A method includes forming an article from a silicon-rich refractory mixture. The silicon-rich refractory mixture includes a silicon-rich silicon carbide preceramic polymer and a silicon carbide powder. The method includes heating the preform to pyrolyze the silicon-rich silicon carbide preceramic polymer and form a silicon-rich refractory material. The silicon-rich refractory material includes the silicon carbide powder and excess silicon in a silicon carbide matrix. The method further includes heating the silicon-rich refractory material to oxidize at least a portion of the excess silicon and form a reinforced refractory material. The reinforced refractory material includes a silicon dioxide phase at grain boundaries of the silicon carbide powder.

A method includes forming an article from a silicon-rich refractory mixture. The silicon-rich refractory mixture includes a silicon-rich silicon carbide preceramic polymer and a silicon carbide powder. The method includes heating the preform to pyrolyze the silicon-rich silicon carbide preceramic polymer and form a silicon-rich refractory material. The silicon-rich refractory material includes the silicon carbide powder and excess silicon in a silicon carbide matrix. The method further includes heating the silicon-rich refractory material to oxidize at least a portion of the excess silicon and form a reinforced refractory material. The reinforced refractory material includes a silicon dioxide phase at grain boundaries of the silicon carbide powder.

A method includes forming a crystallized metal carbide undercoat on a surface of a carbon-carbon composite substrate. The method further includes forming an overcoat on a surface of the undercoat. The overcoat includes a plurality of crystallized ultra-high melting point overcoat layers. Each overcoat layer is sequentially formed by applying a mixture to a surface of an underlying layer and heating the mixture. The mixture includes a plurality of ultra-high melting point refractory ceramic particles and a pre-ceramic polymer. The mixture is heated to a heat treatment temperature to pyrolyze the pre-ceramic polymer and form the overcoat layer in an inert atmosphere or under vacuum. As a result, the overcoat layer includes a crystallized ultra-high melting point polymer-derived ceramic matrix that includes the plurality of ultra-high melting point refractory ceramic particles.

A method includes forming a crystallized metal carbide undercoat on a surface of a carbon-carbon composite substrate. The method further includes forming an overcoat on a surface of the undercoat. The overcoat includes a plurality of crystallized ultra-high melting point overcoat layers. Each overcoat layer is sequentially formed by applying a mixture to a surface of an underlying layer and heating the mixture. The mixture includes a plurality of ultra-high melting point refractory ceramic particles and a pre-ceramic polymer. The mixture is heated to a heat treatment temperature to pyrolyze the pre-ceramic polymer and form the overcoat layer in an inert atmosphere or under vacuum. As a result, the overcoat layer includes a crystallized ultra-high melting point polymer-derived ceramic matrix that includes the plurality of ultra-high melting point refractory ceramic particles.