System and method for forming an ultra-high temperature composite structure

1. A method for forming an ultra-high temperature (UHT) composite structure, the method comprising:

dispensing a first polymeric precursor with a spinneret;

forming a first plurality of nanofibers from the first polymeric precursor;

depositing the first plurality of nanofibers on a collector;

applying a fluid, with a nozzle, onto the first plurality of nanofibers disposed on the collector, the fluid comprising a second polymeric precursor, the first plurality of nanofibers and the fluid defining a two-dimensional layer;

pyrolyzing the two-dimensional layer with a rapid thermal processing assembly; and

forming a second plurality of nanofibers from the first polymeric precursor and depositing the second plurality of nanofibers on the two-dimensional layer subsequent to pyrolyzing the two-dimensional layer.

2. The method of claim 1 , wherein forming and depositing the second plurality of nanofibers occurs subsequent to applying the fluid onto the first plurality of nanofibers.

3. The method of claim 1 , further comprising one of carbothermally or borothermally reducing the two-dimensional layer.

4. The method of claim 1 , further comprising moving the nozzle relative to the collector.

5. The method of claim 1 , wherein the first polymeric precursor is different than the second polymeric precursor.

6. The method of claim 5 , wherein the first polymeric precursor has a greater viscosity than the second polymeric precursor.

7. A method for forming an ultra-high temperature (UHT) composite structure, the method comprising:

sequentially forming a plurality of two-dimensional layers on a collector biased at a collector DC voltage including, for each sequentially-formed two-dimensional layer of the plurality of two-dimensional layers,

dispensing a first polymeric precursor with a spinneret biased at a first DC voltage different than the collector DC voltage, forming a plurality of nanofibers from the first polymeric precursor, and depositing the plurality of nanofibers on the collector; and

dispensing a fluid with an electrospraying apparatus biased at a second DC voltage different than the collector DC voltage and depositing the fluid on the plurality of nanofibers deposited on the collector, the fluid including a second polymeric precursor;

wherein the step of sequentially forming the plurality of two-dimensional layers further includes, for each sequentially-formed two-dimensional layer, pyrolyzing the sequentially-formed two-dimensional layer, including the deposited plurality of nanofibers and the deposited fluid, with a rapid thermal processing assembly.

8. The method of claim 7 , wherein the ultra-high temperature (UHT) composite structure is a graded structure.

9. The method of claim 8 , wherein the plurality of two-dimensional layers includes a first two-dimensional layer and a second two-dimensional layer, the method further comprising changing a ratio of the plurality of nanofibers formed from the first polymeric precursor to a matrix material formed from the second polymeric precursor for the second two-dimensional layer relative to the first two-dimensional layer.

10. The method of claim 7 , wherein the first polymeric precursor is different than the second polymeric precursor.

11. The method of claim 10 , wherein the first polymeric precursor has a greater viscosity than the second polymeric precursor.

12. The method of claim 7 , wherein the rapid thermal processing assembly includes at least one of a laser, an electron beam, or a flash pyrolysis assembly.

13. The method of claim 7 , wherein pyrolyzing the sequentially-formed two-dimensional layer includes carbothermally or borothermally reducing the sequentially-formed two-dimensional layer.

14. The method of claim 7 , wherein the plurality of two-dimensional layers includes a first two-dimensional layer and a second two-dimensional layer, the method further comprising additionally dispensing the second polymeric precursor with the electrospraying apparatus after pyrolyzing the first two-dimensional layer and before forming the second two-dimensional layer of the forming a plurality of two-dimensional layers.