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Foundry molding mixtures with biopolymer binders
Šindlerová, Eliška ; Janský, Vojtěch (referee) ; Pernica, Vítězslav (advisor)
This work is interested in a new modern solutions in the field of foundry binders. Several biopolymer materials suitable for foundry industry are described and the conditions for using these materials and few examples of casting tests with the use of the biopolymer binders. The main reason why the biopolymer materials are coming back to the industry is a huge amount of strict environmental requirements for the ecological behavior of industrial enterprises and current very bad ecological situation. However this inovative solutions doesn´t have to be only benefits for our environment but the can bring various simplifications to the production process, shortening the time required for preparation or technological breaks, and lower the costs of input material and subsequent waste treatment.
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Casting of manganese steels and their use
Dufka, Martin ; Šenberger, Jaroslav (referee) ; Pernica, Vítězslav (advisor)
Austenitic manganese steel, often referred as Hadfield´s steel after its discoverer, has an irreplaceable place in foundry due to its specific properties. Due to local pressures and shocks, surface of castings is hardened, but the cast core retains its toughness. Thus, manganese steel is used for castings of highly stressed machine parts that are subject to abrasive wear. This bachelor thesis is concerned about methods of production, chemical composition, influence of some alloying elements on properties and structure of steel, heat treatment, material properties, reinforcement mechanisms and types of individual deformation reinforcements. Further attention is paid to the most frequent use of manganese castings in practice.
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Melting equipment in foundries
Toufar, Tomáš ; Blažík, Petr (referee) ; Pernica, Vítězslav (advisor)
The aim of this Bachelor thesis is a description of the properties and operation of selected melting equipment in foundries. History of metal processing and development of melting equipment are briefly described. Based on the findings, smeltering systems used in foundry practice were classified and the individual systems were described in terms of their advantages, disadvantages and application. At the end of thesis, melting equipment was assessed from technical-economic point of view.
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Optimation of heavy steel castings
Pernica, Vítězslav ; Veselý, Pavel (referee) ; Šenberger, Jaroslav (advisor)
Diploma thesis deal with definnig the casuses of stell castings defects in the DSB EURO s.r.o Foundry. The main target is to optimise technological parameters for avoiding the surface casting defects. The first stage is the identification of the defects, describing of the main reasons and mechanic. Defect quantification is make from measuring of area and volume of the mended defects. In association with surface defects, the number of the crackings was observed. Finally there are suggested correction actions based on the previous investigation.
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Spectrometric analytical methods for the analysis of metallic materials and the issue of measuring the carbon content in graphitic cast irons
Osička, Ondřej ; Pernica, Vítězslav (referee) ; Kaňa, Václav (advisor)
Competitive metallurgical production is almost impossible without the knowledge of the chemical composition of manufactured and finished melt, or the produced product. With growing customer demands for product quality and product characteristics, increasing technology speed and increasing product purity, there is growing demand for analyzes of chemical composition. These demands are very often against each other, especially the increasing demands on the speed and accuracy of analyzes. Analytical requirements may not only apply to the test technique, but also to the quality of the sample, which is inseparable from it. What is recently seen as the biggest drawback, the new technology is trying to use as its main priority. This is undoubtedly true of atomic emission spectrometry.
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Corrosion resistance of cast duplex stainless steels
Müller, Peter ; Záděra, Antonín (referee) ; Pernica, Vítězslav (advisor)
The master’s thesis deals with corrosion resistance of cast duplex steels. In the first part the corrosion mechanisms and their individual types are described, the second part characterizes the types of stainless steels in terms of their properties, use, structural components, and their impact on mechanical and corrosion properties of steels. Individual chapter is dedicated to duplex steels. In the experimental part the resistance of 1.4517 steel against pitting corrosion depending on the alloy contents and the PREN value was investigated. Four specimens graded according to PREN were cast. Supplemented with sample stirrer blade which was affected by corrosion during service they were subjected to corrosion test according to ASTM G48-11 standard in 6% FeCl3 solution. Cast specimens were subjected to tensile test and impact test.
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Manufacture of cast iron mortar replica
Myška, Martin ; Pernica, Vítězslav (referee) ; Kaňa, Václav (advisor)
This bachelor thesis deals with the complete production technology of mortar replica. The first part describes the historical development of mortar and pestle in Bohemia and in the world. In the second part there is the description of the technological process of production of models and the methods of molding process. Finally, the production of the mold, subsequent casting and purifying process of the mortar are documented.
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3D printing methods for foundry applications
Rendek, Andrej ; Pernica, Vítězslav (referee) ; Krutiš, Vladimír (advisor)
The bachelor thesis is focused on the application of 3D printing methods for foundries, specifically for investment casting technology. The paper describes different printing methods and principles which they are based on with a more detailed description of materials containing their properties and in some cases recommended modifications of the casting process. The last part is devoted to price comparison of three selected methods of model printing for investment casting and dilatometry of six materials with evaluation of their coefficients of thermal expansion and glass transition temperatures.
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Segregation during solidification in austenitic-ferritic stainless steels
Kejha, Richard ; Čech, Jan (referee) ; Pernica, Vítězslav (advisor)
The master thesis deals with processes of segregation in austenitic-ferritic stainless steels. The introductory part consists of characteristics features of austenitic-ferritic steels and theoretical analysis of segregation processes. The second part shows practical measurements of segregation in experimental casting. Macrosegregation was measured on a spectrometric analyzer and simultaneously solved in the simulation program MAGMA. The aim of this thesis is to verify the effect of solidification time and dwell time between liquidus and solidus temperature on the chemical heterogeneity of duplex stainless steel casting of about 500 [mm]. Chemical heterogeneity was solved for selected alloying and accompanying elements such as C, Mo, Ni, Mn, Cr. The microsegregation was not addressed. Comparison of the mechanical properties of cast and heat treated duplex steel was done by tensile testing of samples cut from the center of the casting.
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