Neue Entwicklungen in der Galvanotechnik

New Developments in Electroplating Electrodeposited composite coatings are well known for wear reduction or friction reducing applications. A new development are microcapsules containing composite coatings. Microcapsules have a solid, liquid or gaseous core with a shell from different plastics with a diameter from 0.3 up to 50 μm. Self lubricating coatings, for example, are able to reduce the coefficient of friction from 0.7 to 0.1 (Nickel vs. steel). Wear‐indicating coatings containing micro‐encapsulated perfumes, fluorescent dyes or other detectable substances were developed. New processes for the electroplating on light metals are developed. These coatings are more corrosion resistant than the commercially available layers. The increased corrosion resistance results either by the embedding of encapsulated inhibitors in an interlayer or by an electrically non‐conducting interlayer which separates coating and substrate.     

Status quo und Trends der Galvanotechnik

Status quo and trends in electroplating Electroplating is still one of the most commonly applied surface refinement processes. Besides the automotive industry, one of the largest acceptor of electroplating surfaces, the domain electrical engineering and electronics, construction, engineering, aviation and aerospace technology, the jewellery industry and the medical‐technology (e.g. dental prosthetics) are responsible for the high turnover and development. Constantly rising commodity prices, stricter legal regulations (e.g. EU end‐of‐life vehicle directive), growing demand profiles of the customers in terms of quality and functionality, and increasing environmental awareness always lead to new challenges. By means of this process innovation is created. This paper gives an overview on the status quo of electroplating. In addition, selected current trends are presented.     

Potenziale von ionischen Flüssigkeiten als Elektrolyte in der Galvanotechnik

Application potentials of ionic liquids based electrolytes in electroplating Electroplating is essential for a variety of industries including, electronics, sensors, optics, automotive and aerospace. The electroplating industry, which dates back well over 100 years, is based solely on aqueous electrolytes. The advancement of new materials and increasing requirements to functionalized metallic surfaces however constricts the application potentials of classical electrolyte systems. New application fields for the electroplating industry could arise by further developments and optimisation of aprotic electrolytes based on ionic liquids. In this article a short insight will be presented to possibly applications of ionic liquids as metal electrolytes for surface technology and electroplating. After a short introduction to ionic liquids an overview will be given to relevant physical‐chemical properties of ionic liquids, like metal solubility, viscosity and electrical conductivity. In addition current experimental results from our laboratory to the metal deposition of aluminium, cobalt and palladium will be presented and discussed. The main focus was set in the choice of different electrolyte systems, deposition parameters and achieved surface morphology of the produced metal deposits.     

Zur Bedeutung der funktionellen Galvanotechnik für den Ingenieur

Engineering Plating – A Chance for the Engineer in Future . Electroplating as well as chemical plating will become a more and more applicated procedure to produce special properties of the surface of technical components. Therefore the engineer and the plater have to discuss their problems to find out the best way of protection against the various possible kinds of stressing and to state the necessary rules of construction, materials selection, pretreatment, plating and the following finishing operations. Test methods are to standardize and the properties of the composite substrate/metal layer are to describe and to limit.     

Bedeutung der Vakuumtechnik in der Metallpulver-Technologie

Powder-Technology has developed into a significant and still increasing market. There is a demand for high quality meaning highest purity and spherical particle shape of the powder. In order to reach this aim metal alloys are melted under vacuum and atomized with intertgas. To improve the chemical purity the produced powder is treated under vacuum for instance by the static or dynamic degassing process.     

Erweiterung des Vierscheitelsatzes der Differentialgeometrie mit Anwendung in der Theorie der Koppelkurven der ebenen Getriebe

Zusammenfassung Die Erweiterung des Vierscheitelsatzes ergibt die M?glichkeit auch Aussagen zu treffen über die Scheitelpunkte der ebenen geschlossenen Kurvengattungen mit Singularit?ten wie Doppelpunkten und auch teilweise geradlinig verlaufenden geschlossenen Kurven. Eine Anwendung finden die Ergebnisse in den Koppelkurven der ebenen Getriebe. Schlie?lich wird eine analytische Methode zur Ermittlung der Scheitelpunkte einer bekannten ebenen Kurve angegeben.     

Einsatz der Atom-Absorptions-Spektroskopie in der industriellen Analytik

Application of Atomic Absorption Spectroscopy in Industrial Analysis . Atomic Absorption Spectroscopy is highly useful for the determination of metallic elements in all fields of industrial analysis, due to its high specifity and selectivity, its few interferences, and its high flexibility. Design and function of an Atomic Absorption Spectrophotometer are described, and the different possible interferences are discussed as well as the possibilities for overcoming them. Advantages and disadvantages of the flame as a means of atomisation are mentioned, and the application possibilities of the flameless atomisation, especially in the graphite furnace, are discussed. Examples for the application of AA are given from the fields of metallurgy, oil analysis, chemistry of polymers, and of water analysis.     

Anwendung der Hohlkatodenplasmaquelle in der Vakuumtechnik

Various effective and simple constructed plasma sources can be developed by using the hollow cathode effect. The improve of the plasma efficiency is caused by the penetration of two or more glow regions of different parts of the cathode. The equatation p × d ∽ 1 mbar cm is a rule of thumb for the appearance of the hollow cathode effect. The hollow cathode arc discharge is caused by an additional thermal electron emission besides the effectes of the hollow cathode glow discharge. All this effects are the reason for the higher degree of ionization for a hollow cathode source in comparison with the most other plasma sources. Application of the hollow cathode glow discharge for surface finish are technics like plasmacleaning, electron beam ablation or gas flow sputtering. Latters are new technics which allow the development of new sources for the coating technology. The application of the hollow cathode are discharge is possible by using the thermal energy generated by the electron beam (electron beam heating, electron beam melting, and electron beam evaporation) and by using the different possibilities of coating technologies whith the hollow cathode arc source (plasma enhanced evaporation, plasma enhanced reactive PVD and plasma CVD).     

Die Restspannungen in der Umgebung der kaltverfestigten Bohrung

Zusammenfassung Gegenstand der Untersuchung ist die Spannungsverteilung in der unendlichen elastisch-plastischen Scheibe, die durch die Druckbelastung einer kreisf?rmigen Bohrung hervorgerufen wird. Der Rechnung liegt die Trescasche Flie?bedingung, die zugeordnete Flie?regel sowie lineare isotrope Verfestigung zugrunde. Bestimmt werden ferner die Restspannungen und die Aufweitung der Bohrung.     

Die Etablierung der Evolutionslehre in der Viktorianischen Anthropologie

Theories of Evolution shaping Victorian anthropology. The Science-politics of the X-Club, 1860–1872 This paper discusses the role that a group of evolutionists, the X-Club, played in the epistemic and institutional transformation of Victorian anthropology in the 1860s. It analyses how anthropology has been brought into line with the theory of evolution, which gained currency at the same time. The XClub was a highly influential pressure group in the Victorian scientific community. It campaigned for the theory of evolution in several fields of the natural sciences and had a considerable influence on the modernization of the sciences. Yet, this club also intervened in the anthropological discourse of these years. The X-Club’s meddling with anthropology led to the latter’s evolutionary turn. The introduction of an evolutionary agenda into Victorian anthropology depended not only on the X-Club’s theoretical contributions but also on the structural reformation of the discipline. Its campaigns also aimed at marginalizing the proponents of pre-evolutionary anthropology in its institutions and led to the foundation of a new organization in anthropology: The Anthropological Institute of Great Britain and Ireland. Thus, evolutionary anthropology emerged in the 1860s also as the result of science-politicking rather than just from the transmission of evolutionary concepts through discourse.     

Offene Fragen in der Historiographie der Mathematik

Starting from the thesis that the history of mathematics, for saving its duration and support as a scientific discipline, has to look for the needs and problems of contemporary mathematics, six main problems of contemporary mathematics are listed (concerning partly its social state) and subsequently, 16 questions about the history of mathematics. Moreover, some analogues between the work-sharing of the historians of mathematics and that of the scientists are stated.