Method of making ceramic composite bearings

A method for forming a ceramic matrix composite bearing, the method comprising:

• preparing a layup slurry formed from a mixture including water, a pre-ceramic polymer and a refractory filler, a ratio of the pre-ceramic polymer to the refractory filler being 20% to 50% by weight;
• forming a concentric stack of slurry-impregnated fabric sleeve layers over a rod-shaped inner mold;
• applying an outer mold that, when assembled, forms an inner perimeter in the shape of a tubular cylinder that extends around the concentric stack and the inner mold to form a mold assembly;
• heating the mold assembly to bond together and cure the stack of concentric slurry-impregnated fabric sleeve layers to form a tubular green body therefrom;
• rough cutting the green body to a pre-determined bearing length to form an elongate green bearing;
• rough treating the green bearing including iteratively performing a density-tuning process for one or more cycles until a density of the green bearing meets a pre-determined density parameter, the density-tuning process including performing, in order, steps comprising:
• heat-treating the green bearing in a kiln to create heat-treated bearing;
• and
• performing a polymer infiltration and pyrolysis treatment on the heat-treated bearing:
• conducting dimensional stability treatment processes on the heat-treated bearing;
• and
• performing final grinding and machining of the heat-treated bearing to meet pre-determined specifications.