Prosecution Insights
Last updated: August 14, 2026
Application No. 17/626,954

R-Fe-B SINTERED MAGNET AND GRAIN BOUNDARY DIFFUSION TREATMENT METHOD THEREOF

Non-Final OA §103
Filed
Jan 13, 2022
Priority
Jan 21, 2020 — CN 202010070960.0 +1 more
Examiner
POLLOCK, AUSTIN M
Art Unit
1738
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Golden Dragon Rare-Earth Innovation Technology (Xiamen) Co. Ltd.
OA Round
5 (Non-Final)
52%
Grant Probability
Moderate
5-6
OA Rounds
0m
Est. Remaining
88%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allowance Rate
120 granted / 232 resolved
-13.3% vs TC avg
Strong +36% interview lift
Without
With
+36.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
55 currently pending
Career history
292
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
54.4%
+14.4% vs TC avg
§102
15.6%
-24.4% vs TC avg
§112
25.4%
-14.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 232 resolved cases

Office Action

§103
Detailed Office Action Notice of Pre-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 Request to Continue Examination 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 07/20/26 has been entered. Response to Amendments The amendment filed on 06/22/26 has been entered. Claims 1 – 2, 4 – 5, 8 – 14, and 17 – 20 remain pending. Claims 9 – 10 and 17 – 20 remain withdrawn. Claims 1 – 2, 4 – 5, 8, and 11 – 14 are under examination. Claim Interpretation For clarity of the record, the examiner notes that the constituents of “M” (comprising, Cu, Al, and Ga) is interpreted as also referring to the “M” of the HR-M alloy. To specify, the “M” of the HR-M alloy is interpreted as comprising Cu, Al, and Ga. Claim Rejections Claim 12 is rejected for being incomplete. Claim 12 depends upon claim 3 which has been canceled. Claim Rejections – U.S.C. §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. 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. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1 – 2, 4 – 5, 8, and 11 – 14 are rejected under 35 U.S.C. 103 as being unpatentable over Hidaka (US2017/0103835, cited in the OA on 01/22/25) in view of Miyata (US2011/0210810, cited in the OA 08/09/24) and in further view of Sun (WO2012/013086, using machine translation, cited in the OA on 04/30/25) Regarding claim 1, Hidaka teaches an RTB magnet produced by sintering and diffusing an alloy into the magnetic work [Abstract, 0044], wherein the RTB magnet has a main phase [0067], meeting the claimed limitation of a sintered green body with main phase. Hidaka teaches an exemplary alloy composition which meets the claimed range [Table 2, Example 40]. Element Nd + Tb (“R”) B Al Ga Cu Co Mn Zr Fe Mass% 30.64 0.9 0.2 0.2 0.2 2.0 0.04 0.15 65.67 Hidaka teaches that the sintered magnetic work can be subjected to diffusion treatment using a compound or alloy containing Tb on the surface of the sintered magnet and subjecting it to the diffusion treatment [0100, 0102]. Hidaka does not explicitly teach that the heavy rare earth used in diffusion treatment is applied to at least one non-orientation plane (a plane that is not perpendicular to the magnetization direction). Hidaka discloses that Tb (interpreted as the heavy rare earth) can be used in the form of an alloy [0100], but does not explicitly teach the composition of said alloy. Miyata teaches a R-Fe-B sintered magnet subjected to diffusion treatment [Title, 0029]. Miyata teaches that the diffusion treatment is with a Dy or Tb diffusion source which is applied to non-perpendicular surfaces of the magnet for diffusion, meeting the claimed limitation of having several surfaces and applying HR such that diffusion takes place within a perpendicular direction to the magnetization [Claim 1, Fig 1A]. Miyata explicitly states “that by providing a sintered Nd base magnet block (sintered rare earth magnet, typically Nd2 Fe14 B system) having a sufficient thickness in a magnetization direction, effecting diffusion reaction of Dy or Tb inward from the surfaces of the magnet block excluding the surfaces perpendicular to the magnetization direction, thereby producing the magnet block in which the coercive force near the surfaces is higher than in the interior, and cutting the magnet block in a direction perpendicular to the magnetization direction by means of a cutter blade, wire saw or the like, a plurality of magnet segments of predetermined size can be manufactured from one magnet block absorption” [0025] and as a result, throughput of the process is improved. It would have been obvious to one of ordinary skill in the art before the effective filing date to have applied the diffusion treatment using heavy rare earth magnets as taught by Miyata to the sintered magnet of Hidaka to achieve predictable results. Miyata and Hidaka are both directed to diffusion treatment of heavy rare earth elements into NdFeB sintered magnets (i.e. same field of endeavor). Furthermore, Miyata states that performing the diffusion treatment in this manner allows for the production of multiple magnet segments from one magnet block diffusion which increases the throughput of the process. As such, an ordinarily skilled artisan would be motivated to combine the teachings of Miyata and Hidaka and would have a reasonable expectation of success. Hidaka in view of Miyata teaches that the diffusion treatment is performed by coating surfaces parallel to the magnetization direction and diffusing in directions perpendicular to the magnetization direction, such that the concentration decreases from the diffusion surface to center. In the diffusion direction perpendicular to the magnetization direction, given that “any two points spaced from the diffusion plane by a distance of no more than 500 µm” can include two points essentially next to each (i.e. a distance of ~0 µm), two points this close would possess a first ratio of HR content that was approximately identical (i.e. ~1.0), meeting the claimed range. Additionally, Hidaka teaches that the concentration ratio of Tb at the surface to core in the diffusion direction is 0.4 – 1.0 [0065]. This meets the claimed limitation of “a first ratio of HR contents of any two points spaced from the diffusion plane by a distance of no more than 500 µm is 0.1-1.0”. Moreover, the diffusion takes place in a direction perpendicular to the magnetization. As such, the surfaces that are parallel with the magnetization direction would be coated essentially evenly as reasonably suggested by Hidaka [0102] in view of Miyata [0029]. Therefore, the HR content distributed in the magnetization direction would naturally result in being consistent. Additionally, given that “the second ratio of HR contents of any two points is 0.7-1.0” can include two points essentially next to each (i.e. a distance of ~0 µm), two points this close would possess a ratio of HR content that was approximately identical (i.e. ~1.0), meeting the claimed range. This meets the claimed limitation of “in the magnetization direction, the second ratio of HR contents of any two points is 0.7-1.0” With regards to the relationship of the two ratios, the claimed invention is not distinguished from the prior art solely because the prior art does not disclose the claimed relationship, where the prior art teaches ranges that overlap with or anticipate the individual claimed ranges. That is, the claimed invention is not distinguished from the prior art if the prior art discloses a range/value that satisfies/overlaps with the claimed formula, even if the prior art does not disclose the formula itself. “Patentability of the claims may not rest solely on the fact that the…contents…are calculated from the formula”. See In Re Cooper, 134 F.2d 630, 631–32 (CCPA 1943). To clarify, the prior art combination meets the individual ranges claimed. Additionally to this, the diffusion takes place perpendicular to the magnetization direction by coating surfaces evenly with the magnetization direction. As such, the variation in coating/diffusion material in parallel with the magnetization direction would naturally be less than the variation in the diffusion direction (i.e., the direction perpendicular to magnetization) because the latter requires the material to diffuse through the magnet. Hidaka discloses that Tb (interpreted as the heavy rare earth) can be used in the form of an alloy [0100]. Likewise, Miyata teaches that the Dy or Tb diffusion source can be in the form of an alloy containing Dy or Tb [0044, Claim 1]. However, Hidaka in view of Miyata does not explicitly teach the composition of said alloy. Sun teaches producing a sintered NdFeB magnet [Title] wherein an infiltration step is performed on a base magnetic material to form a grain boundary phase [Page 3, “Summary of Invention”]. Sun teaches that the grain boundary infiltration is an alloy of Ra-Al-X, wherein Ra can be Dy or Tb, and X can include Cu and Ga (as well as optionally Co or Zr) [Page 3, “Summary of Invention”]. Sun teaches that Al reduces the melting point, increases fluidity and wettability; Cu helps increase the coercive force of the magnet, and Ga improves lubricity of the grain boundary and suppresses grain growth [Page 3, “Summary of Invention”]. Lastly, as shown in Tables 1, 3, 5, 7 and 9, the rare earth component of the alloy can range from 40 – 90 wt% (implying the total of the other elements is 10 – 60 wt%), which overlap with the claimed range of HR and “M”. Sun also teaches that the rare earth alloy improves coercivity and corrosion resistance [Page 3, 2nd and 3rd paragraph]. It would have been obvious to one of ordinary skill in the art before the effective filing date to have used the heavy rare earth alloy of Sun in Hidaka as-modified by Miyata. Hidaka, Miyata, and Sun are directed to grain boundary formation of heavy rare earth elements into NdFeB sintered magnets (i.e. same field of endeavor). Furthermore, Hidaka and Miyata both explicitly acknowledge that the heavy rare earth component for diffusion can be an alloy containing said element [0100, Hidaka and 0044, Miyata] and therefore, an ordinarily skilled artisan would have a reasonable expectation of success. As well, a person of ordinary skill in the art would be motivated to use the heavy rare earth alloy taught by Sun because the alloy includes Al and can further include Cu and Ga which each provide different benefits to the infiltration process and/or the magnet itself. These include reducing the melting point, increasing fluidity and wettability for Al; increasing the coercive force of the magnet for Cu, and improving lubricity of the grain boundary and suppressing grain growth for Ga [Page 3, “Summary of Invention”]. Additionally, Sun teaches that the rare earth alloy improves coercivity and corrosion resistance [Page 3, 2nd and 3rd paragraph], both properties would be appreciated by Hidaka which explicitly measures these properties [Table 2] With regards to the overlapping ranges taught, it would have been obvious to an ordinarily skilled artisan before the effective filing date of the claimed invention to have selected overlapping ranges as disclosed. Selection of overlapping ranges has been held to be a prima facie case of obviousness (See MPEP § 2144.05 I). “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)”. "[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. "The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages.". (See MPEP § 2144.05 II) Regarding claim 2, Hidaka in view of Miyata and Sun teaches the invention as applied to claim 1. Given that “any two points spaced from the diffusion plane by a distance of no more than 500 µm” can include two points essentially next to each (i.e. a distance of ~0 µm), two points this close would possess a ratio of HR content that was approximately identical (i.e. ~1.0), meeting the claimed range. Additionally, Hidaka teaches that the concentration ratio of Tb at the surface to core is 0.4 – 1.0 [0065], which falls within the claimed range. Regarding claim 4, Hidaka in view of Miyata and Sun teaches the invention as applied to claim 1. The exemplary alloy of Hidaka teaches containing 0.15 mass% Zr and 0.04 mass% Mn, wherein both of these elements are within the list of “T” elements (meeting the claimed “at least one of the following”) and are a total of 0.19 mass%, which falls within the claimed range of “T” elements [Table 1, Example 2]. Regarding claim 5, Hidaka in view of Miyata and Sun teaches the invention as applied to claim 1. The exemplary alloy of Hidaka teaches containing 0.2 mass% Al, 0.2 mass% Ga, and 0.2 mass% Cu, wherein the total is 0.6 mass%, which falls within the claimed total range of the elements [Table 1, Example 2] Regarding claims 8 and 11 – 14, Hidaka in view of Miyata and Sun teaches the invention as applied to claims 1 – 2 and 4 – 5, respectively. Miyata shows that the sintered magnet is formed into a square block for the diffusion treatment, meeting the claimed limitation of claim 8 and 11 – 14 [Fig 1A]. Response to Arguments Applicant's arguments filed 06/22/26 have been fully considered but they are not persuasive. Applicant argues that Hidaka in view of Miyata and Sun does not teach or suggest the first ratio of HR, the second ratio of HR, and/or their claimed relationship to one another. The examiner respectfully disagrees. Hidaka in view of Miyata teaches that the diffusion treatment is performed by coating surfaces parallel to the magnetization direction and diffusing in directions perpendicular to the magnetization direction, such that the concentration decreases from the diffusion surface to center. In the diffusion direction perpendicular to the magnetization direction, given that “any two points spaced from the diffusion plane by a distance of no more than 500 µm” can include two points essentially next to each (i.e. a distance of ~0 µm), two points this close would possess a first ratio of HR content that was approximately identical (i.e. ~1.0), meeting the claimed range. Additionally, Hidaka teaches that the concentration ratio of Tb at the surface to core in the diffusion direction is 0.4 – 1.0 [0065]. This meets the claimed limitation of “a first ratio of HR contents of any two points spaced from the diffusion plane by a distance of no more than 500 µm is 0.1-1.0”. Moreover, the diffusion takes place in a direction perpendicular to the magnetization. As such, the surfaces that are parallel with the magnetization direction would be coated essentially evenly as reasonably suggested by Hidaka [0102] in view of Miyata [0029]. Therefore, the HR content distributed in the magnetization direction would naturally result in being consistent. Additionally, given that “the second ratio of HR contents of any two points is 0.7-1.0” can include two points essentially next to each (i.e. a distance of ~0 µm), two points this close would possess a ratio of HR content that was approximately identical (i.e. ~1.0), meeting the claimed range. This meets the claimed limitation of “in the magnetization direction, the second ratio of HR contents of any two points is 0.7-1.0” With regards to the relationship of the two ratios, the claimed invention is not distinguished from the prior art solely because the prior art does not disclose the claimed relationship, where the prior art teaches ranges that overlap with or anticipate the individual claimed ranges. That is, the claimed invention is not distinguished from the prior art if the prior art discloses a range/value that satisfies/overlaps with the claimed formula, even if the prior art does not disclose the formula itself. “Patentability of the claims may not rest solely on the fact that the…contents…are calculated from the formula”. See In Re Cooper, 134 F.2d 630, 631–32 (CCPA 1943). To clarify, the prior art combination meets the individual ranges claimed. Additionally to this, the diffusion takes place perpendicular to the magnetization direction by coating surfaces evenly with the magnetization direction. As such, the variation in coating/diffusion material in parallel with the magnetization direction would naturally be less than the variation in the diffusion direction (i.e., the direction perpendicular to magnetization) because the latter requires the material to diffuse through the magnet. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Austin M Pollock whose telephone number is (571)272-5602. The examiner can normally be reached M - F (11 - 8 ET). 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, 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. 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. /AUSTIN POLLOCK/Examiner, Art Unit 1738 /SALLY A MERKLING/SPE, Art Unit 1738
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Prosecution Timeline

Show 6 earlier events
Jul 28, 2025
Response after Non-Final Action
Sep 29, 2025
Non-Final Rejection mailed — §103
Dec 29, 2025
Response Filed
Apr 21, 2026
Final Rejection mailed — §103
Jun 22, 2026
Response after Non-Final Action
Jul 20, 2026
Request for Continued Examination
Jul 21, 2026
Response after Non-Final Action
Jul 28, 2026
Non-Final Rejection mailed — §103 (current)

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Prosecution Projections

5-6
Expected OA Rounds
52%
Grant Probability
88%
With Interview (+36.5%)
3y 2m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 232 resolved cases by this examiner. Grant probability derived from career allowance rate.

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