Course detail
Crystallization of Metals and Alloys
FSI-9KKS Acad. year: 2022/2023 Both semester
In the course, students are made familiar with the theoretical foundations of metal crystallization and the relation between the structure and the properties of castings. Models of the nucleation phase of crystallization and the phase of growth form the necessary basis for a purposeful crystallization control of castings.
Language of instruction
Czech
Supervisor
Department
Learning outcomes of the course unit
Students will have acquired information about the crystallization process of foundry alloys and a grasp of the current possibilities of controlling this process, with the aim of obtaining castings of required structure and properties.
Prerequisites
Students must have the knowledge of the thermodynamics and kinetics of phase transformations (diffusion, phase equilibrium diagrams, phase transformations and their effect on structure and properties), and thermomechanics (stationary and non-stationary transfer of heat by conduction, internal sources).
Planned learning activities and teaching methods
The course is taught through tuition explaining the basic principles and theory of the discipline.
Assesment methods and criteria linked to learning outcomes
The examination consists of a written and an oral part. In the written part the knowledge of sets of topics is tested, which the students were made familiar with in lectures. The oral part serves to test individual items of knowledge and to provide for correct marking.
Aims
The course objective is to make students familiar with the basic processes taking place during the crystallization of foundry alloys. Emphasis is on a purposeful control of these processes, thus leading to castings of required structure and properties.
The study programmes with the given course
Programme D-STG-K: Manufacturing Technology, Doctoral, recommended course
Programme D-STG-P: Manufacturing Technology, Doctoral, recommended course
Type of course unit
Lecture
20 hours, optionally
Syllabus
1. Thermodynamics of crystallization.
2. Three distinct zones with different grain structures in the macrostructure of castings, a survey of the theories explaining their appearance.
3. The nucleation phase of crystallization, nucleation rate, model of homogeneous nucleation, heterogeneous nucleation on a planar substrate.
4. Models of heterogeneous nucleation in the cavities of refractories.
5. The phase of crystal growth, heat transport at the interface and in the mould/casting system.
6. Transport of mass at the interface, appearance of segregation
7. Constitutional supercooling, morphology of phase interface.
8. Control of metal crystallization, dynamic methods, melt modification.
9. Crystallization control in the phase of crystal growth, single crystals.
10. Crystallization of the basic types of foundry alloys.