations and experimental data interpretations are demonstrated. Descriptions of ternary systems in the specially published “Atlas of Phase Diagrams for Lead-Free Soldering” are used as examples. Two surfaces and two phase regions had been “missed” in isothermal sections and isopleths of Au-Bi-Sb system T-x-y diagram. Contradictions in data of the system Ag-Bi-Sn do not give the chance to understand a type of one of three invariant reactions and require other experiments. Mistakes in one of three isothermal sections and in two of five isopleths of the system Ag-Cu-Sn had been founded.