Vapor-mediated synthesis of silicon carbide matrices for ceramic matrix composites by reactive melt infiltration

A method of making a silicon carbide matrix, comprising:

• exposing internal surfaces of a porous composite preform, comprising carbon, to a vapor comprising silicon, wherein:
• the carbon in the preform comprises carbon particles or solid carbon derived from pyrolysis of a liquid precursor;
• the vapor comprising silicon adsorbs on the carbon surfaces and reacts with the carbon so as to form a nanoporous layer of silicon carbide (SiC) on the carbon;
• and a
• majority of the carbon under the nanoporous layer of SiC remaining after the vapor reaction being available for a subsequent reaction with a Si bearing reactive melt;
• exposing the carbon preform surfaces modified with the nanoporous layer of (SiC) to the reactive melt comprising molten silicon, wherein the reactive melt infiltrates first the network of larger pores (passages) in the porous composite preform so as to wet or contact the silicon carbide on the inner surfaces of the pores and then through a network of nanopores in the nanoporous layer of SiC to react with the majority of the carbon so as to form additional silicon 20 carbide at the interfaces with the remaining carbon and eventually filling the entire network of pores including the pores in the network of nanopores.