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Production of aluminum castings using metal inserts in the technology of casting into ceramic shells
Straka, Pavel ; Zemčík, Ladislav (referee) ; Krutiš, Vladimír (advisor)
The thesis is focused on manufacturing of aluminium castings with inserts by the hybrid investment casting technology. Three measures were proposed to avoid shell cracking caused by thermal expansion of insert. It seems that the covering of insert with a wax is the most efective solution, becasue after dewaxing a gap is formed, which allows insert to dilate. The other solution was based on change of molochite sand to quartz, which has a higher thermal expansion. The last mean to prevent the shell from cracking was adjustment of dewaxing cycle from shock to gradual. Ceramic shell was heated from room temperature to 650 °C. This solution did not avoid shell cracking. Then the simulation of shell heating, pouring of metal and the solidification was made. The information obtained by the manufacturing of experimental casting was used to prototype casting of impeller.
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Computational Analysis of SI 3-Cylinder In-line Engine Piston
Špaček, František ; Svída, David (referee) ; Ramík, Pavel (advisor)
The diploma thesis deals with a mechanical and thermal analysis of 3-cylinder petrol engine piston with capacity of 1,2 l and maximal output 47 kW. The computation analysis was created with the use of finite element method in the Ansys application. The strain solution was created using several techniques. The 3D model was made according to a real piston in the Pro/Engineer and was partly simplified for computation. Crank mechanism forces and the load stresses were solved using Mathcad. Calculations are done for three positions of power cycle engine, where the maximal loads of the piston are expected. Last part of the thesis is calculation of safety factor highcyclical fatigue made using Femfat application.
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Production of aluminum castings using metal inserts in the technology of casting into ceramic shells
Straka, Pavel ; Zemčík, Ladislav (referee) ; Krutiš, Vladimír (advisor)
The thesis is focused on manufacturing of aluminium castings with inserts by the hybrid investment casting technology. Three measures were proposed to avoid shell cracking caused by thermal expansion of insert. It seems that the covering of insert with a wax is the most efective solution, becasue after dewaxing a gap is formed, which allows insert to dilate. The other solution was based on change of molochite sand to quartz, which has a higher thermal expansion. The last mean to prevent the shell from cracking was adjustment of dewaxing cycle from shock to gradual. Ceramic shell was heated from room temperature to 650 °C. This solution did not avoid shell cracking. Then the simulation of shell heating, pouring of metal and the solidification was made. The information obtained by the manufacturing of experimental casting was used to prototype casting of impeller.
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Computational Analysis of SI 3-Cylinder In-line Engine Piston
Špaček, František ; Svída, David (referee) ; Ramík, Pavel (advisor)
The diploma thesis deals with a mechanical and thermal analysis of 3-cylinder petrol engine piston with capacity of 1,2 l and maximal output 47 kW. The computation analysis was created with the use of finite element method in the Ansys application. The strain solution was created using several techniques. The 3D model was made according to a real piston in the Pro/Engineer and was partly simplified for computation. Crank mechanism forces and the load stresses were solved using Mathcad. Calculations are done for three positions of power cycle engine, where the maximal loads of the piston are expected. Last part of the thesis is calculation of safety factor highcyclical fatigue made using Femfat application.
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