Manufacturing wear-resistant silicon carbide- or carbon component, coats substrate with diamond crystals and binder, fires and infiltrates with silicon at high temperature

摘要

The component substrate is silicon carbide ceramic or carbon fiber-reinforced carbon. It is coated with a layer or layers containing an organic binder and diamond crystals. It is then heated in an inert atmosphere or vacuum. This decomposes the binder, forming carbon. Simultaneously or subsequently, silicon or a silicon alloy is infiltrated, at a temperature exceeding its melting point, but below 1650[deg] C, still in an inert atmosphere or vacuum. The carbon formed and/or a smaller proportion of diamond, reacts with silicon to beta -SiC. The pores become filled with silicon or silicon alloy. The result is a wear protection layer containing diamond crystal, bonded with beta -SiC. Layer(s) formed on the component surface before infiltration, have a porosity of at least 20. Several such layers are formed, with differing proportions of diamond crystals; in this way, the proportion increases, starting from the surface. Coating is by immersion, injection molding, laminating with sheets, pressing, electrophoretic deposition or hot casting. The ceramic blank is a sheet containing SiC, but free of diamond crystals. This is laminated with a diamond crystal-containing sheet, then subjected to the thermal treatment. In the layer used, a silicide, silicide precursor element or carbide precursor element is included. The blank is porous SiC containing free carbon. The porous SiC blank is dipped in a suspension containing organic binder and diamond crystals. The suspension additionally contains powdered SiC. The blank is R-SiC, LPSSiC, SSiC or SiSiC, consisting predominantly of alpha SiC. The binder is phenolic resin or a starch. The blank or SiC ceramic contains 3-15 wt% of free carbon. An independent claim IS INCLUDED FOR the component with wear protection coating.