Ex Parte Kottilingam et al

Board of Patent Appeals and Interferences

Mar 12, 2009

11036991 (B.P.A.I. Mar. 12, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte SRIKANTH C. KOTTILINGAM and PETER J. DITZEL
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Appeal 2009-1092
Application 11/036,991
Technology Center 3700
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Decided:1 March 12, 2009
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Before: JENNIFER D. BAHR, LINDA E. HORNER, and
STEVEN D.A. McCARTHY, Administrative Patent Judges.

McCARTHY, Administrative Patent Judge.

DECISION ON APPEAL

1 The two month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304 (2008), begins to run from the
Decided Date shown on this page of the decision. The time period does not
run from the Mail Date (paper delivery) or the Notification Date (electronic
delivery).

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STATEMENT OF THE CASE 1
The Appellants appeal under 35 U.S.C. § 134 (2002) from the final 2
rejection of claims 1-18 under 35 U.S.C. § 103(a) (2002) as being 3
unpatentable over the Appellants’ Admitted Prior Art on pages 1-3 of the 4
Appellants’ Specification, Ferrigno (US 5,846,057, issued Dec. 8, 1998) and 5
Smith (US 2003/0000602 A1, publ. Jan. 2, 2003). We have jurisdiction 6
under 35 U.S.C. § 6(b) (2002). We REVERSE. 7
Claims 1 and 10 are the only independent claims on appeal: 8
9
1. A method for welding alloys having 10
directionally-solidified grain structure comprising: 11
breaking down a portion of the directionally-12
solidified grain structure in an area to be welded; 13
recrystallizing grains in the portion of the 14
directionally-solidified grain structure in the area 15
to be welded to form a localized region of grains 16
having a fine grain structure; and 17
welding the alloys in the localized region of 18
grains having a fine grain structure. 19
20
21
10. A method for repairing a turbine 22
component having a directionally-solidified grain 23
structure in at least a portion of the turbine 24
component comprising: 25
breaking down a portion of the directionally-26
solidified grain structure in the turbine component; 27
recrystallizing grains in the portion of the 28
directionally-solidified grain structure in the 29
turbine component to form a localized region of 30
grains having a fine grain structure; and 31
welding the localized region of grains 32
having a fine grain structure. 33
34
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ISSUES 1
The Appellants disclose that the use of fusion welding to repair 2
defects in turbine components such as guide vanes and rotor blades produced 3
from metal having directionally-solidified grain structures was known in the 4
prior art. (Spec. 2, l. 21; see also id. 1, ll. 10-14.) The Appellants also 5
disclose that one technique that might be used for breaking down a portion 6
of a directionally-solidified grain structure is to apply strain energy by 7
means of laser peening. (Spec. 4, ll. 10-14 and 25-27.) Ferrigno discloses 8
laser shock peening the surface of a turbine blade formed from a 9
directionally-solidified nickel-based superalloy material in the vicinity of a 10
crack before welding metallic weld material into the crack. (Ferrigno, col. 6, 11
ll. 41-63; see also id., col. 7, ll. 14-20.) Smith discloses pre-weld or post-12
weld heat treatments when welding an airfoil or airfoil repair material to an 13
integrally bladed rotor (Smith 1, ¶ 0009 and 0011.) 14
The Examiner reasons that the methods of independent claims 1 and 15
12 would have been obvious “because both the strain working steps 16
disclosed by Ferrigno et al or the aging steps disclosed by Smith et al 17
provide a new microstructure surface which has material properties suitable 18
for achieving successful subsequent fusion welding repair.” (Ans. 4.) The 19
Examiner further appears to reason that it would have been obvious to 20
combine the laser shock peening step of Ferrigno with the partial aging step 21
of Smith prior to welding because Ferrigno and Smith describe similar 22
welding techniques. (Ans. 5-6.) 23
This appeal turns on the following issue: 24
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Have the Appellants shown that the Examiner failed to 1
articulate reasoning with some rational underpinning sufficient 2
to support the conclusion that the methods of independent 3
claims 1 and 10 would have been obvious from the Appellants’ 4
Admitted Prior Art, Ferrigno and Smith? 5
6
FINDINGS OF FACT 7
The record supports the following findings of fact (“FF”) by a 8
preponderance of the evidence. 9
1. Ferrigno discloses that laser shock peening imparts deep 10
compressive residual stresses extending into the body from the peened 11
surface. (Ferrigno, col. 6, ll. 61-63.) Ferrigno also states that laser shock 12
peening the surface of a crack before welding metallic weld material into the 13
crack counters the tendency of the weld to suffer mechanical or thermal 14
fatigue failure. (Ferrigno, col. 6, ll. 41-45.) Ferrigno does not disclose any 15
post weld heat treatment for relieving the compressive stresses in the weld 16
region. 17
2. Smith discloses solution treating, oil quenching, heat treating 18
(partially aging) and then cooling an airfoil formed from a nickel-based alloy 19
before welding the airfoil to a hub for an integrally bladed rotor formed from 20
the nickel-based alloy. (Smith 1, ¶ 0009.) Smith further discloses applying 21
a high temperature post weld heat treatment to the weld joint between the 22
hub section and the airfoil subsequent to welding. (Id.) 23
3. Smith uses a post weld heat treatment to relieve residual 24
stresses and restore microstructure to the weld joint and adjacent metal after 25
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welding an undamaged airfoil section to a remaining portion of an integrally 1
bladed rotor airfoil. (Smith 1, ¶ 0011.) 2
3
PRINCIPLES OF LAW 4
The Appellant’s burden in this appeal is to show that the Examiner 5
has identified insufficient evidence to support a conclusion of prima facie 6
obviousness. In re Kahn, 441 F.3d 977, 985-86 (Fed. Cir. 2006)(citing In re 7
Rouffet, 149 F.3d 1350, 1355 (Fed. Cir. 1998)). “[I]f a technique has been 8
used to improve one device, and a person of ordinary skill in the art would 9
recognize that it would improve similar devices in the same way, using the 10
technique is obvious unless its actual application is beyond his or her skill” 11
or unless application would technique would produce unpredictable results. 12
KSR Int’l Co. v. Teleflex, Inc., 550 U.S. ___, 127 S. Ct. 1727, 1740 (2007). 13
That said, “rejections on obviousness grounds cannot be sustained by mere 14
conclusory statements; instead, there must be some articulated reasoning 15
with some rational underpinning to support the legal conclusion of 16
obviousness.” Kahn, 441 F.3d at 988. 17
18
ANALYSIS 19
The Appellants argue that the processes disclosed by Ferrigno and 20
Smith are not so similar that one of ordinary skill in the art would have 21
reason to combine them to suggest the subject matter of claims 1 and 10. 22
(App. Br. 4-5.) Ferrigno suggests that applying laser shock peening to the 23
surface of a crack before adding metallic weld material into the crack 24
counters the tendency of the weld to suffer mechanical or thermal fatigue 25
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failure due to the formation of deep compressive residual stresses in a region 1
near the weld interface. (FF 1.) Ferrigno discloses no pre-weld or post-weld 2
heat treatments for relieving these stresses. In other words, Ferrigno 3
suggests retaining these deep compressive residual stresses during and after 4
welding. Smith discloses welding processes using pre-weld and post weld 5
heat treatments which appear calculated to relieve residual stresses and 6
restore the microstructure in the region of the weld. (FF 2 and 3.) Applying 7
Smith’s stress relieving heat treatments to a laser-peened metal structure 8
such as a turbine blade likely would relieve, at least partially, the deep 9
compressive residual stresses on which Ferrigno relies to counter fatigue 10
failure. 11
Therefore, the methods disclosed by Ferrigno and Smith are not so 12
similar that one of ordinary skill in the art would have had reason to believe 13
that applying Smith’s stress relieving heat treatments would improve a weld 14
formed on a directionally-solidified material laser peened according to the 15
teachings of Ferrigno. Likewise, one of ordinary skill in the art would have 16
lacked reason to believe that combining Ferrigno’s laser peening step with 17
Smith’s stress reducing heat treatments would provide a new microstructure 18
having material properties suitable for achieving successful subsequent 19
fusion welding repair. The teachings of the Appellants’ Admitted Prior Art 20
and Ferrigno alone, without combination with teachings from Smith, does 21
not suffice to show that a method for welding alloys having directionally-22
solidified grain structure including the step of recrystallizing grains in the 23
portion of the directionally-solidified grain structure in the area to be welded 24
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to form a localized region of grains having a fine grain structure would have 1
been obvious. 2
3
CONCLUSIONS 4
The Appellants have shown that the Examiner failed to articulate 5
reasoning with some rational underpinning sufficient to support the 6
conclusion that the methods of independent claims 1 and 10 would have 7
been obvious from the Appellants’ Admitted Prior Art, Ferrigno and Smith. 8
Therefore, the Appellants have shown that the Examiner erred in rejecting 9
independent claims 1 and 10 as well as dependent claims 2-9 and 11-18 10
under § 103(a) as being unpatentable over the Appellants’ Admitted Prior 11
Art on pages 1-3 of the Appellants’ Specification, Ferrigno and Smith. 12
13
DECISION 14
We REVERSE the rejections of claims 1-18. 15
16
REVERSED 17
18
19
20
hh 21
22
SIEMENS CORPORATION 23
INTELLECTUAL PROPERTY DEPARTMENT 24
170 WOOD AVENUE SOUTH 25
ISELIN, NJ 08830 26