Abstract: The present invention relates to a process for vapor-depositing zirconium dioxide on ceramic or metallic substrates, and the heat-insulating layers obtainable by such process.

Abstract: The present invention relates to a method for coating monocrystalline or polycrystalline metal substrates with a ceramic heat-insulating layer of zirconia by electron-beam vapor deposition, and to a method for coating turbine blades made of Ni-based superalloys. The method is characterized in that the metal substrate is moved during the vapor deposition in terms of a superposition of two rotational motions around horizontal axes, but in essentially perpendicular directions.

Abstract: The present invention relates to a process for vapor-depositing zirconium dioxide on ceramic or metallic substrates, and the heat-insulating layers obtainable by such process.In particular, the invention relates to a process for vapor-depositing zirconium dioxide, optionally doped with rare-earth metal oxides or mixtures of such oxides, on ceramic or metallic substrates in a range of substrate temperatures of from 600 to 1550.degree. C. while the substrate is continuously rotated at a speed in the range of from 1 to 300 rpm, characterized in that, following the nucleation phase, the rotational speed and the temperature are adjusted to a range defined by the equations: ##EQU1## where T represents the substrate temperature in .degree. K, and .omega. represents the rotational speed of the substrate in rpm, wherein the rotational speed is varied continuously or discontinuously, or alternatively in alternating senses of rotation.

Abstract: The invention relates to the use of alloys containing50 to 70% by weight of nickel,10 to 40% by weight of chromium,3 to 10% by weight of aluminum,4 to 10% by weight of titanium and1 to 3% by weight of silicon,which alloys have a coefficient of thermal expansion .alpha. in the range of from 12 to 16.times.10.sup.-6 K.sup.-1 between 293 and 1370 K, as an adhesive layer bonding alloys based on nickel or titanium to a ceramic, and to processes for the preparation of said alloys.

Abstract: A sample of material which is to be exposed to a hot gas corrosion is suspended in a pipe and is irradiated with heat radiation through parabolic mirrors through the pipe. Beneath the sample of material, there is found a thermocouple element which is also arranged along the focusing line. The substance stimulating corrosion is provided in a crucible furnace which is heated separately. Through a gas connection, gas or steam is supplied in order to generate the atmosphere stimulating corrosion in the pipe. The variations in weight of the sample of material are continuously measured with a balance.

Abstract: To produce tubes of reactive metals, a melt (14) is removed from the annu gap (13) of a crucible (10). The temperature of the melt (14) is such as to ensure the formation of the solidus-liquidus zone (33) directly behind the annular gap (13), a planar solidification front (34) being created in a non supported region which is not exposed to the direct influence of a cooling means. In the subsequent region, the oriented solidification of the tube with high temperature gradients is realized, and the tube can be shaped or adjusted free of thermal influences. Only thereafter, the tube (25) is exposed to the action of cooling means (26, 31) to cool it without contact. In such a way, it is possible to produce tubes having a high stability and resistance to temperatures for use in turbines, heat exchangers or the like.