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 .
Response to Amendment
The reply filed on February 10, 2026 has been entered into the prosecution for the application. Currently, claims 1-8, 10-12, 14-17, and 19-22 are pending, with claims 1-8 being withdrawn. Claims 9, 13, and 18 have been cancelled. Claims 10 and 21 have been amended.
In view of the amendment to claim 21, the previous rejection of claim 21 under 35 U.S.C. 112 is withdrawn as moot.
All prior art grounds of rejection are maintained.
Claim Rejections - 35 USC § 103
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.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 10-11, 14-17, and 19-22 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pat. Pub. 2004/0192534 to Nixon et al. (hereinafter “Nixon”) in view of U.S. Pat. Pub. 2021/0147302 to Bortoluzzi et al. (hereinafter “Bortoluzzi”) and Kozak, C.M., et al., “Zirconium & Hafnium: Inorganic & Coordination Chemistry,” in Encyclopedia of Inorganic Chemistry (2006) (hereinafter “Kozak”).
Regarding claim 10, Nixon discloses a ceramic matrix composite component (see Abstract and ¶ 0002) comprising ceramic-based reinforcements (fibers, ¶ 0015) disposed in a ceramic matrix (silicon matrix ¶ 0015), wherein the ceramic-based reinforcements are arranged in an array (a fibrous structure, ¶ 0015), and wherein there are gaps defined on an outer surface of the ceramic matrix composite component between adjacent ones of the ceramic-based reinforcements (see Fig. 9, showing gaps between adjacent fibers at a surface of the ceramic matrix composite component). Nixon also discloses a filler composition (boron carbide slurry, ¶ 0076) disposed in the gaps (the fiber preform is soaked in B4C slurry in order to impregnate the preform pores with B4C particles, including necessarily the “pores” or gaps on the surface of the ceramic matrix composite component, ¶ 0080-0081), the filler composition including filler particles (B4C powder, ¶ 0080) disposed in a filler matrix (B4C slurry, ¶ 0076).
Nixon does not explicitly recite that the filler particles are not within the array of ceramic-based reinforcements, or that the filler particles are hafnium oxide (HfO2).
Bortoluzzi discloses a ceramic matrix composite component (¶ 0012) comprising an array of ceramic-based reinforcements (ceramic fibers, ¶ 0022) arranged in an array (fiber preform, ¶ 0022), wherein there are gaps between adjacent ones of the ceramic-based reinforcements (i.e., the “pores and interstices that exist between the ceramic fibers,” ¶ 0025), and wherein the ceramic-based reinforcements (ceramic fibers) are disposed in a ceramic-based matrix (ceramic slurry, ¶ 0025). Bortoluzzi discloses a filler composition that includes filler particles (particulate fillers, ¶ 0028) disposed in a filler matrix (surface layer slurry, ¶ 0027).
Bortoluzzi discloses (¶ 0019) embodiments in which a slurry-based surface layer (i.e., a surface layer slurry containing filler particles) is applied to the edges and only one side of the array of ceramic-based reinforcements, and therefore the filler particles of the surface layer slurry are not within the array of ceramic-based reinforcements.
One of ordinary skill in the art would have found it obvious to modify Nixon with the teaching of Bortoluzzi to apply a surface layer slurry only to the edges and only one side of the array of ceramic-based reinforcements, thereby producing a ceramic matrix composite component wherein the filler particles are not within the array of ceramic-based reinforcements. One would be motivated to do so in order to selectively control the surface characteristics (e.g., surface roughness) of the ceramic matrix composite component, as suggested by Bortoluzzi (¶ 0018).
Nixon modified by Bortoluzzi discloses embodiments in which coated fiber bundles in the ceramic-based matrix have a porosity level (i.e., gap percentage) of about 20-60% (Nixon at ¶ 0079). Nixon modified by Bortoluzzi further discloses that the boron carbide filler particles fill from 5% to 15% of the total volume of the ceramic matrix composite (CMC) material (Nixon at ¶ 0085). So, for example, in an embodiment in which the gaps make up 40% of the volume of the CMC material (i.e., a porosity level of 40%), and the boron carbide filler particles fill 15% of the total volume of the CMC material, the boron carbide filler particles fill (0.15)/(0.40) = 37.5% of the volume of the gaps, thus reading on the limitation of amended claim 10 specifying that the filler particles fill more than 30% of the volume of the gaps.
Nixon as modified by Bortoluzzi does not explicitly teach that the filler particles comprise hafnium oxide (HfO2). However, Nixon as modified by Bortoluzzi teaches that the filler particles may comprise zirconia (i.e., zirconium oxide) (see Bortoluzzi at ¶ 0029, lines 3-4). Kozak, in the same field of endeavor, teaches that zirconium oxide includes hafnium oxide (HfO2) as an impurity (p. 2, col. 2, subsection 3.1). It would have been obvious to one of ordinary skill in the art that the zirconium oxide of Bortoluzzi would contain hafnium oxide (HfO2), as taught by Kozak, which teaches that all zirconium minerals are contaminated by hafnium in their natural state. One of ordinary skill in the art would look to Kozak for detailed information about the zirconium oxide that is taught in a general way by Bortoluzzi, and thus the presence of hafnium oxide (HfO2) in the zirconium oxide would be a predictable result. See MPEP 2143(I)(D). Therefore, Nixon in view of Bortoluzzi and Kozak teaches wherein the filler particles comprise hafnium oxide (HfO2).
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Nixon with the teachings of Bortoluzzi and Kozak in order to produce a ceramic matrix composite component reading on all the limitations of claim 10.
Regarding claim 11, Nixon in view of Bortoluzzi and Kozak discloses wherein the reinforcements are fibers (Nixon at ¶ 0015).
Regarding claim 14, Nixon in view of Bortoluzzi and Kozak teaches that molten silicon is employed to form a “continuous matrix” throughout the composite (Nixon at Abstract); thus, the molten silicon functions as both filler matrix and ceramic-based matrix, and the filler matrix and ceramic-based matrix are continuous with one another.
Regarding claim 15, Nixon in view of Bortoluzzi and Kozak teaches that the filler matrix is in the gaps (Nixon at ¶ 0081, Fig. 9). Nixon in view of Bortoluzzi and Kozak teaches wherein the filler matrix (surface layer slurry, Bortoluzzi at ¶ 0027) is disposed over the ceramic-based reinforcements and ceramic-based matrix (Bortoluzzi at ¶ 0019), the surface layer slurry being applied over “substantially all of the outer surface” of the array of ceramic-based reinforcements (Bortoluzzi at ¶ 0018), thereby producing a ceramic matrix component wherein the filler matrix (surface layer slurry) is disposed over the ceramic-based reinforcements and ceramic-based matrix, and is in the gaps that are on the outer surface of ceramic matrix component (see Nixon, Fig. 9).
Regarding claim 16, Nixon in view of Bortoluzzi and Kozak discloses that the filler matrix (surface layer slurry) may be “a different composition than” the ceramic-based matrix (ceramic slurry) (Bortoluzzi ¶ 0027).
Regarding claim 17, Nixon in view of Bortoluzzi and Kozak discloses that the filler matrix (surface layer slurry) reduces cracking during manufacturing and handling, and that the filler matrix (surface layer slurry) provides the ceramic matrix composite component with a grit blastable smooth surface (Bortoluzzi ¶ 0012), thereby providing at least mechanical or environmental protection to the ceramic matrix composite component.
Regarding claim 19, Nixon in view of Bortoluzzi and Kozak teaches that the B4C filler particles have a uniform distribution of particle size between about 0.8 microns and 10 microns (Nixon at ¶¶ 0076, 0080, 0086).
Regarding claim 20, Nixon in view of Bortoluzzi and Kozak teaches that the ceramic matrix composite component may be a component of a gas turbine engine (Bortoluzzi at ¶ 0004).
Regarding claim 21, Nixon in view of Bortoluzzi and Kozak teaches the ceramic matrix composite of claim 10, as set forth above (see pp. 3-4). Further, Nixon in view of Bortoluzzi and Kozak teaches that the filler particles may comprise transition metal borides (Bortoluzzi at ¶ 0029), which would include hafnium boride (HfB2), hafnium being a transition metal. Nixon in view of Bortoluzzi and Kozak also teaches that the filler particles may comprise rare earth oxides (Bortoluzzi at ¶ 0029), which would include ytterbium oxide (Yb2O3), ytterbium being a rare earth element.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Nixon in view of Bortoluzzi and Kozak as applied to claim 11 above, and further in view of U.S. Pat. Pub. 2019/0284099 to Jackson et al. (hereinafter “Jackson”), with evidence from Zheng et al., “A Multi-Scale Submodel Method for Fatigue Analysis of Braided Composite Structures,” Materials 14 (2021), 4190 (hereinafter “Zheng”).
Regarding claim 12, Nixon in view of Bortoluzzi and Kozak teaches the ceramic matrix composite component of claim 11, as set forth above (see p. 5). However, Nixon in view of Bortoluzzi and Kozak does not explicitly teach the ceramic matrix composite component wherein the fibers are woven or braided to form the array.
Jackson, in the same field of endeavor, teaches a ceramic matrix composite component (Abstract, ¶ 0005) comprising ceramic-based reinforcements (ceramic fibers, ¶ 0010) that are braided to form an array (¶ 0018).
It would have been obvious to one of ordinary skill in the art to modify Nixon in view of Bortoluzzi and Kozak to have the fibers braided to form an array, as taught by Jackson. One of ordinary skill in the art would have been motivated to do so by a desire to take advantage of the superior mechanical properties of braided ceramic matrix composites as compared to unbraided ceramic matrix composites, as evidenced by Zheng (see 4190, p. 1, Introduction, first paragraph).
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Nixon in view of Bortoluzzi and Kozak to have the fibers braided to form an array, as taught by Jackson.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Nixon in view of Bortoluzzi and Kozak as applied to claim 10 above, and further in view of U.S. Pat. Pub. 2018/0002238 to Hockemeyer et al. (hereinafter “Hockemeyer”).
Regarding claim 21, Nixon in view of Bortoluzzi and Kozak teaches the ceramic matrix composite component of claim 10, as set forth above (see pp. 3-4). However, Nixon in view of Bortoluzzi and Kozak does not explicitly teach the ceramic matrix composite component wherein the filler particles include hafnium boride (HfB2) or ytterbium oxide (Yb2O3).
Hockemeyer teaches a ceramic matrix composite (Abstract) with filler particles (particulate fillers, ¶ 0046) that are hafnium boride (HfB2) (¶ 0048, line 19).
It would have been obvious to one of ordinary skill in the art to modify Nixon in view of Bortoluzzi and Kozak to use hafnium boride (HfB2) as filler particles, as taught by Hockemeyer. Motivation to do so would come from a desire for a filler particle that could help control shrinkage the ceramic matrix composite during the formation process (see Hockemeyer at ¶ 0048).
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Nixon in view of Bortoluzzi and Kozak by including hafnium boride (HfB2) as filler particles in the ceramic matrix composite component, as taught by Hockemeyer.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Nixon in view of Bortoluzzi.
Regarding claim 22, Nixon discloses a ceramic matrix composite component (see Abstract and ¶ 0002) comprising ceramic-based reinforcements (fibers, ¶ 0015) disposed in a ceramic matrix (silicon matrix ¶ 0015), wherein the ceramic-based reinforcements are arranged in an array (a fibrous structure, ¶ 0015), and wherein there are gaps defined on an outer surface of the ceramic matrix composite component between adjacent ones of the ceramic-based reinforcements (see Fig. 9, showing gaps between adjacent fibers at a surface of the ceramic matrix composite component). Nixon also discloses a filler composition (boron carbide slurry, ¶ 0076) disposed in the gaps (the fiber preform is soaked in B4C slurry in order to impregnate the preform pores with B4C particles, including necessarily the “pores” or gaps on the surface of the ceramic matrix composite component, ¶ 0080-0081), the filler composition including filler particles (B4C powder, ¶ 0080) disposed in a filler matrix (B4C slurry, ¶ 0076). Nixon teaches wherein the reinforcements are fibers (¶ 0015).
Nixon does not explicitly recite that the filler particles are not within the array of ceramic-based reinforcements, or wherein a ratio of a diameter of the fibers to a diameter of the filler particles is between 0.1 to 24.
Bortoluzzi discloses a ceramic matrix composite component (¶ 0012) comprising an array of ceramic-based reinforcements (ceramic fibers, ¶ 0022) arranged in an array (fiber preform, ¶ 0022), wherein there are gaps between adjacent ones of the ceramic-based reinforcements (i.e., the “pores and interstices that exist between the ceramic fibers,” ¶ 0025), and wherein the ceramic-based reinforcements (ceramic fibers) are disposed in a ceramic-based matrix (ceramic slurry, ¶ 0025). Bortoluzzi discloses a filler composition that includes filler particles (particulate fillers, ¶ 0028) disposed in a filler matrix (surface layer slurry, ¶ 0027).
Bortoluzzi discloses (¶ 0019) embodiments in which a slurry-based surface layer (i.e., a surface layer slurry containing filler particles) is applied to the edges and only one side of the array of ceramic-based reinforcements, and therefore the filler particles of the surface layer slurry are not within the array of ceramic-based reinforcements.
One of ordinary skill in the art would have found it obvious to modify Nixon with the teaching of Bortoluzzi to apply a surface layer slurry only to the edges and only one side of the array of ceramic-based reinforcements, thereby producing a ceramic matrix composite component wherein the filler particles are not within the array of ceramic-based reinforcements. One would be motivated to do so in order to selectively control the surface characteristics (e.g., surface roughness) of the ceramic matrix composite component, as suggested by Bortoluzzi (¶ 0018).
Moreover, Bortoluzzi teaches wherein the fibers have a diameter that is between about 1 μm to about 50 μm (¶ 0022) and the filler particles have a diameter “in the range of about 100 nanometers (nm) up to about 50 micrometers (μm)” (¶ 0029). At the lower end of these taught ranges, a ratio of a diameter of the fibers to a diameter of the filler particles is 10. At the upper end of these taught ranges, a ratio of a diameter of the fibers to a diameter of the filler particles is 1. Thus, Bortoluzzi teaches a ratio of a diameter of the fibers to a diameter of the filler particles that is from 1 to 10, a range which falls within the claimed range of between 0.1 to 24. Therefore, Nixon as modified by Bortoluzzi teaches a ratio of a diameter of the fibers to a diameter of the filler particles that reads on this limitation of claim 22.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Nixon with Bortoluzzi in order to produce a ceramic matrix composite component meeting all the limitations of claim 22.
Response to Arguments
Applicant’s arguments filed February 10, 2026 have been fully considered but they are not persuasive.
On page 5 of the Remarks submitted as part of the reply filed February 10, 2026 (hereinafter “Remarks”), Applicant asserts that the previous Office Action “fails to establish any motivation to include hafnium oxide.” Applicant further develops this line of argument on the following pages, stating that a person of ordinary skill in the art would not “intentionally preserve or exploit hafnium oxide in a ceramic filler composition” (Remarks at p. 5). However, the contention of the present rejection is that the zirconium oxide necessarily and inherently includes some quantity of hafnium oxide, as taught by Kozak. No “modification” of the zirconium oxide filler material taught by Bortoluzzi is necessary; that material will include hafnium oxide as an inevitable consequence of how zirconium oxide occurs in nature. It is not necessary to show that a person of ordinary skill in the art would “intentionally preserve or exploit” hafnium oxide in the filler composition. To support a case of obviousness, it is only necessary to show that hafnium oxide would be present as a result of the combination. Applicant contends that neither Nixon nor Bortoluzzi “identifies any problem that the examiner has identified hafnium oxide as solving, nor do they suggest modifying zirconia-based fillers based on the trace elemental composition” (Remarks at p. 6). This line of argument seems premised on a misreading of the grounds of rejection. Nixon and Bortoluzzi, in combination, teach zirconia-based fillers (see Bortoluzzi at ¶ 0029); those zirconia fillers will necessarily include hafnium oxide. No modification is needed or suggested.
Applicant next seeks to draw an artificial distinction between “mined zirconium material” and “engineered CMC materials” (see Remarks at pp. 6-7). This argument is also unpersuasive. The Office has presented a prima facie case, based on the teachings and evidence of Kozak, that all zirconium oxide contains at least trace amounts of hafnium oxide. If Applicant has evidence that it is possible to produce a zirconium oxide filler material that is entirely free of hafnium oxide (even in trace amounts), Applicant should present that evidence. (Of note, the quoted passage from Section 3.1 of Kozak—see Remarks at p. 6—does not discuss producing zirconium oxide that is free of hafnium.) As the matter stands, the Examiner is unaware of any process for turning zirconium oxide into CMC filler material such that the filler material does not comprise some trace amount of hafnium oxide. Notably, claim 10, as currently worded, requires only that the filler particles comprise hafnium oxide; there is no minimum threshold on the content or proportion of hafnium oxide in the filler material. Filler material with trace amounts of hafnium oxide reads on claim 10 as presently drafted. Similarly, in response to Applicant’s argument that the cited art “does not teach or suggest that hafnium oxide is present in the filler particles in any meaningful or functionally relevant amount” (Remarks at p. 7), it is noted that the claims as presently drafted do not speak in terms of a “meaningful amount” or “functional amount” of hafnium oxide, and neither the claims nor the specification offer any metric for ascertaining what a “meaningful amount” or “functional amount” of hafnium oxide would be. Applicant’s argument seeks to base patentability on features that are not present in the claims.
Applicant states: “An impurity present at trace levels would likely not occupy more than 30% of the volume of the gaps in a ceramic matrix composite component” (Remarks at p. 7). However, claim 10 does not require that hafnium oxide occupy more than 30% of the volume of the gaps. As currently worded following the latest amendment, claim 10 requires that the filler particles occupy more than 30% of the volume of the gaps, and those filler particles comprise hafnium oxide but need not consist wholly or even mostly of hafnium oxide.
With regard specifically to claim 22, Applicant argues that “Bortoluzzi does not disclose or recognize any relationship between fiber diameter and filler particle diameter, nor does it teach selecting fiber and particle sizes in relation to one another” (Remarks at p. 7). However, Bortoluzzi does teach fiber diameter ranges and filler particle diameter ranges which enable fiber-diameter-to-filler-particle-diameter ratios that fall within the broad range recited in claim 22, and that is all that is required. One of ordinary skill in the art, guided by the teachings of Bortoluzzi, would have found it obvious to select a fiber diameter and a filler particle diameter that would lead to a ratio within the claimed range.
Applicant’s arguments with regard to claims 12 and 21 have been considered but are not persuasive. Applicant asserts that neither Jackson nor Zheng nor Hockemeyer cure the alleged “deficiencies” that Applicant has asserted exist in the rejection of claim 10 under Nixon in view of Bortoluzzi and Kozak. Applicant’s arguments against the ejection of claim 10 under Nixon in view of Bortoluzzi and Kozak have been addressed above, and nothing in Applicant’s brief discussion of claims 12 and 21 alters that analysis or requires further rebuttal.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
U.S. Pat. Pub. 2021/0130215 to Cabodi et al. (“Cabodi”) discloses an insulated tuckstone that includes an insulating layer (Abstract); Cabodi teaches that, in a “particularly advantageous embodiment,” the insulating layer is a ceramic matrix composite (CMC) (¶ 0027). Cabodi teaches wherein the CMC includes “inevitable impurities of hafnium oxide, this oxide always being naturally present in zirconia sources at mass contents generally less than 5%, generally less than 2%” (¶ 0086).
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/P.A.F./Examiner, Art Unit 1731
/JENNIFER A SMITH/Primary Patent Examiner, Art Unit 1731
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