Ex Parte Abdo

Board of Patent Appeals and Interferences

Aug 8, 2012

11092793 (B.P.A.I. Aug. 8, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/092,793 03/29/2005 Zafir Abdo 2004P15522US 6807
7590 08/08/2012
Siemens Corporation
Intellectual Property Department
170 Wood Avenue South
Iselin, NJ 08830
EXAMINER
PATEL, DEVANG R
ART UNIT PAPER NUMBER
1735
MAIL DATE DELIVERY MODE
08/08/2012 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte ZAFIR ABDO
____________

Appeal 2011-003116
Application 11/092,793
Technology Center 1700
____________

Before PETER F. KRATZ, HUBERT C. LORIN, and LINDA M. GAUDETTE,
Administrative Patent Judges.

GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL

Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s decision1
finally rejecting claims 1, 3-10, and 12-18, the only claims pending in the
Application.2 We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
The present invention is directed to methods of welding superalloys that are
γ' strengthened. (Spec. 3:17-18.) “Superalloys that are γ'-strengthened include

1 Final Office Action mailed Nov. 12, 2009.
2 Supplemental Appeal Brief filed Jun. 21, 2010 (“Br.”), 5.
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Application 11/092,793

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elements that would form γ' during the welding process.” (Spec. 3:18-19.) “[T]he
high temperature capabilities of superalloys increases with increasing γ' volume
fraction.” (Spec. 1:25-26.) However,
as the level of γ' increases, the superalloy becomes more
susceptible to cracks during a welding process such that, during
welding of these superalloys, the γ phase is convert[ed] to γ'
phase, thereby increasing the γ' percentage, this transformation
leads to volumetric change which in turn applies additional
stresses which lead to the formation of cracks. As such, the
present invention alters the γ/γ' balance to weld the superalloy,
and then restores the γ/γ' balance after welding has occurred. As a
result, the superalloy has no or fewer cracks at the location of the
weld than with prior art methods.
(Spec. 3:19-26.) The Specification discloses two embodiments for altering
the γ/γ' balance. “In [the] first embodiment, the areas to be welded are pre-treated
by using a step of removing γ'-forming elements from the superalloy.” (Spec. 4:6-
7.) “[S]ince these areas of the superalloy have a reduced amount of γ'-forming
elements, less γ' material will be formed during the subsequent welding process,
thereby reducing the formation of cracks during welding.” (Spec. 4:7-10.) “Once
the welding step has been completed, the areas of the superalloy that were welded
may be returned to the original γ/γ' balance of the superalloy using a post-weld
heat treatment step.” (Spec. 5:6-8.) In the second, or
alternative embodiment, . . . a γ-stabilizing material [is added] to
the areas to be welded followed by heat treatment to diffuse the γ
forming phase into the material. . . . [D]uring the welding
process, the γ -stabilizing material stabilizes the γ phase, thereby
reducing the conversion of the γ phase to γ ' phase. As a result,
there is a lower γ' percentage in the areas to be welded and the
resulting welds have lower incidences of crack formation.
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Application 11/092,793

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(Spec. 5:22-28.) Independent claims 1 and 14, respectively, are directed to the
above two embodiments of the invention (cf. Br. 7-8), and are reproduced below
from the Claims Appendix to the Appeal Brief:
1. A method for repairing a weld in a γ'-strengthened superalloy
comprising:

forming a depletion zone in an area to be welded on a superalloy by
pretreating at least one local area of the γ'-strengthened superalloy to be welded to
reduce the formation of γ' materials during a repair welding process, wherein
pretreating comprises removing a portion of γ'-forming elements from the at least
one local area to be welded and wherein the superalloy has an original γ/γ' ratio;

welding the superalloy in the at least one local area to be welded; and

heating the superalloy and weld to substantially restore the original γ/γ' ratio
after the superalloy has been welded with a most minimal formation of cracks in
the weld.

14. A method for repairing a weld in a γ'-strengthened superalloy
comprising:

forming a depletion zone in an area to be welded on a superalloy by
pretreating at least one area of the γ'-strengthened superalloy to be welded to
reduce the formation of γ' materials during a repair welding process wherein pre-
treating comprises:

adding a γ-stabilizing element to the at least one area to be welded,
and

heating the γ-stabilizing element to diffuse the γ-stabilizing element

into the γ'-strengthened superalloy, thereby stabilizing the γ-phase; and

welding the superalloy in the at least one area to be welded, wherein the γ-
stabilizing element stabilizes the γ-phase during the welding step.
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Application 11/092,793

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The Examiner maintains the following grounds of rejection under 35 U.S.C.
§103(a) (Ans.3 3):
1. claims 1, 3, 4, 7, 8, 10, and 12 as unpatentable over Miller4 in view of
Koizumi5 and Kruger6; claims 5, 6, 9, and 13 as unpatentable over the same
combination of references, and further in view of Fernihough7, Fernihough and
Nihei8, Lee9, and Vogt10, respectively;
2. claims 14-16 as unpatentable over Miller in view of Fernihough; and
claims 17 and 18 as unpatentable over the same combination of references, and
further in view of Koizumi and Kruger, and Boegli11, respectively.
Appellant presents separate arguments in support of patentability of
independent claims 1 and 14. (See generally, Br. 11-18.) Accordingly, the
remaining dependent claims stand or fall with claim 1 or claim 14. (See id. at 18.)
We have fully considered Appellant’s arguments in support of patentability.
However, we find a preponderance of the evidence supports the Examiner’s
conclusion of obviousness and, therefore, affirm the Examiner’s decision to reject
claims 1, 3-10, and 12-18 for the reasons expressed in the Answer (Ans. 4-15),
which we incorporate by reference herein. We add the following solely for
emphasis.

3 Examiner’s Answer mailed Apr. 12, 2010, as modified in the Supplemental
Examiner’s Answer filed Sep. 2, 2010.
4 US 5,898,994, issued May 4, 1999
5 US 6,159,314, issued Dec. 12, 2000
6 US 2006/0070882 A1, published Apr. 6, 2006
7 US 6,440,238 B1, issued Aug. 27, 2002
8 US 2005/0067693 A1, published Mar. 31, 2005
9 US 2004/0040863 A1, published Mar. 4, 2004
10 US 6,120,624, issued Sep. 19, 2000
11 US 2005/0067466 A1, published Mar. 31, 2005
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Application 11/092,793

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Appellant concedes Miller “discloses a method of welding a nickel based
superalloy article . . . by first removing an amount of Al and Ti” (Br. 12), i.e., γ’-
forming elements (see Spec. 4:11-13). “Miller does not teach a heat treatment step
to restore to substantially original gamma/gamma-prime ratio” as recited in
appealed claim 1. (Ans. 4; see also, Br. 11.) “Miller does not disclose the steps of
adding a gamma-stabilizing element such as nickel or chromium in the area to be
welded and heating the element to diffuse into the superalloy” as recited in
appealed claim 14. (Ans. 8; see also, Br. 16.)
With respect to the rejection of claim 1, Appellant argues the Examiner erred
in determining one of ordinary skill in the art would have been motivated to apply
a “subsequent heat treatment [as] suggested by Koizumi and Kruger in the repair
method of Miller in order to obtain [a] desired γ/γ' ratio and desired material
properties (Kruger- ¶ 18), including improved creep strength of the superalloy
(Koizumi- col. 1, lines 25-27)” (Ans. 5). (Br. 12-15.) Appellant’s argument is
based on a contention that Koizumi teaches away from repairing welds because
Koizumi separates out the γ' phases at the time of casting. (Br. 14.) The
Examiner, in response, explains in detail why Appellant’s argument is not
supported by Koizumi’s disclosure, noting that Koizumi only removes non-
uniform γ' phases. (Ans. 12.) The Examiner also notes Appellant has not
explained why the invention would have been unobvious given Kruger’s teaching
of a “subsequent heat treatment (similar to solution heat treatment of Koizumi) in
order to obtain desired gamma/gamma-prime phase adjustment in nickel-base
superalloys.” (Ans. 13; see also, Ans. 5 (“Kruger et al. discloses that required
materials properties (such as creep strength disclosed by Koizumi) in Ni-base or
Co-base superalloys can be achieved by subsequent heat treatment in order to
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obtain the desired gamma-gamma prime precipitations or phase adjustment.”).) As
such, Appellant has not convincingly demonstrated the Examiner reversibly erred
in concluding the invention, as claimed in claim 1, would have been obvious
within the meaning of 35 U.S.C. §103(a).
With respect to the rejection of claim 14, Appellant contends the Examiner
reversibly erred in determining the proposed combination of Miller and
Fernihough would have resulted in a method which includes adding a γ-stabilizing
element to stabilize the γ-phase during the welding step. (Br. 17.) As explained by
the Examiner, Appellant’s arguments improperly focus on the individual teachings
of the references and fail to fully address the Examiner’s rejection, which is based
on the combined teachings of the references. (See Ans. 13-14.) While both Miller
and Fernihough disclose a step of removing coatings prior to γ’-depletion as
argued by Appellant (see Br. 17; Ans. 14), Fernihough also teaches application of a
barrier coating which includes Cr, i.e., a γ-stabilizing element (see Spec. 2:25; Ans.
9), after the γ’-depletion, but prior to a subsequent heat treatment (Ans. 14; see
also, Br. 17 (acknowledging this teaching)). Appellant has not explained why the
Examiner erred in determining “[i]t would have been obvious to a person of
ordinary skill in the art at the time of the invention to apply [the] chromium-
containing coating and diffusion heat treatment of Fernihough et al. in the welding
repair of Miller because the coating applied by such preparation protects the
component against corrosion and oxidation due to thermal effect of hot
environment and leads to longer coating lives” (Ans. 14). (See generally, Br. 15-
18.)

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Application 11/092,793

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No time period for taking any subsequent action in connection with this
appeal may be extended under 37 C.F.R. § 1.136(a)(1).
AFFIRMED

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