|
|
Application of biogenous core binder for production of castings in automotive field
Vymyslický, Jakub ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This thesis deals with foundry binders and it is narrowly focused on biogenous binders used for production of castings in automotive field. There is a short overview of all groups of forming and core mixtures at the beginning of the thesis, which describes chemical composition of the mixtures and also development history of the mixtures. The thesis continues by focusing on biogenous binders, which are developed for the automotive field and with another biogenous binders which fits with the automotive field demands. Overview of technological and ecological properties was made for all of the listed biogenous binders. Advantages and disadvantages of the biogenous binders were also noted.
|
|
|
Interaction Core - Melt by Casting of Cylinder Heads from Al Alloys in Semi-Permanent Moulds
Hlavsa, Petr ; Roučka, Jaromír (referee) ; Tegel, Michal (referee) ; Rusín, Karel (advisor)
This dissertation thesis deals with interactions on the interface core - melt by casting of cylinder heads from Al alloys in semi-permanent moulds and solves a specific problem with sticky sand after decoring of a diesel cylinder head casting. It describes in detail the process of core production using the Cold-Box method and process of casting using the progressive technology Rotacast. It theoretically analyses the reaction on the interface core-melt and presents a classification of surface defects by Al castings produced by gravity casting into semi-permanent moulds. It also states the results of technological tests of binders, core mixtures and cores (Cogas analysis). By solution of a problem with sticky sand in intake and exhaust ports of diesel cylinder head casting is used methodology for problem solving DMAIC. All experimental tests are solved in laboratory and production conditions of an international company dealing with casting of cylinder heads from Al alloys in semi-permanent moulds.
|
|
|
Water soluble foundry binders with heat hardening
Dratnal, Lukáš ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
With the increasing foundry requirements we are forced to develop new kinds of foundry binders, either organic or inorganic. There are several requirements for the molding composition and for the proper function. The sand mixture must exhibit appropriate technological, economic and also ecological characteristics. Many environmentally harmful wastes are created from the organic substances contained mainly in binders and catalysts used for molding of the mixture. A good application can be the water-soluble binder cured by heat. These binders allow easy and fast processing and a mixture recoverability.
|
|
| |
|
|
Comparison of environmental and technological properties of various methods of manufacture of foundry moulds and cores
Dlouhá, Monika ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
The roots of foundry manufacture perhaps go back to 2000 BC. Since foundry production in its development has undergone four stages and each of them there was a qualitative jump. From 20 century, the chemicals used in foundry moulds and cores which is the cause producing harmful substances that have a negative impact on the environment. Major sources of harmful substances are just binders, hardeners and catalysts that are needed for bonding of moulding mixture. The third stage deals with the foundry physical processes that are not using today, even though they are most ecological. Nowadays the most used methods Cold-box, Warm-box and Hot-box.
|
|
|
Sands for the production of foundry moulds and cores
Ostrézí, Filip ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
Bachelor thesis deals with properties of most usable sands in foundries and with their advantages, disadvantages and usability. Most used are silica sands, because of their low prices, but they have a lot of disadvantages like discontinued heat dilatation, acidit reaction and health defect. Mainly described are sands from Czech and Slovak Republic and few sands out of Europe. Non-silica sands don´t have so much disadvantages, but their problem is a big price. Most used non-silica and synthetic sands are described.
|
|
|
Modern anorganic foundry binder systems
Kolařík, Martin ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This bachelor thesis deals with newly developed inorganic binder systems. These are mainly developed for their ecological advantages. However, some of the discussed binder systems have better technological properties. Inorganic binder systems are described herein, both on the basis of alkaline silicates and on the basis of inorganic salts. Attention is also paid to bentonite, which is still the most commonly used binder in the world. It turns out that these binder systems will be important for the future of the foundry industry.
|
|
|
Influence of cement moulds on the structure of nodular iron castings
Stachovec, Ivo ; Šenberger, Jaroslav (referee) ; Rusín, Karel (advisor)
The object of the diploma thesis was to solve and to describe the influence of cement sands moulds on the structure of castings with cast iron LKG. The work was intent on watching the tendency of cement sands to the metal penetration of castings, rising of the compounds on the metal mould interface and liquid metal and accompanies elements on the shape of the graphite in the surface of casting. The study of this processes has a big theoretical and a practical meaning, for prevent and prediction of rising of the defects that are attached with unsuitable choice of sand.
|
|
|
OPTIMIZATION OF TECHNOLOGICAL PROPERTIES OF CEMENT SAND MIXTURES
Burianová, Klára ; Nová, Iva (referee) ; Neudert, Alois (referee) ; Rusín, Karel (advisor)
The work deals with optimization of the technological properties of cement-sand mixtures. The main objective is to find the correct mixture of the individual components which contribute to the rapid solidification of the mixture, hence shorter dismantling. The content is also of a method of measuring and recording during the plasticity of the mixture. Also assessment of the velocity of hydration heat cement mixture in the initial stage of the solidification process in the course of the strength properties of the mixture. To assess these phenomena was used calorimetric method used for measuring hydration heat cement mixture. Further measurements plasticity mixtures and mechanical and physical methods for measuring the compressive strength with the help of a measuring instrument LRU-D.
|
|
|
Modern anorganic foundry binder systems
Kolařík, Martin ; Rusín, Karel (referee) ; Cupák, Petr (advisor)
This bachelor thesis deals with newly developed inorganic binder systems. These are mainly developed for their ecological advantages. However, some of the discussed binder systems have better technological properties. Inorganic binder systems are described herein, both on the basis of alkaline silicates and on the basis of inorganic salts. Attention is also paid to bentonite, which is still the most commonly used binder in the world. It turns out that these binder systems will be important for the future of the foundry industry.
|
guest ::
