This Master’s thesis is related to corrosion degradation processes on metal surfaces exposed in different environments. The theoretical part is concern with basic principles in electrochemical and atmospheric corrosion. Practical part describes experimentation of corrosion process of aluminium (99,5) and low carbon steel (11321) in two different atmospheric environments. The conclusion of thesis includes evaluations of the results from practical part and comparison with the theoretical part.

This thesis deals with solving the most serious internal defects in castings made of aluminum alloys which are cast in sand molds in Slévárna a modelárna Nové Ransko Ltd. The problem solving contains a description of the problematic castings with the investigation of the structure and phases and subsequent detailed analysis of their production. The Author of this thesis also examines the influence of Fe and Mn on a possible formation of the internal porosity with the help of test meltings with the evaluation of the internal structural change. The Author’s design solution is a close checking of chemical composition with regard to the ratio Mn / Fe present in the alloy, the purchase of Foundry Degassing Unit to reduce gassiness of melted metals and better control of gassiness with the help of the appropriate equipment for the density Dichte index.

Since aircrafts manufacturers intend to produce low consumption and efficient aircrafts, parts become more and more difficult to machine. Some processes like „air machining“ enables a one-step production for complex aluminium alloy shaped parts. Although the assembly offers a large access to cutting tool, the lack of stiffness for large parts, and especially for thin-walled aeronautics parts implies strong vibrations during machining. The aim of the study is to solve these difficulties in order to keep productivity and improve surface quality. Further innovative solutions are considered like modal analysis, in-phase machining, spindle speed variation, 3 flutes end mill and variable helix angle mill. All propositions are tested on DMG 65 machine tool with Siemens 840D controller. Although vibrations are intrinsic to flexible parts, surface quality has been improved with higher cutting continuity and variable helix angle cutting tool.

Autoclaved aerated concrete is long-time ecological building material with usefull properties. There needs to be done research of its mineralogical compound for reengineering the production. The main mineral compound of AAC is tobermorite, it increases its mechanical properties. In the presence study, we examine the usage of nature and artificial silicious materials. Also, we investigate the influence of sulfate and alumina admixtures, as well as fluidized bed combustion ash, which can be used as the lime and gypsum replacement. Closure of the study is design of the optimal raw material composition, also hydrothermal treatment of autoclaved aerated concrete. In relation to its mechanical properties, mineralogical composition and cost.