THERMALLY SPRAYED AL2O3 LAYERS HAVING A HIGH CONTENT OF CORUNDUM WITHOUT ANY PROPERTY-REDUCING ADDITIVES, AND METHOD FOR THE PRODUCTION THEREOF

摘要

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 α-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 α-Al2O3, having a grain size of >100 nm by means of a method from the group of thermal spraying.