Kinetische Analyse des Verbrennungsvorganges in der Dieselmaschine

Zusammenfassung Die Erkenntnis. da? die Verbrennung in der Dieselmaschine weder bei unver?nderlichem Raum noch bei unver?nderlichem Druck erfolgen kann, zwingt dazu, die Ursachen aufzusuchen, die den wirklichen Verbrennungsverlauf beherrschen. Zu diesem Zweck werden die Beobachtungen an der Maschine im Sinne kinetischer Betrachtungen ausgewertet. Diese zeigen, da? der Verbrennungsverlauf als Funktion einer Geschwindigkeitskonstaten erscheint, die durch die Aktivierungsw?rme, die Aktionskonstante und die Temperatur bestimmt wird. VDI     

Untersuchungen an Schneckenverzahnungen mit der Finiten Elemente Methode

To date, investigations on worm gears under load were based predominantly on experimental tests on test stands. The complex geometrical meshing relationships up until now did not permit any reliable computer-based simulation of worm gears under load. The Hertzian stress in the tooth contact of a worm gear??relevant for wear and pitting??so far has not been able to be reliably determined, from both an experimental as well as a theoretical perspective. Using an FEM model generator, any worm gear set can be created and calculated. Based on these FEM results, peripheral areas can also be investigated in addition to the tooth contact. FEM can be used to evaluate loads that already result in elastic-plastic deformation of the gearing.     

Untersuchungen an magnesiumbasierten Legierungen als neue Materialien in der Implantologie

Exploration of Magnesium Alloys as New Material for Implantation Magnesium‐based alloys show as well a fitting Youngs's Modulus (45 GPa) referring to the corticalis as high physico‐chemical biocompatibility due to its essential character. The biodegradation of Magnesium‐alloys could be used to obtain temporary implants. The corrosion resistance of commercial alloys as AM20 and AZ31 and testing materials with higher biocompatibility, basing on cph Mg‐Li, is tested in a body ullage.     

Untersuchungen an Turbinenschaufelgittern

Ohne Zusammenfassung The online version of the original article can be found at     

Untersuchungen zur Bestimmung der Biegebruchfestigkeit gebundener Schleifmittel

Investigations to determine the bending strength of bonded grinding materials Apart from the process characteristics, the safeness of grinding wheels against the breakage caused by centrifugal forces is of special interest. The calculation of the bursting speed of grinding wheels based on experimentally determined bending strengths deviates significantly from measured bursting speeds. This is because of the incorrect determination of the bending strength based on BGG 931. By taking into account the plane stress conditions in the area of applied load, an improved approach to determine the bending strength of bonded grinding materials was developed.     

Rasterelektronenmikroskopische Untersuchungen an Hochpolymeren

Scanning electron microscopic investigation of high polymers In accordance with the numerous forms in which high polymers appear, the applications of the scanning electron microscope in the investigation of these materials are of many different kinds. The depth of focus of the SEM is so great that widely differing surfaces, including rough fracture surfaces, can be imaged. Applications relating to textile microscopy, the weathering of pigmented paint films, the destructive effects of chemicals on plastics, fracture investigations on thermoplastics, and measurements on foamed plastics and bone cements are described. In addition the SEM provides opportunities for dynamic experiments, as well as enabling the various interactions between electrons and matter to be utilized for discrimination of materials (e.g. by cathodoluminescence) and – when the SEM is used in conjunction with an X-ray spectrometer – for microanalysis. X-ray micrography enables the distribution of pigment and filler agglomerates, glass fibres, pores etc. to be investigated in samples of relatively large volume with a good prospect that representative findings will be obtained.     

Methoden und Probleme der Schliffherstellung zum Zwecke metallographischer Untersuchungen

Methods and problems of cross section preparation for metallografic investigation . By an analysis of some literature it is tried to demonstrate that – in spite of comprehensive researchs – it is impossible to tell in advance the depth of the disturbed layer of a specimen's polished surface whenever the microstructure has been influenced by mechanical or thermical stresses. Only by chemical methods of preparation it is possible to obtain an unchanged microstructure in a polished metal surface. The approved methods are named and there are given some hints at practical proceeding.     

Holographisch-interferometrische Untersuchungen an GFK- und KFK-Bauteilen

Holographic Investigations of Fibre Reinforced Plastic Materials. A review is given on the holographic investigations of fibre reinforced plastic components carried out in the last few years at Dornier System. Several results are discussed in the view of elaboration of qualitative and quantitative test criterions.     

Vergleichende Untersuchungen an Goldschichten auf Silber

Comparative examinations on gold layers applied on silver . By electrolytical deposition, high vacuum evaporation and cladding gold layers of 10–20 μm thickness had been produced on silver. These layers had been examined in their initial state and after different heat treatments on air by a light microscope and a scanning electron microscope. The microhardness of these layers had also been determined and the diffusion between gold and silver had been studied with the electron microanalyzer. Besides the known features of surface structure and hardness certain differences in the tarnishing and diffusion behaviour had been detected. The cause of these differentiations is primarily due to typical processing features.     

Untersuchungen an Ta2N-oxid-schichten

Reactively sputtered Ta₂N films have been oxidized anodically and basic data were measured. The density of the Ta₂O₅N turned out to be 6.1 g/cm³. A Ta₂N thickness anodization voltage ratio of 0.43 nm/V was determined which corresponds to an oxide build-up of 1.40 nm/V. From the measured anodization rate, i.e. the rise in voltage per unit of time at constant current, of 0.54 V/s (j = 1 mA/cm²) and stoichiometric considerations it is concluded, that the nitrogen is not bonded chemically in Ta₂N and Ta₂O₅N.     

Untersuchungen zur Widerstandscharakteristik der Strömung inkompressibler Fluide in permeablen Rohren

Ohne Zusammenfassung     

Probleme der Kriechstromfestigkeit: Untersuchungen über den Einfluß der Prüflösung

Problems of Tracking Tests: Influence of the Test Solution. This Paper reports on the influence of different electrolyts to the results of tracking tests. Specially the influence of the resistivity and the chemical components were explored. 34 materials were tested and the measured values of 16 are fixed in a table. In case of some of them the results are graphically described.     

Untersuchungen zur lokalen Zusammensetzung von Glasfasern mit Hilfe der Röntgenmikroanalyse

Investigations of the Local Composition of Glass Fibers with the Help of the Scanning Electron Microanalysis Various glass-fiber types show different chemical resistance in the surrounding of aggressive media. Through the influence of inorganic acid or alkali media certain elementary glass fibres can be leached. This effect can be seen optically in some kinds of glass-fibers. Other glass-fiber types show no optical change in the surface, although there is an aggressive attack Now it is possible to understand the leaching process in glass-fibers with the help of the scanning electron microanalysis. In that way corrosion procedures of various glass-fiber types can be better described.     

Die Erzeugung der Eigenspannungen an der kaltverfestigten Bohrung

Zusammenfassung Gegenstand der Untersuchung ist der Einflu? des Dornüberma?es auf die Eigenspannungen in der Umgebung der kaltverfestigten Bohrung in der unendlichen elastisch-plastischen Scheibe. Der Rechnung liegt die Trescasche Flie?bedingung, die zugeh?rige Flie?regel sowie die Annahme linearer isotroper Verfestigung zugrunde. Der Gültigkeitsbereich der Ergebnisse wird diskutiert.