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 .
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.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 8/26/25 has been entered.
Claims 1-3, 5, 7-8, 10-13, and 15-18 are pending.
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.
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.
Claim(s) 1-3, 5, 7-8, 10-13, and 15-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Feagin (US 4,740,246, previously cited, hereinafter Feagin’246) in view of Sakamoto (JP H09-314278 A).
Regarding claim 1, Feagin’246 teaches a casting slurry (col 5 lines 14-26, coating composition) for producing shell molds for casting parts comprising a metal alloy (intended use, col 5 lines 14-26, investment casting mold having low reactivity with reactive metals), the slurry comprising powder particles (col 7 lines 35-46, refractory powders or aggregate), a binder (col 3 lines 60-68, Yttria sols as binders for refractories, col 8 lines 1-10), and additives (Table 3, Latex, Sterox, 2-ethyl hexanol, col 9 lines 50-62, Sterox is a low-foaming wetting agent, 2-ethyl hexanol is used as a defoaming agent), wherein the binder comprises colloidal yttrium oxide (col 3 lines 60-68, col 8 lines 1-10, Yttria sol), and the powder particles comprise calcia-stabilized zirconia (col 7 lines 35-46, fused stabilized zirconium oxide having as the stabilizing agent calcium oxide).
Feagin’246 fails to teach the mass ratio of the calcia-stabilized zirconia in the slurry being between 68% and 72% and includes a mass content of calcium oxide in the calcia-stabilized zirconia between 11% and 30%, a mass ratio of the binder in the slurry being comprised between 25% and 35%, a mass ratio of the additives is between 0.5% and 2%, and a viscosity of the slurry is between 0.1 and 2 Pa·s for at least 24 hours after preparation of the slurry, the viscosity measured during application of a shear between 0.1 s-1 and 100 s-1.
However, Feagin’246 discloses an example (Table 3, Slurry 412, Sample U) where the slurry comprises 290 grams of calcia-stabilized zirconia (see col 9 lines 50-52 and col 10 lines 14-20 disclosing the E.F. Stabilized ZrO2is a calcia-stabilized zirconia), 60 grams of Yttria sol, 6 grams of Latex, 10 drops of Sterox, and 30 drops of 2-ethyl hexanol, thus having a mass ratio of the calcia-stabilized zirconia in the slurry of approximately 81% (290 grams of calcia-stabilized zirconia to about 356 total grams of the mixture) and a mass ratio of the Yttria sol binder of approximately 17% (60 grams of Yttria sol to about 356 total grams of the mixture). Furthermore, Feagin’246 teaches relative to the proportions of refractory to be used with the yttria sol, in the case of relatively inactive refractories, these can vary widely depending upon their particle size distributions, the specific gravity of the refractory, the manner of processing, and the application of the mix (col 12 lines 20-42). Variations in these proportions may be made depending upon the particular results desired. In the case of active refractories, somewhat more sol may be required to prolong shelf life of the mix (col 12 lines 40-50). Furthermore, note that a few drops of Sterox and 2-ethyl hexanol were added to improve wetting (col 13 lines 55-65), and that a small amount of latex was added to aid in film formation and better adhesion (col 9 lines 25-32).
It would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the mass ratio of the calcia-stabilized zirconia in the slurry, thus similarly optimizing the mass ratio of the Yttria sol, as Feagin teaches the proportions of the refractory to be used with the yttria sol are result effective variables that can be varied depending on particle size distributions, specific gravity, processing manner, application of the mix, etc, and that the variations can be made depending on particular results desired, such as prolonging shelf life of the mix (col 12 lines 20-42, note that Feagin teaches of more sol (thus correspondingly a lower amount of powder particles) for prolonging shelf life (increasing stability)). It would have been obvious to optimize the amount of additives, such as the Latex, Sterox and 2-ethyl hexanol, as the amount of additives are result effective variables for improving wetting.
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Feagin’246 teaches that the E.F. stabilized zirconia is a commercially available electrically fused calcia-stabilized zirconia having approximately 4% CaO as the stabilizer (col 10 lines 14-20), thus failing to teach a mass content of calcium oxide in the calcia-stabilized zirconia between 11% and 30%.
Sakamoto teaches a mold material used in casting titanium and its alloys (paragraph [0001]). Sakamoto teaches that there are problems when casting titanium and the like, such as a reaction occurring between zirconia and molten titanium (paragraph [0003]), and teaches that conventionally, a partially stabilized zirconia, using a small amount of CaO, is used and still results in the formation of an altered layer (paragraph [0004]). Most of the conventional CaO stabilized zirconia molds have a content of CaO between 0 to 8% (paragraph [0009]). Sakamoto teaches using a large amount of CaO as a stabilizer with Zirconia, in an amount containing 10 to less than 31% wt% CaO (paragraph [0007]), with an example range of 10 to 18% (paragraph [0007]). When a large amount of CaO is used, CaZrO3 is increased, and that when the amount of CaZrO3 increases, the thickness of the affected layer decreases (paragraph [0010-0011]), with an example of an affected layer reduced to approximately one-eighth compared to conventional CaO-stabilized zirconia mold material (paragraph [0017]).
It would have been obvious to one of ordinary skill in the art to modify Feagin’246 such that the stabilized zirconia used in the slurry comprises CaO in an amount of 11% and 30%, as Sakamoto teaches that the larger amount of CaO results in a thinner reaction layer (paragraph [0010-0011]).
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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). "[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See also In re Harris, 409 F.3d 1339, 74 USPQ2d 1951 (Fed. Cir. 2005). MPEP 2144.05(I).
The combination is quiet to a viscosity of the claimed slurry is between 0.1 and 2 Pa·s for at least 24 hours after preparation of the slurry, the viscosity measured during application of a shear between 0.1 s-1 and 100 s-1.
However, note that 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). MPEP 2112.01 (I).
Regarding claim 2, note that the limitation of “the slurry being a contact slurry configured to come into contact with the metal alloy of a part to be molded” is a functional limitation describing the intended use of the slurry. See MPEP 2114(I) and (II), "[A]pparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987). The limitation does not add structure to the composition to further distinguish from the prior art composition.
Note additionally that Feagin’246 does teach the slurry being used as an inner coat which contacts the metal of the part to be molded (col 5 lines 13-26, process for making an investment casting mold, providing the sol and mixing said sol with refractory materials to form a coating composition, applying said coating composition to a pattern shaped in the desired configuration, col 8 lines 38-43, the first coat applied is called the facecoat and the slurry compositions are given in Tables 3 and 4).
Regarding claim 3, the combination teaches wherein a mass content of calcium oxide in the calcia-stabilized zirconia is comprised between 11% and 20% (note Sakamoto discloses examples of 10%, 18%, and 26% CaO, paragraph [0014]).
Regarding claim 5, note that the limitation of “configured for production of shell molds for casting parts comprising a titanium aluminide-based metal alloy” is a functional limitation describing the intended use of the slurry. See MPEP 2114(I) and (II), "[A]pparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987). The limitation does not add structure to the composition to further distinguish from the prior art composition.
Note that Feagin’246 does teach the slurry configured for the production of shell molds for casting parts comprising a titanium aluminide-based metal alloy (col 3 line 60 - col 4 line 7, method of making molds, and casting of titanium alloys such as Ti6Al4V, col 8 lines 1-35, investment cast shell mold).
Regarding claim 7, Feagin’246 teaches a process of producing a shell mold for casting parts (Feagin’246, col 5 lines 14-26, col 8 lines 1-35, preparing molds for casting, investment cast shell mold), the process comprising:
providing a model of a part to be produced (Feagin’246, col 5 lines 14-26, pattern shaped in the desired configuration);
dipping the model in a contact slurry comprising the slurry of claim 1 (Feagin’246, col 5 lines 14-26, applying said coating composition, col 8 lines 18-45, application of coating was by dipping into the slurry, col 8 lines 39-45, first coat is called the facecoat and the slurry compositions are given in Tables 3 and 4);
sandblasting (see applicant’s specification paragraph [0033] defining sandblasting as deposition of a stucco) the dipped model in a contact sand comprising yttrium oxide (Feagin’246, col 8 lines 19-45, while it was still wet, the stucco was applied, see Table 3 Slurry 412 which uses a Yttria stucco);
drying a layer obtained by the preceding steps (Feagin’246, col 8 lines 19-45, the coated finger was allowed to dry);
dipping the model in a reinforcement slurry (Feagin’246, col 9 lines 25-45, dipping of the backup coats, the mold assemblies were then dipped into Slurry 417), sandblasting the model dipped in a reinforcement sand (Feagin’246, col 9 lines 25-45, immediately stuccoed with Remasil 60 stucco), and drying the layer obtained (Feagin’246, col 9 lines 25-45, coating was allowed to harden and recoated), until a desired shell mold thickness is obtained (Feagin’246, col 9 lines 25-45, repeated until a total of seven coats, after all coats were applied, the molds were allowed to dry thoroughly before dewaxing); and
removing the model (Feagin’246, col 5 lines 14-26, heating the resulting coated pattern to melt or burn out the pattern material, col 9 lines 45-53, molds were dewaxed).
Regarding claim 8, the limitations of “the shell mold obtained by the process as claimed in claim 7” is a product-by-process limitation. See MPEP 2113, where "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985).
The process limitations suggest a shell mold having a contact layer formed of the claimed slurry, a yttrium oxide stucco, a reinforcement slurry, and a reinforcement sand.
The combination suggests the same product, as the shell mold of the combination (Feagin’246, col 8 lines 8-45, investment cast shell mold, Sakamoto for the mass content of CaO) is formed from the same process (as discussed in the rejection of claim 7 above) and results in the same structure. Note that the shell mold of the combination would have a first coat, called the facecoat, of the slurry composition (Feagin’246, col 8 lines 38-45, Slurry 412 Sample U, Yttria sol and EF Stabilized ZrO2, where the amount of CaO is larger than conventional, as taught in Sakamoto) and Yttria stucco (Feagin’246, col 8 lines 38-45, Slurry 412 Sample U, Yttria stucco), and backup coatings (Feagin’246, col 9 lines 25-45) of Slurry 417 and Remasil 60 stucco.
Regarding claim 10, Feagin’246 is quiet to the mass ratio of the calcia-stabilized zirconia in the slurry is between 68% and 70%.
However, as discussed above, Feagin’246 discloses an example (Table 3, Slurry 412, Sample U) where the slurry comprises 290 grams of calcia-stabilized zirconia (see col 9 lines 50-52 and col 10 lines 14-20 disclosing the E.F. Stabilized ZrO2is a calcia-stabilized zirconia), 60 grams of Yttria sol, and 6 grams of Latex, thus having a mass ratio of the calcia-stabilized zirconia in the slurry of approximately 81% (290 grams of calcia-stabilized zirconia to about 356 total grams of the mixture), and about 17% binder (60 grams Yttria sol to about 356 total grams of the mixture).
Furthermore, Feagin’246 teaches relative to the proportions of refractory to be used with the yttria sol, in the case of relatively inactive refractories, these can vary widely depending upon their particle size distributions, the specific gravity of the refractory, the manner of processing, and the application of the mix (Feagin’246, col 12 lines 20-42). Variations in these proportions may be made depending upon the particular results desired. In the case of active refractories, somewhat more sol may be required to prolong shelf life of the mix (Feagin’246, col 12 lines 40-50, note that more sol (binder) would correspond to a lower percentage of powder particles, for prolonging shelf life (increasing stability)).
It would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the mass ratio of the calcia-stabilized zirconia in the slurry, as Feagin’246 teaches the proportions of the refractory to be used with the yttria sol are result effective variables that can be varied depending on particle size distributions, specific gravity, processing manner, application of the mix, etc, and that the variations can be made depending on particular results desired, such as prolonging shelf life of the mix (Feagin’246, col 12 lines 20-42).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Regarding claim 11, although Feagin’246 is quiet to the specific mass ratio of the calcia-stabilized zirconia in the slurry is 70%, as noted above, Feagin’246 discloses that proportions of refractory to be used can vary widely depending upon their particle size distributions, the specific gravity of the refractory, the manner of processing, and the application of the mix, and that somewhat more sol may be required to prolong shelf life (col 12 lines 20-50). Furthermore, note that a few drops of Sterox and 2-ethyl hexanol were added to improve wetting (col 13 lines 55-65).
It would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the mass ratio of the calcia-stabilized zirconia in the slurry, thus similarly optimizing the mass ratio of the Yttria sol, as Feagin’246 teaches the proportions of the refractory to be used with the yttria sol are result effective variables that can be varied depending on particle size distributions, specific gravity, processing manner, application of the mix, etc, and that the variations can be made depending on particular results desired, such as prolonging shelf life of the mix (col 12 lines 20-42).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Regarding claim 12, Feagin’246 teaches a casting slurry (col 5 lines 14-26, coating composition) for producing shell molds for casting parts comprising a metal alloy (intended use, col 5 lines 14-26, investment casting mold having low reactivity with reactive metals), the slurry comprising powder particles (col 7 lines 35-46, refractory powders or aggregate) and a binder (col 3 lines 60-68, Yttria sols as binders for refractories, col 8 lines 1-10), wherein the binder comprises colloidal yttrium oxide (col 3 lines 60-68, col 8 lines 1-10, Yttria sol), and the powder particles comprise calcia-stabilized zirconia (col 7 lines 35-46, fused stabilized zirconium oxide having as the stabilizing agent calcium oxide).
Feagin’246 fails to teach the mass ratio of the calcia-stabilized zirconia in the slurry is comprised between 65% and 75% and includes a mass content of calcium oxide in the calcia-stabilized zirconia between 11% and 30%, and a mass ratio of the binder in the slurry is between 25% and 35%; further including a viscosity of the slurry being less than 2 Pa·s for at least 24 hours after preparation of the slurry, the viscosity measured during application of a shear between 0.1 s-1 and 100 s-1.
However, Feagin’246 discloses an example (Table 3, Slurry 412, Sample U) where the slurry comprises 290 grams of calcia-stabilized zirconia (see col 9 lines 50-52 and col 10 lines 14-20 disclosing the E.F. Stabilized ZrO2is a calcia-stabilized zirconia), 60 grams of Yttria sol, and 6 grams of Latex, thus having a mass ratio of the calcia-stabilized zirconia in the slurry of approximately 81% (290 grams of calcia-stabilized zirconia to about 356 total grams of the mixture) and a mass ratio of the Yttria sol binder of approximately 17% (60 grams of Yttria sol to about 356 total grams of the mixture).
Furthermore, Feagin’246 teaches relative to the proportions of refractory to be used with the yttria sol, in the case of relatively inactive refractories, these can vary widely depending upon their particle size distributions, the specific gravity of the refractory, the manner of processing, and the application of the mix (col 12 lines 20-42). Variations in these proportions may be made depending upon the particular results desired. In the case of active refractories, somewhat more sol may be required to prolong shelf life of the mix (col 12 lines 40-50, note that more sol (binder) would correspond to a lower percentage of powder particles, for prolonging shelf life (increasing stability)).
It would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the mass ratio of the calcia-stabilized zirconia in the slurry, thus similarly optimizing the mass ratio of the Yttria sol, as Feagin’246 teaches the proportions of the refractory to be used with the yttria sol are result effective variables that can be varied depending on particle size distributions, specific gravity, processing manner, application of the mix, etc, and that the variations can be made depending on particular results desired, such as prolonging shelf life of the mix (col 12 lines 20-42).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Feagin’246 teaches that the E.F. stabilized zirconia is a commercially available electrically fused calcia-stabilized zirconia having approximately 4% CaO as the stabilizer (col 10 lines 14-20), thus failing to teach a mass content of calcium oxide in the calcia-stabilized zirconia between 11% and 30%.
Sakamoto teaches a mold material used in casting titanium and its alloys (paragraph [0001]). Sakamoto teaches that there are problems when casting titanium and the like, such as a reaction occurring between zirconia and molten titanium (paragraph [0003]), and teaches that conventionally, a partially stabilized zirconia, using a small amount of CaO, is used and still results in the formation of an altered layer (paragraph [0004]). Most of the conventional CaO stabilized zirconia molds have a content of CaO between 0 to 8% (paragraph [0009]). Sakamoto teaches using a large amount of CaO as a stabilizer with Zirconia, in an amount containing 10 to less than 31% wt% CaO (paragraph [0007]), with an example range of 10 to 18% (paragraph [0007]). When a large amount of CaO is used, CaZrO3 is increased, and that when the amount of CaZrO3 increases, the thickness of the affected layer decreases (paragraph [0010-0011]), with an example of an affected layer reduced to approximately one-eighth compared to conventional CaO-stabilized zirconia mold material (paragraph [0017]).
It would have been obvious to one of ordinary skill in the art to modify Feagin’246 such that the stabilized zirconia used in the slurry comprises CaO in an amount of 11% and 30%, as Sakamoto teaches that the larger amount of CaO results in a thinner reaction layer (paragraph [0010-0011]).
The combination is quiet to further including a viscosity of the slurry being less than 2 Pa·s for at least 24 hours after preparation of the slurry, the viscosity measured during application of a shear between 0.1 s-1 and 100 s-1.
However, note that 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). MPEP 2112.01 (I).
Regarding claim 13, see rejection of claim 12 above. The combination is quiet to the viscosity is less than 1 Pa·s for at least 24 hours after preparation of the slurry.
However, note that 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). MPEP 2112.01 (I).
Regarding claim 15, the combination teaches the mass ratio of calcia-stabilized zirconia includes a mass content of calcium oxide in the calcia-stabilized zirconia is comprised between 11% and 20% (Sakamoto, 10 to 31% (paragraph [0007]), with an example at 18% (paragraph [0014])).
Regarding claim 16, the combination teaches the mass ratio of calcia-stabilized zirconia includes a mass content of calcium oxide in the calcia-stabilized zirconia is comprised between 10% and 18%, encompassing the claimed value of 11%. Additionally note that the endpoint of 10% is close to the claimed value of 11%.
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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). "[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See also In re Harris, 409 F.3d 1339, 74 USPQ2d 1951 (Fed. Cir. 2005). MPEP 2144.05(I).
Claim(s) 17-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Feagin’246 as modified by Sakamoto as applied to claim 7 above, and further in view of Sturgis et al (US 6,102,099, previously cited).
Regarding claim 17, the combination teaches casting a part comprising a titanium aluminide-based metal alloy using the shell mold with the desired mold thickness (Feagin’246, col 4 lines 1-10, casting titanium alloys such as Ti6Al4V).
Feagin’246 further teaches the casted part includes a reaction layer (col 1 lines 45-65, reaction layer known in industry as alpha case). Feagin’246 teaches that it is generally recognized that all commercial processes have some alpha case on their casting, which ranges from 0.005 inches to 0.04 inches in thickness depending on process and casting size. Feagin’246 teaches that the alpha case must be milled off before a satisfactory casting is obtained, and that the invention recognizes the reduction of alpha case brought by the mold compositions (col 3 line 60 – col 4 line 10). Similarly, Sakamoto teaches an affected layer (paragraph [0003]) whose thickness is reduced by increasing the amount of CaO used as the stabilizer (paragraph [0010-0011]).
The combination is quiet to the reaction layer having a thickness less than 15 micrometers.
However, as discussed above, Feagin’246 seeks to reduce the alpha case (col 4 lines 1-10), recognizing that the thickness depends on the casting process and casting size (col 3 lines 40-60).
Sturgis et al teaches alpha case on a titanium alloy casting, and further recognizes that the alpha case thickness may vary according to the temperature at which the mold/pattern was fired and/or cast (col 7 lines 35-50). Sturgis et al further teaches that if normal casting procedures result in too much alpha case, then other procedures may be used to decrease alpha case, such as a lower mold cooling temperature, or delayed pouring technique (col 13 lines 45-60).
In light of the teachings of Feagin’246, Sakamoto, and Sturgis et al, it would have been obvious to one of ordinary skill in the art to modify the combination so as to form the reaction layer (alpha case) to be less than 15 micrometers, as Feagin’246 teaches that alpha case is not desired and must be milled off (col 3 line 60 – col 4 line 10), and that alpha case can be reduced by selection of the composition of the mold slurry, such as the amount of CaO (Sakamoto, paragraph [0010-0011]), the casting process (Feagin’246, col 3 lines 40-60), the casting size (Feagin’246, col 3 lines 40-60), mold firing temperature (Sturgis, col 7 lines 35-50), and mold cooling temperature (Sturgis, col 13 lines 45-60).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Regarding claim 18, the combination teaches the powder particles further comprise alumina (Feagin’246, note that the sol of the slurry may further include alumina fibers, col 12 lines 50-55).
Response to Arguments
Applicant’s arguments with respect to the claim(s) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant argues that the prior art fails to teach or suggest the new limitations of “a mass content of calcium oxide in the calcia-stabilized zirconia between 11% and 30%.”
Note that the rejection has been modified to further look towards Sakamoto (JP H09-314278 A) who teaches a mold material used in casting titanium and its alloys (paragraph [0001]). Sakamoto teaches that there are problems when casting titanium and the like, such as a reaction occurring between zirconia and molten titanium (paragraph [0003]), and teaches that conventionally, a partially stabilized zirconia, using a small amount of CaO, is used and still results in the formation of an altered layer (paragraph [0004]). Most of the conventional CaO stabilized zirconia molds have a content of CaO between 0 to 8% (paragraph [0009]). Sakamoto teaches using a large amount of CaO as a stabilizer with Zirconia, in an amount containing 10 to less than 31% wt% CaO (paragraph [0007]), with an example range of 10 to 18% (paragraph [0007]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JACKY YUEN whose telephone number is (571)270-5749. The examiner can normally be reached 9:30 - 6:00.
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, Keith Walker can be reached at 571-272-3458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JACKY YUEN/
Examiner
Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735