Die Herstellung von Dispersionswerkstoffen

The Production of Dispersion Materials The various methods forproducing dispersion materials are compared with the galvanic codeposition of composites. Problems of application technology parameters of galvanic codeposition and possibilities of future developments are discussed.     

Pulvermetallurgische Herstellung von Gradientenwerkstoffen

Preparation of Gradient Materials by Powder Metallurgy In mechanical constructions as well as in electronic devices, the designer is commonly faced with the problem of matching materials properties to the demands for strength. ductility, conductivity, corrosion resistance etc. Usually, these types of demands are quite different in different parts of the component. Composition gradient materials offer an elegant and economic solution to the problem. The article describes a reliable preparation method for gradient materials with a one-dimensional gradient of composition. The method is based on an entirely novel powder metallurgy technique that employes a computer controlled dosing system and a centrifugal forming unit. As the results show, it is possible to select almost any desired property profile.     

Herstellung und Eigenschaften von metallischen Verbundfolien

Properties of metallic composite foils by directionally solidification and rolling . It is known from a serie of investigations that compositeswires consisting of well deformable metals drawn to high degrees of deformation show characteristic anomalies of mechanical and physical properties. Therefore it is interesting to investigate the possibility to prepare by rolling foils with the similar heterogenous structure. First results measured on the thin foils of an eutectic silver-copper alloy are presented. Compound foils of 35 microns thickness showed anomaleous behaviour of Youngs modulus, tensile strength and specific electrical conductivity. This anomaleous behaviour of different properties is caused by size effects. An advantage of such compoundfoils compared with “thin layers” is the easy preparation and handling of the specimens.     

Herstellung von Diamantfilmen aus der Gasphase

One of the most growing and spreading application of thin film techniques are the hard coatings. The Institute of microstructure-technology and optoelectronics (IMO) in Wetzlar as technology service institution is active also in the development of coating processes. Investigations of the surface coating of polymers by SiO₂-like films as well as the development of problem-oriented TiN coatings have been performed. Recently, the diamond coating from the gas phase has attracted high interest. The article describes the status of diamand coating know-how in the IMO.     

Neue Technologie zur Herstellung von Wolframschmelzkarbid

New Manufacturing Technologies of Two Phase Tungsten Carbide A promising application of the inductively coupeld RF Plasma technology is the one‐step spheroidization and solidification of porous, agglomerated particles. The acclomerated particles are produced by spray drying in a solution of binder and agent. The feedstock consists of WC/W₂C with a dispersity of 90 – 120 μm and a carbon concentration of 4.8 mass%. It is the aim of the project to obtain dense spheroidzed particles with definite carbon content in the region of 3.8 – 4.3 mass%.     

Dünnschichtanlagen zur Herstellung von flachen Bildschirmen

The production of flat panel displays requires thin film technologies, which are also known from microelectronics. An essential difference, however, is the substrate size. The deposition of metals, dielectrics and semiconductors is carried out by sputtering and CVD processes in large area in-line systems. Dry etching for the structuring of the substrates is realized in static, single substrate machines.     

Neue Entwicklungen zur Herstellung von Hartstoffschichten mittles Plasma-CVD

New Developments in Preparation of Hard Material Coatings by Plasma CVD In this paper, the technique for the preparation of hard material coatings using a D.C. Plasma is described. Two methods are used: One is direct current (D.C.) non-pulsed glow discharge method and the other is pulsed D.C. glow discharge method. It has been shown that the temperature in chemical vapour deposition (CVD) of TiN can be reduced from about 1000°C in conventional CVD to about 500–600°C by the application of a D.C. non-equilibrium plasma. Emphasis is placed on the new design concept for industrial application by using a pulsed D.C. power source and auxiliary heating device. The structures of the TiN coatings obtained at 600 °C are analysed by means of electron microscope and X-ray diffraction methods. The film deposition rate is 1–3 μm/h. It is concluded that plasma assisted CVD of hard material coatings offers a superior alternative to the conventional CVD method.     

Einsatz von Vakuumpumpen bei der Herstellung von Photovoltaik‐Modulen

Use of vacuum technology in crystal pulling and lamination application in manufacturing of photovoltaic modules Dry compressing screw type vacuum pumps such as the SCREWLINE SP 630/250 are designed to reduce cost of ownership in crystal pulling plant and in lamination processes. The construction of gear house sealings, the easy maintenance of the pump on site and the use of gas ballast guarantee a very reliable performance, and long maintenance and service intervals. In the case of crystal pulling the process does not even need a dust separator at the inlet of the vacuum pump.     

Herstellung von Feinkristallinen oder amorphen BeO-Schichten durch reaktive verdampfung von beryllium

Layers of BeO have been formed in an ultra-high-vacuum system by reactive evaporation of Be according to Auwärter at a partial O₂ pressure of 10^-2 Pa. The BeO layers, which were of an arbitrary thickness, show almost no absorption in the visible wavelength range and may be prepared with surface resistivities (i.e. ratio of resistivity to thickness) greater than 10¹³Ω. with decreasing thickness of the BeO layers and with decreasing temperature of the substrate the grain size becomes smaller. If the substrate is kept at liquid air temperature, amorphous BeO layers are obtained which are of interest for electron microscopical purposes because of their low mass thickness and high resistance to chemicals. Under intense electron bombardment, thin extended monocrystalline BeO foils are formed by recrystallization processes.     

Herstellung von Präzisionsschichten mittels Ionenstrahlsputtern

Precise thin film synthesis by ion beam sputter deposition Ion beam sputter deposition (IBSD) is a promising technique for the fabrication of high performance thin films because of the well defined and adjustable particle energies, which are rather high in comparison to other PVD techniques. Recent developments concerning long‐term stability and lateral uniformity of the ion beam sources strengthen the position of the IBSD technique in the field of precise thin film synthesis. Furthermore, IBSD offers a more independent choice of relevant deposition parameters like particle energy and flux, process gas pressure and deposition rate. In this paper we present our currently installed large area IBSD facility “IonSys 1600”, which was developed by Fraunhofer IWS Dresden and Roth & Rau company (Hohenstein‐Ernstthal). Substrate sizes of up to 200 mm (circular) or up to 500 mm length (rectangular) can be coated and multilayer stacks with up to six different materials are possible. Tailored 1‐ or 2‐dimensional film thickness distributions with deviations of < 0.1 % can be fabricated by a relative linear motion of the substrate holder above an aperture. In order to demonstrate the advantages of the IBSD technique especially for sophisticated materials and films with high requirements concerning purity, chemical composition or growth structure, several examples of deposited multilayers for various applications are presented.     

Einsatz des Explosivschweißens zur Herstellung von Edelmetallplattierungen

Explosive Welding as a Technique for Cladding of Precious Metals The method of explosive welding and the importance of the cladding parameters are described. The “Explosive Weldability Window” is experimentally determined for the material combination AgCu 10/Fe. The behaviour of explosive claddings produced under different conditions during rolling is investigated. Best results are obtained with samples with a wavy interphase, produced under the following cladding parameters: It is shown, that in comparison with conventional methods explosive cladding has advantages both in processing and quality.     

Umformende Herstellung von Al/Mg‐Werkstoffverbunden

Manufacture of Al/Mg‐composites by forming A universal theory for the bonding of metallic materials does not exist. For new material combinations and new joining technologies the bonding properties have to be examined individually. The factors affecting bonding behavior and characteristic like the bond strength have to be investigated. This paper presents a method for generating composites by a forming process and shows innovative possibilities to test and evaluate relevant parameters of the bonding process.     

Herstellung von Metall-Matrix-Verbundwerkstoffen mit metallischen Gläsern

Metal-matrix Composites with Metallic Glasses Metallic glass ribbons are well known for their very high tensile strengths. Since they offer an attractive potential of low-cost volume production, the development of a metallic glass-metal matrix composite should be very attractive. This paper reports first results on the feasibility of fabricating such composites by surface plating or incorporation by various techniques. The influence of fabrication methods on the interfacial bonding was investigated by means of cross-sectional light and electron microscopy.     

Herstellung und Eigenschaften von glasfaserverstärkten Kunststoff-Stahl-Schichtwerkstoffen

Preparation and Properties of Layered Composites of GFK-Steel The development of insulating joints of GFK and steel is described. The strength of the GFK and steel is described. The strength of the GFK and the adhesion between the GFK and steel is in this context of special interest. Results for the Young's Modulus, the ultimate and adhesion strength measured in bursting and bending tests are compared to those measured in tensile- and adhesion tests; the data agree well with each other. The correspondence between literature data of mechanical properties of the GFK and the measured values is satisfying.     

Die Herstellung von Sonderwerkstoffen durch isostatisches Heißpressen

Fabrication of special materials by Isostatic Hot Pressing The process of Isostatic Hot Pressing is described. The principle of compaction is explained. A review of earlier work in the literature is given. The plant in Karlsruhe — the first in the BRD — is described. The technique of right sample preparation is shown by 2 examples. One of those is the compaction of an UO₂-Mo-cermet. During Isostatic Hot Pressing a metallurgical bonding between can and fuel is observed. Some applications of the new process are: the fabrication of fuel pins for fast breeder reactors, cathodes and collectors for thermionic emitters, thermal shock resistant ceramics and metal-ceramic diffusion bonds. In the field of high speed steel and hard-metal with improved lifetime, the new process is advancing.