|
| |
|
|
Processing of Nb-containing TiAl intermetallics and its Physical and Chemical Aspects
Barták, Tomáš ; Dlouhý, Ivo (referee) ; Zemčík, Ladislav (referee) ; Dlouhý, Antonín (advisor)
Prezentovaná práce se zabývá vakuovým indukčním tavením intermetalické slitiny Ti-46Al-7Nb (at. %) v žáruvzdorných kelímcích na bázi Y2O3. Byla provedena série taveb pro teploty přehřátí taveniny 1630, 1680 and 1730 C a při různých dobách výdrže na této teplotě v rozmezí 5 až 30 minut. Ze slitin ztuhlých v tavících kelímcích byly připraveny metalografické výbrusy, které sloužily k hodnocení mikrostruktury a vyhodnocení složení fází. Pro získání těchto dat byly použity metosy elektronové mirkoskopie SEM a EDS. Kvantitativní hodnocení mikrostruktury, zejména obsahu oxidické faze ve slitině, bylo provedeno pomocí software Adaptive Contrast Control (ACC). Analýza obsahu kyslíku ve ztuhlé slitině byla provedena metodou IGF (fúze v inertním plynu). V této práci jsou pochody na rozhraní slitina/oxidický kelímek posuzovány také z termodynamického hlediska a to s použitím aktivit jednotlivých složek v systému. Data prezentovaná v této práci mohou být použita pro nastavení a optimalizaci procesů tavení intermetalik TiAlNb.
|
|
|
Present state of investment casting technology
Mazůrek, Tomáš ; Zemčík, Ladislav (referee) ; Horáček, Milan (advisor)
The bachelor’s thesis elaborated within the scope of full-time study of specialization B-STI Mechanical Engineering is dealing with procedures and methods of production castings using the lost wax casting technology. This literature review deals with the entire production process from casting molds for the production models to the ultimate control of manufactured parts and is structured exactly as the technological process in the manufacture of components. For each of the technological process are given commonly used procedures and new technologies that are developed and are now examined. The second part is specific examples of the use of technology investment pattern at present. The aim of this work is to create a bibliographic search, describing the evolution of technology, investment pattern and its possible use today.
|
|
| |
|
|
Production of aluminum castings using metal inserts in the technology of casting into ceramic shells
Straka, Pavel ; Zemčík, Ladislav (referee) ; Krutiš, Vladimír (advisor)
The thesis is focused on manufacturing of aluminium castings with inserts by the hybrid investment casting technology. Three measures were proposed to avoid shell cracking caused by thermal expansion of insert. It seems that the covering of insert with a wax is the most efective solution, becasue after dewaxing a gap is formed, which allows insert to dilate. The other solution was based on change of molochite sand to quartz, which has a higher thermal expansion. The last mean to prevent the shell from cracking was adjustment of dewaxing cycle from shock to gradual. Ceramic shell was heated from room temperature to 650 °C. This solution did not avoid shell cracking. Then the simulation of shell heating, pouring of metal and the solidification was made. The information obtained by the manufacturing of experimental casting was used to prototype casting of impeller.
|
|
| |
|
|
Investment casting of TiAl alloys
Umshaus, Josef ; Malec, Silvestr (referee) ; Zemčík, Ladislav (advisor)
Intermetallic alloys gama TiAl are prospective materials of future thanks its excellent machanical qualities and low density. However this alloy clash with for wider expansion to the practice on burdensomeness production and processing. Among disavantages belongs to also her bad fluidity. The diploma work is angaged in possibilities imporing fluidity alloys TiAl by the help of centrifuge casting. Casting healthy casts was achieved in experimental part.
|
|
| |
|
|
"Net Shape" technologies suitable for castings
Bartoš, Filip ; Zemčík, Ladislav (referee) ; Horáček, Milan (advisor)
This thesis has the task to gather basic information about the technologies used in the manufacture of finished castings, i.e. without further processing, the so-called "Net-Shape". It is focused on technology investment pattern, the combustible model shell casting "Croning“, die casting pressure, die casting to ingot and centrifugal casting. All these technologies are compared in terms of specific features, range use, production economy, the advantages, disadvantages, the resulting quality of castings and other important factors.
|
|
| |
guest ::
