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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 August 3, 2026, has been entered.
Response to Amendment
Applicant’s amendment (August 3, 2026) has been entered. Claims 1-6 and 9-20 are pending. Claims 7 and 8 are cancelled. Amendment has overcome the rejections under 35 USC 102(a)(1) over Smith et al. “Development and Processing of Novel Aluminum Powder Metallurgy Materials for Heat Sink Applications”.
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) 1-6, 9-16 and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dougherty (US20240058865). Dougherty is cited in the advisory action mailed August 18, 2026. Dougherty is the publication of an application for patent in the United States
Regarding claim 1, Dougherty discloses a densified alloy produced ([0011], [0050], claim 1) produced by liquid phase sintering in binder jet printing (binder jet additive manufacturing) (abstract, [0011], [0013], [0050], [0053], claim 1). Dougherty discloses that the densified alloy comprises a mixture of aluminum, magnesium, and a densification aid which is tin (abstract, [0011], [0014], [0024], [0027], [0051-52], claim 1, claim 6). Dougherty discloses that an amount of magnesium is between 0.5% to 5% by weight of the composition ([0011], [0014], [0024], claim 1), which overlaps a range of 2.5% to 6.5% by weight of the mixture. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II). Dougherty discloses that the densified alloy is densified to a density of greater than 95% of its theoretical density by liquid phase sintering (abstract, [0011], [0013], [0027-28], [0035], [0041], [0053], [0057], claim 1).
The proportion of liquid phase during liquid phase sintering is a condition of the densification step within a process of forming a densified product; therefore, the limitation of densifying at a liquid phase fraction between about 8% to about 20% is a product-by-process limitation for which patentability is determined by the structure implied by the process steps and not by manipulation of the steps. See MPEP 2113. The present specification states: “if about 8% liquid phase is produced during LPS, then full density can be achieved for the four powder materials. Specifically, full densities are achieved if >10% liquid phase fraction is produced during LPS. Once the liquid phase fractions are above 20%, however, it is possible to lose dimensional accuracy for the final bodies” (paragraph [0029] of the disclosure as filed). In remarks filed August 3, 2026, in describing the structure implied by the liquid phase sintering, applicant argues “LPS [liquid phase sintering] involves heating the alloy to a temperature between its solidus and liquidus temperatures so that a controlled amount of liquid phase is generated”. Dougherty discloses liquid phase sintering at a temperature above the solidus (super-solidus) wherein the aluminum part has a density of at least 95% [0013], [0027], [0038] while retaining dimensional accuracy (retain geometry of the printed part) [0040]. Dougherty therefore meets structure implied by densifying by liquid phase sintering at a liquid phase fraction between about 8% to about 20%.
Regarding claims 2-4, Dougherty discloses that the magnesium, the aluminum and the tin are blended to form a single build powder [0026] thereby disclosing that the mixture from which the densified product is formed at some stage has a form which meets the broadest reasonable interpretation of an alloy powder.
Regarding claim 5, Dougherty discloses that an amount of magnesium is between 0.5% to 5% by weight of the composition ([0011], [0014], [0024], claim 1), which encompasses a range of 2.5% to 4% by weight of the mixture. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II).
Regarding claim 6, Dougherty discloses that an amount of the densification aid, which Dougherty discloses as tin is about 0.1 to about 3.0 weight % of the mixture ([0011], [0013-14], [0028], [0050] claim 6), which encompasses a range of about 1% by weight of the mixture. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II).
Regarding claim 9, Dougherty discloses embodiments wherein the aluminum is an aluminum alloy [0015], [0024].
Regarding claim 10, Dougherty discloses a method to form a densified alloy by liquid phase sintering in binder jet printing (abstract, [0011], [0013], [0050], [0053], claim 1). Dougherty discloses mixing aluminum, magnesium, a densification aid which is tin to form a mixture (abstract, [0011], [0014], [0024], [0026-27], [0051-52], claim 1, claim 6). Dougherty discloses that an amount of magnesium is between 0.5% to 5% by weight of the composition ([0011], [0014], [0024], claim 1), which overlaps a range of about 2.5% to 6.5% by weight of the mixture. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II). Dougherty discloses selectively combining the mixture with a binder to form a shape [0021-22]. Dougherty discloses debinding the mixture [0030], [0034]. Dougherty discloses liquid phase sintering the mixture with nitrogen (abstract, [0011], [0021], [0042], [0046]).
Regarding claim 11, Dougherty discloses holding the mixture at about 470
°
C to about 560
°
C between the start of debinding and liquid phase sintering [0037]. A range of 470
°
C to about 560
°
C either directly meets or encompasses a temperature of about 500°C When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II). Applicant is reminded of statements regarding claim 11 in prior office actions by the previous examiner: “[t]here are numerous interpretations of how this disclosure from Smith [or in the present instance Dougherty] could read on the claim as currently presented; please note, there are no bounds to the duration of the hold nor is there any recitation of the debinding conditions or liquid phase sintering conditions. As one example, the increasing of the temperature from the de-binding to the hold at 30 minutes for sintering at 630C could meet the claimed ‘holding’ at about 500C because the increase in temperature from 400C to 630C would necessarily pass through the temperature of 500C for some duration such that a ‘hold’ at or around 500C would necessarily occur.”
Regarding claims 12-14, Dougherty discloses that the magnesium, the aluminum and the tin are blended to form a single build powder [0026] thereby disclosing that the mixture from which the densified product is formed at some stage has a form which meets the broadest reasonable interpretation of an alloy powder.
Regarding claim 15, Dougherty discloses that an amount of magnesium is between 0.5% to 5% by weight of the composition ([0011], [0014], [0024], claim 1), which encompasses a range of 2.5% to 4% by weight of the mixture. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II).
Regarding claim 16, Dougherty discloses that an amount of the densification aid, which Dougherty discloses as tin is about 0.1 to about 3.0 weight % of the mixture ([0011], [0013-14], [0028], [0050] claim 6), which encompasses a range of about 1% by weight of the mixture. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II).
Regarding claim 18, Dougherty discloses embodiments wherein the aluminum is an aluminum alloy [0015], [0024].
Regarding claim 19, Dougherty discloses a densified alloy produced ([0011], [0050], claim 1) produced by liquid phase sintering in binder jet printing (binder jet additive manufacturing) (abstract, [0011], [0013], [0050], [0053], claim 1). Dougherty discloses that the densified alloy comprises a mixture of aluminum, magnesium, and a densification aid which is tin (abstract, [0011], [0014], [0024], [0027], [0051-52], claim 1, claim 6). Dougherty discloses that an amount of the densification aid, which Dougherty discloses as tin is about 0.1 to about 3.0 weight % of the mixture ([0011], [0013-14], [0028], [0050] claim 6), which encompasses a range of about 1% by weight of the mixture. Dougherty discloses that an amount of magnesium is between 0.5% to 5% by weight of the composition ([0011], [0014], [0024], claim 1), which overlaps a range of 2.5% to 6.5% by weight of the mixture. Doughertty discloses that the aluminum is provided as 5XXX or 6XXX series aluminum [0015], [0024] all of which are alloys for which aluminum is the predominant constituent and therefore the remainder when accounting for all elements of the mixture. The composition disclosed by Dougherty ([0011], [0013-15], [0024], [0028], claim 1, claim 6) overlaps that recited in claim 19. When claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists, and generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. See MPEP 2144.05(I-II). Dougherty discloses that the densified alloy is densified to a density of greater than 95% of its theoretical density by liquid phase sintering (abstract, [0011], [0013], [0027-28], [0035], [0041], [0053], [0057], claim 1).
The proportion of liquid phase during liquid phase sintering is a condition of the densification step within a process of forming a densified product; therefore, the limitation of densifying at a liquid phase fraction between about 8% to about 20% is a product-by-process limitation for which patentability is determined by the structure implied by the process steps and not by manipulation of the steps. See MPEP 2113. The specification states: “if about 8% liquid phase is produced during LPS, then full density can be achieved for the four powder materials. Specifically, full densities are achieved if >10% liquid phase fraction is produced during LPS. Once the liquid phase fractions are above 20%, however, it is possible to lose dimensional accuracy for the final bodies” (paragraph [0029] of the disclosure as filed). In remarks filed August 3, 2026, in describing the structure implied by the liquid phase sintering, applicant argues “LPS [liquid phase sintering] involves heating the alloy to a temperature between its solidus and liquidus temperatures so that a controlled amount of liquid phase is generated”. Dougherty discloses liquid phase sintering at a temperature above the solidus (super-solidus) wherein the aluminum part has a density of at least 95% [0013], [0027], [0038] while retaining dimensional accuracy (retain geometry of the printed part) [0040]. Dougherty therefore meets structure implied by densifying by liquid phase sintering at a liquid phase fraction between about 8% to about 20%.
Regarding claims 20, Dougherty discloses that the magnesium, the aluminum and the tin are blended to form a single build powder [0026] thereby disclosing that the mixture from which the densified product is formed at some stage has a form which meets the broadest reasonable interpretation of an alloy powder.
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Dougherty (US20240058865) as applied to claim 10 above, and further in view of Kato (US20240033819). Kato is the publication of an application for patent in the United States, effectively filed prior to the earliest effective filing date of the present application.
Regarding claim 17, Dougherty discloses that the densified alloy is densified to a density of greater than 95% of its theoretical density by liquid phase sintering (abstract, [0011], [0013], [0027-28], [0035], [0041], [0053], [0057], claim 1). Dougherty discloses that a liquid phase is present in the liquid phase sintering [0013], [0027], [0038]. Dougherty discloses sintering at a temperature sufficient for the mixture to reach a super-solidus state [0034]. Dougherty discloses a temperature of 610
°
C to about 660
°
C so that the temperature at which a portion but not all of the material is in the liquid phase [0040]. Dougherty is silent on the proportion of liquid during the liquid phase sintering.
Kato teaches a method to form a densified alloy by liquid phase sintering in binder jet printing [0017], [0034], [0041], [0072]. Kato teaches mixing aluminum and magnesium to form a mixture [0017], [0031]. Kato teaches selectively combining the mixture with a binder to form a shape [0041], [0072], [0074]. Kato teaches debinding (degreasing) the mixture [0041], [0061], [0074]. Kato teaches liquid phase sintering the mixture [0018], [0038], [0042], [0068], [0075-76]. Kato teaches densification of the densified alloy to a high relative density [0016], [0024], [0038], [0042-43], [0082]. Kato teaches it is desirable to select conditions such that the amount of liquid phase able to be estimated at approximately 10 to 30% of the total aluminum mixture [0086], [0091]. Kato teaches that when the proportion of liquid phase is reduced, the sintering may be insufficient [0068]. Kato further teaches that if the amount of liquid phase during sintering may become excessive, the shape retention rate after sintering may be poor, and it may not be possible to obtain a sintered product with the desired shape [0068].
Both Dougherty and Kato teach similar processes for producing a densified aluminum alloy part by liquid phase sintering in a binder jetting process.
It would have been obvious for one of ordinary skill in the art, at the time of filing to density in the liquid phase sintering disclosed by Dougherty applied above, at a proportion of liquid phase of about 10% to about 30% because Kato teaches that reduced liquid phase in sintering may result in insufficient sintering [0068], that excessive liquid phase may result in poor shape retention [0068], and that a proportion of liquid between about 10% and about 30% is targeted to achieve the favorable results [0086], [0091]. The liquid phase sintering disclosed by Dougherty (abstract, [0011], [0013], [0027-28], [0035], [0041], [0053], [0057], claim 1) must necessarily occur with some proportion of liquid phase, and the liquid proportion of about 10-30% taught by Kato [0086], [0091], would predictably yield the results of controlling the proportion of liquid phase in the sintering taught by Kato [0068], which yield the intended result of the liquid phase sintering disclosed by Dougherty [0027], [0038], [0040].
Response to Arguments
Applicant’s arguments, see arguments regarding Smith (Smith et al. “Development and Processing of Novel Aluminum Powder Metallurgy Materials for Heat Sink Applications”.), filed August 30, 2026, with respect to the rejection(s) of claim(s) 1-6 and 9-20 under 35 USC 102(a)(1) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Dougherty (US20240058865).
Note that the present statements of rejection expressly consider applicant’s remarks regarding product-by-process limitations.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SEAN P O'KEEFE whose telephone number is (571)272-7647. The examiner can normally be reached MR 8:00-6:30.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally Merkling can be reached at (571) 272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SEAN P. O'KEEFE/ Examiner, Art Unit 1738
/SALLY A MERKLING/ SPE, Art Unit 1738
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