Chapter 5 focuses on the CALPHAD approach and its thermodynamic basis with the crucial concept of “phase." The origins, development, and principles of the CALPHAD method are briefly explained and current software is compiled (Thermo-Calc, Pandat, FactSage, and more). Thermodynamic modeling of Gibbs energy is introduced, from simple pure substances to complex solution phases. Examples of how to establish a thermodynamic database are given, and key issues on the consistency, coherency, quality assurance, and safety of the database are emphasized. The most important application examples in the computational design of alloys and their processing are separated in two levels. In the first level, solely thermodynamic CALPHAD databases are required. It is shown which type of calculations have proved most useful to guide design. In the second level, applications using extended CALPHAD-type databases with kinetic and thermophysical material parameters are outlined for casting, solidification, and heat treatment processes. The use of advanced CALPHAD-type software packages is demonstrated. Finally, a case study on design of Al alloys with improved hot cracking resistance is presented with these tools.

Chapter 8 focuses on the design of important Al- and Mg-based light alloys. Selected examples show how CALPHAD simulation tools can be used to understand and predict the effect of alloying elements and processing conditions on alloy properties and how to use that in the design of alloys. For Al alloys, two case study examples using the extended CALPHAD-type databases are demonstrated. For cast alloy A356 (Al–Si,Mg), the solidification simulation involving dedicated microsegregation modeling is presented. For the wrought alloy 7xxx (Al–Zn,Mg/Cu), elaborate heat treatment simulation with precipitation kinetics is the design tool. For Mg alloy structural components, simulations of solidification path and T6 heat treatment of AZ series (Mg–AlZn) and the development of Mg–Al–Sn-based (AT) cast alloys involving also microsegregation simulation are demonstrated. Finally, the design of biomedical Mg alloy implants utilizing the CALPHAD method and the state-of-the-art bioresorbable Mg alloy stent to cure coronary artery disease is presented.

The advance of human civilization with materials development from the Stone Age to the Information Age is the starting point of Chapter 1, highlighting significant roles of computational design of materials. Important terms (model, simulation, database, and materials design) used in computational materials science are defined. The past and present development of computational design of materials is then introduced. A few milestones for alloy design, such as the Hume–Rothery rule, the Phase Computation (PHACOMP) method, and the calculation of phase diagrams (CALPHAD) approach, are highlighted. The past two-decade focus on three aspects in computational design of materials (multiscale/multilevel modeling methodologies, simulation software, and scientific database) in the core of the Materials Genome Initiative is emphasized. A general framework of materials design is demonstrated with two flowcharts: through-process simulation of Al alloys during heat treatment, and the three stages for the development of engineering materials. The two-part structure of the book – fundamentals and case studies – is explained.