Production of BN-Composite Materials

A process comprising:

• infiltrating or infiltrating and coating surface porosity of a substrate with a boron-comprising precursor, and
• contacting the boron-comprising precursor with a nitrogen-comprising reactant to convert the boron-comprising precursor to BN in the surface porosity or in the surface porosity and on the surface of the substrate.

(canceled)

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A composite material comprising a substrate phase comprising BN or other boron-nitrogen reaction product in surface porosity or in surface porosity and on a surface of the substrate phase, reducing the surface porosity of the composite material relative to that of the substrate phase.

A process comprising:

• infiltrating or infiltrating and coating surface porosity of substrate material comprising a carbide, nitride, or a carbide-nitride composite with a boron-comprising precursor solution also comprising a nitrogen source, and
• contacting the boron-comprising precursor with a nitrogen-comprising reactant at elevated temperature to convert the boron-comprising precursor to a boron-nitrogen reaction product comprising BN and/or other boron-nitrogen reaction product(s) in the surface porosity or in the surface porosity and on the surface of the substrate to reduce the surface porosity of the substrate.

A composite material comprising a carbide, nitride, or a carbide-nitride substrate phase comprising BN and/or other boron-nitrogen reaction product(s) in surface porosity or in surface porosity and on a surface of the substrate phase.

(canceled)