Neuere Entwicklungen auf dem Gebiet der Vakuumbogenbeschichtung

Actually millions of tools and engine components are coated with hard coatings by cathodic vacuum arc deposition monthly. Most of the coatings are applied for abrasion protection. But also coatings for decoration or corrosionprotection are usual. The most important coating is TiN, but also a great number of different kinds of coatings are available for various applications. Recent developments are dedicated to fit the coat- substrat combination for the specific application or to coat materials with a low thermal load capacity. On the other hand the technology of the coating- devices are improved permanently. Coating chambers from a size of some ten centimetres to some metres with fully automatic process control are available.     

Entwicklungen auf dem Gebiet des Laserschweißens

Some Developments in Laser Beam Welding . The development of continuous high power lasers leads to new possibilities in welding thicker sheet. This has been proved by joining metals with YAG- and CO₂-laser beams. Technical limits of several laser-systems are critically discussed and some examples are given for the application of the high intensity beams.     

Entwicklungstendenzen auf dem Gebiet der organischen Beschichtungen

Development trends in the field of organic coatings . Modern materials for organic coatings are supposed to permit economic processing and should be unobjectionable in environmental terms. These requirements can only incompletely be satisfied by modification of conventional products. Thus the aspects are good for water-soluble binders as well as for solvent-less materials curing by chemical reaction only. However, developments in the processing field are becoming even more important than those of materials. Electrostatic spraying procedures and dipping techniques with trichlorethylene as solvent demonstrate the progress made in generally approved methods. The use of powder as coating material, the method of film-curing by electron beams, and the electro-coating process, however, are novel procedures based on appropriate physical effects.     

Stand und Entwicklung auf dem Gebiet der Kupferwerkstoffe

State of Art and Development of Copper and Copper Alloys The state of art and the developments of copper and copper alloys is reviewed by using selected examples. Developments in productions techniques of semis is considered as well as developments in materials. With production techniques, considerable improvements in efficiency and improved production facilities can be reported. In the field of development of new and improving known materials the standstill of the sixties has been overcome.     

Entwicklungsmöglichkeiten und Entwicklungstendenzen auf dem Gebiet der Hochtemperatur-Legierungen

Possible Trends and Developments in the Field of High Temperature Alloys. The continuing development of super-alloys that has for some 25 years allowed a steady increase in the operating-temperature of gas turbines is now closely approaching the limit set by the ultimate operating temperatures of the materials themselves. In order to increase these limits and thus ensure continued progress in this direction new alloys and new processes need to be developed. Possible means for the improvement of conventional super-alloys have been suggested such as:

• new powder metallurgical processes
• production of cast/forged thin section blades by the “Squeeze-Casting”-process
• increasing the ductility of cast alloys by modifying the morphology of primary precipitates in the casting
• increasing the working temperature by means of precipitates having increased dissolution temperatures.

In connexion with this subject, the process of directional solidification, developed during the past 10 years, is briefly discussed with particular reference to its application in the production of columnar and single-crystal super-alloys and eutectic composite materials. The properties of directionally solidified super-alloys as well as directionally solidified eutectic composite materials are summarised in the light of present day knowledge.     

Neue Trends in der Vakuummeßtechnik

There are no spectacular and innovative changes with regard to the vacuum process control technique. It is rather about minor improvements and modifications produced by developments, standards, improvements in process etc. This statement applies for all pressure respectively working ranges between atmospheric pressure and XHV.     

Entwicklung auf dem Gebiet der Lebensdauervorhersage an mehrachsig beanspruchten komplexen Bauteilen

Developments of Fatigue Life Prediction Methods for Components with Multiaxial Stress States For further reductions of the structural weight of modern light weight constructions the explicit consideration of multiaxial stress states becomes increasingly important. In the present paper a survey of prediction methods for the evaluation of the life behaviour close to the endurance limit and in the finite life range is given. A main characteristic of the prediction methods especially for the limited life range is that individual stress-strain events similar to closed hysteresis loops under uniaxial constant amplitude conditions have to be present. In order to overcome this limitation, a new fatigue life evaluation procedure has been developed. The prediction method is based on a threedimensional elastic-plastic finite element model together with the material model after Mróz to account for the elasticplastic material behaviour. The fatigue damage is evaluated on the basis of plastic work using a new incremental damage law. The new method is briefly described.     

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.     

Schweißtechnik im Chemie-Anlagenbau. Beispiele zur Auswahl und schweißtechnischen Verarbeitung der Werkstoffe im Hinblick auf ihre Betriebsbewährung

Welding Engineering in Chemical Systems Construction – Examples for Selection and Welding Processing of Materials as to Their Operational Verification Welding manufacturing occupies undoubtedly a key position in the construction of chemical apparatus and systems. It is possible to application-specifically select out of a variety of structural materials and welding fillers. Corrosion resistance, thermal and mechanical characteristics, especially any differences in the time-history of loading are the crucial criteria. In addition, the effects of welding on the material properties must be considered. Below examples will be given as to material criteria concerning specifications and selection, but primarily with respect to the corrodibility of stainless CrNi(Mo) steels and the appropriate welding fillers.     

Einfluss der Schweißparameter auf das Ermüdungsverhalten hochfester Baustähle

High strength low alloy steels are used in many different engineering areas. A commonly used joining technique for those steels is fusion welding. Generally, these components have to withstand fatigue due to dynamic loading. Using thermal joining techniques affect the mechanical properties of the steel. This study focuses on the influence of the heat input on the microstructure of high strength low alloy steels (S690). Furthermore, the fatigue behaviour with special regard to crack initiation and crack propagation is characterized.     

Vorhersage der Schwingfestigkeit von Schweißverbindungen auf der Basis des statistischen Größeneinflusses

Prediction of the fatigue strength of welded joints based on the statistical size effect With increasing length of welding seams the fatigue strength decreases. This effect is confirmed in fatigue tests on butt joints and cruciform joints. The influence of the length of the welding seam on the fatigue strength depends on the scatter of the parameters describing the geometry of the welding seam. The theory of the statistical size effect worked well in fitting and predicting the test results. The fatigue strength of welded joints is well predicted, if no other influences like e. g. residual stresses change the fatigue strength. Additionally a method for the calculation of crack propagation is proposed, which takes in account angular and linear misalignement as well as local changes of the geometry of the welding seam.     

Schweißen mit dem Laserstrahl im Vakuum

Welding with the Laser Beam in Vacuum In the vehicle industry, beam welding methods are successfully applied for the joining of high‐quality parts. Here, the focus is mainly put on drive section components. Especially in component manufacturing of couplings, toothed wheel – shaft joints and drive shafts, electron beam welding using small vacuum cycle chambers is applied. The application of powerful solid‐state lasers results, however, often in negative consequences, such as soiling by process emissions or increased tendency to spatter. The application of laser beam welding in vacuum allows for the reduction of these side effects and, at the same time, for the increase of penetration depth and weld quality. This article introduces first results gained from tests made with workpieces from the vehicle industry.     

Anwendung des Programms COMO III bei OR-Untersuchungen auf dem Gebiet Luftverteidigung/Flugabwehr

Zusammenfassung Das Programm COMO III, das seit 1975 bei der IABG in zahlreichen OR-Untersuchungen auf den Gebieten der Luftverteidigung und Flugabwehr verwendet wird, hat sich für derartige Untersuchungen als sehr gut geeignet erwiesen. Hervorzuheben sind insbesondere die benutzerfreundliche und flexible Dateneingabe für die Simulationsläufe sowie der modulare Aufbau des Modells, der es ermöglicht, die Abbildung der zu untersuchenden Systeme beliebig zu verfeinern oder zu aggregieren. COMO III sieht außerdem standardmäßig eine benutzerorientierte Datenausgabe vor, die für die meisten Untersuchungszwecke ausreicht und keinen zusätzlichen Programmaufwand erfordert.

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Summary The COMO III program has been used by IABG since 1975 for a great number of OR studies on air defence problems. The program has proved to be very well qualified for this purpose. In particular, the user-friendly and flexible data input for simulation runs should be stressed as well as the modular structure of the program which allows an optionally refined or aggregated modelling of the systems to be studied. Besides this, COMO III provides a standardised user-oriented data output which is sufficient for most study purposes and needs no additional programming effort.