| Course Unit Code | 618-2037/02 |
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| Number of ECTS Credits Allocated | 6 ECTS credits |
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| Type of Course Unit * | Compulsory |
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| Level of Course Unit * | First Cycle |
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| Year of Study * | Second Year |
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| Semester when the Course Unit is delivered | Winter Semester |
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| Mode of Delivery | Face-to-face |
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| Language of Instruction | Czech |
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| Prerequisites and Co-Requisites | Course succeeds to compulsory courses of previous semester |
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| Name of Lecturer(s) | Personal ID | Name |
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| BEN001 | Ing. Jaroslav Beňo, Ph.D. |
| RAD913 | Ing. Filip Radkovský, Ph.D. |
| Summary |
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The subject is focused on theoretical and practical aspects of moulding mixtures manufacture and control. The attention is devoted to mutual interaction of sand – binder system and to individual technologies of moulds and cores manufacture.
General methods of testing and control of moulding mixtures is also presented here.
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| Learning Outcomes of the Course Unit |
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Acquired knowledge:
- student will be able to characterize individual technologies for molding and core mixture manufacture
- student will be able to define basic methods for testing of molds and cores mixtures together with their regulation based on their physical – chemistry and technological properties.
Acquired skills:
- student will be able to predict mutual interactions of sand – binder system
- student will be able to apply their theoretical knowledge in order to quality control of molding mixture in relation to selected technology
- know the procedure and methodology for complex and time-consuming tests evaluation sand and bentonite mixture based on visual methodology
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| Course Contents |
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1. Classification of materials for molds and cores manufacture. Composition of molding mixtures. Sands - general characterization, classification. Evaluation of quality of natural and artificial sands. Determination of basic sands parameters
2. Silica sands, genesis, physical – chemistry and technological properties, disadvantages of silica sands and their elimination (defects caused by retarded thermal dilatation)
3. Non - silica sands, natural and artificial sands. Classification, general characterization and possibility of their utilization. Structure of molding mixture. Porosity and permeability of molding mixtures
4. Thermo-physical properties of molding mixtures. Coefficient of thermal accumulation, constant of solidification and determination of solidification time (Chvorinov rule). Specific surface area, methods of its determination, Coefficient of angularity and its influence on technological properties of molding mixture
5. Activation of sand grains, methods and significance. Reclamation of sands, methods and evaluation of quality reclaim. Alternative ways of reclamation. Molding mixture strengths, Adhesion - Cohesion strengths of binders. Activation of artificial resins (silanization), methods.
6. Binder systems of the I.-IV. Generation, general characterization. Clay binders of foundry technology, structure and properties. Role of water in clay minerals. Kinds of water, optimal moisture determination. Clay - water interactions. Montmorillonitic clays - Bentonites
7. Properties of bentonite molding mixtures. Activation of bentonites, mechanism, chemism and its influence on binder quality. Changes of bentonite binder after thermal exposition. Control of green sand systems (JBS). Oolitization, advantages and disadvantages.
8. Additives of green sand system. Carriers of Pyrolysis Carbon (PC), . Other additives of green sand systems. Function and utilization. Theory of LC. Optimal Concentration of PC in a mold, casting defects due to abundance and/or absence of PC. Other additives of JBS.
9. Chemicization of mould and core manufacture. Binder system of the II. Generation – alkali silicates, manufacture, general characterization. Structure of colloidal solution, gelation process Methods and principles of alkali silicates curing
10. CT – and ST – mixtures with alkali silicates. CO2 – process. Self-setting mixtures with liquid hardeners. Problems with collapsibility of mixtures with sodium silicates. Renaissance of mixtures based on sodium silicates. CT- a ST – směsi s alkalickými silikáty. Technology of salt cores preparation, manufacture and utilization.
11. Binder systems of the II. Generation based on organic resins. Moulding and cores mixtures based on phenol – formaldehyde resins. Croning method, preparation, manufacture of shells, defects and reclamation.. HOT-BOX method and its versions. Gisag COLD-BOX method (No - bake ). Selection of suitable sands, collapsibility and reclamation. Advantages and disadvantages.
12. Molding and cores mixtures based on furan resins. ST - furan mixtures. Types of acid catalysts. Influence of components temperature on run and velocity of process. Reclamation with utilization of multistage magnetic separation. Quality of chromite reclaims. Resol – CO2 process Selection of suitable sands, collapsibility and reclamation.
13. Chemistry of polyurethane binders. Alkyd-oil polyurethanes. Phenol polyurethanes. Methods of core manufacture PUR COLD-BOX, PEP-SET. Saccharide binders and additives.
14. Binders systems of the III. and IV. Generation, application of physical and biological ways of binding for mold manufacture. Principle, utilization, advantages and disadvantages of individual technologies.
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| Recommended or Required Reading |
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| Required Reading: |
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Sand Binder Systems III - XIII. Foundry Management and Technology. Cleveland:Penton, 1995, roč. 124. ISSN 0360-8999
Mold & core test handbook. 3rd ed. Des Plaines: American Foundry Society, c2001-2006. ISBN 0-87433-228-1.
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JELÍNEK, P. Pojivové soustavy slévárenských formovacích směsí : chemie slévárenských pojiv. Ostrava: OFTIS, 2004. ISBN 80-239-2188-6.
JELÍNEK, P. Disperzní soustavy slévárenských formovacích směsí: Ostřiva. Ostrava: OFTIS, 2000. ISBN 80-238-6118-2.
Slévárenství. Brno: Svaz sléváren ČR, 2000-, roč.47-. ISSN 0037-6825
Mold & core test handbook. 3rd ed. Des Plaines: American Foundry Society, c2001-2006. ISBN 0-87433-228-1.
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| Recommended Reading: |
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| GOODRICH, G. M., ed. Casting defects handbook: iron & steel. Schaumburg: American Foundry Society, c2008. ISBN 978-0-87433-314-5. |
ELBEL, T. Vady odlitků ze slitin železa: (klasifikace, příčiny a prevence). Brno: MATECS, 1992.
GOODRICH, G. M., ed. Casting defects handbook: iron & steel. Schaumburg: American Foundry Society, c2008. ISBN 978-0-87433-314-5. |
| Planned learning activities and teaching methods |
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| Lectures, Individual consultations, Tutorials, Other activities |
| Assesment methods and criteria |
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| Task Title | Task Type | Maximum Number of Points
(Act. for Subtasks) | Minimum Number of Points for Task Passing |
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| Credit and Examination | Credit and Examination | 100 (100) | 51 |
| Credit | Credit | 30 | 16 |
| Examination | Examination | 70 | 35 |