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Structure and Properties of Cast Nickel-base Superalloys
Fukátková, Pavla ; Němec, Karel (referee) ; Hutařová, Simona (advisor)
This thesis is focused on changes of microstructure of nickel - base superalloys (alloy ZH6K) from the point of view of quantitative and qualitative classification. These phases especially phase ´ and the carbides significantly influence mechanical and other characteristics during the strain and temperature load action. Specimens were observed after thermal and thermal-strain exposition by light microscope and by scanning electrone microscope. There was used the image analysis for the following classification. The part of the thesis is the theoretical summary of the microstructure, chemist and the characteristic of the nickel - base superalloys.
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Embrittlement of TiAl intermetalics induced by surface oxidation
Fukátková, Pavla ; Jan, Vít (referee) ; Dlouhý, Ivo (advisor)
This work aimed to study the effect of surface oxidation of TiAl intermetallic alloys, its fracture behavior and study the formation and stability of picked coatings that could prevent these phenomena. ?-TiAl alloy (Ti46Al7Nb) was examined by three different coatings (AlCr, AlCrN and AlCrNAg). Firstly, it was carried out short-term exposure to high temperature in an inert atmosphere for all coatings. Secondly, there were experiments of cyclic exposure to high temperature in normal atmosphere and isothermal high-temperature exposure in a normal atmosphere. During high-temperature experiments in normal atmosphere mass gain was measured and it was monitored a surface texture. Finally, the most promising coatings were chosen, and those were evaluated in bending strength.
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Structure and Properties of Cast Nickel-base Superalloys
Fukátková, Pavla ; Němec, Karel (referee) ; Hutařová, Simona (advisor)
This thesis is focused on changes of microstructure of nickel - base superalloys (alloy ZH6K) from the point of view of quantitative and qualitative classification. These phases especially phase ´ and the carbides significantly influence mechanical and other characteristics during the strain and temperature load action. Specimens were observed after thermal and thermal-strain exposition by light microscope and by scanning electrone microscope. There was used the image analysis for the following classification. The part of the thesis is the theoretical summary of the microstructure, chemist and the characteristic of the nickel - base superalloys.
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Embrittlement of TiAl intermetalics induced by surface oxidation
Fukátková, Pavla ; Jan, Vít (referee) ; Dlouhý, Ivo (advisor)
This work aimed to study the effect of surface oxidation of TiAl intermetallic alloys, its fracture behavior and study the formation and stability of picked coatings that could prevent these phenomena. ?-TiAl alloy (Ti46Al7Nb) was examined by three different coatings (AlCr, AlCrN and AlCrNAg). Firstly, it was carried out short-term exposure to high temperature in an inert atmosphere for all coatings. Secondly, there were experiments of cyclic exposure to high temperature in normal atmosphere and isothermal high-temperature exposure in a normal atmosphere. During high-temperature experiments in normal atmosphere mass gain was measured and it was monitored a surface texture. Finally, the most promising coatings were chosen, and those were evaluated in bending strength.
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