Abstract It is usually an advantage if the particle temperature during arc spraying is very high in order to achieve adequate adhesion. In the capacitor industry, however, the material to be coated is very sensitive and damage occurs at temperatures between 120 deg C and 180 deg C, that is, well below the melting point of the materials to be sprayed. Freshly developed arc spraying systems enable spraying materials to be processed at the lowest possible temperatures, which is presented in this article. This discussion attempts to strengthen the readers' background on the production steps used for capacitor end spray. Paper includes a German-language abstract.

Abstract In this paper, a quantitative model for determining the viscous behavior of two-phase particles when they hit the substrate is derived and used for the production of silicon-nitride composite layers. Plasma spray deposition is carried out using a Sulzer-Metco unit and powder feed system in which the powder is injected into the jet external to the nozzle. Silicon nitride-YAS layers with low melting points are developed so that the YAS matrix successfully protects the silicon nitride from decay. The model is developed from the observed layer behavior and provides a basis for the further development of ceramic-matrix composite layers. Paper includes a German-language abstract.

Abstract Yttrium oxide-stabilized zirconium dioxide is mainly used in thermal barrier coatings. However, the desired higher gas inlet temperatures have initiated the search for novel materials. Low thermal conductivity and high melting points are important criteria for the selection of these materials. This paper investigates a zirconate material with a pyrochlore structure and a high melting point. In addition, it investigates the sintering behavior of the coatings at elevated temperatures. Dilatometer tests are carried out at 1200 deg C for at least 70 hours. For samples which had been annealed for 24 hours at 1250 deg C, the change in the porosity distribution is determined by means of mercury porosimetry. The paper presents the first results of thermal cycling tests on a plasma-sprayed coating. These first results are very promising. Paper includes a German-language abstract.