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Surface treatment of selected steels using electron beam
Matlák, Jiří ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
The aim of diploma thesis was preparation of hardened layer on three chosen types of materials with different alloying components content without surface melt by using electron beam technology. The influence of chosen process parameters was observed on the prepared hardened layers properties and shapes. In the first part of bibliographic search there are described electron beam properties, possibilities of his influencing and control. There is given example of complete set of electron beam are mentioned in the second part of theoretical research.
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Comparison of laser welding and electron beam welding technology
Trost, Daniel ; Búda, Jaroslav (referee) ; Mrňa, Libor (advisor)
Thesis presents a comparison of technical evaluation of two welding technologies – dismountable connection of two materials, in this case superalloy Inconel 718. On the basis of the technological park of Honeywell Aerospace Olomouc s.r.o. coming into consideration still used the electron beam welding method which is compared in this work with the laser welding due to speed up the welding and a little heat input during the process of the welding.
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Weldability of cobalt alloys by hybrid method Laser-TIG
Herčík, Tomáš ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
The master thesis summarizes the critical situation of the lack of a cobalt used in different industry branches. Due to its increasing price, it will not be possible to use in existing applications. One of these applications is production of cobalt alloys where the replacement of this element is impossible. This type of material keeps mechanical properties at high temperature. However, a suitable choice of technology can achieve at least its savings. In the field of welding, the alloys are joined without any use of an additional material. The possible solution could be the use of hybrid technologies or electron beam. Verification of weldability of both methods was realised in experimental parts and evaluated by destructive methods. The investigation was performed on wear resistant alloy Stellite 6B.
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Surface melting of graphitic cast iron for hard layer preparation and its optimization
Adam, Ondřej ; Matlák, Jiří (referee) ; Jan, Vít (advisor)
The aim of bachelor thesis is description of microstructures, which were created by surface melting of ductile iron by using electron beam technology. The first part of bibliographic search deals with carbon and its effect on iron. The second part is focused on the general knowledge about cast irons, especially on graphitic cast irons. The last part of bibliographic search deals with electron beam technology. The practical part presents a microstructures, which were created by surface melting. Temperature cycles of the different material areas are described based on microstructures. In the end of bachelor thesis, there are chosen remelted layer with the best parametres and surface melting technology is optimized.
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Microstructure stability of electron beam welds
Rončák, Ján ; Havlík, Petr (referee) ; Jan, Vít (advisor)
The aim of this bachelor thesis is an evaluation of microstructure and functionality of welded joints by using methods of material engineering. At first, there are various methods of welding described in the theoretical part. In the second part, the thesis introduces every material that is used to create a welded joint. The final part then offers an explanation of every method used to analyse the process of welding. The joints were created on two specimens without any filler material and at the machine that uses electron beam. The first joint is a combination of austenitic hadfield steel with ferrite-perlite carbon steel and in the second case combined with stainless ferritic steel with high amount of chromium.
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Electroless selective deposition of silver nanoparticles
Salajková, Zita ; Bartoš, Miroslav (referee) ; Kolíbal, Miroslav (advisor)
Silver nanoparticles have a widespread use in the field of plasmonics. Since deposition of nanoparticles from colloidal solutions onto an exact location on a substrate is difficult, it seems advantageous to grow the nanoparticles in-situ. The presented work is focussed at selective deposition of~silver nanoparticles from colloidal solution or from solution reach of silver ions under assistance of focussed electron beams. Successful deposition could lead to growth of well defined nanostructures directly at the substrate surface. The effect of electron beam intensity to surface quality is studied (silica reduction, surface morphology) as well as effect of pH to particle properties. Outputs are used as a part in theoretical description of selective deposition and confirmed by following advanced experiments. The light assisted deposition and growth of nanostructures is described at the end of the presented work.
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Multiphase Ti-Ni layer on titanium substrate by local alloying
Husťák, Miroslav ; Havlík, Petr (referee) ; Jan, Vít (advisor)
The theory section of this thesis is to describe properties and utilisation of titanium and titanium alloys as well as to deal with various methods of surface treatment and means of alloying a titanium surface layer with nickel. The experimental chapter of this thesis is to describe the creation of a hard surface layer on titanium substrate. In order to achieve a hard surface layer, a layer of nickel was electrodeposited on substrate made of commercially pure ASTM Grade 2 titanium which was subsequently melted with the help of an electron beam. A layer with changed chemical composition and microstructure was created by applying the aforementioned method on the titanium surface. In order to achieve a homogeneous microstructure in the surface layer, several samples with the surface layer were prepared by utilising different parameters of the electron beam. The samples were later tested for their microstructural homogeneity, chemical composition, and hardness.
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Nickel silicides layer by electron beam melting of electro deposited layer
Petr, Jiří ; Pantělejev, Libor (referee) ; Jan, Vít (advisor)
This master’s thesis deals with the possibility of creating a compact nickel-silicide layer on austenitic substrates. The theoretical part describes a variety of surface treatments, silicide division, and basic principles of electron beam. The experimental part contains a description of used experimental methods for evaluation of samples, creation of Ni-Si coating using electroplating, and the parameters of electron beam used for melting the sample coating. The last part is devoted to structural evaluation of the sample coating and its microhardness.
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