Abstract: A method is provided for producing an erosion-resistant layer or coating on the surface of a metallic workpiece. The method includes providing a thermally sprayable alloy of Ni-Cr-Fe-B-Si and thermally spraying the alloy on the workpiece to a specified thickness, following which the sprayed-on layer is heated in vacuum to a temperature between 250.degree. C. to 400.degree. C. for a time at the stated temperature of about 5 to 30 minutes sufficient to effect degassing of the layer. The temperature of the layer is thereafter raised to a range of about 800.degree. C. to 950.degree. C. and maintained at that temperature in vacuum for between 5 to 30 minutes. The temperature at the layer is then raised to between 900.degree. C. and 1100.degree. C. under a protctive atmoshpere at a pressure of between 200 to 600 mm Hg to effect fursion of the layer at above its melting point, following which the coated metallic workpiece is finally cooled to room temperature under the protective atmosphere.

Abstract: The present invention relates to a heat insulating separation wall between the combustion chamber of a solid fuel rocket and a chamber containing an electronic control installation of said rocket.

Abstract: The invention relates to an air purifier comprising a mercury lamp emitting electrons and generating ozone during the purification. The air purifier is surrounded by a non-conductive casing absorbing molecules negatively charged due to the emitted electrons. As a result the ozone molecules become positively charged and may therefore recombine with negatively charged ozone molecules to produce neutral oxygen molecules.