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
Applicant’s amendment filed on 13 August 2025 has been entered. Claims 1, 12, and 19 are amended. Claims 18 and 20 have been canceled. Claims 21 and 22 are added. Claims 1-17, 19, 21, and 22 are pending.
Applicant's arguments with respect to the rejection(s) of Claims 1, 2, 4-12, and 15-20 rejected under 35 U.S.C. 103 as being unpatentable over Shi et al. (US 20160160660) in view of Huang et al. (US 20120171039) have been fully considered but they are not persuasive.
Applicant has contended that the Shi in view of Huang does not teach “the seal located between, and spacing-apart, the silicon-based coating and the non-reactive coating” of amended claim 1 since the alleged coating 126 of Huang is a bondcoat ([0028]) to facilitate bonding of the layer 128 to the CMC. Applicant further contended if Huang's layers 126 and 128 were to be incorporated into Shi, there would be no reason to have the seal located between, and spacing-apart, the layers 126 and 128. Rather, both layers 126 and 128 would be located on the CMC 12 of Shi, because 1) that is what Huang teaches and 2) if the layer 128 was spaced-apart from the CMC (and thus not bonded to the CMC) the bondcoat layer 126 would be unnecessary.
The Examiner does not agree. The seal 16 of Shi may be made of the same material as the coating 126 of Huang (see Shi para. 0026-0027 and Huang para. 0028), i.e. silicon or silicon carbide. Therefore, the non-reactive coating 128 of Huang would be capable of being bonded to the seal of Shi. A person of ordinary skill in the art applying the combination of Shi and Huang would have to choose where to place the seal 16 of Shi. As there are only a small number of possible arrangements, it would have been possible for one of ordinary skill in the art to select placing the seal between the silicon and non-reactive coatings. Furthermore, selecting such an arrangement amounts to mere rearrangement of parts.
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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 1, 2, 4-12, and 15-17, 19, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Shi et al. (hereafter Shi – US 20160160660) in view of Huang et al. (hereafter Huang – US 20120171039).
Claim 1 recites “a section of a gas turbine engine.” Shi teaches such a section of a gas turbine engine, as will be shown.
Shi teaches (Figs. 1-4) a section of a gas turbine engine, comprising: a ceramic component 12; a metallic component 14; a seal 16 situated between the metallic component and the ceramic component at a sealing interface (para. 0022).
However, Shi does not teach a silicon-based coating disposed on the ceramic component at the sealing interface; and a non-reactive coating disposed on the metallic component at the sealing interface, the seal located between, and spacing-apart, the silicon based coating and the non-reactive coating the non- reactive coating providing thermochemical protection against interaction between the ceramic component, the silicon-based coating, and the metallic component.
Huang teaches (Fig. 5) a section of a gas turbine engine, comprising: a ceramic component 122; a metallic component 124, a silicon-based coating 126 disposed on the ceramic component; and a non-reactive coating 128 disposed on the metallic component, the non-reactive coating providing thermochemical protection against interaction between the ceramic component, the silicon-based coating, and the metallic component (para. 0032).
Huang further teaches the silicon coating serves as a bond coating and the non-reactive coating facilitates preventing a transfer of free silicon from CMC substrate material 122 to the nickel-based alloy (para. 0032).
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Huang to the section of a gas turbine engine of Shi to have a silicon-based coating disposed on the ceramic component at the sealing interface; and a non-reactive coating disposed on the metallic component at the sealing interface, the non- reactive coating providing thermochemical protection against interaction between the ceramic component, the silicon-based coating, and the metallic component, as both references and Applicant’s invention are directed to sections of a gas turbine engine. Doing so would result in a preventing a transfer of free silicon to the metallic component, as recognized by Huang.
The seal 16 of Shi may be made of the same material as the coating 126 of Huang (see Shi para. 0026-0027 and Huang para. 0028), i.e. silicon or silicon carbide. Therefore, the non-reactive coating 128 of Huang would be capable of being bonded to the seal of Shi. A person of ordinary skill in the art applying the combination of Shi and Huang would have to choose where to place the seal 16 of Shi. As there are only a small number of possible arrangements, it would have been possible for one of ordinary skill in the art to select placing the seal between the silicon and non-reactive coatings
Regarding Claim 2, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1, wherein at least one of the silicon-based coating and the non-reactive coating are machinable by at least one of grinding, ultrasonic machining, water guided laser, and milling (the non-reactive coating would be capable of being machinable).
Regarding Claim 4, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1, wherein the silicon-based coating includes at least one of rare earth silicates, alkaline earth silicates, alkaline earth aluminosilicates, silicon, silicon oxides, silicon carbides, silicon oxycarbides, barium-magnesium aluminosilicate, mullite, zircon, hafnon, and combinations thereof (para. 0028).
Regarding Claim 5, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 4, wherein the silicon-based coating includes at least one of silicon, silicon oxides or silicon oxycarbides (para. 0028).
Regarding Claim 6, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1, wherein the silicon-based coating is at least 50% atomic weight silicon (para. 0028, elemental silicon).
Regarding Claim 7 Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1, wherein the silicon-based coating has a thickness of between about 20 and about 100 mils (para. 0029).
Regarding Claim 8, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1, wherein the non-reactive coating is zirconia- or hafnia-based (para. 0028).
Regarding Claim 9, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1, wherein the silicon-based coating acts as an environmental barrier (would be capable of this in same way as Applicant’s).
Regarding Claim 10, Shi, as modified with Huang in Claim 1 above, teaches (Shi Figs. 1-4) the section of claim 1, wherein the ceramic component is a ceramic matrix composite component (para. 0023).
Regarding Claim 11, Shi, as modified with Huang in Claim 1 above, teaches (Shi Figs. 1-4) the section of claim 1, wherein the seal is a ceramic matrix composite seal (para. 0026).
Claim 12 recites “method of providing a seal in a gas turbine engine.” Shi teaches such a method, as will be shown.
Shi teaches (Figs. 1-4) a method of providing a seal in a gas turbine engine, comprising:
providing a seal 16 at a sealing interface between a ceramic component 12 and a metallic component 14 (see para. 0022);
However, Shi does not teach disposing a silicon-based coating on the ceramic component at the sealing interface; and disposing a non-reactive coating on the metallic component at the sealing interface, the non-reactive coating providing thermochemical protection against interaction between the ceramic component, the silicon-based coating, and the metallic component.
Huang teaches (Fig. 5) a section of a gas turbine engine, comprising: a ceramic component 122; a metallic component 124, a silicon-based coating 126 disposed on the ceramic component; and a non-reactive coating 128 disposed on the metallic component, the non-reactive coating providing thermochemical protection against interaction between the ceramic component, the silicon-based coating, and the metallic component (para. 0032).
Huang further teaches the silicon coating serves as a bond coating and the non-reactive coating facilitates preventing a transfer of free silicon from CMC substrate material 122 to the nickel-based alloy (para. 0032).
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Huang to the section of a gas turbine engine of Shi to have disposing a silicon-based coating on the ceramic component at the sealing interface; and disposing a non-reactive coating on the metallic component at the sealing interface, the non-reactive coating providing thermochemical protection against interaction between the ceramic component, the silicon-based coating, and the metallic component, as both references and Applicant’s invention are directed to sections of a gas turbine engine. Doing so would result in a preventing a transfer of free silicon to the metallic component, as recognized by Huang.
Regarding Claim 15, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the method of claim 12, wherein the silicon-based coating rare earth silicates, alkaline earth silicates, alkaline earth aluminosilicates, silicon, silicon oxides, silicon carbides, silicon oxycarbides, barium-magnesium aluminosilicate, mullite, hafnon, zircon, and combinations thereof (para. 0028).
Regarding Claim 16, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the method of claim 12, wherein the silicon-based coating is at least 50% atomic weight silicon (para. 0028).
Regarding Claim 17, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the method of claim 12, wherein the non-reactive coating is zirconia- or hafnia-based (para. 0028).
Regarding Claim 19, Shi, as modified with Huang in Claim 1 above, teaches (Shi Figs. 1-4) the method of claim 12, wherein the ceramic component is a ceramic matrix composite component (para. 0023).
Regarding Claim 21, Shi, as modified with Huang in Claim 1 above, teaches (Shi Figs. 1-4) the seal has a first side in contact with, and sealing against, the silicon-based coating, and a second, opposite side in contact with, and sealing against, the non-reactive coating (as described above, it would be obvious to arrive to this arrangement).
Claims 3, 13, 14, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Shi in view of Huang, and further in view of Shoemaker et al. (hereafter Shoemaker – US 20180306063).
Regarding Claim 3, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 1.
However, modified Shi does not teach the silicon-based coating has a surface roughness of less than about 200 Ra.
Shoemaker teaches (Fig. 3) a section comprising a seal 42IS for turbine ceramic component 50S, the component being coated and machined to form a surface with a low roughness compared to the as-formed CMC material, which may have an undesirable surface roughness for sealing (para. 0061).
Shoemaker teaches (para. 0061) the machining the roughness of the coating is based on improved sealing, and therefore the roughness of the coating is a results effective variable dependent on desired sealing. It would have been obvious to a person having ordinary skill in the art to apply the teachings of Shoemaker to optimize the roughness of the coating of modified Shi through routine experimentation for a particular system to arrive at a surface roughness of less than about 200 Ra since the shear stress imparted by the pump is a recognized results effective variable. Doing so would result in improved sealing, as recognized by Shoemaker.
.
Regarding Claim 13, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the method of claim 12.
However, modified Shi does not teach machining at least one of the silicon-based coating and the non-reactive coating by at least one of grinding, ultrasonic machining, water guided laser, and milling, wherein the machining smooths a surface of the silicon-based coating or the non-reactive coating.
Shoemaker teaches (Fig. 3) a method comprising providing a seal 42IS for turbine ceramic component 50S, the component being coated and machined to form a surface with a low roughness compared to the as-formed CMC material, which may have an undesirable surface roughness for sealing (para. 0061).
Shoemaker teaches (para. 0061) the machining the roughness of the coating is based on improved sealing, and therefore the roughness of the coating is a results effective variable dependent on desired sealing. It would have been obvious to a person having ordinary skill in the art to apply the teachings of Shoemaker to machine the roughness of the coating of modified Shi through routine experimentation for a particular system to arrive at a surface roughness of less than about 200 Ra since the shear stress imparted by the pump is a recognized results effective variable. Doing so would result in improved sealing, as recognized by Shoemaker.
Regarding Claim 14, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the method of claim 13, wherein the silicon-based coating has a surface roughness of less than about 200 Ra after the machining (see rejection of Claim 13).
Regarding Claim 21, Shi, as modified with Huang in Claim 1 above, teaches (Huang Fig. 5) the section of claim 21, wherein a surface of the non-reactive coating that is sealed against the seal is smoother than an underlying surface of the metallic component that the non- reactive coating is disposed on (see rejection of Claim 13).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW BUI whose telephone number is (571) 272-0685. The examiner can normally be reached on 7:30 AM - 4:30 PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Courtney Heinle can be reached on (571) 270-3508. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
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/ANDREW THANH BUI/Examiner, Art Unit 3745
/COURTNEY D HEINLE/Supervisory Patent Examiner, Art Unit 3745