Ralf Bandorf Dr.  Wolfgang Diehl Dipl.‐Ing  Ulrike Heckmann Dipl.‐Phys.  Simone Kondruweit Dr.  Andreas Pflug Dr.  Harald Holeczek Dipl.‐Ing.  Martin Metzner Dr.  Udo Klotzbach Dr.  Andreas Leson Dr.  Otmar Zimmer Dr. 《真空研究与实践》2008,20(5):14-19

Propositions and Trends – With Functional Surfaces into the Future Functional surfaces are the key to innovative products. Already today the properties, lifetime, and costs for most industrial and consumer products are determined by functionalised surfaces. Three Fraunhofer Institutes supported by the BMBF investigated the actual state of the art of production technology regarding functional surfaces, their future perspectives and the research and development demand. The results are published in the study “Production technology for the generation of functional surfaces” available at info@ist.‐ fraunhofer.de and the essentials are summarised in this article.  相似文献   

    

Volker Weihnacht Dr.‐Ing.  Andreas Brückner  Sven Bräunling 《真空研究与实践》2008,20(3):6-10

ta‐C coated tools for dry forming of aluminum sheets The suitability of ta‐C coated tool surfaces for sheet forming of aluminum alloys was examined by strip‐draw testing. It was shown that ta‐C coatings, which are known as DLC coatings with superior wear resistance are also favourable concerning the anti‐adhesive behaviour. In attempts with AlMg5Mn‐ as well as Al99Mg1‐sheet materials several hundred sheets could be formed without noticeable aluminum adhering at the ta‐C coated tool surface. Neither the coefficients of friction nor the surface qualities of the aluminum sheets worsened during the observed period. Compared with tests of uncoated tools in combination with lubricants, the dry ta‐C coated tool behaves comparable with a good lubricant. In a real clinch test with aluminum sheets the positive results from strip‐draw experiments were confirmed. Using ta‐C coated clinching stamps and no lubricants a large number of clinching processes could be performed without noticeable adhering and increase of stripping forces.  相似文献   

    

Wolfgang Neodon Dipl.‐Phys.  Olaf Zywitzki Dr.‐Ing.  Torsten Kopte Dr. rer. nat. 《真空研究与实践》2007,19(5):6-13

Reconstruction of Baroque Mirrors of the Historical Green Vault in the Dresden Royal Palace On the 1^st September 2006 the Federal Chancellor Dr. Angela Merkel inaugurated the reconstructed Historical Green Vault, the treasury museum of the Saxon electors and kings. Since its destruction on 13^th February 1945 two generations have been working scientific‐artistically in order to set the course for its reconstruction. The idea of a baroque mirror chamber has firstly been implemented on a sequence of 8 rooms in the Green Vault. The original mirrors, which were covered with tin amalgam, had a considerably lower reflexivity modern day silver mirrors. From originally 423 m² mirror surface, only 60 m² could be reused. For the restoration and reconstruction of the original mirrors extensive analytic investigations became necessary, which the state‐owned company Sächsisches Immobilien‐ und Baumanagement (SIB) commissioned the Fraunhofer Institute for Electron Beam and Plasma Technology (FEP). On basis of these results the responsible restoration commission decided to replace partly destroyed mirror surfaces using the historical tin amalgam mirror technology. The fully destroyed jewel room would be restored with mirrors including partial gold etching. Due to hygienical and temporal reasons those mirrors were coated through a mercury‐free vacuum thin film technology ‐ the magnetron sputtering. The results show that a layer system consisting of tin‐bronze‐titanium and protective lacquers represent an adequate replacement for the original tin amalgam mirrors. The procedure allows relatively uncomplicated partial silverings and a subsequent inserting of artistic gold etchings.  相似文献   

    

P. Munzert Dr. Ing.  U. Schulz Dr. rer. nat.  N. Kaiser Prof. 《真空研究与实践》2007,19(6):11-15

Metallized polymer substrates offering highest reflectance are not yet state of the art. Coating organic substrate materials is still a task that is connected with multiple problems. Insufficient adhesion of coatings on polymer substrates represents one of the main difficulties. We could show by experiment that aluminium and silver layers indicate good coating adhesion on many different polymers if they are deposited by vacuum evaporation considering certain process parameters. High reflectance values and a good climatic stability of the metal coated polymer parts are other important challenges to plastic mirrors. By performing roughness measurements on the different polymer samples and by comparing reflection values obtained after coating these samples the impact of the polymers surface quality on the reflectance after metal coating has been investigated. Particularly high reflectance above 97% was realized with a protected silver mirror as well as with dielectric enhanced aluminium. Applying these layer systems excellent reflection properties has been obtained on several plastic substrates comparable to those on glass mirrors. Furthermore the dielectric layers used for reflection enhancement showed the ability to protect the aluminium coating against climatic influences.  相似文献   

    

Sven A. Werner Dipl.‐Ing. 《Mauerwerk》2010,14(1):25-30

Klinkermauerwerk als traditionelles Fassadenelement wird heutzutage in der sog. zweischaligen Bauweise erstellt. Dies ermöglicht eine echte Trennung von Fassade und Tragstruktur, und zusätzlich wird der Einsatz von Dämmmaterial zwischen den zwei Schalen ermöglicht. Diese weit verbreitete Technik ist in Deutschland durch die DIN 1053 geregelt und definiert. Erst seit kurzem gibt es den Bedarf, über die Regelungen der derzeit gültigen DIN 1053‐1:1996‐11 hinaus Lösungen für bautechnische Anforderungen beim zweischaligen Mauerwerk zu finden. Auslöser dafür sind die veränderten Anforderungen an den Wärmebedarf von Gebäuden. Durch die Einführung der EnEV im Jahre 2002 und deren fortlaufende Verschärfung wird immer deutlicher, dass Wärmeverluste über die Fassadenflächen minimiert werden müssen. Dies führt häufig zu Überschreitungen der zulässigen Schalenabstände gemäß DIN 1053, um die geforderten Dämmstärken erreichen zu können. Auch weitere Einflussfaktoren wie z. B. Wärmebrückenverluste durch Abfangkonsolen oder Luftschichtanker rücken stärker in den Fokus. Im Folgenden wird darauf eingegangen, wie Planer und Ingenieure auf die ständig steigenden Anforderungen reagieren können und welche Lösungen die Firma Halfen als Hersteller von Verblendabfangkonstruktionen anbieten kann. Current Developments for Brickwork Support Systems. Brickwork masonry is a traditional building material for façade constructions and is applied today in a two cavity construction. This enables a strict separation of loadbearing structure and façade elements and thus allows for insulation in between. This common building technique is defined in regulation DIN 1053 for Germany. Recently demands for solutions beyond the above mentioned regulations can be detected. The Main reasons for this are increasing requirements for insulation and focus on energy consumption of buildings. In Germany the EnEV (an Energy Saving Regulation) has come into force in 2002. This regulation specifies that energy loss via façade areas have to be reduced to a minimum and the requirements are increasingly becoming more and more effective with each edition. This leads to increased cavities beyond the specifications of the currently available DIN 1053‐1:1996‐11 mainly due to the required insulation thicknesses. Other influences such as thermal bridges due to brickwork support brackets and brick ties come into focus, too. The following essay will show how designer and engineers can react to the ongoing changes and increasing requirements and which solutions can be provided by company Halfen as a supplier of brickwork support systems.  相似文献   

    

N. Grittner  H. von Senden gen. Haverkamp Dipl.‐Ing.  O. Stelling  D. Bormann  K. Schimanski  M. Nikolaus  A. von Hehl  Fr.‐W. Bach  H.‐W. Zoch 《Materialwissenschaft und Werkstofftechnik》2009,40(12):901-906

Rod Extrusion of Titanium‐Aluminum Composites The combination of different metals enables the processing of materials with local optimized properties. Thus, the production of metallic composites is associated with high standards in manufacturing technologie. Focus of the following investigations is the rod extrusion process of titanium‐aluminum‐composites. Besides the mechanical properties, the formation of the bonding zone and the mechanisms of adhesion in the bonding zone were investigated. The influence of specimens’ preparation and of different coatings used improve bonding were a matter of particular interest. Whereas coatings of copper or nickel inhibit the formation of a strong bonding due to the formation of oxide layers, sealed titanium cores can reach a mechanical strength of up to 100 MPa after rod extrusion. Compared to other joining technologies, an impairment of the base metal via formation of heat affected zones, pores or grain coarsening does not occur.  相似文献   

    

B. Rammer Dipl.‐Ing.  T. Weber  M. Schütze 《Materialwissenschaft und Werkstofftechnik》2008,39(1):29-32

Development of diffusion coatings on nickel base alloys for the use in chlorine‐containing high temperature processes To open up the possibility of using sewage sludge ashes as fertilizers the removal of their heavy metal contents is obligatory. A process newly developed at the BAM Berlin executes this separation in highly chlorine‐containing atmospheres at temperatures of up to 1000 °C [1]. Unfortunately there are no materials available which can withstand such conditions over longer periods of time. This project deals with the development of materials that allow the operation in highly corrosive environments. The corrosion resistance of nickel base alloys against chlorine‐induced high‐temperature corrosion will be optimized by application of aluminum‐ and/or silicon‐containing diffusion coatings. As coating method the pack cementation process was selected. In this process, the metal to be coated is embedded in a powder, consisting of the coating metal, a halogen‐distributor (e.g. ammonium chloride) and aluminum oxide as filler material. During an annealing process of several hours at temperatures of 800 to 1000 °C, gaseous metal halides form. They diffuse through the powder pack and decompose at the substrate surface, thereby depositing the coating metal. Subsequent solid phase diffusion results in the formation of a protective diffusion layer. From the thermodynamic point of view, materials with a high content of aluminum and silicon show best prerequisites to build up slow‐growing, stable oxide layers with a high potential to protect the material against corrosive attacks. The actual performance of the materials will be examined in long‐time tests under simulated field conditions (high temperatures and chlorine‐containing atmospheres).  相似文献   

    

B. Reinhold Prof. Dr.‐Ing.  M. Härtel  K. Angermann 《Materialwissenschaft und Werkstofftechnik》2008,39(12):907-913

Aluminium‐deposition from aprotic electrolyte – an old concept with new style Organo‐aluminium complex compounds have been used for many years as elec‐trolyte for the galvanic deposition of aluminium. For the galvanic deposition suitable electrolyte are aprotic complexes of type MX·2 AlR₃ solved in liquid aromatic hydrocarbons. By using aluminium‐magnesium alloy anodes or by using separate aluminium and magnesium anode circuits also AlMg‐alloy layers with high alkali resistance from aprotic electrolyte can be deposited. The aluminium layers have a microcristalline and low‐porous structure. The galvanic aluminization has become an issue of great interest for industrial applications due to its excellent corrosion behaviour and due to the fact that the resistance to hydrogen embrittlement can not be exceeded at deposition from non‐aqueous electrolyte. Therefore the galvanic aluminization from organo‐aluminium electrolyte becomes more and more important being expressed in numerous industrial examples.  相似文献   

    

Detleff Schermer Dr.‐Ing.  Ekkehard Fehling Prof. Dr.‐Ing.  Jochen Stürz Dipl.‐Ing. 《Mauerwerk》2008,12(1):13-18

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T. Michler Dr.‐Ing. 《Materialwissenschaft und Werkstofftechnik》2007,38(1):32-35

The formation of martensite in metastable austenitic stainless steels was investigated. The results showed that the formation of martensite in 304 grade stainless steels due to the exposure to cryogenic temperatures is negligible. The amount of formed martensite is dependent on the chemical composition of the actual heat but for standard grades the amount is not expected to exceed a very few percent. In welds the formation of martensite is not promoted by the presence of δ‐ferrite. The formation of martensite due to cold forming at room temperature can reach around 20 %. Cold forming with subsequent exposure to cryogenic temperatures does not lead to additional formation of martensite due to the exposure to low temperatures. Cold forming at low temperatures leads to the highest amount of martensite formed in metastable stainless steels.  相似文献