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 .
Claim Status
An amendment, filed 8/10/2026. Claims 7-9 are canceled; claims 14-21 are newly added. Claims 1-6 and 10-21 are currently pending, claims 1-6 are withdrawn.
Election/Restrictions
Applicant’s election without traverse of Group II, Claims 10-13 and newly added claims 14-22, in the reply filed on 8/10/2026 is acknowledged.
Claims 1-6 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected group I (claims 7-9 drawn to Group I have been canceled), there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 8/10/2026.
Claim Objections
Claim 10 is objected to because of the following informalities: Elected claim 10, drawn to a method, depends on the powder of claim 1, now withdrawn. Claim 10 should be amended to incorporate the subject matter of claim 1. Appropriate correction is required.
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.
Claim 19-21 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.
Claim 19 recites the limitation "the first powder" in line 2 and “the second powder” in line 3. There is insufficient antecedent basis for these limitations in the claim.
Claim 20 recites the limitation "the first powder" in line 1 and “the second powder” in line 2. There is insufficient antecedent basis for these limitations in the claim.
Claim 21 recites the limitation "the first powder" in line 1 and “the second powder” in line 2. There is insufficient antecedent basis for these limitations in the claim. Additionally, it is unclear if the claim attempts to modify the required oxygen content of 950 ppm or less for the group of particles, as the recited second powder has an oxygen content exceeding 950 ppm. If interpreted to exceed the oxygen content of 950 ppm, the claim would also be subject to a rejection under 35 U.S.C. 112(d).
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 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.
Claim(s) 10-15, 17-18, and 20-21 are rejected under 35 U.S.C. 103 as being unpatentable over Ohmori et al. (US 2025/0229327) in view of Dougherty (US 2024/0058865) and Chung (US 2022/0339704).
With respect to Claims 10 and 21, Ohmoro teaches a method of additively manufacturing a 3D object using a binder jetting technique, the method comprising forming a powder layer of an aluminum or aluminum alloy powder, selectively applying a liquid binder to the powder layer by jetting (i.e. a modeling liquid), repeating the formation of the powder layer and the application of the modeling liquid to form a green body comprising a multilayer stack of bound powder having the desired geometry of the object, and sintering the green body to obtain the 3D object. (para. 6-8, 116-121).
Ohmori teaches wherein the binder/modeling liquid comprises a resin and a solvent, in particular, wherein the solvent may be an organic solvent and/or water. (para. 7, 38, 116). The reference teaches wherein the modeling liquid comprises a resin and an organic solvent and specifically envisions a solvent without water addition, and therefore, is deemed to teach where the modeling liquid is substantially free of water.
Additionally, Ohmori teaches wherein the aluminum or aluminum alloy powder has an oxygen content of 0.5 mass% or less, preferably, 0.05-0.3 mass%, in order to suppress the influence of oxide film generated on the surfaces of the powder particles improving sinterability. (para. 24, 28, 59, 79). Ohmori teaches wherein the aluminum powder has a volume-based 50% cumulative particle diameter of 10 to 50 microns. (para. 30)
Thus, Ohmori teaches a method comprising each of the steps of claim 10, wherein the powder comprises a group of particles having an identical aluminum or aluminum alloy composition wherein the group of particles includes 50% by mass or greater of aluminum and an oxygen content overlapping the instantly claimed range. It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Ohmori further teaches wherein the aluminum or aluminum alloy powder has a volume-based 50% cumulative particle diameter (D50) of 10 to 50 microns, and thus, is drawn to a powder having particle size encompassing the recited peaks at 40-70 microns and 10-30 microns (para. 73-78); however, the reference does not specifically teach a particle distribution having the two peak tops as instantly claimed.
Chung teaches a method of additive manufacturing comprising metal particles, wherein “the metal particles have a particle size in a range from 1 μm to 200 μm. A particle size or size range can represent an average size or diameter (e.g., approximate or equivalent spherical diameter) of a particle size distribution, for example a number-, mass-, or volume-average size or diameter. A particle size or size range can alternatively or additionally represent lower and upper boundaries of a size particle size distribution, for example minimum/maximum particles sizes resulting from sieve cuts, 1%/99% sizes from a cumulative size distribution, 5%/95% sizes from a cumulative size distribution, etc. For example, the particle size of the metal particles can be at least 1, 2, 5, 10, 15, 20, 30, 40, 50, or 60 μm and/or up to 10, 20, 30, 40, 50, 60, 80, 100, 120, 150, or 200 μm. In some embodiments, the metal particle suspension can include two or more different types of metal particles having different size or size distribution characteristics, for example being formed from the same or different materials. For example, two different types of metal particles can have average sizes (number-, mass-, or volume-average sizes) in a ratio ranging from 1.5:1 to 10:1 (e.g., at least 1.5:1, 2:1, or 3:1 and/or up to 3:1, 5:1, 8:1, or 10:1 with the first powder having the larger average size). In another refinement, the boron-containing particles (or sintering aid more generally) have a particle size in a range from 0.01 μm to 20 μm (e.g., a number-, mass-, or volume-average size or diameter, such as at least 0.01, 0.1, 0.2, 0.5, or 1 μm and/or up to 1, 2, 3, 5, 10, or 20 μm, for example 0.1 μm to 3 μm or 0.2 μm to 2 μm). In another refinement, the metal particles and the boron-containing particles have average sizes (number-, mass-, or volume-average sizes) in a ratio in a range from 5:1 to 100:1 (e.g., at least 5:1, 10:1, 15:1, or 20:1, or 30:1 and/or up to 30:1, 50:1, 80:1, or 100:1 with the metal particles having the larger average size).” (para. 6, 71).
Thus, Chung teaches selecting metal particles for additive manufacturing having a bimodal size distribution with a first set of particles having a larger particle size, a second set of particles having a smaller particle size, and controlling both the respective particles sizes and the ratio of the larger and smaller particle sizes. Chung teaches that the selection of such particle size distributions is a result effective variable. (see para. 27 reciting “a maximum cure depth (or equivalently, a maximum layer thickness) is generally directly proportional to metal particle size: Smaller particles have more scattering and lower cure depths, while larger particles have less scattering and higher cure depths. As a counter to the scattering effect, the undesirable settling of metal particles in a layer after application increases with increasing size: Larger particles settle relatively more rapidly than smaller particles, possibly leading to an inhomogeneous, segregated spatial distribution of metal particles before full curing, which in turn results in an inhomogeneous metal particle distribution in the eventual green part and a misshapen final sintered part. This settling inhomogeneity for relatively larger particles is more pronounced in relatively thicker layers.”).
Dougherty teaches a method of binder jetting additive manufacturing for forming a 3D object by successive steps of depositing an aluminum alloy powder selectively depositing a binder on each layer, followed by sintering, wherein the aluminum alloy powder comprises a particle size of 2-75 microns and may exhibit a bimodal particle distribution. (para. 2, 8, 11-15, 22-27). Thus, Dougherty teaches the utility of a bimodal particle size distribution for aluminum powders used in binder jet additive manufacturing.
Thus, Ohmori and Dougherty are both drawn to binder jet additive manufacturing methods of forming an object from an aluminum powder having an overlapping particle size range. It would have been obvious to one of ordinary skill in the art to modify the method of Ohmori to select an aluminum/aluminum alloy powder having a bimodal particle size distribution from the overlapping portion of the size ranges, in order to obtain an aluminum/aluminum alloy powder with good characteristics for binder jet additive manufacturing.
Furthermore, in view of the teachings of Chung, it would have been obvious to one of ordinary skill in the art to select an aluminum powder having a bimodal particle size distribution with a first peak top in a particle diameter range of 40-70 microns and a second peak top in a particle size diameter range of 10-30 microns wherein a ratio of the frequency of the first and second peak tops is 1.5 or greater, in order to balance powder properties such as flowability, sinterability, and layer uniformity. In other words, Chung teaches tailoring the particle size distribution of a metal powder, including within the overlapping particle diameter range, peak tops, and frequency ratio. It would have been obvious to one of ordinary skill in the art to modify the method of Ohmori in view of Dougherty and Chung to select from the portions of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 11, Ohmori teaches a binder jet method wherein the modeling liquid (binder) is ejected at high speed. (see para. 83). Dougherty, also drawn to a binder jet method, teaches that such methods are known to comprise an inkjet printhead to carry out the ejection of the modeling liquid. (para. 8, 22). Accordingly, in view of Ohmori and Dougherty, it would have been obvious to one of ordinary skill in the art to modify the method Ohmori in view of Dougherty and Chung to apply the modeling liquid comprising ejecting the modeling liquid by inkjet printing, as taught by Dougherty, in order to selectively eject/jet the modeling liquid on layers of powder.
With respect to Claim 12, Ohmori teaches removing unnecessary powder (i.e. powder not bound by the selective deposition of modeling liquid) and sintering the green body. (para. 116-119). The reference also teaches wherein the modeling liquid comprises a thermosetting resin, thermoplastic resin, or a photocurable resin, and thus, teaches a modeling liquid comprising one or more resins that require a heating step to cure/set. As taught by Ohmori, heating the multilayer stack is known to reduce curing time and therefore, the reference teaches a heating step prior to an excess powder removal step. (para. 31-33). Accordingly, it would have been obvious to one of ordinary skill in the art to carry out one or more heating steps to cure the individual layers and including the multilayer stack, as taught by Ohmori and/or Dougherty, followed by removing excess powder deposited on the compact in order to obtain a compact for sintering.
With respect to Claim 13, Ohmori teaches sintering the compact and one of ordinary skill in the art would recognize that such a sintering step also comprises removing the binder/resin. (para. 116-134). The claim is not interpreted to require separate heating steps so long as the compact is heated at a temperature sufficient for removing the resin and sintering as the binder would be removed prior to sintering. Dougherty teaches that after excess powder is removed, the compact is subjected to a binder burnout (i.e. debinding) step and then a sintering process. (para. 34). It would have been obvious to one of ordinary skill in the art to carry out a step of heating to remove the resin from the compact and heating, as taught by Ohmori, in order to form a solidified object. Alternatively, it would have been obvious to one of ordinary skill in the art to modify the method of Ohmori to first carry out a resin removal step by heating the compact, followed by a step of heating to sinter the resin-removed compact, as taught by Dougherty, in order to ensure uniform and/or complete resin removal and sintering and to obtain a solidified aluminum-based object.
With respect to Claims 14-15, 18, and 20, Ohmori in view of Dougherty and Chung teach a method comprising controlling the particle size (including D10 and D90), particle size distribution, and relative frequency/abundance of particle sizes, including ranges overlapping the instantly claimed ranges. (see rejection of claim 10 above; see also Ohmori, para. 30-33, 74-78). It would have been obvious to one of ordinary skill in the art to select an aluminum powder having a particle size distribution, including D10 and D90 values and contents of particles having first and second sizes, meeting the respectively claimed properties of cl aims 14-15, 18, and 20, from the overlapping portions of the ranges, in order to balance powder properties such as flowability, sinterability, and layer uniformity. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05. Furthermore, with respect to Claim 18, Chung specifically teaches using two separate powders of the same composition to achieve the desired first and second particle sizes and combined particle size distribution. (see para. 23, 26, 27).
Claim(s) 16 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Ohmori et al. (US 2025/0229327) in view of Dougherty (US 2024/0058865) and Chung (US 2022/0339704), as applied to claim 10 above, further in view of Conlon (US 2026/0166621).
With respect to Claim 16, Ohmori in view of Dougherty and Chung are silent as to the moisture content of the powder for forming 3D objects.
Conlon teaches metal powder, and method of making thereof, the powder suitable for additive manufacturing, wherein the powder comprises a moisture content of 150 ppm or less and oxygen content of 900 ppm or less. (para. 24-25, 65-76). The reference teaches that the metal powder may comprise an aluminum alloy and has the benefit of improved utility for additive manufacturing techniques while also being non-combustible and non-explosible. (para. 1, para. 26-29).
Thus, Ohmori, Dougherty, Chung and Conlon are drawn to methods comprising metal powders, including aluminum-based powders, for additive manufacturing. It would have been obvious to one of ordinary skill in the art to modify the method of Ohmori in view of Dougherty and Chung, to select an aluminum powder having a low oxygen content and moisture content of 150 ppm or less, as taught by Conlon, in order to obtain an aluminum-based powder suitable for the method of additive manufacturing while also reducing risks of combustion and explosion.
With respect to Claim 19, Ohmori teaches wherein the powder has a spherical shape or shape similar to a spherical shape (see, e.g. para. 86), but is silent as to specific sphericity value(s).
Conlon teaches metal powder, and method of making thereof, the powder suitable for additive manufacturing, wherein the powder comprises a sphericity of 0.85 or more, including 0.95 or more. (para. 57, 65)(see also rejection of claim 16 above). The reference teaches that the metal powder may comprise an aluminum alloy and has the benefit of improved utility for additive manufacturing techniques while also being non-combustible and non-explosible. (para. 1, para. 26-29).
Thus, Ohmori, Dougherty, Chung and Conlon are drawn to methods comprising metal powders, including aluminum-based powders, for additive manufacturing. It would have been obvious to one of ordinary skill in the art to modify the method of Ohmori in view of Dougherty and Chung teaching first and second powders (see rejection of claim 18), to select first and second powders having respective sphericity values of 0.85 or more, as taught by Conlon, deemed to teach contents of first and second particles having sphericity values overlapping the respectively claimed ranges, in order to obtain an aluminum-based powder suitable for the method of additive manufacturing while also reducing risks of combustion and explosion. In other words, it would have been obvious to one of ordinary skill in the art selecting from the overlapping sphericity values to select a first powder having a first sphericity value (wherein all or substantially all of the powder particles have said first sphericity value) and to select a second powder having a second sphericity value (wherein all or substantially all of the powder particles have said second sphericity value), from overlapping portions of the ranges. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Hu (US 2023/0175630) comprising a bimodal metal powder particle distribution, but not drawn to method of additive manufacturing as in claim 10.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN A HEVEY whose telephone number is (571)270-0361. The examiner can normally be reached Monday-Friday 9:00-5:30.
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/JOHN A HEVEY/ Primary Examiner, Art Unit 1735
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