Abstract: Multi-layer composite product, featuring low emissivity in the mid-infrared band (as wavelength range 2,5–5 ?m) and far-infrared (as wavelength range 8.0–14.0 ?m) bands, as well as low reflexivity in the near-infrared (at a wavelength range of 0.7–2.5 ?m) and in the visible (as wavelength range 0.3–0.7 ?m) bands, including a base constructed with low-density and/or high thermal-resilience structural materials, covered with optionally doped coating, and where, between the base and the coating, at least one intermediate layer of metals or metal oxides is planned for insertion.

Abstract: A silicon carbide-based thermal spray powder contains at least one boride chosen from zirconium boride, titanium boride and hafnium boride. The powder is prepared by mixing and aggregation of powders containing the compounds in question. Said thermal spray powder is used to deposit, via the plasma spraying technique, a silicon carbide-based coating on a metallic or non-metallic substrate. The figure shows the X-ray crystallogram obtained, for a silicon carbide-based powder, according to the invention, after thermal spraying. The substantial identity of this crystallogram with the one obtained prior to thermal spraying demonstrates that the silicon carbide has been deposited on the substrate without decomposing.

Abstract: A process for the preparation of a composite multilayer product with selective optical properties comprises the operation of depositing, by thermal plasma spraying of powders, a coating of semiconductor oxides doped with oxides of elements chosen from the group consisting of transition metals and metals in the groups III-A and V-A of the periodic table of elements, in which the coating obtained maintains the composition and doping of the thermal plasma sprayed powders substantially unchanged. The figure shows the X-ray diffraction spectrum of a coating deposited according to the process of the present invention.

Abstract: Process for the manufacturing of ceramic-matrix composite layers resistant to very high temperatures, comprising the steps of: preparing the powders for the feeding of the deposition plant by wet mixing of the ceramics constituting the material in form of fine powders and atomizing the suspension in the presence of a hot air jet; and depositing by plasma thermal spraying with an inert gas flow and with a >30 kPa pressure in a deposition chamber. This process forms composite layers having a very high resistance, apt to be employed as coatings for vehicles, of the type destined to reenter Earth atmosphere from outer space and to be launched again therein.

Abstract: Multi-layer composite product, featuring low emissivity in the mid-infrared band (as wavelength range 2,5-5 &mgr;m) and far-infrared (as wavelength range 8.0-14.0 &mgr;m) bands, as well as low reflexivity in the near-infrared (at a wavelength range of 0.7-2.5 &mgr;m) and in the visible (as wavelength range 0.3-0.7 &mgr;m) bands, including a base constructed with low-density and/or high thermal-resilience structural materials, covered with optionally doped coating, and where, between the base and the coating, at least one intermediate layer of metals or metal oxides is planned for insertion.

Abstract: Process for the preparation of articles in Titanium coated with a layer of Titanium oxide is described, wherein the metallic Titanium is subjected to the following steps: optional conditioning of the surface; anodic oxidation treatment, in an electrolytic cell of which it represents the anode, in a bath made of an aqueous solution comprising sulfuric acid, hydrochloric acid and hydrofluoric acid; and forming onto the metallic surface, by effect of electrolysis, an oxide layer having a >1 &mgr;m thickness and containing a single crystalline phase made of anatase (one of the two allotropic tetragonal shapes of Titanium oxide). Object of the invention are also the articles in Titanium coated with a thick layer of anatase so obtainable, and the use thereof as photocatalysts, under the action of an ultraviolet radiation.

Abstract: Process for the manufacturing of ceramic-matrix composite layers resistant to very high temperatures, comprising the steps of: preparing the powders for the feeding of the deposition plant by wet mixing of the ceramics constituting the material in form of fine powders and atomizing the suspension in the presence of a hot air jet; and depositing by plasma thermal spraying with an inert gas flow and with a >30 kPa pressure in a deposition chamber. This process forms composite layers having a very high resistance, apt to be employed as coatings for vehicles, of the type destined to reenter Earth atmosphere from outer space and to be launched again therein.

Abstract: A process for the deposition of thick coatings with a thickness >1 mm on products made of copper or alloys thereof, wherein said products are subjected to the following operations: surface activation of the product made of copper or alloys thereof; optional heat stabilization to a temperature below the ones causing deterioration of the chemical and physical properties of the copper or alloys thereof; deposition of a first layer, for example of Ni or alloys thereof; optional interdiffusion heat treatment; optional activation of the surface of the first layer; thermal stabilization of said product at a temperature of between 20.degree. and 400.degree. C.

Abstract: A process for producing YBCO powders by pyrolysis involves preparing a clear aqueous solution containing the ions yttrium, barium and copper, in the final proportions desired for the powder, in the form of complex compounds, preferably citric complex compounds, and in the presence of a detonating system such as a combination of ammonium ions and nitrate ions. The clear solution is then concentrated by evaporation, until a violent combustion is triggered which is carried out at a high temperature, higher than 250.degree. C. and preferably higher than 850.degree. C.

Abstract: A device for the continuous production of ceramic conductors, for example, yttrium, barium and copper oxide type, which includes an endless belt and a tank and conduit for feeding solution from the tank onto the endless belt to form a liquid layer containing the desired proportion of metal ions on the endless belt. The endless belt passes through a furnace where the liquid is evaporated from the liquid layer and the residual metal salts are treated in an oxidizing atmosphere to produce ceramic oxides. A scraper is provided to remove the resulting ceramic oxides from the endless belt.