DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-11, in the reply filed on 19 June 2026, is acknowledged.
The requirement is still deemed proper and is therefore made FINAL.
Claims 12-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 19 June 2026.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-11 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claims 1, 2, and 4-7, the use of parentheses renders the claim indefinite because it is unclear whether the limitation(s) within the parentheses are defining an abbreviation of the preceding term or further limiting the preceding term (i.e. a subset thereof). See MPEP § 2173.05(d).
Claims 3 and 8-11 are rejected as being dependent on a rejected claim.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 10 is rejected under 35 U.S.C. 112(d) as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 10 recites the hypersonic aeronautical vehicle is a hypersonic aircraft. There does not appear to be a structural distinction between these terms (i.e. aero=air and vehicle=craft), and therefore claim 10 fails to further limit the limitations of the claim on which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5 and 7-11 are rejected under 35 U.S.C. 103 as being unpatentable over Trice et al. (US 2018/0127630) in view of Zhang et al. (Ceramics International 2014, NPL previously cited) and Feng et al. (Corrosion Science 2021 (avail. Online), NPL previously cited).
Claim 1: Trice teaches high emissivity coatings for bodies exposed to high-temperature environments (paragraph 0003), such as hypersonic vehicle structures (paragraph 0004). Materials considered for such structures often focus on ultra-high temperature ceramics (UHTCs) such as ZrB2 and HfB2 with SiC added for oxidation resistance (paragraph 0004). A thermal protection system (TPS) can be applied in the form of a coating to provide an extra barrier that impedes the heating and oxidation processes that occur during service (paragraph 0028). The coatings can be formed via suspension plasma spray (paragraph 0030). An example TPS is shown by Trice in Fig. 9 with “before oxidation” and “after oxidation” schematics. A ZrB2/SiC (ZBS) TPS doped with a rare-earth element is plasma-sprayed to a UHTC structure, where the UHTC substrate may have like or similar composition to undoped TPS material and where the added rare-earth is Sm3+ (paragraph 0062). The rare-earth oxidizes to Sm2O3 and likewise cation oxides of the refractory material such as ZrO2 may be present, and may be present as a separate distinct layer (paragraph 0062). The ZBS TPS forms porous ZrO2 after oxidation above 1773 K, and likewise the Sm3+ doped TPS composition forms a thin layer of Sm2O3 over the ZrB2 and/or ZrB2/ZrO2 composite substrate after oxidation above the same temperature (paragraph 0064). Trice depicts these materials after oxidation as a layer of ZrB2/SiC (i.e. corresponding to the instantly claimed second layer), followed by a ZrO2 oxide layer, and further capped with a layer of Sm2O3 oxide layer (Fig. 9), and also teaches that crystalline phases present in the post-ablation coatings include SmZrO (with varying coefficients depending on the doping amount) (paragraph 0066, Table 3).
Since Trice teaches that the formation of silica scale protects the underlying structure up to 1773 K before it begins to evaporate (paragraph 0009), whereas Sm2O3 and ZrO2 have high emissivity at high temperatures with Sm2O3 having a broader range of temperatures (paragraph 0038). This teaching, in view of the layered structure after oxidation and that the Sm2O3 may include ZrO2 along with post-ablation phases including a SmZr oxide phase, would render obvious to one of ordinary skill in the art to include Sm2O3 and ZrO2 as a separate outer layer (i.e. intentionally layered; i.e. corresponding to the instantly claimed fourth layer of samaria-modified zirconium oxide) to be able to utilize the benefit of higher emissivity even before oxidation of the ZrB2/SiC layer and because this is considered a separation of parts (i.e. the parts being the layers after oxidation) (see MPEP 2144.04-V-C), and one would have had a reasonable expectation of success. However, Trice does not teach a layer of SiC between the substrate and the layer of ZrB2/SiC (i.e. a first layer of SiC) or a layer of ZrC-ZrO2 (i.e. the instantly claimed third layer).
In a related field of endeavor, Zhang discloses a study of the ablation resistance of ZrB2-SiC coating materials for carbon/carbon (C/C) composites used as thermal-structural components, and particularly for use at application requirements of higher temperature above 2000 K and high-pressure gas flow (Section 1). Zhang teaches that weak bonding strength between a ZrB2-SiC coating and the matrix (of the C/C composite) restricts the ablation resistance of the coating and teaches placing a SiC inner layer between the ZrB2-SiC coating and the C/C composites to act as a bonding layer in order to relieve the mismatch of the coefficient of thermal expansion (CTE) (Section 1).
As Trice and Zhang both teach a layer of ZrB2-SiC for thermal protection in use for high temperature applications, they are analogous. It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the coating of Trice to include a bond layer of SiC below the layer of ZrB2-SiC as taught by Zhang because the bond layer of SiC is known to relieve CTE mismatch, and one would have had a reasonable expectation of success. However, Zhang-modified Trice does not teach the layer of ZrC-ZrO2 (i.e. the instantly claimed third layer).
In a related field of endeavor, Feng teaches ultra-high temperature ceramics for protecting carbon/carbon composites in aerospace fields requiring ability to withstand oxidizing atmospheres at high temperatures (Section 1). Feng teaches a multilayer coating having a layer of ZrC-ZrO2 as a middle layer (Section 1). The multilayer coating kept good integrity including surviving a second ablation cycle compared to the single layer coatings (Section 3.2). Feng teaches that the enhanced ablation mechanism possibly may be due to forming a dense scale on the outermost layer that hinders oxygen permeation, oxidation of ZrC into ZrO2 develops a porous structure which favors crack deflection and stress dissipation, and these contribute to lowered temperature in the bottom layer along with lessened vaporization of molten SiO2 and depletion of SiC by active oxidation (Section 3.4). Feng further teaches that the ZrC-ZrO2 coating has a moderate coefficient of thermal expansion (CTE) that provides a gradient for compatibility with other layers (i.e. the other layers used were an oxide layer and a carbide layer) (Section 1).
As Feng, Zhang, and Trice all teach ultra-high temperature ceramics for protection in aerospace fields requiring ability to withstand oxidizing atmospheres at high temperatures (i.e. protective coatings), they are analogous. It would have been obvious to one of ordinary skill in the art before the effective filing date to further modify the coating of Zhang-modified Trice to include a layer of ZrC-ZrO2 as a middle layer because Feng teaches that the ZrC-ZrO2 layer results in hindered oxygen permeation and favors crack deflection and stress dissipation which contribute to lowered temperature in the bottom layer along with lessened vaporization of molten SiO2 and depletion of SiC by active oxidation and because the ZrC-ZrO2 coating has a moderate coefficient of thermal expansion (CTE) that provides a gradient for compatibility with other layers, and one would have had a reasonable expectation of success.
Claim 2: Trice teaches that the total hemispherical emissivity (i.e. emissivity at all angles) of the coating having 5 and 8 mol% samaria-doped ZrB2-SiC (i.e. the emissivity of the coating is an indication of the emissivity of the outer layer containing samaria, as Trice teaches in paragraph 0062 that the rare-earth, such as Sm3+, oxidizes during service to form the necessary high emissivity layer) is about 0.8-0.9 at temperatures of 600-1600 °C (Fig. 11). Although the exact radiation wavelength is not specified, the dependence on temperature (i.e. infrared waves) is presented and Trice teaches that near and far infrared wavelengths of interest is about 0.7-1000 µm, which overlaps the instantly claimed range. The courts have held that a prima facie case of obviousness exists where claimed ranges overlap, lie inside of, or are close to ranges in the prior art. See MPEP § 2144.05. It is noted that as of the writing of this Office Action, no demonstration of a criticality to the claimed ranges has been presented.
Claim 3: The arrangement of the coating of Feng-modified, Zhang-modified Trice, as outlined above, results in the layer of samaria and zirconia (i.e. the fourth layer comprising samaria-modified zirconium oxide) being the outermost layer.
Claim 4: Trice teaches that the amount of samaria doped in ZBS is between 1 and 10 mole percent, more typically between 3 and 8 mole percent (paragraph 0066) and the coating is applied by suspension plasma spray (paragraph 0051). This is considered to result in the instantly claimed crystal structure of non-equilibrium tetragonal ZrO2 stabilized with Sm2O3 because substantially identical materials treated in a substantially identical manner have substantially identical properties and functions (i.e. in comparison to the materials and method forming the instantly claimed phase as outlined in paragraph 0027 of the instant specification). See MPEP § 2112.01.
Claim 5: Trice teaches the coating as being for hypersonic structures but does not teach specifically the instantly claimed composite material for the substrate. However, Zhang teaches that carbon/carbon (C/C) composites may be used as a material for thermal-structural components at high temperatures for which ultra-high temperature ceramics (UHTCs) may be used as an anti-ablation coating (Section 1) and specifically uses bulk 2D C/C composites (i.e. carbon fiber reinforced carbon matrix composite) (Section 2.1 and evidenced in SEM images of Figs. 7a and 7b). Therefore, it would have been obvious to one of ordinary skill in the art to modify the coating of modified Trice by using a C/C composite as a substrate as taught by Zhang because such material is known to be used for thermal-structural components used at high temperatures and requiring a UHTC anti-ablation coating, and one would have had a reasonable expectation of success.
Claim 7: The limitations of claim 7 are included in instant claim 5 but is directed to an article of manufacture instead of to the coating. Each of the instantly claimed features are outlined above regarding claims 1 and 5.
Claim 8: Trice teaches the UHTC coating as being for hypersonic vehicles (paragraph 0004) such as missiles and manned aircraft (i.e. a hypersonic aeronautical vehicle) (paragraph 0009).
Claim 9: Trice teaches the surfaces include nose tips and wing leading edges (i.e. a leading edge of the hypersonic aeronautical vehicle) where the geometry of these edges increases the convective heat flow to the surface with temperatures reaching as high as 2273 K (i.e. about 2000°C) (i.e. subject to high temperatures during flight through earth atmosphere) (paragraph 0009). This temperature range (i.e. up to about 2273 K, or up to about 2000°C) overlaps the instantly claimed range of temperatures. See MPEP § 2144.05.
Claim 10: Trice teaches the UHTC coating as being for hypersonic vehicles (paragraph 0004) such as missiles and manned aircraft (i.e. a hypersonic aeronautical vehicle; i.e. a hypersonic aircraft) (paragraph 0009).
Claim 11: Trice teaches the surfaces (to be coated) include nose tips (i.e. leading edge of a nose) and wing leading edges (paragraph 0009).
Allowable Subject Matter
Claim 6 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims as well as requiring overcoming all other rejections outlined above.
The following is a statement of reasons for the indication of allowable subject matter:
The closest prior art is the teachings of Trice in view of Zhang and Feng as outlined above. Although the layers as applied do not necessarily require additional components in the materials to be applied in forming the coating layers, Zhang teaches that oxidation of ZrB2 to form ZrO2 occurs during the spraying process (i.e. application by plasma spray), and therefore at least the second layer (i.e. the layer of ZrB2-SiC) would have some amount of ZrO2 upon application. Furthermore, Trice teaches that silica also forms from oxidation of the SiC (i.e. during use at high temperature) and mixes with the rare-earth oxide layer (i.e. the layer containing Sm2O3 would also contain SiO2). Collectively, these teachings suggest that the coating cannot consist of the recited materials as claimed.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KIM S HORGER whose telephone number is (571)270-5904. The examiner can normally be reached M-F 9:30 AM - 4:00 PM EST.
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/KIM S. HORGER/Examiner, Art Unit 1784
Prosecution Insights