Course detail

Crystallization of Metals and Alloys

FSI-9KKSAcad. year: 2020/2021

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.

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).

Co-requisites

Not applicable.

Recommended optional programme components

Not applicable.

Recommended or required reading

Flemings, M.C.: Solidification Processing. 1st ed. New York: McGraw-Hill Book Company. 1974
Nobuo Sano ed.: Advanced Physical Chemistry for Process Metallurgy. 1st ed. San Diego: Academic Press. 1997
Karlsson, L.: Modeling in Welding, Hot Powder Forming and Casting. 1st ed. Materials Park, Ohio: ASM International. 1997
Stefanescu, D.M.:Science and Engineering of Casting Solidification. 1st ed. New York: Kluwer Academic/Plenum Publishers. 2002

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.

Language of instruction

Czech, English

Work placements

Not applicable.

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.

Classification of course in study plans

  • Programme D-STG-P Doctoral, 1. year of study, winter semester, 0 credits, recommended

Type of course unit

 

Lecture

20 hours, optionally

Teacher / Lecturer

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.