Crystallization and phase separation: New insights for materials!

Crystallization and phase separation: New insights for materials!

On March 17, 2025, a new review article on crystallization and phase separation was published in the journal Progress in Materials Science. In this extensive work, Dr. Wolfgang Wisniewski, a research assistant at the Chair of Electron Microscopy and Microstructure Analysis, and Prof. Dr. Christian Rüssel from the Friedrich Schiller University Jena explains the fundamental processes of microstructure formation that are crucial for the properties of materials. Technicianmathe.de emphasizes that glasses and glass melts in particular offer interesting insights into the course of these processes.

The authors recognize that the processes in glasses take place much more slowly due to their high viscosity. This enables controlled transformations, which is important for the targeted production of certain materials. Wisniewski and Rüssel have also written other review articles about glass ceramics in recent years and, with their current article, show how microstructures can be specifically adjusted to optimize the properties of materials.

Crystallization process

Crystallization is described as a physical process in which a substance changes from the liquid to the solid phase, while the enthalpy of crystallization is released. This heat-changing energy release plays a central role in materials engineering, as well Wikipedia explained. Artificial conditions, such as vaccination with germs, can accelerate this process.

The review article also covers the state of research over the last five decades and emphasizes the importance of techniques such as backscattered electron diffraction (EBSD). This method has evolved over the last 15 years for local orientation measurement and phase identification and is of fundamental importance for Wisniewski's research. Of particular note is the discovery of parallels between early oxidation stages of metallic alloys and the crystallization of glasses.

Phases and their transformations

In materials engineering, a distinction is made between different physical states: plasma, gas, liquid and solid. The order of the building blocks increases from plasma with the lowest order to solids with maximum structure. Technicianmathe.de describes that phases are separated from each other by interfaces and can exist in different states but with a homogeneous composition. A phase change from liquid to solid occurs during crystallization when the molten metal is slowly cooled.

The speed of crystallization and the number of nuclei are crucial for the success of the process. Innovative processes such as thermal evaporation in a vacuum oven or cathode sputtering are used in industry. Successful crystallization requires careful control of the temperature as it remains constant during the phase transformation until the process is complete.

In summary, the review article not only provides valuable information about current research on crystallization, but also shows how this knowledge can be used practically in the development of new materials. The work of Wisniewski and Rüssel is an important contribution to a deeper understanding of these complex processes, which are of central importance in modern materials engineering.