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 .
Status of the Claims
Claims 1, 7, 11, and 29-34 are pending and rejected. Claims 8, 9, 13, and 18-20 are withdrawn and claims 2-6, 10, 12, 14-17, and 21-28 are cancelled.
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.
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, 7, 11, and 29-33 are rejected under 35 U.S.C. 103 as being unpatentable over Schlichting, US 2008/0113218 A1 (provided on the PTO-892 of 8/9/2017) in view of Hongoh, US 2012/0034491 A1, Duval, US 2010/0242477 A1 (provided on the PTO-892 of 7/30/2019), and Ogburn, US 7,619,728 B2.
Regarding claim 1, Schlichting teaches a process for coating a component (abstract and 0004), comprising:
applying a bond coat on a substrate of the component (providing the article with an optional bond coat, 0020 and Fig. 1);
applying a thermal barrier coating material comprising yttria stabilized zirconia (YSZ) to the bond coat (applying a ceramic based component as a TBC or thermal barrier coating to the bond coat, 0024 and Fig. 1, where the TBC is YSZ or yttria stabilized zirconia, 0043, claim 30, and claim 52); and
selectively infiltrating a blocking material into the thermal barrier coating material (impregnating at least one inert compound using a solution based process into the pores and interstices of the TBC, 0028, such that the inert compound is considered to be selectively infiltrated into the TBC since it is impregnated into the pores, indicating that the pores are selected for the infiltration and where the inert material is considered a blocking material because it’s properties prevent sand and CMAS from penetrating the TBC and reaching the surface of the coated article, 0039, indicating it blocks such materials from reaching the coated article).
Schlichting further teaches that the inert compound or blocking material is applied using a solution-based process where the suspension comprises a solvent, at least one inert compound, and at least one UV or heat curable resin, at least one dispersant and/or at least one surfactant (0028). They teach that after curing the TBC coated article, the article is dried to remove, i.e. evaporate or burn off the excess solvent, dispersant, and/or resin materials (0030). They teach that the dispersant includes polymers such as PMMA and polyvinyl alcohol (0031). They teach that the inert compound comprises a cubic crystalline structure of formula A3B2X3O12, where A comprises at least one of the metals selected from the group consisting of Ca+2 and Mg+2, B comprises at least one of the metals selected from the group consisting of Al+3, and X comprises at least one of the metals selected from the group consisting of Si+4 (0004), so as to provide a list of materials in which a calcium magnesium alumino silicate compound can be formed. Therefore, the inert compound is considered to be a filler of the blocking material since it is not removed during the heating process and the solvent, resin and/or the dispersant, i.e. PMMA or PVA, are considered to be carriers because they are mixed with the filler and then removed during the heating process. Therefore, the blocking material comprises a filler material and a carrier, where the filler material can be selected to be materials comprising a calcium magnesium alumino silicate (CMAS) compound and the carrier is removed. They teach that the process provides a graded structure in the TBC (0005).
They do not specifically teach that the compound is CMAS.
Hongoh teaches a process for forming a coating system on a turbine engine component that comprise the steps of providing a substrate, depositing a TBC on the substrate, depositing a reactive with known CMAS reaction kinetics on the thermal barrier coating, and activating the reactive layer prior to the component being placed in service (abstract). They teach that the CMAS risk is mitigated and the durability of the thermal barrier coating can be increased by creating an activated reactive layer with known CMAS reaction kinetics on the thermal barrier coating, prior to service (0004). They teach that the component is a turbine engine component that includes a bond coat and a TBC (0010-0012 and Fig. 1-2). They teach that the TBC is a material such as YSZ (0012). They teach that the CMAS resistant layer may be deposited on the TBC, where the layer includes chemically conditioned CMAS material (0014). They teach that create the CMAS layer, a powder mixture is prepared that includes silica, calcium oxide, magnesium oxide, and alumina (0015 and Table 1). They teach that the chemical composition provides a powder mixture, which after thermo-chemical reaction with the thermal barrier coating layer, has a melting temperature significantly higher than the melting temperature of the CMAS encountered in field engine applications (0015). They teach that the top CMAS layer may have graded characteristics from the interface with the TBC for better adherence and strain compatibility (0017). They teach that after deposition, the deposited film of CMAS is subjected to a heat treatment at 2100-200°F for up to 24 hours to form an active reaction layer (0018). They teach that the heat treatment turns the CMAS layer into CMAS glass, which reacts with the layer 16 underneath with a nucleating agent, transition to form globular anorthite phase or to form a cubic garnet type crystal structure, depending on the nucleating agents that are used (0019). They teach that upon contact with the common CMAS in a high temperature environment, the common CMAS with lower melting temperature will not readily dissolve into the reaction layer, and even if it does, it will recrystallize quickly within the reaction layer, which prohibits further CMAS penetration into the TBC (0020). They teach that it protects the TBC from spallation can significantly increase the durability of the turbine engine component and save maintenance costs by reducing and/or eliminating CMAS attacks (0020).
From the teachings of Hongoh, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Schlichting to have selected a CMAS compound as the filler material because Hongoh teaches that such a material is known to protect TBCs against CMAS encountered in field engine applications after a heat treatment due to a thermo-chemical reaction such that it will be expected to provide a desirable compound for protecting the TBC.
They do not teach removing the carrier of the blocking material via a heat treat process during initial gas turbine engine operations or that the component is specifically for a gas turbine engine.
Hongoh teaches performing a heat treatment at 2100-2200°F (0018). They teach that the turbine engine component may be a combustor panel or a turbine blade (0010). They teach that the durability of TBC systems in gas turbine engines is limited due to CMAS (0002), where the process is directed to mitigating CMAS (0004), suggesting that the part is for a gas turbine engine.
Schlichting further teaches that after curing the TBC coated article, the article may be dried to remove, i.e. evaporate or burn off, the excess solvent, dispersant, and/or resin materials where the drying may be done at a temperature of about 750°F to about 1600°F (0030). They also teach that to facilitate the formation of the respective crystalline structures of the inert compound the coated article may be heat treated at a temperature of about 1200°F to about 2000°F for about 30 minutes to about 350 minutes (0034).They teach that the article may include blades, vanes, stators, mid-turbine frames, fuel nozzles and the like and that the articles include those having an airfoil (0040-0042).
Duval teaches a method for the application of a protection for a thermal barrier coating system of a heat engine having a thermal barrier coating system that includes a bond coat layer and a thermal barrier coating layer having a porous structure (abstract). They teach that a substance is applied inside the engine as a liquid or carried by a liquid by spraying and/or by flowing it across a hot gas exposed surface of the barrier coating layer so that the substance covers and/or at least partly penetrates into the porous structure (abstract and Fig. 1). They teach that the invention relates to protection of thermal barrier coating systems and base metal parts of gas turbines and other heat engines (0003, 0017, and 0018), indicating that the thermal barrier coating system is applied to components of a gas turbine engine. They teach that the thermal barrier coating is applied to a base metal, e.g. the turbine blade base material, where turbine blades are protected (0032 and 0085), indicating that turbine blades used in gas turbine engines are provided with TBC coatings including a bond layer and a thermal barrier layer. They teach applying a barrier, such as a physical and/or chemical barrier onto the thermal barrier coating and/or at least partially within the porosity of the TBC (0017). They teach that the substance, which can be a sealing substance, a reactive substance, or a combination thereof, applied onto the TBC is a liquid or carried by a liquid that penetrates into the pores of the TBC (0020-0021).They teach that the sealing and reactive substances are hardened under the influence of exposure to air, heat, irradiation, hardening agents or a combination thereof (0065). They teach that the substances are in a form of a sol-gel, slurry, emulsion, dispersion, solution of polymeric/oligomeric/monomeric based materials, or a mixture thereof, where a carrier liquid for the substance can be an aqueous solvent, organic solvent, in particular ethanol, acetone, or mixtures thereof (0066). Duval teaches that the sealing and reactive substances can be hardened during the initial stages of the restart of the thermal engine when the temperature is increasing, and/or normally final hardening takes place within the first few hours of normal operation at operation temperature (0065), indicating that the liquid in the substance is either removed or hardened during initial operation of the engine. They teach applying the substance to the thermal barrier coating layer either prior to the initial start-up of the engine, and/or during washing cycle and/or before a next subsequent operation interval of the heat engine (0020). They teach that the use of heat for the hardening is particularly advantageous and easily possible in the present context when the method is applied to thermal barrier coating systems being arranged within heat engines, as for hardening the available heat of the engine can be used when the thermal engine starts up after the washing cycle or when starting a new operation interval (0094). They teach that engines normally have operation intervals of more than 24000 hours (0022). They also teach that the method includes the establishment and/or renewal of a protection onto a thermal barrier coating system (0018), indicating that the process is not only directed towards repair parts. Therefore, they teach applying the substance and removing the liquid or hardening the liquid during initial operation of the engine.
Ogburn teaches that a gas turbine typically operates at an internal temperature of about 2192°F (Col. 1, lines 25-40).
From the teachings of Hongoh and Duval, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention that the component of Schlichting is to be used in a gas turbine engine because Schlichting teaches that the article may comprise a part used in turbomachinery such as airfoils, blades, vanes, stators, mid-turbine frames, combustor panels, fuel nozzles guides, where the coating is directed to protecting from CMAS, Hongoh teaches that turbine blades are parts of a gas turbine engine component which needs protection from CMAS, and Duval teaches using TBCs for gas turbine engine parts such as blades, indicating that the articles of Schlichting are used in gas turbine engines. Further, from the teachings of Duval and Ogburn, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Schlichting in view of Hongoh to have removed the carrier via a heat treat process during gas turbine engine initial operations because Duval teaches that a liquid substance can be hardened during initial operation of the thermal engine, where operation intervals are more than 24000 hours, Ogburn teaches that gas turbines have an internal operating temperature of about 2192°F, where Hongoh teaches heating from 2100-2200°F and Schlichting teaches performing a heat treatment in a range of 1200-2000°F for 30-360 minutes for removing the carrier and facilitating the formation of the desired crystalline structure such that the process will reach a desired temperature for the thermo-mechanical reaction and a temperature greater than that needed for resin removal and crystallization such that it will be expected to desirably remove the carrier and carry out the reaction between the CMAS and the TBC. Further, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have also provided the process when forming the coatings on new parts and not only on repair parts because Schlichting is directed to coating an article with the protective coating and not to repair coatings such that by providing the coating system to a new part and heating to remove the carrier in a green run of the gas turbine engine initial operations it will also be expected to provide the protective coating as desired to a new part.
As to forming silicate phases, Schlichting teaches that the heat treatment facilitates the formation of the crystalline structures of the inert compound when heated to a temperature in the range of about 1200°F to about 2000°F (0034). They teach that the inert compound of formula (I) may comprise garnet (0038). They teach that the garnet material alone or in combination with the TBC coatings may react with the CMAS to provide a reaction product (0043). They teach that a garnet layered or combined with a TBC such as 7YSZ may react with CMAS to form a reaction product comprising at least a complex oxide compound with the garnet crystalline structure and coexist with silicate oxyapatites (0043). They teach that the reaction product or products form throughout the entirety of the garnet alone or in combination with the TBC to provide a reaction barrier or sealant composition as a layer upon the TBC or throughout the TBC (0044-0045). Therefore, since Schlichting teaches that the YSZ TBC reacts with CMAS to form a reaction product, and the filler material is suggested to be a CMAS material, where Hongoh indicates that the CMAS coat undergoes a thermo-chemical reaction with the TBC, the process is also expected to provide at least some reaction of the materials to provide a rare-earth silicate phase as claimed. Further, since Schlichting in view of Hongoh, Duval, and Ogburn provide the claimed process, where the TBC is YSZ and the filler is CMAS and the heat treatment is done during initial gas turbine engine operations, the resulting process is also expected to result in the formation of high temperature rare-earth silicate plates or phases. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”. Therefore, when heating the CMAS material during the initial gas turbine engine operations, it is also expected to effectuate the reaction of the materials to form high temperature rare-earth silicate plates or phases because it will result in the formation of the crystalline CMAS phases while in contact with the YSZ TBC.
As to the infiltration forming a multi-phase material layer coating system, Schlichting teaches that the TBC is formed from YSZ and the inert compound is suggested to be a calcium magnesium alumino silicate-based compound, i.e. a compound containing calcium, magnesium, aluminum, and silicate. Therefore, since they provide the process of claim 1, using the claimed materials, and heating during initial operations of the gas turbine engine, the resulting infiltration is also expected to result in forming a multi-phase material layer coating system. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Alternatively, Schlichting also teaches that the inert material may also comprise an inert compound of formula A4B6X6O26 (formula II), where A comprises at least one of the metals selected from the group consisting of rare-earth elements such as Gd+3, La+2, Ce+2--, etc., B comprises at least one of the metals selected from the group consisting of rare-earth elements such as Gd+3, Sc+2, Y+2, etc., and X comprises at least one of the metals selected from the group consisting of Si+4 (0037), such that another inert compound comprising rare-earth silicates can be included along with the CMAS base compound. Schlichting teaches that the at least one inert compound of formula I may comprise garnet and the component of formula II may comprise oxyapatite, where formula II comprises rare-earth metals (0036-0038), such that a mixture of garnet and oxyapatite phases will be provided.
As to forming a multi-phase pre-reacted surficial region, Duval further teaches that not the whole thickness of the thermal barrier coating layer is infiltrated by the sealing substance, but rather only a surficial section or partial layer thereof is infiltrated (0088 and Fig. 1). They teach that it is preferably to have a thin layer of infiltration thickness, T, in order to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance (0095).
From this, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have infiltrated the coating or blocking material into only a surficial region of the pores of the TBC and not throughout the thickness of the TBC because Duval teaches that it is preferably to only infiltrate a sealing substance to a surficial section of a sealing and/or reactive material to provide a thin layer to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance such that it will be expected to successfully protect the underlying TBC while also minimizing the negative effects. Therefore, in the process of Schlichting in view of Hongoh, Duval, and Ogburn, the inert material will be infiltrated so that it is in the upper portion of the TBC, i.e. a surficial region, where Schlichting teaches that the inert compound provides a coating layer (0040 and Fig. 3), such that the multi-phase material layer coating system will form a multi-phase surficial region. While Schlichting in view of Hongoh, Duval, and Ogburn do not teach that the multiphase system is pre-reacted, since they provide the process of claim 1 including using CMAS filler and the YSZ TBC, the resulting process is also expected to provide a pre-reacted surficial region. Further, Hongoh teaches that a reaction occurs between the CMAS layer and the TBC (0015), suggesting that CMAS will be pre-reacted with the TBC prior to encountering common CMAS during operation. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”. Schlichting also teaches that the coating broadly comprises a reaction product of at least one silicate-based material and a thermal barrier coating composition broadly comprising a ceramic based compound; and at least one inert compound (0008), indicating that the multi-phase material, i.e. coating material, will provide a reacted surficial region in that it will react with the TBC material, i.e., YSZ.
Regarding claim 7, Schlichting in view of Hongoh, Duval, and Ogburn suggests the limitations of instant claim 1.
Schlichting further teaches that the coating or blocking material is applied using techniques such as contacting the component with a solution using methods such as sol gel and slurry through dipping, brushing, painting, etc. (0028).
Hongoh teaches applying the CMAS resistant layer using a solution-precursor plasma spray (SPPS) that uses a solution atomizer for application (0016).
From the teachings of Hongoh and Schlichting, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have SPPS to have applied the coating or blocking material because Hongoh teaches that such a process is suitable for applying a solution containing powdered material, and Schlichting teaches applying a solution for impregnating the TBC such that it will be expected to provide a suitable method of solution application of the materials for infiltration/impregnation.
Regarding claim 11, Schlichting in view of Hongoh, Duval, and Ogburn suggests the limitations of instant claim 1. Schlichting further teaches that the inert compound or blocking material is applied using a solution-based process where the suspension comprises a solvent, at least one inert compound, and at least one UV or heat curable resin, at least one dispersant and/or at least one surfactant (0028). They teach that after curing the TBC coated article, the article is dried to remove, i.e. evaporate or burn off the excess solvent, dispersant, and/or resin materials (0030). They teach that the dispersant includes polymers such as PMMA and polyvinyl alcohol (0031). They teach that the inert compound comprises a cubic crystalline structure of formula A3B2X3O12, where A comprises at least one of the metals selected from the group consisting of Ca+2 and Mg+2, B comprises at least one of the metals selected from the group consisting of Al+3, and X comprises at least one of the metals selected from the group consisting of Si+4 (0004). Therefore, the inert compound is considered to be a filler of the blocking material since it is not removed during the heating process and the resin and/or the dispersant, i.e. PMMA or PVA, are considered to be sacrificial polymers because they are removed or sacrificed during the heating process.
Regarding claim 29, Schlichting in view of Hongoh, Duval, and Ogburn suggest the limitations of instant claim 1. Schlichting further teaches that the garnet and/or oxyapatite materials react with the CMAS and/or other components of the molten sand (0043). They teach that the inert compound forms a protective layer on the ceramic layer, i.e. TBC (abstract and 0024). They teach that the inert properties, hardness of garnet and oxyapatite, and resultant porosity values are enough to prevent the sand and CMAS from penetrating the TBC of the invention (0039).
Hongoh teaches that the process mitigates CMAS risk (0004). They teach that the CMAS layer protects the thermal barrier coating from spallation by preventing common CMAS from dissolving into the reaction layer and prohibiting further penetration into the layer (0020).
Therefore, the surface region of the coating of Schlichting in view of Hongoh, Duval, and Ogburn is considered to mitigate damage to the TBC by CMAS.
Further, since Schlichting in view of Hongoh, Duval, and Ogburn provide the process of claim 1, including the materials of the TBC and the filler, the resulting multi-phase pre-reacted surficial region is also expected to mitigate damage to the TBC material by CMAS. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 30, Schlichting in view of Hongoh, Duval, and Ogburn suggest the limitations of instant claim 1. As discussed above for claim 1, the inert compound is suggested to be CMAS. Schlichting also teaches that the inert material may also comprise an inert compound of formula A4B6X6O26 (formula II), where A comprises at least one of the metals selected from the group consisting of rare-earth elements such as Gd+3, La+2, Ce+2--, etc., B comprises at least one of the metals selected from the group consisting of rare-earth elements such as Gd+3, Sc+2, Y+2, etc., and X comprises at least one of the metals selected from the group consisting of Si+4 (0037), such that another inert compound comprising rare-earth silicates can be included along with the CMAS base compound. Schlichting teaches that the at least one inert compound of formula I may comprise garnet and the component of formula II may comprise oxyapatite, where formula II comprises rare-earth metals (0036-0038), such that a mixture of garnet and oxyapatite phases will be provided. They teach that the resultant layer of the at least one inert compound may have a porosity of no more than about 20% by volume (0039), such that the resulting layer will provide a pre-sealed structure since the porosity range will include one in which the porosity is 0% by volume to provide a sealed layer. Further, the resulting layer is formed in the process of removing the carrier (0030), such that the carrier is removed to provide a second phase, i.e., garnet and/or oxyapatite phase, where the first phase is provided by the ceramic TBC coating, which alters the TBC coating material with a pre-sealed structure.
Hongoh also teaches that common CMAS will not readily dissolve into the CMAS reaction layer, and if it does, it recrystallizes quickly, prohibiting further CMAS penetration into the TBC (0020), indicating that the layer will seal the TBC.
Further, since Schlichting in view of Hongoh, Duval, and Ogburn provide the process of claim 1, including the materials of the TBC and the filler, a second phase that alters the TBC material with a pre-sealed structure is also expected to occur when the carrier is removed. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 31, Schlichting in view of Hongoh, Duval, and Ogburn suggest the process of claim 1. As discussed above for claim 30, Schlichting teaches that the layer of the at least one inert compound may have a porosity of no more than about 20% by volume (0039), such that the layer will provide a pre-sealed structure since the porosity range will include one in which the porosity is 0% by volume to provide a sealed layer. Further, the resulting layer is formed in the process of removing the carrier (0030), such that the carrier is removed to provide a sealed TBC. They also teach that the coated articles have a seal or a coated seal of the coating of the invention (0042), further indicating that the coating material will form a seal.
As to sealing with a rare earth apatite composition, Schlichting teaches that the heat treatment facilitates the formation of the crystalline structures of the inert compound when heated to a temperature in the range of about 1200°F to about 2000°F (0034). They teach that the inert compound of formula (I) may comprise garnet (0038). They teach that the at least one inert compound may also comprise a mixture of the inert compound of formula (I) and the inert compound of formula (II), where the inert compound of formula (II) may comprise oxyapatite (0038). They teach that the compound of Formula (II) includes rare earth elements (0004). They teach that the garnet and/or oxyapatite material alone or in combination with the TBC coatings may react with the CMAS to provide a reaction product (0043). They teach that a garnet and/or oxyapatite layered or combined with a TBC such as 7YSZ may react with CMAS to form a reaction product comprising at least a complex oxide compound with the garnet crystalline structure and coexist with silicate oxyapatites (0043). They teach that the reaction product or products form throughout the entirety of the garnet and/or oxyapatite alone or in combination with the TBC to provide a reaction barrier or sealant composition as a layer upon the TBC or throughout the TBC (0044-0045). Therefore, since Schlichting teaches that the YSZ TBC reacts with CMAS to form a reaction product, and the filler material is suggested to be a CMAS material, where the coating can include an oxyapatite, the process is also expected to provide at least some reaction of the materials to provide a rare-earth oxyapatite or apatite phase as claimed (where the rare earth can be included from the reaction with the YSZ TBC).
Further, since Schlichting in view of Hongoh, Duval, and Ogburn provide the claimed process, where the TBC is YSZ and the filler is CMAS and the heat treatment is done during initial gas turbine engine operations, and Schlichting indicates that the coating provides a sealed structure so as to pre-seal the TBC, the resulting process of removing the carrier is expected to result in pre-sealing the TBC with a rare earth apatite composition. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claims 32 and 33, Schlichting in view of Hongoh, Duval, and Ogburn suggest the process of claim 1, where, as discussed above for claim 1, Duval suggests forming a surficial region with the coating and not to infiltrate the entire thickness of the TBC. As discussed above for claims 30 and 31, the removal of the carrier is also expected to result in sealing the TBC with a rare earth apatite composition. Therefore, when removing the carrier it will produce and upper layer of the TBC which comprises the TBC material sealed with a ceramic composition, i.e., the CMAS coating material that alone or in combination with an inert compound of formula II provides a rare earth oxyapatite or apatite composition as discussed above for claim 31.
Claim 34 is rejected under 35 U.S.C. 103 as being unpatentable over Schlichting in view of Hongoh, Duval, and Ogburn as applied to claim 32 above, and further in view of Rigney, US 2005/0106315 A1 (provided on the PTO-892 of 7/30/2019).
Regarding claim 34, Schlichting in view of Hongoh, Duval, and Ogburn suggests the limitations of instant claim 32. Schlichting further teaches that the coating has a thickness of about 0.25 mils to about 15 mils in thickness, or 6.35 to 381 microns, where the thickness range may be broadened or narrowed depending on the particular application of the article (0042).
They do not teach the infiltration depth of the blocking material into the thermal barrier coating material.
Rigney teaches a repaired component comprising an engine run component having a base metal substrate and a bond coat (abstract). They teach that the method is applicable to components that operate within high temperature environments such as high- and low-pressure turbine nozzles and blades, shrouds, combustor liners and augmentor hardware of gas turbine engines, where other examples include airfoils and vanes (0015). They teach that a ceramic thermal barrier coating may be applied over the bond coat, where the thermal barrier coating layer is a ceramic thermal barrier coating (0024). They teach that the ceramic thermal barrier coating may have a thickness of between about 3 mils and about 10 mils, more typically on the order of about 5 mils (0024).
From the teachings of Rigney, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claim invention to have formed the TBC to have a thickness of about 5 mils or between about 3 to 10 mils because Rigney teaches that TBCs typically have such a thickness such that it will provide the desired and predictable result of forming a TBC to a thickness sufficient for insulating the component of the gas turbine engine.
As discussed above for claim 1, Duval teaches that not the whole thickness of the thermal barrier coating layer is infiltrated by the sealing substance, but rather only a surficial section or partial layer thereof is infiltrated (0088 and Fig. 1). They teach that the thickness of the infiltrated layer section is typically in the range of less than 30% of the total thickness of the thermal barrier coating layer (0088). They teach that preferably the thickness T of the infiltrated layer section is in the range of 1/4 to 1/3, in particular between 1/5 and 1/3 of the thickness of the thermal barrier coating (0095 and Fig. 1). They teach that it is preferable to have thin layer T in order to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance (0095).
From the teachings of Duval and Rigney, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Schlichting in view of Hongoh, Duval, Ogburn, and Rigney to have infiltrated the coating or blocking material into the pores of the TBC to a depth range of less than 30% of the total thickness of the thermal barrier coating layer as indicated by Duval because Duval teaches that such depths are desirable, that it is preferable to have thin layer T in order to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance, that the layer is used to protect the thermal barrier coating, where the layer is a sealing and/or reactive material (where the material of Schlichting is reactive to provide a sealing layer) and that the substrate is a turbine for a gas turbine engine such that it will provide the desired and predictable result of infiltrating the pores to a depth that will successfully protect the underlying TBC while also minimizing negative effects. Therefore, Schlichting in view of Duval, Biondo, and Rigney suggest infiltrating the coating material to a depth of less than 38.1 microns for a TBC having a thickness or 5 mils (127 microns) or less than a range of 22.86-76.2 microns (from a range of 3-10 mils or 76.2-254 microns) since Rigney suggests forming the TBC to have a thickness of about 5 mils (about 127 microns) or 3-10 mils (76.2-254 microns) and Duval suggests infiltrating the pores to a depth of less than 30% of the thickness of the TBC layer, indicating that the material will not infiltrate through the entirety of the TBC and it will infiltrate to a depth range overlapping the claimed range. Therefore, the range suggested by Schlichting in view of Duval, Biondo, and Rigney overlaps the range of instant claim 34 for a depth of less than 30% of the TBC. According to MPEP 2144.05, “in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.” In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976).
Claims 1, 7, 11, and 29-33 are rejected under 35 U.S.C. 103 as being unpatentable over Hongoh, US 2012/0034491 A1 in view of Schlichting, US 2008/0113218 A1 (provided on the PTO-892 of 8/9/2017), Duval, US 2010/0242477 A1 (provided on the PTO-892 of 7/30/2019), and Ogburn, US 7,619,728 B2.
Regarding claim 1, Hongoh teaches a process for forming a coating system on a turbine engine component that comprise the steps of providing a substrate, depositing a TBC on the substrate, depositing a reactive with known CMAS reaction kinetics on the thermal barrier coating, and activating the reactive layer prior to the component being placed in service (abstract). They teach that the CMAS risk is mitigated and the durability of the thermal barrier coating can be increased by creating an activated reactive layer with known CMAS reaction kinetics on the thermal barrier coating, prior to service (0004). They teach that the component is a turbine engine component that includes a bond coat and a TBC (0010-0012 and Fig. 1-2). They teach that the TBC is a material such as YSZ (0012). They teach that the CMAS resistant layer may be deposited on the TBC, where the layer includes chemically conditioned CMAS material (0014). They teach that to create the CMAS layer, a powder mixture is prepared that includes silica, calcium oxide, magnesium oxide, and alumina (0015 and Table 1). They teach that the chemical composition provides a powder mixture, which after thermo-chemical reaction with the thermal barrier coating layer, has a melting temperature significantly higher than the melting temperature of the CMAS encountered in field engine applications (0015). They teach that the top CMAS layer may have graded characteristics from the interface with the TBC for better adherence and strain compatibility (0017). They teach that after deposition, the deposited film of CMAS is subjected to a heat treatment at 2100-200°F for up to 24 hours to form an active reaction layer (0018). They teach that the heat treatment turns the CMAS layer into CMAS glass, which reacts with the layer 16 underneath with a nucleating agent, to transition to form globular anorthite phase or to form a cubic garnet type crystal structure, depending on the nucleating agents that are used (0019). They teach that upon contact with the common CMAS in a high temperature environment, the common CMAS with lower melting temperature will not readily dissolve into the reaction layer, and even if it does, it will recrystallize quickly within the reaction layer, which prohibits further CMAS penetration into the TBC (0020). They teach that it protects the TBC from spallation and can significantly increase the durability of the turbine engine component and save maintenance costs by reducing and/or eliminating CMAS attacks (0020). They teach that the durability of the TBC used in gas turbine engines is limited by CMAS deposits (0002), such that the turbine component is understood to be for a gas turbine component since it is directed towards mitigating CMAS which is a problem in gas turbines.
They do not teach selectively infiltrating the TBC using the claimed process.
Schlichting teaches a process for coating a component (abstract and 0004), comprising:
applying a bond coat on a substrate of the component (providing the article with an optional bond coat, 0020 and Fig. 1);
applying a thermal barrier coating material comprising yttria stabilized zirconia (YSZ) to the bond coat (applying a ceramic based component as a TBC or thermal barrier coating to the bond coat, 0024 and Fig. 1, where the TBC is YSZ or yttria stabilized zirconia, 0043, claim 30, and claim 52); and
selectively infiltrating a blocking material into the thermal barrier coating material (impregnating at least one inert compound using a solution based process into the pores and interstices of the TBC, 0028, such that the inert compound is considered to be selectively infiltrated into the TBC since it is impregnated into the pores, indicating that the pores are selected for the infiltration and where the inert material is considered a blocking material because it’s properties prevent sand and CMAS from penetrating the TBC and reaching the surface of the coated article, 0039, indicating it blocks such materials from reaching the coated article).
Schlichting further teaches that the inert compound or blocking material is applied using a solution-based process where the suspension comprises a solvent, at least one inert compound, and at least one UV or heat curable resin, at least one dispersant and/or at least one surfactant (0028). They teach that after curing the TBC coated article, the article is dried to remove, i.e. evaporate or burn off the excess solvent, dispersant, and/or resin materials (0030). They teach that the dispersant includes polymers such as PMMA and polyvinyl alcohol (0031). They teach that the inert compound comprises a cubic crystalline structure of formula A3B2X3O12, where A comprises at least one of the metals selected from the group consisting of Ca+2 and Mg+2, B comprises at least one of the metals selected from the group consisting of Al+3, and X comprises at least one of the metals selected from the group consisting of Si+4 (0004), so as to provide a list of materials which can include calcium magnesium alumino silicate compound. Therefore, the inert compound is considered to be a filler of the blocking material since it is not removed during the heating process and the solvent, resin and/or the dispersant, i.e. PMMA or PVA, are considered to be carriers because they are mixed with the filler and then removed during the heating process. Therefore, the blocking material comprises a filler material and a carrier, where the filler material can be selected to be materials comprising a calcium magnesium alumino silicate (CMAS) compound and the carrier is removed. They teach that the process provides a graded structure in the TBC (0005).
From the teachings of Schlichting, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Hongoh to have formed the CMAS layer by selectively infiltrating a blocking material comprising the CMAS compound and a resin and then to have removed the resin or carrier by a heat treatment because Schlichting teaches that such a process is suitable for forming a CMAS-resistant layer in a TBC having a graded structure such that it will be expected to provide the protective layer as desired. Therefore, the component of a gas turbine engine will be formed by applying a bond coat on a substrate of the component, applying a TBC comprising YSZ to the bond coat, and selectively infiltrating a blocking material into the TBC, the blocking material comprising a filler material and a carrier, wherein the filler material is a CMAS compound, and removing the carrier.
They do not teach removing the carrier of the blocking material via a heat treat process during initial gas turbine engine operations or that the component is specifically for a gas turbine engine.
Hongoh teaches performing a heat treatment at 2100-2200°F (0018). They teach that the turbine engine component may be a combustor panel or a turbine blade (0010).
Schlichting further teaches that after curing the TBC coated article, the article may be dried to remove, i.e. evaporate or burn off, the excess solvent, dispersant, and/or resin materials where the drying may be done at a temperature of about 750°F to about 1600°F (0030). They also teach that to facilitate the formation of the respective crystalline structures of the inert compound the coated article may be heat treated at a temperature of about 1200°F to about 2000°F for about 30 minutes to about 350 minutes (0034).They teach that the article may include blades, vanes, stators, mid-turbine frames, fuel nozzles and the like and that the articles include those having an airfoil (0040-0042).
Duval teaches a method for the application of a protection for a thermal barrier coating system of a heat engine having a thermal barrier coating system that includes a bond coat layer and a thermal barrier coating layer having a porous structure (abstract). They teach that a substance is applied inside the engine as a liquid or carried by a liquid by spraying and/or by flowing it across a hot gas exposed surface of the barrier coating layer so that the substance covers and/or at least partly penetrates into the porous structure (abstract and Fig. 1). They teach that the invention relates to protection of thermal barrier coating systems and base metal parts of gas turbines and other heat engines (0003, 0017, and 0018), indicating that the thermal barrier coating system is applied to components of a gas turbine engine. They teach that the thermal barrier coating is applied to a base metal, e.g. the turbine blade base material, where turbine blades are protected (0032 and 0085), indicating that turbine blades used in gas turbine engines are provided with TBC coatings including a bond layer and a thermal barrier layer. They teach applying a barrier, such as a physical and/or chemical barrier onto the thermal barrier coating and/or at least partially within the porosity of the TBC (0017). They teach that the substance, which can be a sealing substance, a reactive substance, or a combination thereof, applied onto the TBC is a liquid or carried by a liquid that penetrates into the pores of the TBC (0020-0021).They teach that the sealing and reactive substances are hardened under the influence of exposure to air, heat, irradiation, hardening agents or a combination thereof (0065). They teach that the substances are in a form of a sol-gel, slurry, emulsion, dispersion, solution of polymeric/oligomeric/monomeric based materials, or a mixture thereof, where a carrier liquid for the substance can be an aqueous solvent, organic solvent, in particular ethanol, acetone, or mixtures thereof (0066). Duval teaches that the sealing and reactive substances can be hardened during the initial stages of the restart of the thermal engine when the temperature is increasing, and/or normally final hardening takes place within the first few hours of normal operation at operation temperature (0065), indicating that the liquid in the substance is either removed or hardened during initial operation of the engine. They teach applying the substance to the thermal barrier coating layer either prior to the initial start-up of the engine, and/or during washing cycle and/or before a next subsequent operation interval of the heat engine (0020). They teach that the use of heat for the hardening is particularly advantageous and easily possible in the present context when the method is applied to thermal barrier coating systems being arranged within heat engines, as for hardening the available heat of the engine can be used when the thermal engine starts up after the washing cycle or when starting a new operation interval (0094). They teach that engines normally have operation intervals of more than 24000 hours (0022). They also teach that the method includes the establishment and/or renewal of a protection onto a thermal barrier coating system (0018), indicating that the process is not only directed towards repair parts. Therefore, they teach applying the substance and removing the liquid or hardening the liquid during initial operation of the engine.
Ogburn teaches that a gas turbine typically operates at an internal temperature of about 2192°F (Col. 1, lines 25-40).
From the teachings of Duval and Ogburn, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Schlichting in view of Hongoh to have removed the carrier via a heat treat process during gas turbine engine initial operations because Duval teaches that a liquid substance can be hardened during initial operation of the thermal engine, where operation intervals are more than 24000 hours, Ogburn teaches that gas turbines have an internal operating temperature of about 2192°F, where Hongoh teaches heating from 2100-2200°F and Schlichting teaches performing a heat treatment in a range of 1200-2000°F for 30-360 minutes for removing the carrier and facilitating the formation of the desired crystalline structure such that the process will reach a desired temperature for the thermo-mechanical reaction and a temperature greater than that needed for resin removal such that it will be expected to desirably remove the carrier and carry out the reaction between the CMAS and the TBC. Further, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have also provided the process when forming the coatings on new parts and not only on repair parts because Schlichting is directed to coating an article with the protective coating and not to repair coatings such that by providing the coating system to a new part and heating to remove the carrier in a green run of the gas turbine engine initial operations it will also be expected to provide the protective coating as desired to a new part.
As to forming silicate phases, Hongoh teaches that the reactive layer formed from heat treatment turns the CMAS layer into CMAS glass which reacts with the TBC underneath with nucleating agent resulting in the formation of globular anorthite phase or a cubic garnet type crystal structure (0019).
Schlichting teaches that the inert compound of formula (I) may comprise garnet (0038). They teach that the garnet material alone or in combination with the TBC coatings may react with the CMAS to provide a reaction product (0043). They teach that a garnet layered or combined with a TBC such as 7YSZ may react with CMAS to form a reaction product comprising at least a complex oxide compound with the garnet crystalline structure and coexist with silicate oxyapatites (0043). They teach that the reaction product or products form throughout the entirety of the garnet alone or in combination with the TBC to provide a reaction barrier or sealant composition as a layer upon the TBC or throughout the TBC (0044-0045).
Therefore, since Schlichting teaches that the YSZ TBC reacts with CMAS to form a reaction product, the TBC of Hongoh is YSZ, and the filler material is a CMAS material, the process is also expected to provide at least some reaction of the materials to provide a rare-earth silicate phase as claimed. Further, since Hongoh in view of Schlichting, Duval, and Ogburn provide the claimed process, where the TBC is YSZ and the filler is CMAS and the heat treatment is done during initial gas turbine engine operations, the resulting process is also expected to result in the formation of high temperature rare-earth silicate plates or phases. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”. Therefore, when heating the CMAS material during the initial gas turbine engine operations, it is also expected to effectuate the reaction of the materials to form high temperature rare-earth silicate phases because it will result in the formation of the crystalline CMAS phases while in contact with the YSZ TBC.
As to the infiltration forming a multi-phase material layer coating system, since Hongoh in view of Schlichting, Duval, and Ogburn provide the process of claim 1, using the claimed materials, and heating during initial operations of the gas turbine engine, the resulting infiltration is also expected to result in forming a multi-phase material layer coating system. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
As to forming a multi-phase pre-reacted surficial region, Duval further teaches that not the whole thickness of the thermal barrier coating layer is infiltrated by the sealing substance, but rather only a surficial section or partial layer thereof is infiltrated (0088 and Fig. 1). They teach that it is preferably to have a thin layer of infiltration thickness, T, in order to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance (0095).
From this, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have infiltrated the coating or blocking material into only a surficial region of the pores of the TBC and not throughout the thickness of the TBC because Duval teaches that it is preferably to only infiltrate a sealing substance to a surficial section of a sealing and/or reactive material to provide a thin layer to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance such that it will be expected to successfully protect the underlying TBC while also minimizing the negative effects. Therefore, in the process of Hongoh in view of Schlichting, Duval, and Ogburn, the CMAS material will be infiltrated so that it is in the upper portion of the TBC, i.e. a surficial region, where Hongoh teaches that the CMAS provides a coating layer (0017 and Fig. 1), such that the multi-phase material layer coating system will form a multi-phase surficial region. Further, since they provide the process of claim 1 including using CMAS filler and the YSZ TBC, where Hongoh teaches that the CMAS and the TBC undergo a thermo-chemical reaction, the resulting process is also expected to provide a pre-reacted surficial region. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 7, Hongoh in view of Schlichting, Duval, and Ogburn suggests the limitations of instant claim 1. Hongoh teaches applying the CMAS resistant layer using a solution-precursor plasma spray (SPPS) that uses a solution atomizer for application (0016).
Schlichting further teaches that the coating or blocking material is applied using techniques such as contacting the component with a solution using methods such as sol gel and slurry through dipping, brushing, painting, etc. (0028).
From the teachings of Hongoh and Schlichting, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have SPPS to have applied the coating or blocking material because Hongoh teaches that such a process is suitable for applying a solution containing powdered material, and Schlichting teaches applying a solution for impregnating the TBC such that it will be expected to provide a suitable method of solution application of the materials for infiltration/impregnation.
Regarding claim 11, Hongoh in view of Schlichting, Duval, and Ogburn suggests the limitations of instant claim 1. Schlichting further teaches that the inert compound or blocking material is applied using a solution-based process where the suspension comprises a solvent, at least one inert compound, and at least one UV or heat curable resin, at least one dispersant and/or at least one surfactant (0028). They teach that after curing the TBC coated article, the article is dried to remove, i.e. evaporate or burn off the excess solvent, dispersant, and/or resin materials (0030). They teach that the dispersant includes polymers such as PMMA and polyvinyl alcohol (0031). Therefore, when forming the infiltrated CMAS layer using the process of Schlichting, the CMAS compound is considered to be a filler of the blocking material and the resin and/or the dispersant, i.e. PMMA or PVA, are considered to be sacrificial polymers because they are removed or sacrificed during the heating process.
Regarding claim 29, Hongoh in view of Schlichting, Duval, and Ogburn suggest the limitations of instant claim 1. Hongoh teaches that the process mitigates CMAS risk (0004). They teach that the CMAS layer protects the thermal barrier coating from spallation by preventing common CMAS from dissolving into the reaction layer and prohibiting further penetration into the layer (0020). Therefore, the surface region of the coating is considered to mitigate damage to the TBC by CMAS.
Further, since Hongoh in view of Schlichting, Duval, and Ogburn provide the process of claim 1, including the materials of the TBC and the filler, the resulting multi-phase pre-reacted surficial region is also expected to mitigate damage to the TBC material by CMAS. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 30, Hongoh in view of Schlichting, Duval, and Ogburn suggest the limitations of instant claim 1. Hongoh teaches that common CMAS will not readily dissolve into the CMAS reaction layer, and if it does, it recrystallizes quickly, prohibiting further CMAS penetration into the TBC (0020), indicating that the layer will seal the TBC.
Further, since Hongoh in view of Schlichting, Duval, and Ogburn provide the process of claim 1, including the materials of the TBC and the filler, a second phase that alters the TBC material with a pre-sealed structure is also expected to occur when the carrier is removed. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 31, Hongoh in view of Schlichting, Duval, and Ogburn suggest the process of claim 1. Since, Hongoh in view of Schlichting, Duval, and Ogburn provide the claimed process, where the TBC is YSZ and the filler is CMAS and the heat treatment is done during initial gas turbine engine operations, and Hongoh indicates that the coating provides a sealed structure so as to pre-seal the TBC (as discussed above for claim 30), the resulting process of removing the carrier is expected to result in pre-sealing the TBC with a rare earth apatite composition. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Alternatively, Schlichting teaches that the inert compound of formula (I) may comprise garnet (0038). They teach that the at least one inert compound may also comprise a mixture of the inert compound of formula (I) and the inert compound of formula (II), where the inert compound of formula (II) may comprise oxyapatite (0038). They teach that the compound of Formula (II) includes rare earth elements (0004). They teach that the garnet and/or oxyapatite material alone or in combination with the TBC coatings may react with the CMAS to provide a reaction product (0043). They teach that a garnet and/or oxyapatite layered or combined with a TBC such as 7YSZ may react with CMAS to form a reaction product comprising at least a complex oxide compound with the garnet crystalline structure and coexist with silicate oxyapatites (0043). They teach that the reaction product or products form throughout the entirety of the garnet and/or oxyapatite alone or in combination with the TBC to provide a reaction barrier or sealant composition as a layer upon the TBC or throughout the TBC (0044-0045).
From this, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have included an inert compound of formula II with the CMAS compound because Schlichting teaches that such a compound can be used with a compound that can comprise CMAS, where the compound is desirable for imparting CMAS resistance such that it will be expected to provide a desirable mixture of materials for forming a protective coating. Therefore, since Schlichting teaches that a YSZ TBC reacts with CMAS to form a reaction product, and the filler material is a CMAS material, where the coating is suggested to include an oxyapatite (compound of formula II), the process is also expected to provide at least some reaction of the materials to provide a rare-earth oxyapatite or apatite phase as claimed (where the rare earth can be included from the reaction with the YSZ TBC).
Regarding claims 32 and 33, Hongoh in view of Schlichting, Duval, and Ogburn suggest the process of claim 1, where, as discussed above for claim 1, Duval suggests forming a surficial region with the coating and not to infiltrate the entire thickness of the TBC. As discussed above for claims 30 and 31, the removal of the carrier is also expected to result in sealing the TBC with a rare earth apatite composition. Therefore, when removing the carrier it will produce and upper layer of the TBC which comprises the TBC material sealed with a ceramic composition, i.e., the CMAS coating material that alone or in combination with an inert compound of formula II provides a rare earth oxyapatite or apatite composition as discussed above for claim 31.
Claim 34 is rejected under 35 U.S.C. 103 as being unpatentable over Hongoh in view of Schlichting, Duval, and Ogburn as applied to claim 32 above, and further in view of Rigney, US 2005/0106315 A1 (provided on the PTO-892 of 7/30/2019).
Regarding claim 34, Hongoh in view of Schlichting, Duval, and Ogburn suggests the limitations of instant claim 32. Hongoh teaches that the coating has a thickness of up to approximately 50 microns (0014).
They do not teach the infiltration depth of the blocking material into the thermal barrier coating material.
Rigney teaches a repaired component comprising an engine run component having a base metal substrate and a bond coat (abstract). They teach that the method is applicable to components that operate within high temperature environments such as high- and low-pressure turbine nozzles and blades, shrouds, combustor liners and augmentor hardware of gas turbine engines, where other examples include airfoils and vanes (0015). They teach that a ceramic thermal barrier coating may be applied over the bond coat, where the thermal barrier coating layer is a ceramic thermal barrier coating (0024). They teach that the ceramic thermal barrier coating may have a thickness of between about 3 mils and about 10 mils, more typically on the order of about 5 mils (0024).
From the teachings of Rigney, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claim invention to have formed the TBC to have a thickness of about 5 mils or between about 3 to 10 mils because Rigney teaches that TBCs typically have such a thickness such that it will provide the desired and predictable result of forming a TBC to a thickness sufficient for insulating the component of the gas turbine engine.
As discussed above for claim 1, Duval teaches that not the whole thickness of the thermal barrier coating layer is infiltrated by the sealing substance, but rather only a surficial section or partial layer thereof is infiltrated (0088 and Fig. 1). They teach that the thickness of the infiltrated layer section is typically in the range of less than 30% of the total thickness of the thermal barrier coating layer (0088). They teach that preferably the thickness T of the infiltrated layer section is in the range of 1/4 to 1/3, in particular between 1/5 and 1/3 of the thickness of the thermal barrier coating (0095 and Fig. 1). They teach that it is preferable to have thin layer T in order to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance (0095).
From the teachings of Duval and Rigney, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Hongoh in view of Schlichting, Duval, and Ogburn to have infiltrated the coating or blocking material into the pores of the TBC to a depth range of less than 30% of the total thickness of the thermal barrier coating layer as indicated by Duval because Duval teaches that such depths are desirable, that it is preferable to have thin layer T in order to minimize negative effects such as strain within the layer or thermal conductivity by the sealing substance, that the layer is used to protect the thermal barrier coating, where the layer is a sealing and/or reactive material (where the material of Hongoh is considered to provide a sealing layer as discussed above) and that the substrate is a turbine for a gas turbine engine such that it will provide the desired and predictable result of infiltrating the pores to a depth that will successfully protect the underlying TBC while also minimizing negative effects.
Therefore, Hongoh in view of Schlichting, Duval, Ogburn, and Rigney suggest infiltrating the coating material to a depth of less than 38.1 microns for a TBC having a thickness or 5 mils (127 microns) or less than a range of 22.86-76.2 microns (from a range of 3-10 mils or 76.2-254 microns) since Rigney suggests forming the TBC to have a thickness of about 5 mils (about 127 microns) or 3-10 mils (76.2-254 microns) and Duval suggests infiltrating the pores to a depth of less than 30% of the thickness of the TBC layer, indicating that the material will not infiltrate through the entirety of the TBC and it will infiltrate to a depth range overlapping the claimed range. Therefore, the range suggested by Schlichting in view of Duval, Biondo, and Rigney overlaps the range of instant claim 34 for a depth of less than 30% of the TBC. According to MPEP 2144.05, “in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.” In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976).
Response to Arguments
Applicant’s arguments dated 11/18/2025 have been fully considered.
In light of the amendments to the claims, the previous 112(b) rejection is withdrawn.
As to Applicant’s arguments over Schlichting, is noted that Schlichting is directed to preventing at least one component of sand such as CMAS from penetrating the ceramic based compound of the TBC. Hongoh provides a chemically conditioned CMAS that is applied over a TBC, such as a YSZ TBC, so as to react with the TBC resulting in a cubic garnet type crystal structure that has a melting temperature significantly higher than the common CMAS encountered in the field. Hongoh indicates that common CMAS will not readily dissolve into the formed reaction layer and even if it does, it recrystallizes quickly, which prohibits further CMAS penetration into the TBC. Therefore, applying the chemically conditioned CMAS material into the YSZ TBC of Schlichting is understood to provide protection from the common CMAS, i.e. sand, as desired by Schlichting. Specifically, the chemically conditioned CMAS material of Hongoh is understood to be different from the common CMAS encountered in the field (sand) because it provides the protection required from common CMAS. Further, as noted above the chemical formula of Schlichting used as the blocking compound can include a calcium alumino silicate material. It is noted that Applicant’s previous arguments were considered persuasive in that Schlichting alone was not sufficient to suggest using a CMAS material, and therefore Hongoh was included to specifically indicate that a chemically conditioned CMAS can be used to protect a TBC from common CMAS.
Further, the rejection includes using Hongoh as a primary reference where Hongoh teaches using a graded coating and Schlichting as a secondary reference which teaches a process of forming a graded coating to provide CMAS protection. It is noted that both Hongoh and Schlichting are directed to providing protection from common CMAS, where the chemically conditioned CMAS of Hongoh is understood to be different from the common CMAS because it reacts with the TBC to provide protection from common CMAS and if common CMAS were capable of providing the same reaction and protection, protection from common CMAS would not be needed.
Conclusion
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTINA D MCCLURE whose telephone number is (571)272-9761. The examiner can normally be reached Monday-Friday, 8:30-5:00 EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Gordon Baldwin can be reached at 571-272-5166. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CHRISTINA D MCCLURE/Examiner, Art Unit 1718 /GORDON BALDWIN/Supervisory Patent Examiner, Art Unit 1718