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 1-5) in the reply filed on 12/29/2026 is acknowledged. Claims 6-10 are withdrawn. Claims 1-5 are examined herein.
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 1-5 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 1 recites “the heavy-rare-earth grain-boundary diffusion region at regions, which have normal directions consistent with three axes of a three-dimensional Cartesian coordinate system, of the surface layer” in line 6-8. The meaning of the limitation is not clear. Grain boundary diffusion regions are grain boundaries and grain boundaries have irregular shape. Thus, one of ordinary skill in the art would not understand the scope of “at regions, which have normal directions consistent with three axes of a three-dimensional Cartesian coordinate system, of the surface layer”. Appropriate correction is required.
Claim 4 recites “with respect to an outer surface of the corresponding surface layer of the neodymium-iron-boron magnet is within 80% of a distance from the outer surface to a center of the neodymium-iron-boron magnet”. The meaning of this limitation is unclear. Does it mean that diffusion depth from an outer surface is 80% or less of a distance from the outer surface to the center of the neodymium-iron-boron magnet? Appropriate correction is required.
The term “gradually” in claim 5 (line 6) is a relative term which renders the claim indefinite. The term “gradually” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-2 and 4-5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Nakamura (US 2006/0213584).
Regarding claims 1-2 and 4, Nakamura teaches a neodymium-iron-boron magnet, wherein the neodymium-iron-boron magnet is subjected to grain boundary diffusion of a heavy rare earth element such as Dy element (Abstract; [0019] to [0050]). Nakamura discloses that the entire surfaces of the magnet are coated with DyF3 and diffusion of Dy is performed after the coating ([0047]), which meets the limitation that the heavy-rare-earth grain boundary diffusion region is located at each surface of the neodymium-iron-boron magnet.
Nakamura further discloses that the neodymium-iron-boron magnet comprises a Dy grain boundary diffusion region at a surface layer and the magnet has higher Dy concentration at the surface and the Dy concentration decreases towards the center of the magnet ([0043] to [0050]). Table 1 of Nakamura shows a change of Dy concentration with the distance from magnet surface and the data from Table 1 is plotted in the following chart by the Examiner:
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277
471
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From the chart above, the Dy diffusion depth is estimated to be 628 µm based on a linear regression using the two data points at 200 µm and 500 µm. Nakamura discloses that the magnet has a size of 10 mm x 10 mm x 2 mm and diffusion of Dy is performed from all six surfaces ([0046]; [0047]). Thus, there is a portion of 0.744 mm thick (calculated by 2 mm -0.628 mm x2 = 0.744 mm) along the thickness direction and 8.744 mm wide (calculated by 10 mm -0.628 mm x2= 8.744 mm) along the length and width directions of the magnet that is a non-diffusion region wherein the Dy concentration is not changed by Dy diffusion as recited in claims 1 and 4. The non-diffusion region has a volume of 8.744 mm x 8.744 mm x 0.744 mm = 56.8844 mm3. The volume fraction of the non-diffusion region is 56.8844/(10x10x2) = 28.44 vol.% and meet the limitation recited in claim 2.
The diffusion depth along the thickness direction is 628 µm and the distance from the surface to the magnet center along the thickness direction is 2 mm/2= 1 mm. 0.628/1=62.8%, which meets the limitation that diffusion depth from an outer surface is 80% or less of a distance from the outer surface to the center of the neodymium iron boron magnet as recited in claim 4. Nakamura discloses that the coercivity is increased by 425 kA/m (i.e. 5.34 kOe) by Dy diffusion heat treatment ([0048]), which meets the coercivity limitation recited in claim 4.
Regarding claim 5, Nakamura discloses that in a depth direction of the magnet, the concentration of Dy gradually decreases (Table 1).
Nakamura discloses that the entire surfaces of the magnet are coated with DyF3 and diffusion is performed after the coating ([0047]). Since the edge portion of the magnet receives Dy diffusion from two surfaces while a central portion of the outer surfaces receives Dy diffusion from only one surface, one of the ordinary skills in the art would expect that the magnet disclosed by Nakamura meets the limitation that the Dy concentration is the highest at the edge portion and Dy decreases gradually decreases from the edge portion towards the central portion of the magnet outer surfaces as recited in claim 5.
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 3 is rejected under 35 U.S.C. 103 as being unpatentable over Nakamura (US 2006/0213584), as applied to claim 1 above, and further in view of Bae (Journal of Alloys and Compounds, 612(2014)183-188, IDS dated 11/14/2024).
Regarding claim 3, Nakamura does not explicitly disclose a diffusion amount of heavy rare earth elements. Bae teaches a grain boundary diffusion of Dy into a NdFeB sintered magnet (Page 184, 1st column, 3rd paragraph), which is analogous to the method of Nakamura. Bae discloses that when the DyHx diffusion amount is 0.12 wt%, the coercivity is increased by 3 kOe (Fig. 6). Thus, it would be obvious to one of ordinary skill in the art to diffuse 0.12 wt% DyHx as taught by Bae in the process of Nakamura in order to increase the coercivity by 3 kOe as disclosed by Bae.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Xiaowei Su whose telephone number is (571)272-3239. The examiner can normally be reached 8:00-5:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Hendricks can be reached at 5712721401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/XIAOWEI SU/Primary Examiner, Art Unit 1733