Methods of fabricating oxide/metal composites and components produced thereby

An oxide/metal composite component for use in a system in which the oxide/metal composite component is subjected to elevated temperatures exceeding 500° C. and up to at least 2000° C., the oxide/metal composite component produced by a method comprising:

• providing a fluid reactant and a porous preform that has a pore volume and contains a solid oxide reactant that defines a solid volume of the porous preform, the fluid reactant comprising a Cu—Y liquid that contains yttrium as a displacing metal and the solid oxide reactant of the preform consisting of niobium oxide in which niobium cations in the niobium oxide are displaceable species, the yttrium of the fluid reactant being capable of displacing the niobium cations in the solid oxide reactant to produce yttria as a solid oxide reaction product and niobium metal as a solid metal reaction product;
• infiltrating the porous preform with the fluid reactant by means of a pressureless reactive infiltration process to react the yttrium of the fluid reactant with the niobium oxide of the solid oxide reactant at a temperature that is lower the melting point of yttrium to produce the oxide/metal composite component of niobium metal particles dispersed within a matrix of yttria without forming diffusion bonds between the niobium metal particles and the yttria, during which the yttrium of the fluid reactant replaces the niobium cations of the solid oxide reactant to produce the yttria and the niobium metal that together define a reaction product volume, the pore volume is filled by the reaction product volume, and the reaction product volume is greater than the solid volume lost by the solid oxide reactant as a result of the reaction of the yttrium and the niobium oxide, wherein the oxide/metal composite component comprises an yttria/niobium composite containing the yttria and niobium metal without diffusion bonds between the niobium metal particles and the yttria;
• and
• forming an yttria coating on the oxide/metal composite component.

An oxide/metal composite component for use in a system in which the oxide/metal composite component is subjected to elevated temperatures exceeding 500° C. and up to at least 2000° C., the oxide/metal composite component produced by a method comprising:

• providing a fluid reactant and a porous preform that has a pore volume and contains a solid oxide reactant that defines a solid volume of the porous preform, the fluid reactant comprising at least yttrium as a displacing metal and the solid oxide reactant of the preform comprising at least one oxide in which cations of the oxide are displaceable cation species, the displacing metal of the fluid reactant being capable of displacing the cations in the solid oxide reactant to produce at least a solid oxide reaction product and a solid metal reaction product;
• and
• infiltrating the porous preform with the fluid reactant by means of a pressureless reactive infiltration process to react the displacing metal of the fluid reactant with the displaceable cation species of the solid oxide reactant to produce the oxide/metal composite component of niobium metal particles dispersed within a matrix of yttria without forming diffusion bonds between the niobium metal particles and the yttria, during which the displacing metal of the fluid reactant at least partially replaces the displaceable cation species of the solid oxide reactant to produce the solid oxide reaction product and the solid metal reaction product that together define a reaction product volume, the pore volume is at least partially filled by the reaction product volume, and the reaction product volume is greater than the solid volume lost by the solid oxide reactant as a result of the reaction of the displacing metal and the solid oxide reactant, wherein the oxide/metal composite component comprises an oxide/metal composite without diffusion bonds between the niobium metal particles and the yttria and the solid oxide reaction product of the oxide/metal composite possesses linear thermal expansion values within 10% of linear thermal expansion values of the solid metal reaction product throughout a temperature range of 250° C. to at least 2000° C.