METHOD OF FABRICATING A CERAMIC ARTICLE
A method of fabricating a ceramic article includes serially depositing first, second and third different materials within a porous structure using, respectively, first, second and third different processing techniques, to form a ceramic-containing article. The first, second and third materials differ by at least one of composition and microstructure. The first, second and third different processing techniques differ by at least one of modes of delivery of precursor materials into the porous structure and formation mechanisms of the first, second and third different materials from the precursor materials. The deposition of the first material is controlled such that there are first residual voids in the porous structure in which the second material is deposited. The deposition of a second material is controlled such that there are second residual voids in the porous structure in which the third material is deposited.
1 . A method of fabricating a ceramic article, the method comprising:
serially depositing first, second and third different materials within a porous structure using, respectively, first, second and third different processing techniques, to form a ceramic-containing article, the first, second and third different materials differing by at least one of:
composition and
microstructure, and
the first, second and third different processing techniques differing by at least one of:
modes of delivery of precursor materials into the porous structure and
formation mechanisms of the first, second and third different materials from the precursor materials,
the depositing of the first material being controlled such that there are first residual voids in the porous structure into which the second material is deposited and the depositing of the second material being controlled such that there are second residual voids in the porous structure into which the third material is deposited.
2 . The method as recited in claim 1 , further comprising selecting respective compositions of at least two materials of the first, second and third different materials to be reactive with each other during the deposition.
3 . The method as recited in claim 1 , further comprising selecting respective compositions of at least two of the first, second and third different materials to be chemically inert with each other during the deposition.
4 . The method as recited in claim 1 , wherein the first residual voids are interconnected pores that are unfilled by the first material and the second residual voids are micro-cracks within the second material.
5 . The method as recited in claim 1 , wherein the first residual voids and the second residual voids are interconnected pores, the interconnected pores of the second residual voids being within the second material.
6 . The method as recited in claim 1 , wherein the porous structure is a fiber structure.
7 . The method as recited in claim 1 , wherein the deposition of the first material provides a continuous coating on the porous structure.
8 . The method as recited in claim 1 , wherein the first, second and third different processing techniques are selected from the group consisting of chemical vapor infiltration of a gas, polymer infiltration and pyrolysis of a polymer, melt infiltration of a metallic material and vapor infiltration of a metallic material.
9 . The method as recited in claim 8 , wherein the third processing technique includes one of the melt infiltration of the metallic material or the vapor infiltration of the metallic material.
10 . The method as recited in claim 1 , wherein the second processing technique includes the deposition of a preceramic polymer including a filler that chemically reacts with at least one of the first material and the third material.
11 . The method as recited in claim 1 , wherein at least one of the first, second and third different processing techniques includes chemically reacting a precursor material deposited thereby with a residual amount of unreacted precursor material from another of the first, second and third different processing techniques.
12 . The method as recited in claim 1 , wherein at least two of the first, second and third materials include ceramic materials.
13 . A method of fabricating a ceramic article, the method comprising:
serially depositing first, second and third different materials within a porous structure using, respectively, first, second and third different processing techniques selected from the group consisting of chemical vapor infiltration of a gas, polymer infiltration and pyrolysis of a polymer, melt infiltration of a metallic material and vapor infiltration of a metallic material, to form a ceramic-containing article, the first, second and third different materials differing by at least one of:
composition and
microstructure,
the depositing of the first material being controlled such that there are first residual voids in the porous structure into which the second material is deposited and the depositing of the second material being controlled such that there are second residual voids in the porous structure into which the third material is deposited.
14 . The method as recited in claim 13 , wherein the first, second and third different processing techniques are, respectively, the chemical vapor infiltration of the gas, the polymer infiltration and pyrolysis of the polymer and one of the melt infiltration of the metallic material or the vapor infiltration of the metallic material.
15 . The method as recited in claim 13 , wherein the third processing technique is one of the melt infiltration of the metallic material or the vapor infiltration of the metallic material.
16 . The method as recited in claim 13 , wherein the ceramic-containing article is substantially fully dense and substantially free of voids.
17 . The method as recited in claim 13 , wherein the third processing technique is melt infiltration of a metallic material or vapor infiltration of a metallic material, the first processing technique is the polymer infiltration and pyrolysis of a polymer and the second processing technique is the chemical vapor infiltration of a gas to deposit a continuous protective layer of the second material around the first material to limit reaction between the later deposited metallic material deposited by the melt infiltration or vapor infiltration.
18 . The method as recited in claim 13 , wherein the porous structure is an unstable fiber structure and the first processing technique provides a continuous layer of the first material that rigidizes the fiber structure such that the fibers maintain a desired fiber arrangement upon the second and third processing techniques.
19 . A ceramic article fabricated by a method comprising:
serially depositing first, second and third different materials within a porous structure using, respectively, first, second and third different processing techniques, to form a ceramic-containing article, the first, second and third different materials differing by at least one of:
composition and
microstructure, and
the first, second and third different processing techniques differing by at least one of:
modes of delivery of precursor materials into the porous structure and
formation mechanisms of the first, second and third different materials from the precursor materials,
the depositing of the first material being controlled such that there are first residual voids in the porous structure into which the second material is deposited and the depositing of the second material being controlled such that there are second residual voids in the porous structure into which the third material is deposited.
20 . The article as recited in claim 19 , wherein the ceramic-containing article includes the porous structure with the first material disposed in voids of the porous structure, the second material disposed at least in the first residual voids of the porous structure and the third material disposed in at least the second residual voids in the porous structure