Method and composition for diffusion treatment of ceramic materials

摘要

The present invention provides a composition and method for use in diffusion coating ceramic workpieces. In an especially preferred form, the composition comprises: Chromium 45-50 wt % Silicon Carbide 3.5-5.0 wt % Vanadium Boride 0.5-1.5 wt % Ammonium Halide 5.0-6.0 wt % Aluminum Oxide Remainder, the sum of all the components being 100 wt %. The components, in powdered form, are weighed and mixed in a container. The workpieces are placed in the container. The container is hermetically sealed and heated to a temperature of approximately 1000 DEG C. The workpieces and the composition are kept at approximately 1000 DEG C. for a predetermined period of time sufficient to permit a surface layer of desired thickness to form. The container is then cooled in a conventional cooling chamber down to approximately 300 DEG -350 DEG C. and air cooled to room temperature. The container is opened and the workpieces are removed. The composition and method of the present invention provide diffusion coatings on ceramic base materials which decrease the brittleness of the base material and improve the chemical resistance of the base material to aggressively corrosive environments.