Self-healing matrix for a ceramic composite
A method for forming a self-healing ceramic matrix composite (CMC) component includes depositing a first self-healing particulate material in a first region of a CMC preform of the CMC component and depositing a second self-healing particulate material having a different chemical composition than the first self-healing particulate material in a second region of the CMC preform distinct from the first region.
1. A method for forming a self-healing ceramic matrix composite (CMC) component, the method comprising:
depositing a first self-healing particulate material in a first region of a CMC preform of the CMC component, wherein the first self-healing particulate material is capable of sealing cracks in the matrix;
depositing a second self-healing particulate material in a second region of the CMC preform, wherein the second self-healing particulate material is capable of regenerating an environmental barrier coating and wherein the first and second regions are non-overlapping and the second self-healing particulate material is absent from the first region;
wherein the first and second self-healing particulate materials have different chemical compositions; and
wherein the CMC preform is a fiber structure having the first and second regions and wherein depositing the first and second self-healing particulate materials in the CMC preform comprises:
infiltrating the fiber structure with a first slurry comprising the first self-healing particulate material; and
infiltrating the fiber structure with a second slurry comprising the second self-healing particulate material; and
densifying the first and second regions with a ceramic matrix through chemical vapor infiltration following the steps of depositing the first and second self-healing particulate materials.
2. The method of claim 1 , wherein the first self-healing particulate material is selected from a group consisting of silicon boride, boron carbide, silicon borocarbide, silicon boronitrocarbide, aluminum nitride and mixtures thereof, and wherein the second self-healing particulate material is selected from a group consisting of borides of rare earth elements, hafnium boride, zirconium boride, titanium boride, tantalum boride, silicides of rare earth elements, hafnium silicide, zirconium silicide, titanium silicide, tantalum silicide, molybdenum disilicide, aluminum oxide, alkaline metal oxides, oxide of rare earth elements, hafnium oxide and zirconium oxide and mixtures thereof.
3. The method of claim 2 , wherein the first region comprises an inner core of the CMC preform, and wherein the second region comprises an outer region of the CMC preform including an outer surface of the CMC preform.
4. The method of claim 3 , and further comprising depositing the first self-healing particulate material in the second region.
5. The method of claim 2 , wherein the first region is located on a first side of the CMC preform and wherein the second region is located on a second side opposite the first side of the CMC preform, and wherein the second side of the CMC preform is configured for use in a high temperature environment and wherein the first side of the CMC preform is configured for use in a lower temperature environment.
6. The method of claim 2 , and further comprising depositing the first and second self-healing particulate materials in a third region of the CMC preform located between the first and second regions of the CMC preform.
7. The method of claim 1 , wherein the entire fiber structure is infiltrated with the first slurry and wherein the method further comprises removing the first slurry from the second region before infiltrating the fiber structure with the second slurry.
8. The method of claim 1 , wherein the entire fiber structure is infiltrated with the first slurry and dried before infiltrating the fiber structure with the second slurry.
9. The method of claim 8 , wherein a size of the second self-healing particulate material is greater than a size of the first self-healing particulate material, and wherein the size of the second self-healing particular material limits a penetration depth into the fiber structure.
10. The method of claim 1 , wherein a first portion of the fiber structure comprising the first region of the CMC preform is infiltrated with the first slurry and a second portion of the fiber structure comprising the second region of the CMC preform is infiltrated with the second slurry, and wherein the first and second portions of the fiber structure overlap to form a third region of the fiber preform comprising both first and second self-healing particulate materials.
11. The method of claim 1 , wherein the first and second slurries comprise mixtures of silicon carbide particulates and the first and second self-healing particulate materials, respectively, and wherein between 2 and 30 percent of the total particulate material by volume of the first slurry is the first self-healing particulate material, and wherein between 5 and 30 percent of the total particulate material by volume of the second slurry is the second self-healing particulate material.
12. The method of claim 1 , wherein between 5 and 30 percent of the total particulate material by volume of the first slurry is the first self-healing particulate material, and wherein between 10 and 30 percent of the total particulate material by volume of the second slurry is the second self-healing particulate material.