Materials Science and Engineering

Biography

Biography: Jan Vrestal

Abstract

Phase diagram calculation is powerful tool for characterizing materials (materials genome) in the process of materials development, because properties of materials, especially technological parts, are strongly influenced by created phase microstructure. Produced microstructure during long-time annealing of technological parts during industrial service, where materials are in or near equilibrium state, determine beneficial properties of materials. Present state of CALPHAD (Calculation of Phase Diagrams) method is characterized by using of sophisticated softwares for calculation of phase diagrams (e.g. Thermocalc, Pandat, FactSage etc.) and number of databases which has been created for different types of materials (e.g. solders, steels, aluminium alloys, oxides etc.). Required information for development/validation of databases are gained experimentally (thermodynamic quantities measurement) and theoretically (ab initio calculations). Rules for creating valid databases can be straightforward formulated.

From the point of view of material properties, intermetallic phases are very important (Sigma-phase, Z-phase, Chi phase, Laves phases, Heusler phases etc.). Models used for expression of thermodynamic functions of these phases make it possible to calculate phase diagrams in technologically important cases which is possible to confirm experimentally. The calculations of this type can help to explore the implications of Materials Science and Engineering.