Bandsägen für die Steinbearbeitung – aktuelle Technologieentwicklung

Bandsawing machines for stone cutting – state of the art Due to an EU‐research‐project BaSST a new process was developed to cut slabs and tiles in granite, marble and sandstone out of a huge stoneblock by means of a bandsaw. Such natural stones are very hard, the cutting forces generated to the sawband have to be limited. This was realized with a pivoting sawband, which allows to vary the effective length of engagement depending of the dimension of the material. Simoultaneausly a sawband with diamond cutting segments was developed and tested. Over a long period of optimization a long lifetime of the sawband was reached. The end of the service life was determined by normal wear of the cutting segments and not by breakage of the sawband together with very high cutting rates and excellent cutting surfaces. The outstanding advantage of this new cutting process is a high flexibility for the production, so far unknown till now, a very good cut quality and a remarkable reduced waste of material due to the thin sawband. The number of slabs cut from a block can be doupled due to the thin kerf of the sawband. The new cutting process allows to cut slabs and tiles from a block in a very economic way and under best environmental conditions.     

Innovative Lösungsansätze für das Fügen von AMCs

Innovative solutions for joining AMCs The application of aluminium matrix composite materials (AMC) in structural components requires appropriate joining technologies. One important aspect is the preservation of the properties of the composite during the joining process. The thermal load of the base material is particularly critical as a result of the process‐related heat input. In order to keep it low, adapted joining technologies and low‐melting fillers are essential. The combination of an ultrasound process and an induction heating offers various advantages. On the one hand, the ultrasound introduction achieves a destruction of the surface oxides and therefore a wetting of the joining surfaces without the use of flux. On the other hand, local inductive heating allows to realise very short joining times so that the heat input into the base materials to be joined can be reduced to a minimum. The application form of the fillers plays an important role for the achievable compound strengths. Selected test results will show the advantages and disadvantages of different variants.     

Revolution statt Evolution – Innovative Folientechnik für die Kfz‐Außenhaut

Revolution in Place of Evolution – Innovative Foil Technique for Automotive Body Shell Foil techniques represent an innovative option compared to traditional automotive painting. Cost reduction demands and light weight construction has brought forth the requirement to apply polymers at automotive body shells. Particularly, thermoplastic polymers enable a large freedom for the design of modern cars at moderate costs. The foil technique is also a promising approach for an introduction of long glass fibre reinforced thermoplastics into the outer body skin and to reach a Class A finish. One technology is the colormatchable foil technique (CFT). In cooperation with BASF Coatings AG, Münster INPRO developed this new technology to the stage of fundamental feasibility. This new technology stands short before its introduction in practice.     

Neuentwicklungen für den Verschleiß‐ und Korrosionsschutz beim Plasma‐Pulver‐Auftragschweißen

New developments for wear an corrosion protection by weld surfacing with plasma transmitted arc process Highly wear‐resistant claddings which contain carbides can be applied by weld surfacing with the PTA process. The use of vanadium carbide prevents undesirable reactions with the matrix material. Thus, highly corrosion‐resistant Fe‐based claddings can be produced for applications in the food and marine industries, and Ni‐based claddings can be applied to components exposed to inorganic acid attack. A combined test is applied for determining the relative effect of corrosion under combined exposure to abrasive wear and corrosion and indicates the primacy of abrasive wear for behaviour in operation.     

Reinforced masonry beams under shear load – Proposals for future designs / Bewehrte schubbeanspruchte Mauerwerksbalken – Vorschläge für zukünftige Bemessungen

This article is written against the backdrop of the work of the European standardisation committees on the amendment of EN 1996‐1‐1 [N 4] which will also exert an influence on the design of reinforced masonry in Germany. This paper focusses on the design approaches of DIN EN 1996‐1‐1 for untensioned reinforced masonry beams under shear load in the ultimate limit state (ULS). Proposals are made to discuss their revision. The contents of E DIN 1053‐3 [N 3] and of the final draft of the guideline ”Flat Lintels” [7] are taken into account.     

Neu entwickelte TiAl‐Basislegierungen für den Leichtbau von Triebwerks‐ und Motorkomponenten – Eigenschaften,Herstellung, Anwendung

Newly Developed TiAl Base Alloys for Lightweight Components in Jet Engines and Internal Combustion Engines – Properties, Production, Application Titanium aluminides are a most promising high temperature materials alternative to conventional heat‐resistant steels and superalloys for high‐performance automotive and aircraft engine applications. Intermetallic TiAl base alloys offer striking advantages for high temperature and mechanical loading applications. The specific weight of about 3.8 ‐ 4.1 g/ccm is low, the oxidation and burn resistance at temperatures up to 800 °C are good. The elastic stiffness is high and the temperature strength is enhanced. Feasible applications in combustion engines are valves, pistons and exhaust gas turbocharger rotors. Blades, vanes and discs for jet engines are under development, as well. Due to the extraordinary high specific Young’s modulus (ca. 46 GPa ccm/g) and 0.2 %‐yield strength up to 1 GPa of the TiAl base alloys in the as‐extruded state some applications at lower temperatures have also been taken into consideration, e.g. connecting rods and piston pins. The paper reviews constitutional related properties of the advanced TiAl base alloys with the respect to the industrial manufacturing of components and structural applications.     

Flussmittelfreies Hartlöten unter reaktiver Prozessgasatmosphäre – ein alternatives Verfahren zum Fügen von Aluminiumwerkstoffen

Flux‐free brazing under reactive process gas atmosphere – an alternative process for joining of aluminium materials Due to the high affinity of aluminium towards oxygen, joining of aluminium materials has ever been a challenge. In particular the efficiency of the process and the abandonment of fluxes during controlled atmosphere brazing have been within the focus of current research projects. The specific addition of reactive gases to the inert process gas atmosphere offers a suitable possibility of aluminium brazing without the use of fluxes. Under the application of hydrogen chloride the activation of the brazing and the workpiece surfaces is to be initiated, thus leading to dissolving the oxide layers. Moreover, the strongly reducing gas silane is used, which specifically removes oxygen and water residuals from the controlled atmosphere. Through a suitable controlled atmosphere brazing process the combination of both, reductive and activating additions, is to be used and tested upon their influence on the gas mixtures and materials used [1–5].     

Schweißen von Hohlstrukturen und offenporösen Metallschäumen für den Einsatz in Kombi‐Kraftwerken

Welding of Hollow Structures and Open‐Porous Metal Foams for Application in Combined Cycle Power Plants For applications within the scope of novel cooling concepts joining technologies for sandwich composites and open‐porous metal foams are researched in the context of the Collaborative Research Centre 561 “Thermally highly loaded, porous and cooled multi‐layer systems for combined cycle power plants”. The research motivation and application fields of the different structures are defined. Welding processes and strategies for manufacturing these structures are specified as well as the joining technologies’ characteristics. Planned future works for enhancements of the processes and structures are listed.     

Performance labels for assessing the sustainability of buildings – from offices to detached and semi‐detached houses / Gütesiegel für die Nachhaltigkeitsbewertung von Gebäuden – Vom Bürobau bis zu Ein‐ bis Zweifamilienwohnhäusern

For some time now, certain types of buildings in Germany have been required to undergo a sustainability assessment. Increasingly, that now also includes residential buildings. A research project is currently underway to develop and test suitable criteria for the assessment of small residential buildings, the preliminary results of which were showcased at the BAU 2015 trade fair in Munich. With the help of examples, this article presents the criteria and provides some information on their application.     

National Standards of the People’s Republic of China – Thoughts of revision on technical specification for application of autoclaved aerated concrete / Nationale Standards der Volksrepublik China – Gedanken zur Überarbeitung der technischen Spezifikationen für die Anwendung von dampfgehärtetem Porenbeton

The revision task on technical specification for application of autoclaved aerated concrete products JGJ/T17 is under way, which was assigned in November 2013.The framework, thoughts and contents of revision on the specification are presented in this paper.