Zjemňování zrna protlačované hořčíkové slitiny AZ31 procesem Ecap

Extruded Mg – 3%Al – 1% Zn (AZ31) magnesium alloy was subjected to ECAP (Equal Channel Angular Pressing) processing at 523 K (250 °C). At the processing temperature of 523 K, fine grains with the average grain size of 2 – 3 μm are formed as a result of dynamic recrystallization originated by fine Mg17Al12 (γ) phase particles having 200 nm diameter dynamically – precipitated during ECAP processing. Microstructural evolution during ECAP was studied systematically using optical microscope and transmission electron microscope.Protlačená hořčíková slitina Mg – 3%Al – 1%Zn (AZ31) byla zpracována procesem ECAP (úhlové protlačování rovnostranným kanálem) realizovaného při teplotě 523 K (250 °C). Při teplotě 523 K bylo dosaženo zjemnění průměrné velikosti zrna 2 - 3 μm, které bylo dosaženo dynamickou rekrystalizací jemné γ faze Mg17Al12 s průměrnou velikostí 200 nm. Vývoj mikrostruktury během ECAP byl systematicky studován na optickém mikroskopu a využitím transmisní elektronové mikroskopie

Vliv geometrie pájeného spoje na jeho mechanické vlastnosti

This paper deals with influence of soldered joint geometry on measurement of its mechanical properties. Mechanical properties of soldered lap-joints of four lead-free solders with different geom-etry were measured. In conclusion using of samples with one interface solder – soldered material for measurement of soldered joints mechanical properties is recommended.Příspěvek se zabývá vlivem tvaru geometrie pájeného spoje na jeho mechanické vlastnosti. Byly naměřené mechanické vlastnosti přeplátovaných spojů čtyř bezolovnatých pájek S různou geo-metrií spojů vzorků. V závěru je doporučeno měření mechanických vlastností pájených spojů pouţi-tých vzorků S jedním rozhraním pájka – pájený materiál

Mechanické vlastnosti oceli DC01 tvářené metodou DRECE

The main goal of the paper is a review of current achieved results given by processing of steel DC01 by DRECE (Dual Rolls Equal Channel Extrusion) forming process, whose prototype equipment has been put in service in the end of 2009 at VŠB – Technical University of Ostrava, Faculty of Mechanical Engineering and Department of Mechanical Technology. The paper analyses the effect of the DRECE forming process on the mechanical properties and deep – drawing sheet metal formability of the steel DC01.Příspěvek uvádí současné výsledky ze zpracování oceli DC01 tvářecím procesem DRECE, jehož prototype byl na konci roku 2009 uveden do provozu pod záštitou VŠB – Technické university Ostrava, Fakulty strojní, Katedry mechanické technologie. Příspěvek analyzuje vliv tvářecí metody DRECE na mechanické vlastnosti a hlubokotažnost oceli DC01

Initial Assessment for SA 8000 implementation

Import 11/07/2012Tato diplomová práce se zabývá požadavky normy SA 8000 a jejím zavedením do integrovaného systému řízení ve společnosti Hutní montáže, a.s. První část této práce je zaměřená na požadavky a obsah normy SA 8000, jako je dětská či nucená práce, práce přesčas apod. Dále je zde představena společnost HM, a.s. a její politika integrovaného systému řízení, kontroly jakosti a bezpečnost práce. Přípravnou fází zavádění manažerských systémů, v tomto případě společenské odpovědnosti, je vstupní přezkoumání. Samotné přezkoumání je provedeno v souladu s legislativními předpisy a ostatní dokumentací HM, a.s. Pro zjištěné nesrovnalosti jsou k dispozici navrhovaná opatření a celkový návrh na začlenění SA 8000 do stávajícího systému HM, a.s.This thesis addresses the requirements of the SA 8000 standard and its implementation in to the integrated management system in the company Hutní montáže, a.s. The first part of this work is focused on standard SA 8000 content and requirements, such as child or forced labour, overtime, etc. There is also presented Hutní montáže, a.s., and its integrated management system policy, quality control and safety. Preparatory phase of implementation of management systems, in this case, social responsibility, is an initial assessment. The actual review is done in accordance with legal requirements and other documentation of HM, a.s. For the observed discrepancies are available the proposed measures and the overall proposal how to include the SA 8000 to the current management system of Hutní montáže, a.s.Prezenční546 - Institut environmentálního inženýrstvívýborn

Imitatio Alexandri in the Hellenistic Art

Tato bakalářská práce se zabývá problémem imitace Alexandra Velikého v období helénismu. Také zahrnuje vybrané portréty Alexandra Velikého a to jak prezentoval svoji osobu. Práce se rovněž okrajově věnuje politické situaci, která nastala po jeho smrti, neboť se promítla do umění i sebepropagace diadochů. Imitatio Alexandri je zde zachyceno i v rovině bohů a héroů, jelikož docházelo ke vzájemnému ovlivňování božských a Alexandrových portrétů. Napodobování Alexandra helénistickými vládci je rozděleno do kapitol podle dynastií či jednotlivých panovníků. Závěr práce poukazuje na podobnosti i odlišnosti Alexandrových nástupců a přináší ucelený pohled na imitatio Alexandri i stručné chronologické shrnutí. Klíčová slova imitatio Alexandri, napodobování, Alexandr Veliký, helénistické uměníThis Bachelor thesis deals with the problem of imitation of Alexander the Great in the Hellenistic era. It also includes selected portraits of Alexander the Great and describes how he used his self-presentation. This work also involves the political situation which occured after his death since it is reflected in the art and self-promotion of the Diadochi. Imitatio Alexandri in this thesis is illustrated also on the level of deities and heroes because of mutual influencing of divine and Alexander's portraits. Imitation of Alexander the Great by Hellenistic rulers is divided into chapters according to royal dynasties or individual rulers. In conclusion, the thesis points out the similarities and differences of Alexander's successors and provides a comprehensive view of imitatio Alexandri and also brief chronological summary. Keywords imitatio Alexandri, imitation, Alexander the Great, Hellenistic ArtInstitute for Classical ArcheologyÚstav pro klasickou archeologiiFilozofická fakultaFaculty of Art

Závislosť digitálneho obrazu textúry materiálu od vlnovej dĺžky svetelného zdroja

The article deals with methodology of measuring the influence of light source spectre on digital image of material texture. Special original measurement system was used for creating special texture images at various lighting conditions. Structure and principle of functioning of the system are described in the article. In the conclusion a relation between the lighting and wave length on the texture quality is examined using a correlation method.Článok sa zaoberá metodikou merania vplyvu spektra svetelného zdroja na digitálny obraz textúry materiálu. Na tvorbu špeciálnych obrazov textúry pri rôznych podmienkach osvetlenia bol použitý pôvodný merací systém. Štruktúra a princíp činnosti tohto systému sú v článku popísané. Záverom je korelačnou analýzou skúmaný vzťah intenzity osvetlenia a vlnovej dĺžky na kvalitu textúry

Investigation of Heat Affected Zone of Steel P92 Using the Thermal Cycle Simulator

This work is focused on mechanical properties and microstructure of heat affected zone (HAZ) of steel P92. The thermal cycle simulator was used for modeling a fine grained zone of HAZ. Hardness and impact toughness were measured on simulated samples. Microstructural analysis using optical microscopy was performed on selected samples. Achieved results were compared with the values of a real welded joint. The thermal cycle simulator allows transferring the properties of very small HAZ to the sufficiently large sample where the tests of the mechanical properties can be performed. A satisfactory accordance was found when comparing the microstructure and mechanical properties of real welds and simulated samples

Potential of Using TPM to Increase the Efficiency of Production Processes

The goal of the submitted paper is to implement the principles of TPM and to achieve almost 100% usability of machines, when there will be no failures and unwanted incidents. The effectiveness of implementing the TPM principles has been experimentally verified in an engineering company. Workplaces for the assembly of rails on Unimatic lines were chosen as a pilot workplace. Prior to the implementation of the TPM, analyses of technical downtime and unplanned shutdowns of the manufacturing devices due to failures, unplanned repairs and maintenance were carried out. The resulting analysis concentrated mainly on two main variables - total cumulative technical downtime at individual workplaces and frequency of occurrence of failures in individual sections of the workplaces. The presented approach and the results obtained underline the importance of applying the TPM principles in practice and their indisputable contribution to the ability to increase business performance. The TPM\u27s progressive maintenance management system represents a prerequisite for the reduction of production costs and losses resulting from unscheduled failures now and in the future

Electric Resistance Welding of Austenitic and Galvanized Steel Sheets

Nowadays the automotive industry is predominantly using heterogeneous welded joints. The welding of an austenitic and galvanized steel sheet is one of the most common applications, which are using resistive spot welding (RSW); it is a process in which contacting metal surfaces are joined by the heat obtained from resistance to an electric current. The electrodes used influence the quality of a heterogeneous welded joint. This paper describes the influence of the electrodes used, their material and shapes, and the final heterogeneous welded joint, which consists of two or three sheets. They will be compared with each other two electrode materials: CuCr1Zr original (material used for both electrodes) of new material CuCr1Zr (upper electrode replacement) and CuCo2Be (removable bottom electrode). Furthermore, the improved electrode geometry where the original planar electrode is passed to the electrode with radius surface, due to poor access to the point of welding. The aim of this research was to achieve a better quality of spot welded joints consisting of two or three sheets

The effect of tungsten carbide particles content in a weld deposit on its abrasion resistance

U radu se daje analiza naslage zavara koja sadrži čestice karbida volframa. U ispitivanju je primijenjen postupak elektrolučnog zavarivanja u zaštićenoj atmosferi miješanog plina s dva tipa žice s jezgrom. Izabrana elektroda s jezgrom tipa "F-Durit G" već sadrži čestice karbida volframa. Druga primijenjena opcija bila je elektroda s jezgrom tipa "Megafil A 864M" s povećanim sadržajem borona. U drugoj su varijanti čestice karbida volframa veličine 1-2 mm dodane u zavar i tako je stvoren sloj od kompozitnog materijala. Za spomenuti pokus izabrana su dva različita nivoa parametara zavarivanja, a mi smo ispitivali svojstva završne naslage zavara, a naročito otpor na abraziju.This paper describes the study of a weld deposit which contains tungsten carbide particles. For testing the process of gas metal arc welding in a protective atmosphere of a mixed gas with two types of cored wires were used. The selected cored electrode of a "F-Durit G" type already contains the tungsten carbide particles. The second used option was a cored electrode of a "Megafil A 864M" type with an increased boron content. For the second variant tungsten carbide particles with a 1-2 mm size were added to the weld pool, and a composite material layer was thus created. For the mentioned test two different levels of welding parameters were selected and the final weld deposit properties, particularly their abrasion resistance, were examined