DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group I (claims 1-10) in the reply filed on September 17, 2025 is acknowledged.
Claims 11-14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on September 17, 2025.
Claim Objections
Claims 11-14 are objected to because of the following informalities: in the most recent listing of claims, filed September 17, 2025, claims 11-14 bear the status identifier “Withdrawn,” but the text of the claims has been deleted. This is contrary to the requirements for a claim listing in an amendment; the text of withdrawn claims should still be included in the claim listing. See 37 C.F.R. 1.121(c)(3); MPEP 714. Appropriate correction is required.
Claim Interpretation
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art.
In line 5 of claim 1, line 4 of claim 15, line 4 of claim 23, and line 4 of claim 27, the word “finer” is read as indicating that the primary grains of silicon carbide have a smaller d50 than the primary grains of crystalline boron carbide (B4C), this interpretation appearing to be the broadest reasonable interpretation using the plain meaning of the claim language, in view of other limitations within the claims (such as the limitations in lines 3 and 6 of claim 1, for instance, setting a mean grain size d50 > 100 μm for B4C primary grains and d50 < 70 μm for the silicon carbide primary grains) and in view of Applicant’s Specification (see, e.g., p. 8, lines 21-26, and p. 9, lines 13-14).
In claims 9, 21, and 26, where the claim recites that “shaping of the shaped composite body takes place in plate form,” the phrase “takes place in plate form” is interpreted to mean that shaped composite body is in the shape of a plate, this reading appearing to be the broadest reasonable interpretation, using the plain meaning of the claim language, in agreement with Applicant’s Specification (see p. 7, line 17–p. 8, line 1; p. 8, lines 13-17).
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-10 and 15-27 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The term “primary grains,” which appears in independent claims 1, 15, 23, and 27, as well as in multiple dependent claims, is undefined, and its meaning is unclear. The Specification provides no definition or guidance as to the meaning of “primary grains.” Moreover, in claims 1, 15, 23, and 27, “primary grains” is used to designate both grains of boron carbide (B4C) and grains of silicon carbide (SiC). Hence, one of ordinary skill in the art is left uncertain as to the scope of the claims.
For purposes of claim interpretation, “primary grains” will be treated as designating a category of grains that includes both boron carbide (B4C) grains and silicon carbide (SiC) grains (this being consistent with the Specification, see p. 5, line 26 – p. 6, line 2). Further, also for purposes of claim interpretation, “primary grains” will be treated as indicating a “first category” of particles, in distinction to a secondary category of particles produced by a reaction of metallic silicon with free carbon (see Specification, p. 3, lines 14-19).
Claim 1, in lines 9-10, includes a limitation reciting “controlled carbon adding that influences a siliconizing procedure to implement a silicon carbide matrix” (emphasis added). The term “influences” in line 10 is unclear in context, and thereby renders the meaning and scope of the claim indefinite. The term is not defined in the claims, and the Specification offers no guidance on the meaning of the term. It is unclear whether the controlled carbon adding induces the siliconizing procedure, or controls the siliconizing procedure, or sets a limit on the progress of the siliconizing procedure and the extent to which free metallic silicon is reacted with free carbon to form secondary silicon carbide. Any of these meanings, and others, could fit the term “influences” as used in claim 1. A substantially identical limitation, including the word “influences,” also appears in independent claims 15, 23, and 27, and thus those claims suffer from the same indefiniteness.
For purposes of claim interpretation, “controlled carbon adding that influences a siliconizing procedure to implement a silicon carbide matrix” will be treated as indicating, broadly, that controlled carbon adding contributes to a siliconizing procedure to implement a silicon carbide matrix, this being the broadest reasonable interpretation consistent with the plain meaning of the claim language and the Specification (see p. 3 of the Specification).
In claim 27, the last three lines recite “a composite structure comprising the shaped composite body and the backing material is configured to provide ballistic protection against ammunition comprising a tungsten carbide-cobalt (WC/Co) core, including M993 and M995 ammunition types” (emphasis added). In the quoted portion of the claim, the phrase “configured to provide ballistic protection” is vague to the point of rendering the claim indefinite. Firstly, it is unclear how the shaped composite body and the backing material are “configured” to achieve a particular result or material property of the composite structure; it is not clear, for instance, if the components are “configured” for the stated objective by being arranged in a particular spatial arrangement, or by being combined or adhered to one another in a particular manner, or by being present in a particular thickness, for example. Secondly, the term “ballistic protection” is ambiguous. Almost any material will provide some degree of ballistic protection; a plate that can stop a given ammunition round might have different composition or properties (e.g., thickness) compared to a plate that can deflect that same given ammunition round; a structure that offers protection against glancing blows might be ineffective against direct hits. The terms identified above are not defined in the claim, and the Specification does not offer definite guidance on either point (see pp. 10-11, giving different definitions for “protection” for different described embodiments). As such, this language fails to provide a clear-cut indication of the scope of the subject matter embraced by the claim and thus renders the claim indefinite. See Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244, 1255, 85 USPQ2d 1654, 1663 (Fed. Cir. 2008); MPEP 2173.05(g). The claim language does not set forth well-defined boundaries of the invention but rather only states a problem solved; moreover, the ambiguity of the term “ballistic protection,” noted above, leaves it unclear to what degree the stated problem is indeed solved. Thus, one of ordinary skill in the art would not know from the claim terms what structure is encompassed by the claim. MPEP 2173.05(g).
For purposes of claim interpretation, “configured to provide ballistic protection” will be treated as meaning that, when the composite structure is hit by a single bullet of the specified ammunition, there is no penetration of the bullet through the full thickness of the composite structure (i.e., the shaped ceramic body and the backing material) (see Applicant’s Specification, pp. 10-11, application examples 6 and 7).
Claims not specifically mentioned are rejected by reason of their dependence from a rejected base claim.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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) 1-4, 6, and 15-18 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Pat. Pub. 2009/0295048 to Matsumoto et al. (hereinafter “Matsumoto”).
Regarding claim 1, Matsumoto teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic (¶ 0030; claim 3), a microstructure of which is determined by primary grains of crystalline B4C grains (¶ 0028). Matsumoto teaches B4C grains of mean grain size d50 in the range of 10 μm to 200 μm (¶ 0062); this range overlaps the recited range of > 100 μm and < 500 μm in claim 1. In a case where claimed ranges “overlap or lie inside ranges disclosed by the prior art,” a prima facie case of obviousness exists (see MPEP 2144.05). Matsumoto teaches wherein the microstructure is further defined by primary grains of a finer silicon carbide with d50 in the range of 0.1 μm to 5 μm (¶ 0066; see also ¶ 0115, Examples 1-3, teaching silicon carbide powder having an average grain diameter of 0.6 μm), a range that falls within the recited range of d50 < 70 μm. Matsumoto teaches wherein primary grains are siliconized bonded by secondarily formed silicon carbide (¶¶ 0057, 0069). Matsumoto teaches controlled carbon adding (see ¶¶ 0067-0070) that influences a siliconizing procedure (¶ 0057) to implement a silicon carbide matrix comprising primary and secondary silicon carbide portions with a content of free metallic silicon (see ¶¶ 0060, 0072). Matsumoto teaches wherein crystalline B4C grains fractions are embedded in that silicon carbide matrix (see ¶ 0063, describing dispersed B4C grains surrounded and covered with “the reacted product,” i.e., the secondarily formed silicon carbide resulting from the reaction of added carbon with impregnated molten silicon).
Matsumoto teaches that “the preferable mixing ratio of each of the raw materials is 0-45 parts by weight of the carbon source, with respect to the total 100 parts by weight of the 10-90 parts by weight of boron carbide and the 90-10 parts by weight of initial injected silicon carbide” (¶ 0097). Matsumoto also teaches that “the preferable silicon amount,” i.e., the amount of free metallic silicon to be reacted with carbon to produce secondarily formed silicon carbide, “is 105-200% of the silicon amount required for making the carbon transform into silicon carbide and further completely filling the void, and further preferably, 110-150%” (¶ 0101). These taught ranges overlap the recited ranges in claim 1 for primary grains of B4C grains, primary grains of silicon carbide grains, secondarily formed silicon carbide, and free metallic silicon. Within the taught ranges, one of ordinary skill in the would have found it obvious to select amounts for each of the components such that the respective weight percentages would read on the limitations of claim 1. For example, a composition comprising 50 parts per weight of boron carbide (B4C) and 50 parts per weight of silicon carbide (i.e., primary grains of silicon carbide) (see Example 4, ¶ 0116, and Example 6, ¶ 0118), together with 10 parts by weight of carbon black and 35.1 parts by weight of molten silicon would produce, after reaction of the carbon black with the molten silicon, weight percentages outlined in the table below:
Component
Raw Material Parts by Weight
Composite Body Parts by Weight
Composite Body Weight %
B4C
50
50
34.5%
SiC (primary)
50
50
34.5%
Carbon black
10
Metallic Si
35.1
SiC (secondary)
33.4
23.0%
Remaining Metallic Si
11.7
8.1%
(In the above example, the amount of molten silicon initially introduced is 150% of the amount required for making the carbon transform into silicon carbide—see ¶ 0101—and the remainder of unreacted free metallic silicon is deduced from the excess 50% of molten silicon:
(
10 g C
)(
1 mol C
)(
1.50 mol Si
)(
28.086 g Si
)
= 35.1 g Si
12.010 g C
1.00 mol C
1 mol Si
Then, 10 g C react with 23.4 g Si to form 33.4 g SiC, leaving 35.1 – 23.4 = 11.7 g free metallic silicon.) Thus, it would have been obvious, given the teachings of Matsumoto, to produce a shaped composite body wherein a content (or fraction) of primary grains of crystalline B4C grains is > 10% by weight and < 50% by weight, wherein a content (or fraction) of primary grains of silicon carbide is > 10% by weight and < 50% by weight, wherein a content (or fraction) of secondarily formed silicon carbide is > 5% by weight and < 25% by weight, and wherein a content of free metallic silicon is > 1% by weight and < 20% by weight.
Hence, Matsumoto teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic reading on every limitation of claim 1.
Regarding claim 2, Matsumoto teaches the shaped composite body as claimed in claim 1 and, in particular, teaches wherein “the preferable mixing ratio of each of the raw materials is 0-45 parts by weight of the carbon source, with respect to the total 100 parts by weight of the 10-90 parts by weight of boron carbide and the 90-10 parts by weight of initial injected silicon carbide” (¶ 0097) and wherein “the preferable silicon amount required for the reaction sintering is 105-200% of the silicon amount required for making the carbon transform into silicon carbide and further completely filling the void, and further preferably, 110-150%” (¶ 0101). Within these taught ranges, one of ordinary skill in the would have found it obvious to select amounts for each of the components such that the primary grains are siliconized bonded by secondarily formed silicon carbide with a fraction of > 15%, by weight, and < 25%, by weight, as shown above in the discussion of claim 1 (see p. 8).
Regarding claim 3, Matsumoto teaches primary grains of a finer silicon carbide with d50 in the range of 0.1 μm to 5 μm (¶ 0066; see also ¶ 0115, Examples 1-3); this range falls within the recited range of d50 < 40 μm.
Regarding claim 4, Matsumoto teaches the shaped composite body as claimed in claim 1. Further, Matsumoto teaches that the shaped composite body is manufactured via pressure slip casting with liquid silicon infiltration at temperatures between 1430°C-1800°C (¶¶ 0092-0093); this method of manufacturing is substantially identical to the method described for producing the claimed invention (compare with Applicant’s Specification, p. 6, lines 25-28). Because Matsumoto teaches a shaped composite body substantially identical in composition to the claimed invention and produced by a method substantially identical to the method of producing the claimed invention, one of ordinary skill in the art reasonably would expect that shaped composite body of Matsumoto necessarily would possess physical properties substantially identical to those of the claimed invention—including a density gradient that is < 2%, by weight—since products of identical composition are presumed not to have mutually exclusive properties (see MPEP 2112.01(II)). 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 (see MPEP 2112.01(I), first paragraph).
Regarding claim 6, Matsumoto teaches wherein shaping of the shaped composite body is carried out by slip casting (¶ 0075).
Regarding claim 15, Matsumoto teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic (¶ 0030; claim 3), a microstructure of which is determined by primary grains of crystalline B4C grains (¶ 0028). Matsumoto teaches B4C grains of mean grain size d50 in the range of 10 μm to 200 μm (¶ 0062); this range overlaps the recited range of > 100 μm in claim 15. In a case where claimed ranges “overlap or lie inside ranges disclosed by the prior art,” a prima facie case of obviousness exists (see MPEP 2144.05). Matsumoto teaches wherein the microstructure is further defined by primary grains of a finer silicon carbide (¶ 0066). Matsumoto teaches wherein primary grains are siliconized bonded by secondarily formed silicon carbide (¶¶ 0057, 0069). Matsumoto teaches controlled carbon adding (see ¶¶ 0067-0070) that influences a siliconizing procedure (¶ 0057) to implement a silicon carbide matrix comprising primary and secondary silicon carbide portions with a content of free metallic silicon (see ¶¶ 0060, 0072). Matsumoto teaches wherein crystalline B4C grains fractions are embedded in that silicon carbide matrix (see ¶ 0063, describing dispersed B4C grains surrounded and covered with “the reacted product,” i.e., the secondarily formed silicon carbide resulting from the reaction of added carbon with impregnated molten silicon).
Matsumoto teaches that “the preferable mixing ratio of each of the raw materials is 0-45 parts by weight of the carbon source, with respect to the total 100 parts by weight of the 10-90 parts by weight of boron carbide and the 90-10 parts by weight of initial injected silicon carbide” (¶ 0097). Matsumoto also teaches that “the preferable silicon amount,” i.e., the amount of free metallic silicon to be reacted with carbon to produce secondarily formed silicon carbide, “is 105-200% of the silicon amount required for making the carbon transform into silicon carbide and further completely filling the void, and further preferably, 110-150%” (¶ 0101). These taught ranges overlap the recited ranges in claim 1 for primary grains of B4C grains, primary grains of silicon carbide grains, secondarily formed silicon carbide, and free metallic silicon. Within the taught ranges, one of ordinary skill in the would have found it obvious to select amounts for each of the components such that the respective weight percentages would read on the limitations of claim 1. For example, a composition comprising 50 parts per weight of boron carbide (B4C) and 50 parts per weight of silicon carbide (i.e., primary grains of silicon carbide) (see Example 4, ¶ 0116, and Example 6, ¶ 0118), together with 10 parts by weight of carbon black and 35.1 parts by weight of molten silicon would produce, after reaction of the carbon black with the molten silicon, weight percentages outlined in the table below:
Component
Raw Material Parts by Weight
Composite Body Parts by Weight
Composite Body Weight %
B4C
50
50
34.5%
SiC (primary)
50
50
34.5%
Carbon black
10
Metallic Si
35.1
SiC (secondary)
33.4
23.0%
Remaining Metallic Si
11.7
8.1%
(In the above example, the amount of molten silicon initially introduced is 150% of the amount required for making the carbon transform into silicon carbide—see ¶ 0101—and the remainder of unreacted free metallic silicon is deduced from the excess 50% of molten silicon:
(
10 g C
)(
1 mol C
)(
1.50 mol Si
)(
28.086 g Si
)
= 35.1 g Si
12.010 g C
1.00 mol C
1 mol Si
Then, 10 g C react with 23.4 g Si to form 33.4 g SiC, leaving 35.1 – 23.4 = 11.7 g free metallic silicon.) Thus, it would have been obvious, given the teachings of Matsumoto, to produce a shaped composite body wherein a fraction of primary grains of crystalline B4C grains is 30-40% by weight, , wherein a fraction of secondarily formed silicon carbide is 15-25% by weight, and wherein a content of free metallic silicon is < 15% by weight.
Hence, Matsumoto teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic reading on every limitation of claim 15.
Regarding claim 16, Matsumoto teaches primary grains of a finer silicon carbide with d50 in the range of 0.1 μm to 5 μm (¶ 0066; see also ¶ 0115, Examples 1-3); this range falls within the recited range of d50 < 40 μm.
Regarding claim 17, Matsumoto teaches the shaped composite body as claimed in claim 15. Further, Matsumoto teaches that the shaped composite body is manufactured via pressure slip casting with liquid silicon infiltration at temperatures between 1430°C-1800°C (¶¶ 0092-0093); this method of manufacturing is substantially identical to the method described for producing the claimed invention (compare with Applicant’s Specification, p. 6, lines 25-28). Because Matsumoto teaches a shaped composite body substantially identical in composition to the claimed invention and produced by a method substantially identical to the method of producing the claimed invention, one of ordinary skill in the art reasonably would expect that shaped composite body of Matsumoto necessarily would possess physical properties substantially identical to those of the claimed invention—including a density gradient that is < 2%, by weight—since products of identical composition are presumed not to have mutually exclusive properties (see MPEP 2112.01(II)). 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 (see MPEP 2112.01(I), first paragraph).
Regarding claim 18, Matsumoto teaches wherein shaping of the shaped composite body is carried out by slip casting (¶ 0075).
Claim 5, 9, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Matsumoto in view of WO 2005079207 A2 to Aghajanian et al. (hereinafter “Aghajanian”).
Regarding claim 5, Matsumoto teaches the shaped composite body as claimed in claim 1. Further, Matsumoto teaches that the free metallic silicon in the shaped composite body may include impurities, including boron (see ¶¶ 0072-0073). However, Matsumoto does not explicitly teach wherein dissolved boron is contained within the free metallic silicon in a proportion between > 0.05 and <5%, by weight.
Aghajanian, in the same field of endeavor, teaches a composite material comprising a boron carbide filler or reinforcement phase and a silicon carbide matrix produced by the reactive infiltration of an infiltrant having a silicon component (Abstract). Aghajanian teaches that dissolved boron is included in the molten silicon in order to inhibit reaction between the molten silicon and the boron carbide component (p. 12, ¶ 0057). Aghajanian teaches that “a few weight percent of elemental boron” is dissolved in the molten silicon (p. 13, ¶ 0062).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by including dissolved boron within the free metallic silicon in a proportion of “a few weight percent,” as taught by Aghajanian; in this context, “a few weight percent” is interpreted as encompassing amounts (e.g., 3 wt.% or 4 wt.%) that lie within the claimed range of > 0.05 and <5%, by weight. One of ordinary skill in the art would have been motivated to modify Matsumoto as taught by Ide by a desire to minimize or inhibit reaction between molten free metal silicon and the primary grains of boron carbide (B4C), in order to maximize the boron carbide loading within the shaped composite body and also in order to avoid cracking within the shaped composite body (see Aghajanian at p. 12, ¶ 0057).
Regarding claim 9, Matsumoto teaches the shaped composite body as claimed in claim 1. However, Matsumoto does not explicitly teach wherein shaping of the shaped composite body takes place in plate form.
Aghajanian, in the same field of endeavor, teaches wherein shaping of the shaped composite body takes place in plate form (p. 14, ¶ 0064).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping the shaped composite body in plate form, as taught by Aghajanian. One of ordinary skill in the art, equipped with the teachings of Aghajanian, would have found it a straightforward matter to shape the shaped composite body in plate form, with predictable results and a high probability of success. See MPEP 2143(I)(C).
Regarding claim 21, Matsumoto teaches the shaped composite body as claimed in claim 15, as set forth above (see p. 12). However, Matsumoto does not explicitly teach wherein shaping of the shaped composite body takes place in plate form.
Aghajanian, in the same field of endeavor, teaches wherein shaping of the shaped composite body takes place in plate form (p. 14, ¶ 0064).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping the shaped composite body in plate form, as taught by Aghajanian. One of ordinary skill in the art, equipped with the teachings of Aghajanian, would have found it a straightforward matter to shape the shaped composite body in plate form, with predictable results and a high probability of success. See MPEP 2143(I)(C).
Claim(s) 7-8, 19-20, and 23-25 are rejected under 35 U.S.C. 103 as being unpatentable over Matsumoto in view of U.S. Pat. Pub. 2016/0083300 to Ide et al. (hereinafter “Ide”).
Regarding claim 7, Matsumoto teaches the shaped composite body as claimed in claim 1. However, Matsumoto does not explicitly teach wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process.
Ide, in the same field of endeavor, teaches a process for producing a reaction bonded silicon carbide shaped composite body (shaped member) (¶¶ 0001, 0008), the shaped composite body including boron carbide in some embodiments (¶ 0036). Ide teaches wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process (¶ 0110).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping of the shaped composite body via a powder bed 3D printing process, as taught by Ide. One of ordinary skill in the art would be motivated to shape the shaped composite body via a powder bed 3D printing process, as taught by Ide, by a desire to eliminate the need for use of a molding die and to minimize need for post-shaping the resultant shaped composite body (see Ide at ¶ 0041).
Regarding claim 8, Matsumoto as modified by Ide teaches wherein a mixture of SiC and B4C powder (Ide at ¶ 0036) is built up by means of binder (phenol resin, Ide at ¶¶ 0062, 0116) by powder bed printing to give a three-dimensional component (green body, Ide at ¶¶ 0113, 0117) and is subsequently siliconized (Ide at ¶ 0122).
Regarding claim 19, Matsumoto teaches the shaped composite body as claimed in claim 15. However, Matsumoto does not explicitly teach wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process.
Ide, in the same field of endeavor, teaches a process for producing a reaction bonded silicon carbide shaped composite body (shaped member) (¶¶ 0001, 0008), the shaped composite body including boron carbide in some embodiments (¶ 0036). Ide teaches wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process (¶ 0110).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping of the shaped composite body via a powder bed 3D printing process, as taught by Ide. One of ordinary skill in the art would be motivated to shape the shaped composite body via a powder bed 3D printing process, as taught by Ide, by a desire to eliminate the need for use of a molding die and to minimize need for post-shaping the resultant shaped composite body (see Ide at ¶ 0041).
Regarding claim 20, Matsumoto as modified by Ide teaches wherein a mixture of SiC and B4C powder (Ide at ¶ 0036) is built up by means of binder (phenol resin, Ide at ¶¶ 0062, 0116) by powder bed printing to give a three-dimensional component (green body, Ide at ¶¶ 0113, 0117) and is subsequently siliconized (Ide at ¶ 0122).
Regarding claim 23, Matsumoto teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic (¶ 0030; claim 3), a microstructure of which is determined by primary grains of crystalline B4C grains (¶ 0028). Matsumoto teaches B4C grains of mean grain size d50 in the range of 10 μm to 200 μm (¶ 0062); this range overlaps the recited range of > 100 μm in claim 23. In a case where claimed ranges “overlap or lie inside ranges disclosed by the prior art,” a prima facie case of obviousness exists (see MPEP 2144.05). Matsumoto teaches wherein the microstructure is further defined by primary grains of a finer silicon carbide with d50 in the range of 0.1 μm to 5 μm (¶ 0066; see also ¶ 0115, Examples 1-3, teaching silicon carbide powder having an average grain diameter of 0.6 μm), a range that falls within the recited range of d50 < 70 μm. Matsumoto teaches wherein primary grains are siliconized bonded by secondarily formed silicon carbide (¶¶ 0057, 0069). Matsumoto teaches controlled carbon adding (see ¶¶ 0067-0070) that influences a siliconizing procedure (¶ 0057) to implement a silicon carbide matrix comprising primary and secondary silicon carbide portions with a content of free metallic silicon (see ¶¶ 0060, 0072). Matsumoto teaches wherein crystalline B4C grains fractions are embedded in that silicon carbide matrix (see ¶ 0063, describing dispersed B4C grains surrounded and covered with “the reacted product,” i.e., the secondarily formed silicon carbide resulting from the reaction of added carbon with impregnated molten silicon).
Matsumoto teaches that “the preferable mixing ratio of each of the raw materials is 0-45 parts by weight of the carbon source, with respect to the total 100 parts by weight of the 10-90 parts by weight of boron carbide and the 90-10 parts by weight of initial injected silicon carbide” (¶ 0097). Matsumoto also teaches that “the preferable silicon amount,” i.e., the amount of free metallic silicon to be reacted with carbon to produce secondarily formed silicon carbide, “is 105-200% of the silicon amount required for making the carbon transform into silicon carbide and further completely filling the void, and further preferably, 110-150%” (¶ 0101). These taught ranges overlap the recited ranges in claim 1 for primary grains of B4C grains, primary grains of silicon carbide grains, secondarily formed silicon carbide, and free metallic silicon. Within the taught ranges, one of ordinary skill in the would have found it obvious to select amounts for each of the components such that the respective weight percentages would read on the limitations of claim 1. For example, a composition comprising 50 parts per weight of boron carbide (B4C) and 50 parts per weight of silicon carbide (i.e., primary grains of silicon carbide) (see Example 4, ¶ 0116, and Example 6, ¶ 0118), together with 10 parts by weight of carbon black and 35.1 parts by weight of molten silicon would produce, after reaction of the carbon black with the molten silicon, weight percentages outlined in the table below:
Component
Raw Material Parts by Weight
Composite Body Parts by Weight
Composite Body Weight %
B4C
50
50
34.5%
SiC (primary)
50
50
34.5%
Carbon black
10
Metallic Si
35.1
SiC (secondary)
33.4
23.0%
Remaining Metallic Si
11.7
8.1%
(In the above example, the amount of molten silicon initially introduced is 150% of the amount required for making the carbon transform into silicon carbide—see ¶ 0101—and the remainder of unreacted free metallic silicon is deduced from the excess 50% of molten silicon:
(
10 g C
)(
1 mol C
)(
1.50 mol Si
)(
28.086 g Si
)
= 35.1 g Si
12.010 g C
1.00 mol C
1 mol Si
Then, 10 g C react with 23.4 g Si to form 33.4 g SiC, leaving 35.1 – 23.4 = 11.7 g free metallic silicon.) Thus, it would have been obvious, given the teachings of Matsumoto, to produce a shaped composite body wherein a fraction of primary grains of crystalline B4C grains is > 10% by weight, wherein a fraction of primary grains of silicon carbide is > 10% by weight, wherein a fraction of secondarily formed silicon carbide is > 5% by weight, and wherein a content of free metallic silicon is < 20% by weight.
However, Matsumoto does not explicitly teach wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process for wall thickness > 10 mm.
Ide, in the same field of endeavor, teaches a process for producing a reaction bonded silicon carbide shaped composite body (shaped member) (¶¶ 0001, 0008), the shaped composite body including boron carbide in some embodiments (¶ 0036). Ide teaches wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process (¶ 0110). Ide teaches wherein the shaped composite body produced via a powder bed 3D printing process has a wall thickness > 10 mm (see ¶¶ 0113, 0164).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping of the shaped composite body via a powder bed 3D printing process for wall thickness > 10 mm, as taught by Ide. One of ordinary skill in the art would be motivated to shape the shaped composite body via a powder bed 3D printing process, as taught by Ide, by a desire to eliminate the need for use of a molding die and to minimize need for post-shaping the resultant shaped composite body (see Ide at ¶ 0041).
Hence, Matsumoto as modified by Ide teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic reading on every limitation of claim 23.
Regarding claim 24, Matsumoto as modified by Ide teaches primary grains of silicon carbide with d50 in the range of 0.1 μm to 5 μm (see Matsumoto at ¶ 0066); this range falls within the recited range of d50 < 40 μm.
Regarding claim 25, Matsumoto as modified by Ide teaches wherein a mixture of SiC and B4C powder (Ide at ¶ 0036) is built up by means of binder (phenol resin, Ide at ¶¶ 0062, 0116) by powder bed printing to give a three-dimensional component (green body, Ide at ¶¶ 0113, 0117) and is subsequently siliconized (Ide at ¶ 0122).
Claim(s) 10 and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Matsumoto in view of Ide and U.S. Pat. Pub. US2010/0111744 to Schleiss et al. (hereinafter “Schleiss”).
Regarding claim 10, Matsumoto teaches the shaped composite body as claimed in claim 1, as set forth above (see p. 8). Regarding claim 22, Matsumoto teaches the shaped composite body as claimed in claim 15, as set forth above (see p. 12). However, Matsumoto does not explicitly teach wherein shaping of the shaped composite body is performed with an envelope volume > 200 x 200 x 200 mm.
Ide, in the same field of endeavor, teaches a process for producing a reaction bonded silicon carbide shaped composite body (shaped member) (¶¶ 0001, 0008), the shaped composite body including boron carbide in some embodiments (¶ 0036). Ide teaches wherein shaping of the shaped composite body is carried out via a selective laser sintering (SLS) 3D printing process (¶ 0110; Abstract). It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping of the shaped composite body via a powder bed 3D printing process, as taught by Ide. One of ordinary skill in the art would be motivated to shape the shaped composite body via a powder bed 3D printing process, as taught by Ide, by a desire to eliminate the need for use of a molding die and to minimize need for post-shaping the resultant shaped composite body (see Ide at ¶ 0041).
Matsumoto as modified by Ide does not explicitly teach that shaping of the shaped composite body is performed with an envelope volume > 200 x 200 x 200 mm.
Schleiss, in the related field of endeavor of selective laser sintering (SLS) 3D printing processes (Abstract), teaches a 3D printing process in which shaping of a shaped composite body is performed in a processing chamber with an envelope volume that “best measures” 0.2 m3 to 3 m3 (¶ 0050), which is considerably larger than the 200 x 200 x 200 mm = 8,000,000 mm3 = 0.008 m3 recited in claims 10 and 22.
It would have been obvious to one of ordinary skill in the art to use the teachings of Schleiss to modify Matsumoto as modified by Ide to the extent of performing the 3D printing process in an envelope volume of 0.2 m3 to 3 m3, as taught by Schleiss. Design incentives and market forces—e.g., demand for ballistic armor of a large size, for instance for vehicle panels—would have prompted one of ordinary skill in the art to look to Schleiss. One of ordinary skill in the art would have found it a straightforward matter to adapt the teaching of Schleiss to the teachings of Matsumoto as modified by Ide, with predictable results and a high probability of success. See MPEP 2143(I)(F).
Claim 26 is rejected under 35 U.S.C. 103 as being unpatentable over Matsumoto in view of Ide as applied to claim 23 above, and further in view of Aghajanian.
Regarding claim 26, Matsumoto in view of Ide teaches the shaped composite body as claimed in claim 23, as set forth above (see p. 19). However, Matsumoto as modified by Ide does not explicitly teach wherein shaping of the shaped composite body takes place in plate form.
Aghajanian, in the same field of endeavor, teaches wherein shaping of the shaped composite body takes place in plate form (p. 14, ¶ 0064).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto as modified by Ide by shaping the shaped composite body in plate form, as taught by Aghajanian. One of ordinary skill in the art, equipped with the teachings of Aghajanian, would have found it a straightforward matter to shape the shaped composite body in plate form, with predictable results and a high probability of success. See MPEP 2143(I)(C).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Matsumoto in view of Ide and U.S. Pat. No. 8,128,861 to Aghajanian et al. (hereinafter “Aghajanian II”).
Regarding claim 27, Matsumoto teaches a shaped composite body of a reaction-bonded, silicon-infiltrated mixed ceramic (¶ 0030; claim 3), a microstructure of which is determined by primary grains of crystalline B4C grains (¶ 0028). Matsumoto teaches B4C grains of mean grain size d50 in the range of 10 μm to 200 μm (¶ 0062); this range overlaps the recited range of > 100 μm in claim 27. In a case where claimed ranges “overlap or lie inside ranges disclosed by the prior art,” a prima facie case of obviousness exists (see MPEP 2144.05). Matsumoto teaches wherein the microstructure is further defined by primary grains of a finer silicon carbide with d50 in the range of 0.1 μm to 5 μm (¶ 0066; see also ¶ 0115, Examples 1-3, teaching silicon carbide powder having an average grain diameter of 0.6 μm), a range that falls within the recited range of d50 < 70 μm. Matsumoto teaches wherein primary grains are siliconized bonded by secondarily formed silicon carbide (¶¶ 0057, 0069). Matsumoto teaches controlled carbon adding (see ¶¶ 0067-0070) that influences a siliconizing procedure (¶ 0057) to implement a silicon carbide matrix comprising primary and secondary silicon carbide portions with a content of free metallic silicon (see ¶¶ 0060, 0072). Matsumoto teaches wherein crystalline B4C grains fractions are embedded in that silicon carbide matrix (see ¶ 0063, describing dispersed B4C grains surrounded and covered with “the reacted product,” i.e., the secondarily formed silicon carbide resulting from the reaction of added carbon with impregnated molten silicon).
Matsumoto teaches that “the preferable mixing ratio of each of the raw materials is 0-45 parts by weight of the carbon source, with respect to the total 100 parts by weight of the 10-90 parts by weight of boron carbide and the 90-10 parts by weight of initial injected silicon carbide” (¶ 0097). Matsumoto also teaches that “the preferable silicon amount,” i.e., the amount of free metallic silicon to be reacted with carbon to produce secondarily formed silicon carbide, “is 105-200% of the silicon amount required for making the carbon transform into silicon carbide and further completely filling the void, and further preferably, 110-150%” (¶ 0101). These taught ranges overlap the recited ranges in claim 1 for primary grains of B4C grains, primary grains of silicon carbide grains, secondarily formed silicon carbide, and free metallic silicon. Within the taught ranges, one of ordinary skill in the would have found it obvious to select amounts for each of the components such that the respective weight percentages would read on the limitations of claim 1. For example, a composition comprising 50 parts per weight of boron carbide (B4C) and 50 parts per weight of silicon carbide (i.e., primary grains of silicon carbide) (see Example 4, ¶ 0116, and Example 6, ¶ 0118), together with 10 parts by weight of carbon black and 35.1 parts by weight of molten silicon would produce, after reaction of the carbon black with the molten silicon, weight percentages outlined in the table below:
Component
Raw Material Parts by Weight
Composite Body Parts by Weight
Composite Body Weight %
B4C
50
50
34.5%
SiC (primary)
50
50
34.5%
Carbon black
10
Metallic Si
35.1
SiC (secondary)
33.4
23.0%
Remaining Metallic Si
11.7
8.1%
(In the above example, the amount of molten silicon initially introduced is 150% of the amount required for making the carbon transform into silicon carbide—see ¶ 0101—and the remainder of unreacted free metallic silicon is deduced from the excess 50% of molten silicon:
(
10 g C
)(
1 mol C
)(
1.50 mol Si
)(
28.086 g Si
)
= 35.1 g Si
12.010 g C
1.00 mol C
1 mol Si
Then, 10 g C react with 23.4 g Si to form 33.4 g SiC, leaving 35.1 – 23.4 = 11.7 g free metallic silicon.) Thus, it would have been obvious, given the teachings of Matsumoto, to produce a shaped composite body wherein a fraction of primary grains of crystalline B4C grains is > 10% by weight, wherein a fraction of primary grains of silicon carbide is > 10% by weight and < 50% by weight, wherein a fraction of secondarily formed silicon carbide is > 5% by weight, and wherein a content of free metallic silicon is < 20% by weight.
Matsumoto does not explicitly teach wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process.
Ide, in the same field of endeavor, teaches a process for producing a reaction bonded silicon carbide shaped composite body (shaped member) (¶¶ 0001, 0008), the shaped composite body including boron carbide in some embodiments (¶ 0036). Ide teaches wherein shaping of the shaped composite body is carried out via a powder bed 3D printing process (¶ 0110).
It would have been obvious to one of ordinary skill in the art to modify Matsumoto by shaping of the shaped composite body via a powder bed 3D printing process, as taught by Ide. One of ordinary skill in the art would be motivated to shape the shaped composite body via a powder bed 3D printing process, as taught by Ide, by a desire to eliminate the need for use of a molding die and to minimize need for post-shaping the resultant shaped composite body (see Ide at ¶ 0041).
Matsumoto as modified by Ide does not explicitly teach wherein the shaped composite body is combined with at least one layer of a backing material comprising at least one of a polymer, a carbon fiber, a glass fiber, a metal, or combinations thereof, and a composite structure comprising the shaped composite body and the backing material is configured to provide ballistic protection against ammunition comprising a tungsten carbide-cobalt (WC/Co) core, including M993 and M995 ammunition types.
Aghajanian II, in the same field of endeavor, teaches boron carbide reinforced silicon carbide composite materials as armor for stopping ballistic projectiles (Col. 12, lines 46-52). Aghajanian II teaches a ballistic armor system that includes a ceramic layer and a backing layer (Col. 17, lines 36-40). Aghajanian II teaches wherein the backing layer material comprises at least one of a polymer, a glass fiber, and a metal (such as aluminum, iron, or titanium) (Col. 17, lines 50-56). Aghajanian II teaches wherein a composite structure comprising the shaped composite body and the backing material is configured to provide ballistic protection against ammunition comprising a tungsten carbide-cobalt (WC/Co) core, including M993 ammunition type (Col. 45, lines 23-29
It would have been obvious to one of ordinary skill in the art to modify Matsumoto as modified by Ide in order to combine the shaped ceramic body with at least one layer of a backing material comprising at least one of a polymer, a glass fiber, and a metal, and to configure the shaped ceramic body and the at least one layer of backing material to provide ballistic protection against ammunition comprising a tungsten carbide-cobalt (WC/Co) core, including M993 ammunition type, as taught by Aghajanian II. One of ordinary skill in the art would be motivated to include at least one layer of a backing material in order to “catch” any backward propelled fragments of the shaped ceramic body when that shaped ceramic body is impacted by a bullet (see Aghajanian II at Col. 17, lines 46-48).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
U.S. Pat. No. 3,765,300 to Taylor et al. (“Taylor”) teaches composite ceramic bodies of boron carbide, silicon carbide and silicon, particularly useful as ceramic armor, produced by forming a mixture of granular boron carbide and a temporary binder into a desired shape and setting the binder to obtain a coherent green body which is siliconized at a temperature in the range of about 1500-2200°C, whereupon molten silicon infiltrates the body and reacts with some of the boron carbide (Abstract).
U.S. Pat. No. 5,019,430 to Higgins et al. (“Higgins”) teaches a method of producing a silicon carbide-based body by infiltrating with molten silicon a porous compact comprising silicon carbide, carbon, and a secondary phase dispersed within the compact, the secondary phase comprising a titanium compound or a metal carbide (Abstract). In some embodiments, the metal carbide is boron carbide (claim 7).
U.S. Pat. Pub. 2020/0189145 to Cramer et al. (“Cramer”) teaches a method for indirect additive manufacturing of an object constructed of boron carbide, silicon carbide, and free silicon, comprising: (i) producing a porous preform constructed of boron carbide and silicon carbide by an indirect ceramic additive manufacturing (ICAM) process in which particles of a powder mixture become bonded together with an organic binder, wherein the powder mixture comprises: a) boron carbide particles, and b) silicon carbide particles, wherein at least 80 vol % of the silicon carbide particles are larger than the boron carbide particles; and wherein the boron carbide and silicon carbide particles are each included in an amount of 40-60 wt. % of the powder mixture, provided that the foregoing amounts sum to at least 95 wt. %; (ii) subjecting the porous preform to a temperature of 500-900° C. to volatilize the organic binder; and (iii) infiltrating molten silicon into pores of the porous preform to produce the object.
U.S. Pat. Pub. 2023/0034822 to Sant et al. (“Sant”) teaches an antiballistic armor-plating component that includes a ceramic body made of a material comprising, as percentages by volume, between 35% and 55% of silicon carbide, between 20% and 50% of boron carbide, and between 15% and 35% of a metallic silicon phase or of a metallic phase including silicon (Abstract).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PAUL A. FORSYTH whose telephone number is (703) 756-5425. The examiner can normally be reached M - Th 8:00 - 5:30 EDT and F