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Improving of use properties of lead-acid accumulator
Szabó, Jaroslav ; Tonar, Karel (referee) ; Abraham, Pavel (advisor)
Lead-acid accumulators are the oldest and most common type of secondary cells. There are still some problems to solve. Grid corrosion in sulphuric acid is one of them, which reduced lifetime of lead-acid accumulators. The first part of work is focusing on a general theoretic description of lead – acid accumulators. Following is a description of the workstation and method of measuring. The final part of the text is measuring on an experimental cell.
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Evaluation of corrosion properties of biodegradable ZE41 magnesium alloy
Honč, Jiří ; Minda, Jozef (referee) ; Tkacz, Jakub (advisor)
This thesis deals with evaluation of corrosion properties of biodegradable magnesium alloy ZE41. Corrosion characteristics of ZE41 wrought magnesium alloy specimens with polished and grinded surface were examined by electrochemical methods. 0,1M NaCl solution was used as corrosive environment. Short-term tests were performed using linear polarization method, by which the corrosion potential, corrosion current density and corrosion rate was determined. Long-term evolution of corrosion behavior in terms of polarization resistance was studied by electrochemical impedance spectroscopy (EIS) during 168 hours. Also, the corrosion products were characterized by scanning electron microscope (SEM) with energy-dispersive spectroscopy (EDS). Based on the results, the influence of phase composition and surface treatment on corrosion characteristics was discussed.
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Evaluation of electrochemical properties of wrought Mg-Al-Zn type magnesium alloys
Slouková, Karolína ; Hadzima, Branislav (referee) ; Tkacz, Jakub (advisor)
The aim of this master’s thesis is electrochemical characteristics evaluation of magnesium alloys. The theoretical part describes the properties of magnesium and its alloys and their corrosion characteristics. In the experimental part are presented results of corrosion resistance measurement of two types of wrought magnesium alloys. It was AZ31 and AZ61 magnesium alloys, which were measured in Hank’s solutions with addition of ions Ca2+ and Mg2+ (SBF+) and without addition of the ions (SBF). The solution temperature during the measurement was 37 ± 1 °C. The experiments were used electrochemical impedance spectroscopy (EIS) and potentiodynamic tests using linear polarization (LP). EIS measurements were done in times of 5 minutes, 1, 2, 4, 8, 12, 24, 48, 72, 96 and 168 hours. Potentiodynamic tests were only short-term and they started after 5 minutes of stabilization. Both methods were used for measuring the electrochemical characteristics of polished and ground surface of the samples. The most important measurement results were polarization resistance, corrosion potential and corrosion current density. The electrochemical measurements are used to estimate the chemical composition influence and alloy’s structure of the corrosion resistance.
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Evaluation of corrosion properties of biodegradable ZE41 magnesium alloy in simulated body fluid
Handlíř, Tadeáš ; Minda, Jozef (referee) ; Tkacz, Jakub (advisor)
The bachelor thesis is focused on the evaluation of the effect of processing of biodegradable magnesium alloy ZE41 on its corrosion properties. The corrosion properties of ZE41 wrought magnesium alloy specimens with polished and ground surface were evaluated based on the results of the electrochemical characteristics that took place in the simulated body fluid. Short-term tests were performed using linear polarization method, by which the corrosion potential, corrosion current density and corrosion rate was determined. Long-term evolution of corrosion behavior in terms of polarization resistance was studied by electrochemical impedance spectroscopy (EIS) during 168 hours. Also, the corrosion products were studied by scanning electron microscope (SEM). Based on the results, the influence of surface treatment and phase composition on corrosion characteristics was evaluated.
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Evaluation of corrosion properties of biodegradable ZE41 magnesium alloy in simulated body fluid
Handlíř, Tadeáš ; Minda, Jozef (referee) ; Tkacz, Jakub (advisor)
The bachelor thesis is focused on the evaluation of the effect of processing of biodegradable magnesium alloy ZE41 on its corrosion properties. The corrosion properties of ZE41 wrought magnesium alloy specimens with polished and ground surface were evaluated based on the results of the electrochemical characteristics that took place in the simulated body fluid. Short-term tests were performed using linear polarization method, by which the corrosion potential, corrosion current density and corrosion rate was determined. Long-term evolution of corrosion behavior in terms of polarization resistance was studied by electrochemical impedance spectroscopy (EIS) during 168 hours. Also, the corrosion products were studied by scanning electron microscope (SEM). Based on the results, the influence of surface treatment and phase composition on corrosion characteristics was evaluated.
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Evaluation of corrosion properties of biodegradable ZE41 magnesium alloy
Honč, Jiří ; Minda, Jozef (referee) ; Tkacz, Jakub (advisor)
This thesis deals with evaluation of corrosion properties of biodegradable magnesium alloy ZE41. Corrosion characteristics of ZE41 wrought magnesium alloy specimens with polished and grinded surface were examined by electrochemical methods. 0,1M NaCl solution was used as corrosive environment. Short-term tests were performed using linear polarization method, by which the corrosion potential, corrosion current density and corrosion rate was determined. Long-term evolution of corrosion behavior in terms of polarization resistance was studied by electrochemical impedance spectroscopy (EIS) during 168 hours. Also, the corrosion products were characterized by scanning electron microscope (SEM) with energy-dispersive spectroscopy (EDS). Based on the results, the influence of phase composition and surface treatment on corrosion characteristics was discussed.
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Evaluation of electrochemical properties of AZ31 magnesium alloy prepared by sqeeze casting
Mikulášová, Kristýna ; Drábiková, Juliána (referee) ; Tkacz, Jakub (advisor)
The bachelor thesis deals with electrochemical characterization of corrosion properties of magnesium alloy AZ31. This alloy produced by squeeze casting method was exposed to a corrosive environment of 0,1 M solution of NaCl. Scanning electron microscopy (SEM) with elemental analysis measured by energy dispersive spectroscopy (EDS) was used for the evaluation of the AZ31 magnesium alloy’s surface. Consequently, short term corrosion tests (5 min) were undertaken by potentiodynamic tests. Long term tests (168 h) were measured by electrochemical impedance spectroscopy (EIS). The effects of different alloy surface treatment (grinding and polishing) on the corrosion rate of the AZ31 magnesium alloy produced by squeeze casting method were evaluated by measured results.
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Evaluation of electrochemical properties of wrought Mg-Al-Zn type magnesium alloys
Slouková, Karolína ; Hadzima, Branislav (referee) ; Tkacz, Jakub (advisor)
The aim of this master’s thesis is electrochemical characteristics evaluation of magnesium alloys. The theoretical part describes the properties of magnesium and its alloys and their corrosion characteristics. In the experimental part are presented results of corrosion resistance measurement of two types of wrought magnesium alloys. It was AZ31 and AZ61 magnesium alloys, which were measured in Hank’s solutions with addition of ions Ca2+ and Mg2+ (SBF+) and without addition of the ions (SBF). The solution temperature during the measurement was 37 ± 1 °C. The experiments were used electrochemical impedance spectroscopy (EIS) and potentiodynamic tests using linear polarization (LP). EIS measurements were done in times of 5 minutes, 1, 2, 4, 8, 12, 24, 48, 72, 96 and 168 hours. Potentiodynamic tests were only short-term and they started after 5 minutes of stabilization. Both methods were used for measuring the electrochemical characteristics of polished and ground surface of the samples. The most important measurement results were polarization resistance, corrosion potential and corrosion current density. The electrochemical measurements are used to estimate the chemical composition influence and alloy’s structure of the corrosion resistance.
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Improving of use properties of lead-acid accumulator
Szabó, Jaroslav ; Tonar, Karel (referee) ; Abraham, Pavel (advisor)
Lead-acid accumulators are the oldest and most common type of secondary cells. There are still some problems to solve. Grid corrosion in sulphuric acid is one of them, which reduced lifetime of lead-acid accumulators. The first part of work is focusing on a general theoretic description of lead – acid accumulators. Following is a description of the workstation and method of measuring. The final part of the text is measuring on an experimental cell.
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