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Extremely low cycle fatigue life of magnesium alloy
Novák, Marek ; Věchet, Stanislav (referee) ; Zapletal, Josef (advisor)
The goal of this bachelor´s thesis is to predict the fatigue life of magnesium alloy AZ61 in the very low cycle count range (less than 100), which also called extremely low fatigue (ELCF) range. Life prediction predicted by Manson-Coffin´s law is higher than the experimental values show. The main problem is that the slope of the real life curve in the ELCF range is different than the slope of the predicted one. A new regression function with additional material parameters has to be found to match the experimentally measured values. The thesis deals with the literature search of the ELCF range and models of fatigue life prediction in the said range. Furthermore, in the experimental part of the thesis, magnesium alloy AZ61 without any heat treatment has been measured for mechanical and fatigue properties. Also, the microstructure of the alloy was observed. Measured values of fatigue life in the ELCF and LCF range were fitted by a regression function proposed by L. Xue.
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Fatigue Behaviour of AZ31 and AZ61 Magnesium Alloys
Gejdoš, Pavel ; Lukáč, Pavel (referee) ; Kohout, Jan (referee) ; Podrábský, Tomáš (advisor)
This doctoral thesis deals with the fatigue behaviour of AZ31 and AZ61 magnesium alloy casted by advanced methods of casting squeeze casting. Based on the regression functions and measured fatigue data were determined fatigue characteristics of these alloys. The work also extends into the area of fatigue cracks in the AZ31 alloy. Were measured fatigue crack propagation rate on modified cylindrical specimens. The paper also outlines the possibilities for describing the fatigue behaviour of AZ61 alloy in extremely low-cycle fatigue.
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Extremely low cycle fatigue life of magnesium alloy
Novák, Marek ; Věchet, Stanislav (referee) ; Zapletal, Josef (advisor)
The goal of this bachelor´s thesis is to predict the fatigue life of magnesium alloy AZ61 in the very low cycle count range (less than 100), which also called extremely low fatigue (ELCF) range. Life prediction predicted by Manson-Coffin´s law is higher than the experimental values show. The main problem is that the slope of the real life curve in the ELCF range is different than the slope of the predicted one. A new regression function with additional material parameters has to be found to match the experimentally measured values. The thesis deals with the literature search of the ELCF range and models of fatigue life prediction in the said range. Furthermore, in the experimental part of the thesis, magnesium alloy AZ61 without any heat treatment has been measured for mechanical and fatigue properties. Also, the microstructure of the alloy was observed. Measured values of fatigue life in the ELCF and LCF range were fitted by a regression function proposed by L. Xue.
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Fatigue Behaviour of AZ31 and AZ61 Magnesium Alloys
Gejdoš, Pavel ; Lukáč, Pavel (referee) ; Kohout, Jan (referee) ; Podrábský, Tomáš (advisor)
This doctoral thesis deals with the fatigue behaviour of AZ31 and AZ61 magnesium alloy casted by advanced methods of casting squeeze casting. Based on the regression functions and measured fatigue data were determined fatigue characteristics of these alloys. The work also extends into the area of fatigue cracks in the AZ31 alloy. Were measured fatigue crack propagation rate on modified cylindrical specimens. The paper also outlines the possibilities for describing the fatigue behaviour of AZ61 alloy in extremely low-cycle fatigue.
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