Course detail
Fundamentals of Foundry Theory
FSI-POB Acad. year: 2025/2026 Summer semester
The course makes students familiar with the physical properties of molten alloys, their flow in mould channels, and the interactions between the melt and the mould. Models of the nucleation phase of crystallization and of the growth phase form the necessary basis for a purposeful control of the crystallization of castings. The analysis of the processes taking place in a cooling casting is focused on the appearance of stress in the casting and on the effects and possibilities of reducing it.
Language of instruction
Czech
Number of ECTS credits
6
Supervisor
Department
Entry knowledge
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), thermomechanics (stationary and non-stationary transfer of heat by conduction, internal sources, transfer of heat by convection), and hydromechanics (properties of fluids, equilibrium of forces in fluids at rest, motion of fluids in fields of force).
Rules for evaluation and completion of the course
Awarding the course-unit credit is conditional on attendance at exercises. 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.
Attendance in lectures is recommended, attendance in exercises is obligatory.
Attendance at the exercises is required, being checked by the leader of practicals. In the case of absence from exercises, the leader assigns a topic for independent written work.
Aims
The course objective is to make students familiar with the basic processes taking place while the mould is being filled with molten alloys and while these alloys crystallize and cool down to room temperature. The emphasis is on a purposeful control of these processes so that castings of required properties can be obtained.
Students will have become familiar with the basic processes taking place while the mould is being filled with molten alloys and when the latter crystallize and cool down to room temperature. Emphasis is on a purposeful control of these processes in order that castings or required properties can be obtained.
The study programmes with the given course
Programme N-SLE-P: Foundry Technology, Master's, compulsory
Type of course unit
Lecture
39 hours, optionally
Syllabus
1. Description of substances using physical quantities, thermophysical and thermodynamic properties of substances.
2. Surface tension of metals and alloys, measurement of surface tension.
3. Hydrostatics – wettability of liquids, penetration of melt into the form of buoyancy of liquids.
4. Hydrodynamics – ideal fluid, Bernoulli's equation, free stream, flow in the channels of the inlet system.
5. Hydrodynamics – binding liquid, viscosity, hydraulic losses, loss height, liquid, Bernoulli's equation, free flow, flow in the channels of the inlet system, laminar and turbulent flow, fluidity of metals and alloys.
6. Thermodynamics of solidification, three different regions with different grain structure in the macrostructure of the casting, an overview of the theories of their formation.
7. Methods of heat transfer, conduction, radiation and heat flow, heat transfer coefficients.
8. Nucleation stage of solidification, nucleation rate, model of homogeneous nucleation and heterogeneous nucleation on a plane substrate. Models of heterogeneous nucleation in refractories cavities.
9. Stage of crystal growth, heat transport at the phase interface and in the mold-casting system. Transport of mass at the phase interface, the emergence of segregation of elements during solidification.10. Constitutional supercooling, phase interface morphology.
11. Control of solidification of metals, dynamic methods, melt modification, control of crystallization in the stage of crystal growth, single crystals.
12. Crystallization of basic types of foundry alloys. Volume changes during the solidification of castings and their consequences, thermal nodes, concentrated and scattered deposits.
13. Formation of thermal and phase stresses in the casting. Consequences of tension in the cooling casting, formation of cracks, cracks and collapse of the casting, possibilities of reducing tension in the casting.
Laboratory exercise
14 hours, compulsory
Syllabus
1. Practical tests of running property (the Curry spiral, platelets of varying thicknesses), aluminium, cast iron
2. Thermophysical properties of the mould, establishing experimentally the heat accumulation coefficient of mould bf
3. Solidification of castings, experimental determination of the solidification constant
4. Experimental measurement of temperature fields in the casting and in the mould, condensation zone
5. Experimental measurement of temperature vs. time in the casting and in non-insulated, insulated and exothermal risers
6. Solidification vs. time in an experimental casting
7. Shrinkage of castings during cooling, measuring the shape and dimensions of castings using 3D scanning.
Exercise
12 hours, compulsory
Syllabus
1. Introduction to metal flow, theory of running property, basic tests of running property
2. Gating systems, their types, calculation of simple gating systems (underpressure, overpressure)
3. Introduction to the measurement of temperature fields, possibilities of measuring by thermocouples, optical pyrometers and thermocamera
4. Casting risering, calculation of modules, evaluation of experiments
5. PC simulation of solidification, prediction of shrinkage cavities, comparison of simulation and experiment
6. Stress and casting deformations, PC simulation of stress