Reinigung vor der Beschichtung

Cleaning before Coating Information is provided concerning measures for cleaning mainly glass substrates immediately before coating. Besides the individual cleaning techniques also cleanning cycles are discussed.     

Flächeneinfluss bei der PACVD‐Beschichtung

Impact of the active surface on properties of DLC films in the PACVD coating chamber. In the automotive industry, economic and stable industrial processes to apply hard coatings for tribological applications are required. Hence detailed knowledge about the influence of coating parameters on the film characteristics is essential. the following paper deals with the process of plasma activated chemical vapor deposition with focus on the effect of the parameter “active area in the coating chamber“ on the properties of diamond‐like‐carbons (DLC). the coatings are deposited in an industrial coating chamber using reactive magnetron sputtering with a pulsed bias voltage (40 kHz) and at constant pressure. During the investigation of the influence of active area and current density on the mechanical and tribological properties of the DLC films, the expected correlation between active area and current density could be confirmed. By regulating the current density, consistent film properties could be achieved, independently of the active area in the chamber. Furthermore improved wear characteristics of the film – crucial for the endurance of heavily loaded automotive components – were achieved by adapting the load pattern of the chamber.     

Gasturbinen mit Dampfzusatz vor und hinter der Brennkammer

Zusammenfassung Unter vereinfachenden Annahmen kann man den Einflu? eines Zusatzes von Sattdampf oder überhitztem Dampf zum Gasturbinenproze? auf den Wirkungsgrad, den Luftdurchsatz, die Abgastemperatur u. a. m. schnell berechnen und übersichtlich darstellen. Untersucht werden insbesondere Anlagen ohne und mit Luftvorw?rmung. Den Vorteilen einer Wirkungsgradverbesserung und einer Verminderung des Luftdurchsatzes auf Grund des Dampfzusatzes stehen die Nachteile der h?heren Gestehungskosten der Anlage durch Hinzukommen des Dampferzeugers sowie der Kosten für die erforderliche Reinigung des Wassers gegenüber. Bei Wirtschaftlichkeitsbetrachtungen dürften die Wasserreinigungskosten den Ausschlag geben.     

Plasmavorbehandlung und Beschichtung von Kunststoffolien. Teil 1: Beschichtung von unbehandelten Kunststoffolien

Plasma Pretreatment and Coating of Polymer Films. Part 1: Coating of Non-treated Polymer Films The food packaging industry demands cheap polymer films possessing a high barrier against permeation of gases, moisture and flavor. Candidates for the most successful materials fulfilling these requirements are vacuum web coated biaxial oriented polypropylene (BOPP) films containing a thin inorganic barrier layer. For a good adhesion of the barrier layer on the BOPP films, the polymer film must be pretreated. The industry uses the Corona atmosphere plasma. This work is separated in three parts. The first part describes the experimental setup and the properties of vacuum web coated layers on polymer films. The next part contains the results of the systematic modification of polymer surfaces by atmosphere and low pressure plasmas. The influence of the surface properties on the final functionality of the coated films is given. In the last part, the discussion of the results of the first and second part reveals systematic relations between the production parameters of the high barrier films and their final functionality. These results firstly reveal the adhesion mechanism of the inorganic barrier layers of the polymer films and the necessary surface properties of the polymer films, in order to get cheap high barrier films by vacuum web coating.     

Beschichtung und Reinigung von Oberflächen mit Atmosphärendruck‐Plasmen. Coating and cleaning of surfaces with atmospheric pressure plasmas

Since long time dielectric barrier discharges have been in use for technical applications such as ozone synthesis and surface activation treatment of polymers for subsequent printing, pasting, or laquering. A new field of applications for these discharges is opened by their use for plasma‐based coating and cleaning processes at atmospheric pressure. By introducing gaseous monomers (like hydrocarbons, fluorocarbons, silicon‐organic compounds) into the discharge zone, coatings can be deposited on electrically conductive or insulating substrates. Barrier discharges in oxygen containing gases can also be used for the degreasing of surfaces. Owing to the possibility, to sustain barrier discharges in very small volumes, new perspectives are opened for the geometrically structured modification of chemical and physical properties of surfaces as well as for the modification or coating of internal surfaces in microfluidic devices.     

Plasmavorbehandlung und Beschichtung von Kunststoffolien. Teil 2: Experimentelle Ergebnisse der Plasmavorbehandlung von Kunststoffolien

Plasma Pretreatement and Coating of Polymer Films. Part 2: Experimental Results of the Plasma Pretreatment of Polymer Films The food packaging industry demands cheap polymer films possessing a high barrier against permeation of gases, moisture and flavor. Candidates for the most successful materials fulfilling these requirements are vacuum web coated b iaxial o riented p olypropylene (BOPP) films containing a thin inorganic barrier layer. For a good adhesion of the barrier layer on the BOPP films, the polymer film must be pretreated. The industry uses the Corona atmosphere plasma. This work is separated in three parts. The first part describes the experimental setup and the properties of vacuum web coated layers on polymer films [1]. The next part contains the results of the systematic modification of po } ymer surface by atmosphere and low pressure plasmas. The influence of the surface properties on the final functionality of the coated films is given. In the last part, the discussion of the results of the first and second part reveals systematic relations between the production parameters of the high barrier films and their final functionality. These results firstly reveal the adhesion mechanism of the inorganic barrier layers of the polymer films and the necessary surface properties of the polymer films, in order to get cheap high barrier films by vacuum web coating.     

Plasmavorbehandlung und Beschichtung von Kunststoffolien. Teil 3: Auswertung der experimentellen Ergebnisse und Diskussion

Plasma Pretreatment and Coating of Polymer Films. Part 3: Analysis of the Experimental Results and Discussion The food packaging industry demands cheap polymer films possessing a high barrier against permeation of gases, moisture and flavour. Candidates for the most successful materials fulfilling these requirements are vacuum web coated biaxial oriented polypropylene (BOPP) films containing a thin inorganic barrier layer. For a good adhesion of the barrier layer on the BOPP films, the polymer film must be pretreated. The industry uses the Corona atmosphere plasma. This work is separated in three parts. The first part describes the experimental setup and the properties of vacuum web coated layers on polymer films[1] The next part contains the results of the systematic modification of polymer surface by atmosphere and low pressure plasmas[2]. The influence of the surface properties on the final functionality of the coated films is given. In the last part, the discussion of the results of the first and second part reveals systematic relations between the production parameters of the high barrier films and their final functionality. These results firstly reveal the adhesion mechanism of the inorganic barrier layers of the polymer films and the necessary surface properties of the polymer films, in order to get cheap high barrier films by vacuum web coating.     

Entwicklung einer neuartigen wirtschaftlichen,eisenbasierten Beschichtung zur Erhöhung der Lebensdauer von Gussbauteilen unter dem Gesichtspunkt der Korrosionsbeständigkeit

Cast irons are widely used to produce parts in rotating machines, e.g. in pumps, due to their excellent casting properties, machinability and good mechanical properties as well as their high economic advantages compared to other materials. However, they have to be replaced by more expensive materials in combination with more complex processes to meet the increased requirements of corrosion and erosion resistance. A more economical approach to increase the corrosion and erosion resistance of components of cast irons is to prevent the parts from corrosive and erosive attacks by means of a protective coating. In this research work, a novel economical iron based protective coating system based on a FeCrMnBC alloy was developed via atmospheric plasma spraying and investigated in terms of its corrosion behavior. The results show a significant improvement compared to uncoated substrate EN‐GJL‐250. This novel coating exhibits a high potential to protect parts of cast irons.     

Abschirmung von Kunststoffen durch Beschichtung im Vakuum

Vacuum coating for shielding of plastics Shielding coatings can be deposited selectively on plastic housings by vacuum assisted processes. The mechanical properties of the polymer material are not affected. Uncoated areas maintain their visual appearance, i.e. refinishing operations are not required. Due to their high electrical conductivity, Aluminium and Copper films provide a high shielding effectiveness for electromagnetic waves. They are applied successfully to devices in a wide variety of industrial sectors if electromagnetic compatibility (EMC) has to be ensured. If applications under harsh environmental conditions are encountered, protective coatings deposited during the same vacuum cycle, are the best solution. Similarly, combinations of properties like shielding and solderability can be achieved by vacuum coating, e.g. with Copper / Tin layers. In case that for example transparency in the visual regime is specified in conjunction with dissipation of electrostatic charges or with attenuation of high – frequency interferences, indium tin oxide (ITO) films are well proven.     

Gießformherstellung durch Beschichtung von Modellen

Casting molds, produced by coating of prototypes A new method for the cost effective production of forming tools is introduced. These tools can be used for the production of prototypes and small series of products. The new method for the production of moulds and injection moulding tools consists of the following steps: ?coating of a positive model with a hard coating by physical vapour deposition (PVD)‐technologies ?deposition of a support coating, consisting of a metal coating, applied by an atmospheric plasma spraying technology ?embedding in a polymer removing of the positive model ?completion of the tool by adding the moulding equipment By using such a tool it is possible to produce more than 1000 parts of a polymer (enforced by glass fibre) or more than 1500 parts of a regular polymer.     

Zur Position von Mathematik und Mathematiker/innen in der Industrieforschung vor 1945

The paper considers the status of mathematics and mathematicians in German industrial labs from the 1920s. As an example, we take the use of statistical methods in the electrical engineering company Osram in Berlin. In the United States, the former employee and member of a special mathematical research department of the Bell Telephone Laboratories, Walter Andrew Shewhart (1891–1967), is regarded as the father of statistical quality control. Although the first textbook on applications of mathematical statistics to problems of mass production was published in Germany in 1927, Germany was nevertheless generally considered as conservative in using statistical methods until 1945. In the past we have known little about whether and how these methods were actually applied in German industry before 1945. The present analysis is based on laboratory reports and other sources. It shows that in this field of research there was a close cooperation between industry and university, which was cut off in the mid 1930s due to the Nazi regime. Furthermore, we discovered that female researchers – such as Iris Runge (1888–1966) in the Osram company – could as individuals play a decisive role as mathematical consultants. The position of Runge will be described and compared with the position of mathematical researchers in other industrial labs.

am Beispiel früher Anwendung von mathematischer Statistik in der Osram G.m.b.H. Hans Wu?ing zum 80. Geburtstag gewidmet

     

Bestimmung der Porenkonfiguration vor Rißspitzen bei Kriechermüdung von austenitischem Stahl

Experimental determination of the cavity configuration in front of the crack tip in the case of creep-fatigue of austenitic steel

1 Zum 60. Geburtstag von Prof. Dr.-Ing. habil. K.-T. Rie

If used in the high temperature low-cycle fatigue regime, austenitic steel can fail die to the formation and growth of grain boundary cavities. In this case the failure is dominated by the interaction of the intercrystalline crack and the grain boundary cavities. The formation and growth of cavities depend on stress and strain. Because of the notch effect, the local stress and strain at the crack tip are increased. Therefore in the crack tip region also an increased cavity density can be expected. The critical cavity configuration for the interaction of the crack and cavities in the crack tip region can be reached earlier then in the rest of the material. In the presented study, the cavity configuration close to the crack tip was determined by experiment to get the basis for a local crack growth model. It is shown that the cavity density in the crack tip region is higher then in the rest of the material. Because of this, also a high microcrack density at the crack tip can be observed. An interdependence between the crack growth rate, the distance and the size of the cavities was found to be proved true.     

Beschichtung von Kunststoffgehäusen zur Sicherung der elektromagnetischen Verträglichkeit elektronischer Geräte

The increasing level of electromagnetic radiation in the environment requires actions, which guarantee the electromagnetic compatibility of electronic devices. A very important step in this direction is the electromagnetic shielding of plastic housings by metallization. This is a new challange to the surface technology. This paper describes the possibilities for metalizing of plastics and shows especially the potential of the vacuum technology in comparison with electrochemical deposition, atmospheric thermal spraying and other methods. From the ecological and economical point of view the deposition in the high vacuum is more favourable. Disadvantages are the limited homogeneity of the layer thicknes and the thermal stress of the substrates during deposition. Worldwide there are efforts to overcome these disadvantages.