Solidification and Phase Diagrams

Foundry technology and related casting process is introduced as the initial source for equilibrium or quasi-static solidification of pure metals and their alloys, and ceramic materials. As a result, solidification induces the evolution of microstructural features used to develop phase diagrams with the aid of cooling curves. The most relevant aspect of foundry technology is the pouring of a melt (liquid metal) into a sand or metal mold containing a hollow cavity and the subsequent liquid-to-solid (L-S) phase transformation, known as solidification due to an outward thermal energy flow and related thermal resistance within the solidification domain. Therefore, optimal thermophysical properties of the mold and the solidifying melt are essential for making high-quality castings. Understanding the microstructural evolution upon solidification of an alloy from its molten state is an essential task for assessing the atomic structure of phases and microstructure-property relationships. Thus, it is important to develop the procedure for constructing equilibrium phase diagram and to understand the microstructural evolution attributed to the nucleation and growth mechanism that form the phases cited in a phase diagram.