National Repository of Grey Literature 20 records found  1 - 10next  jump to record: Search took 0.02 seconds. 
"Influence of speed of cooling during the casting solidification to the final casting structure and mechanical properties Al castings made by lost-wax technology"
Žák, Štěpán ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
The diploma thesis deals with the influece of the cooling speed during the solidification of the Al casting on its mechanical properties and stucture. The influence of the wall thickness of the casting and the method of cooling by means of luiquid and compressed air were investigated. Mechanical properties were evaluated using a tensile test, the structure was evaluated by means of the DAS parameter. The improvement of the material properties using both methods was confirmed. When using the method of cooling by means of liquid, excellent final values of mechanical properties and fineness of structure were achieved.
Optimization of wax pattern technology in the company Alucast
Šmatelka, Jakub ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
This diploma thesis deals with the problem of wax patterns manufacturing in investment casting technology (lost wax process). This technology is very sensitive to the exact execution in each phase of the whole process, from concept design up to the final casting expedition. During most operations, dimensional changes occur, which is affecting the accuracy of the final casting. No matter how big these changes are, but especially if they occur with the least variance. One of the first phases in this technology is making wax patterns. There are several ways of making the wax patterns and this thesis is describing two different methods used in the Alucast foundry. One is based on using “soft waxes” enabling using low pressure machines, the other one on the “hard waxes” where the injection machine with higher presses is being used (SOM). These two above mentioned technologies are compared in this work.
The Proposal of Improving of HR Management of Diverse Teams in High-tech Firm
Derka, Martin ; Cileček, Jarmil (referee) ; Rašticová, Martina (advisor)
Master’s thesis deals with the analysis of personnel management in selected high-tech company. The theoretical part of thesis describes the basic concepts of personnel management, diverse teams and characteristics of the high-tech sector. In the practical part is analyzed the current state using questionnaires and subsequently proposed recommendations, including their economic evaluation.
Present state of investment casting technology - ceramic moulds
Šmíd, Jiří ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
This bachelor thesis is focused to the production of ceramic moulds and connected problems during the shelling process. The survey of materials and equipment is given in this work and also possible defects and their causes in the ceramic shells.
Using "reverse engineering" approach when making replica of Al casting by lost wax technology
Bezděk, Adam ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
The aim of this thesis was to produce a prototype casting of aluminum alloy with usage of reverse engineering technology. In a production process surface quality and dimensional accuracy was optimized. 3D scanning, FDM technology, ABSplus surface finishing possibilities and investment casting technology is introduced in theoretical part of this thesis. Practical part of the thesis includes description of original parts, their 3D scanning, usage of RE and RP, production of new castings and evaluation of their dimensional accuracy and surface roughness.
Possibilities of using numerical simulations in investment casting technology
Čagánek, Radim ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
The diploma thesis deals with the possibilities of using numerical simulation in investment casting technology. The first chapter of practical part deals with the use of simulations in the design of gating system for the shape-complex casting. At the same time, the practical part verified the accuracy of the simulation by test castings on which the X- ray inspection was performed. The results showed that the occurrence of internal defects predicted by simulation corresponded to the locations in the test casts. Next part of the thesis describes improvement of the use of liquid metal (so called “yield”) by numerical simulations. Two specific castings were chosen to perform simulation of current and newly designed variant of the gating system.
"Optimizing the Al casting heat treatment"
Ostrézí, Barbora ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
This master’s thesis focuses on the heat treatment of the aluminium alloy AlSi7Mg0,6 and also investigates the effects of different coolants usage on its mechanical properties. First part is dedicated to the description of aluminium alloys, their chemical composition, behaviour and mechanical properties with particular attention to the Al-Si-Mg alloys. This part was followed by the summary of commonly used heat treatment of aluminium alloys. The third part is dedicated to the experiment. Castings and test specimens were wax casted at Alucast, s.r.o. company. After annealing, the samples were quickly cooled down in four different coolants and underwent tensile testing. Their mechanical properties (tensile strength, yield point and ductility) were evaluated as well as microstructure. In the last part, the achieved results are presented.
Dimensional stability of investment Al castings
Úředníček, Lukáš ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
The aim of this paper is to compare a bottom filling of a ceramic form made by lost wax process and a top filling conventional method. A computer simulation of filling and casting solidification will contribute to this comparison. The comparison includes evaluation of readings DAS and characteristic readings of porosity with chosen varieties of casting. The results show that the readings DAS did not change much but characteristic readings of porosity were much better at bottom filling. The computer simulation also showed a certain contribution in the field of model smelting technology.
Education of Company's Top Management with a Focus on "Soft Skills" and Work in a Team
Mikulková, Veronika ; Cileček, Jarmil (referee) ; Zich, Robert (advisor)
My bachelor thesis is concerned with the education of top management in small and medium enterprises focused on “soft skills“ and team cooperation. The study concludes with particular proposals of education modules to help the top management become more effective and beneficial. The analysis of educational needs proceeds from questionnaire investigations, subsequent evaluation and finding the most convenient alternatives of educational platform and techniques clearing the way of raising effectiveness in team and general behaviour of top management.
Increasing of mechanical properties of aluminium castings made by lost wax technology
Němec, Jiří ; Cileček, Jarmil (referee) ; Horáček, Milan (advisor)
This diploma thesis is concerned with improving the mechanical properties of aluminium castings produced using investment casting technology by HIP (Hot Isostatic Pressing). Comparing the mechanical properties of separately casted test bars and integrally casted test bars for individual types of production. It was demonstrated that HIP technology has a positive effect on mechanical properties of castings, especially for ductility.

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