Abstract: The invention relates to the nozzle construction for thermal spraying by means of a suspension, in which particles are contained, or a precursor solution, by means of which particles or precursor solution a layer is formed on a substrate, and which suspension or precursor solution is fed into a burner chamber or into a plasma torch, in which heating and acceleration of the particles is achieved, wherein a connection point for feeding the suspension or the precursor solution, a holder, and a nozzle insert are present. The nozzle insert has, with a tubular element arranged in the direction of the burner chamber or perpendicularly in HVOF flame or plasma torch and with an end face arranged opposite the burner chamber, a flange-shaped expanded section, which lies against a seat formed in the holder in the installed state.

Abstract: An yttrium oxide coating has a porosity of 1.5% or less and contains monoclinic yttrium oxide at a ratio of 1% or more and 30% or less to the sum of monoclinic yttrium oxide and cubic yttrium oxide in the coating. The coating is formed, for example, by thermal spraying a thermal spraying material containing yttrium oxide particles and a dispersion medium.

Abstract: The disclosure provides a method of producing thermally sprayed Al2O3 coatings having a high content of corundum without any property-reducing additives. The coatings may be utilized particularly in the field of electrical insulation, as a dielectric, and as protection from wear. The thermally sprayed Al2O3 coatings have a porosity of no more than 19%, and a high content of ?-Al2O3 (content of corundum) of at least 72% by volume. The coatings have a specific electrical resistance of >1·1012 Ohms·cm, and a purity of >97%. The production of said coatings is carried out utilizing aqueous or alcoholic suspensions made from substantially pure ?-Al2O3, having a grain size of >100 nm by thermal spraying.

Abstract: The invention relates to thermally sprayed Al2O3 layers having a high content of corundum without any property-reducing additives, and to a method for the production of said layers. The invention may be utilized particularly in the field of electrical insulation, as a dielectric, and as protection from wear. According to the invention, the thermally sprayed Al2O3 layers are characterized in that they have a porosity of no more than 19%, and a high content of ?-Al2O3 (content of corundum) of at least 72% by volume. The layers have a specific electrical resistance of >1·1012 Ohms·cm, and a purity of >97%. The production according to the invention of said layers is carried out utilizing aqueous or alcoholic suspensions made from pure ?-Al2O3, having a grain size of >100 nm by means of a method from the group of thermal spraying.