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Investigation of Reliability for Solder Joints
Toufar, Michal ; Somer, Jakub (referee) ; Szendiuch, Ivan (advisor)
It evaluates the importance of soldering in a protective atmosphere. Factors influencing the process of reflow soldering in a protective atmosphere of nitrogen. Evaluates the quality of solder joints due to a defined residual oxygen during the soldering proces. According finishes used on the resulting quality connections for two types of lead free solder.
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Lead-Free Voids Cause Mechanisms and Influence on Reliability
Šimon, Vojtěch ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
The aim of this work is to analyze reliability of lead-free solder join, in particular the voids generated during the soldering process. The main target of the theoretical part of the work is to isolate basic mechanisms of formation of the voids and optimize the soldering process. The practical part of the paper is based on monitoring the count and size of the voids in a solder join. An X-Ray tomograph has been chosen as a non-destructive method of detection. The statistical part of this work compares conventional soldering of the entire board with local soldering by IR radiation.
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Emisivity and its Impact on the Heat Conductivity
Gančev, Jan ; Hejátková, Edita (referee) ; Szendiuch, Ivan (advisor)
This work deals with the issue of emissivity and its impact on the heat dissipation.The first part describes the basics of thermal management, the issue of emissivity and its measurement. In the second, experimental part, are dedicated the emissivity values of examined specimens. These values are then used as initial conditions for the thermal simulation. In the last part are compared the measured results and the simulated results and is evaluated the impact of emissivity for the heat dissipation.
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Optimization of Machining Parameters Abradable Sprayed used in the Aerospace Industry
Krajkovič, Pavel ; Osička, Karel (referee) ; Kalivoda, Milan (advisor)
This thesis is focused on machining of thermal spray coatings. Particularly on testing of machining parameters and their influence on different types of abradable coatings used in the aerospace industry. The aim of research work is to test the parameters, measure cutting forces by using a dynamometer and their impact on the quality of the machined surface. Determination of the optimal machining parameters for different types of coatings based on results of measurements and the evaluation of surface quality. There are also presented techniques of thermal spray application and methods of coating evaluation. Further it describes a method of measuring cutting forces by using the dynamometer and methods of surface quality evaluation.
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Hot dip galvanizing of the steel construction
Pometlo, Stanislav ; Vyplašil, Evžen (referee) ; Kubíček, Jaroslav (advisor)
This master´s thesis deals with hot dip galvanizing of steel constructions and their protection from corrosion. This work describes the origin of corrosion of steel and its corrosion in different areas and presents degreasing and pickling before hot dip galvanization. It describes possibilities of making zinc layer by the wet and draw method of hot dip galvanization. Furthermore, it puts forward reactions between zinc and iron, possible defects of the zinc layer and influence of the hot dip galvanizing on the steel constructions. The experimental part examines the influence of the hydrogen charging on the material and the time of the flux operation on the quality of layer. The work further analyses the changing of mechanical properties of steels Hardox 500 and Weldox 700 as a result of the hydrogen embrittlement during pickling by the hydrochloric acid.
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surface finish for the container CASTOR
Tomek, Jan ; Kubíček, Jaroslav (referee) ; Žák, Ladislav (advisor)
Master’s thesis deals with the problems of the inner surface finish design for the CASTOR container. In the theoretical part are analyzed properties of metallic surfaces with their defects and various options of surface finishes for increased protection. The practical part of the thesis is focused on the design of appropriate technologies for specific requirements of the surface finish for the CASTOR container, creating test samples and their evaluation.
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Reliability of lead free solder joint
Paško, Martin ; Knotek, Tomáš (referee) ; Stejskal, Petr (advisor)
This thesis deals with voids formation in lead-free soldered joint. In theoretical part are described types of voids, voids formation, effect on join reliability, effect reflow profile on voids formation and effect of surface finish on voids formation. In practical part is investigated a effect of thermal stress on voids growth.
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Monitoring of Solder Spreading Velocity on Metal Surface
Růžička, Miroslav ; Dušek,, Karel (referee) ; Starý, Jiří (advisor)
This work deals with flushing monitoring of spreading velocity on solder finishes Niau, OSP, Sn deposited on copper plated base material FR4 using digital cameras. After the reflow process is measured by length of spreading solder and size of wetting angle. It evaluates and compares the time dependence of velocity of spreading solder, length of solder spreading and wetting angle for NiAu, OSP, Sn finishes at different temperatures reflow and surface treatment.
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