Abstract Laser beam cladding is a versatile method for the deposition of functional surface layers, the generation of prototypes and the repair welding of components. It is a thermal process characterized by a highly localized energy input. The powder-fed laser beam cladding process uses CO2- and, more recently, Nd:YAG- and direct diode lasers at a typical processing speed within 0.3 and 1.5 m/min. The present work investigates the extension of process parameters towards significantly higher speed and thermal efficiency. In this study, a focused Nd:YAG laser beam was used, which produces a small melt pool. Furthermore high processing speed leads to interaction times in the range of milliseconds. With minimal overall heat input, functional layers with a thickness of tenths of millimeters are obtained and the surface area processed per time unit is increased. Paper text in German.

Abstract Ni and Ti aluminides show a high potential for lightweight applications at elevated temperatures. The strength of TiAl can be increased, if directionally solidified structures are producable. Recent developments of superalloys show that the laser rapid prototyping can be used to generate directionally solidified parts. To generate directionally solidified TiAl parts, first the problem of crack formation has to be solved. The solution was developed by the use of Ti48Al2Cr alloy and an adjusted cooling of the sample. Second the process parameters have to be chosen in a way, that directional solidification occurs. For this a macroscopic process simulation including the modeling of the feedstock material and a microstructure simulation is build up. The correlation of experiments and simulation will lead to process guidelines for laser rapid prototyping of directionally solidified TiAl parts. Paper text in German.

Abstract BIAS Bremen and SLV Rostock have received approval from the classification society "Germanischer Lloyd" for the novel manufacture and replacement of certain engine components with the powder-fed laser-beam plating process. This paper discusses the development of a procedure based on theoretical and experimental examinations on comparable test components. It is observed that, using this simulation tool, a reliable forecast of material conditions, which consequently emerge from the thermal cycle during laser surface treatment is possible. Paper includes a German-language abstract.

Abstract This paper aims to analyze the effect of the nature of the core material, the geometry of the buffer rods, as well as the nature and thickness of the cladding material on the ultrasonic propagation properties of these guidance components. The development of ultrasonic waveguides was studied in order to address the need for operation under strict conditions. The effects of the composition and thickness of the cladding as well as the type and geometry of the core were investigated with straight and tapered aluminum oxide and 1018 steel rods for the core and with plasma-sprayed aluminum oxide or aluminum oxide-chromium oxide for the coating. The results show that tapered plated buffer rods perform better than their unclad straight counterparts. They also indicate that the addition of chromium oxide to aluminum oxide is promising in a broader temperature range in which these conductors can be used. Paper includes a German-language abstract.

Abstract Alloying of the melt with nitrogen in order to improve material properties is well known in steel-making. This effect can also be used in plasma-powder-welding for a distinct improvement of corrosion- and wear-resistance. Using alloys comparable to material numbers 1.4016 and 1.4404 the influence of the process parameters in plasma-powder-welding on the proportion of nitrogen in the cladding is shown. In addition recommendations are made for the regulation of nitrogen concentrations, that are located far above saturation concentration of the alloys mentioned above. With the recommended parameters it was for the first time achieved to succesfully produce claddings with a nitrogen percentage by weight of up to 0.85 at a partial pressure between 0.045 and 0.065 MPa that allow reproducibility. Paper text in German.