Ex Parte Gorman et al

Board of Patent Appeals and Interferences

Apr 28, 2009

10830685 (B.P.A.I. Apr. 28, 2009)

1
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte MARK DANIEL GORMAN,
IRENE SPITSBERG, BRETT ALLEN BOUTWELL,
RAMGOPAL DAROLIA, ROBERT WILLIAM BRUCE, and
VENKAT SUBRAMANIAM VENKATARAMANI
____________

Appeal 2009-0897
Application 10/830,6851
Technology Center 1700
____________

Decided:2 April 28, 2009
____________

Before CHARLES F. WARREN, JEFFREY T. SMITH, and
MARK NAGUMO, Administrative Patent Judges.
NAGUMO, Administrative Patent Judge.
DECISION ON APPEAL

1 Application 10/830,685, Mixed Metal Oxide Ceramic Compositions for
Reduced Conductivity Thermal Barrier Coatings, filed 22 April 2004. The
specification is referred to as the “685 Specification,” and is cited as “Spec.”
The real party in interest is listed as The General Electric Company.
(Appeal Brief (Amended), filed 28 November 2007 (“Br.”), 1.)
2 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, 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 Notification Date (electronic delivery).
Appeal 2009-0897
Application 10/830,685

2
A. Introduction
Mark Daniel Gorman, Irene Spitsberg, Brett Allen Boutwell,
Ramgopal Darolia, Robert William Bruce, and Venkat Subramaniam
Venkataramani (“Gorman”) timely appeal under 35 U.S.C. § 134(a) from the
final rejection3 of claims 1, 7-13, and 19-25. We have jurisdiction under
35 U.S.C. § 6. We AFFIRM.
The subject matter on appeal relates to ceramic compositions
comprising zirconia [ZrO2], hafnia [HfO2], and a metal oxide that is said to
stabilize the tetragonal phase of the zirconia. The compositions are said to
be particularly useful as thermal barrier coatings (“TBC”) on, e.g., parts of
turbine engines.
Representative Claim 1 is reproduced from the Claims Appendix to
the Principal Brief on Appeal:
1. A ceramic composition, which comprises:
1. from about 80 to about 94.5 mole % of a main
ceramic component, wherein the main ceramic
component comprises
from about 90 to about 94 mole % zirconia and
from about 6 to about 10 mole % hafnia; and
2. from about 5.5 to about 20 mole % of a stabilizer
metal oxide selected from the group consisting of yttria,
calcia, scandia, magnesia, india, lanthana, gadolinia,
neodymia, samaria, dysprosia, erbia, ytterbia, europia,
praseodymia, and mixtures thereof,
3. wherein the ceramic composition comprises up to
about 8 mol % hafnia.
(Claims App., Br. 11; indentation and paragraphing added.)

3 Office action mailed 19 March 2007 (“Final Rejection”; cited as “FR”).
Appeal 2009-0897
Application 10/830,685

3
Independent claim 10 covers a thermally protected article comprising
a substrate and a thermal barrier coating comprising a ceramic as claimed in
claim 1. Claim 21, which depends ultimately from claim 10, covers a
turbine shroud having a thermal barrier coating from about 30 to
about 70 mils thick.
The Examiner has maintained the following grounds of rejection:4
A. Claims 1 and 7-9 stand rejected under 35 U.S.C. § 103(a) in
view of Becher.5
B. Claims 10-13, 19, 20, and 22-25 stand rejected under
35 U.S.C. § 103(a) in view of the combined teachings of
Becher and Murphy.6
C. Claim 21 stands rejected under 35 U.S.C. § 103(a) in view of
the combined teachings of Becher, Murphy, and Spitsberg.7
Gorman presents substantively distinct arguments for independent
claims 1 and 10, and for dependent claim 21. Gorman contends that the
Examiner failed to establish a prima facie case of obviousness in all the
rejections because Becher does not, in Gorman’s view, support the
equivalence of ceria (CeO2) with magnesia (MgO), calcia (CaO), or
yttria (Y2O3) in ZrO2: HfO2 ceramic compositions. Gorman objects to the
rejection of claims 10 and 23 on the further grounds that there is no

4 Examiner’s Answer mailed 23 January 2008. (“Ans.”).
5 Paul F. Becher and Eric F. Funkenbusch, Ternary Ceramic Alloys of
Zr-Ce-Hf Oxides, U.S. Patent 4,971,933 (1990).
6 Kenneth S. Murphy, Stabilized Zirconia Thermal Barrier Coating with
Hafnia, U.S. Patent Application Publication US 2003/0118873 A1
(26 June 2003), based on an application filed 21 December 2001.
7 Irene Spitsberg and Hongyu Wang, Low Thermal Conductivity Thermal
Barrier Coating System and Method Therefor, U.S. Patent 6,558,814 B1
(6 May 2003), based on an application filed 3 August 2001.
Appeal 2009-0897
Application 10/830,685

4
indication in Becher that the ceramic compositions taught to have improved
fracture toughness would be useful as thermal barrier coatings. Moreover,
Gorman objects that “Murphy is directed to compositions including at least
about 15 weight % hafnia,” which is more than the “up to about 8 mol %
hafnia” recited in the claims. As for claim 21, Gorman argues that
Spitsberg, on which the Examiner relies for coating thicknesses, does not
cure the defects of Becher or Murphy.
The Examiner responds that Becher teaches magnesia, calcia, ceria,
and yttria as stabilizers that produce tetragonal zirconia, and that it would
therefore have been obvious to substitute magnesia, calcia, or yttria for ceria
in compositions containing zirconia and hafnia to stabilize zirconia in the
tetragonal phase. The Examiner argues further that Gorman is merely
attacking the references individually, rather than addressing what the person
having ordinary skill in the art would have learned from the combined
teachings of Becher and Murphy.
The critical issue regarding the rejection of claim 1 is whether
Gorman has shown that the Examiner erred reversibly in finding that Becher
teaches the functional equivalence of magnesia, calcia, or yttria with ceria in
zriconia:hafnia ceramic compositions.
The critical issue regarding the rejections of claims 10 and 21 is
whether the Examiner erred reversibly in finding motivation to combine the
teachings of Becher and Murphy.
Appeal 2009-0897
Application 10/830,685

5
B. Findings of Fact
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
The 685 Specification
1. The 685 Specification uses the term “thermal barrier coating”
(“TBC”) to refer to a coating that reduces heat flow to the underlying
substrate. (Spec. 5, ¶ [0019].)
2. According to the 685 Specification, TBCs are “usually prepared” from
ceramics such as metal oxide phase-stabilized zirconia, including yttria-,
scandia-, ceria-, calcia-, and magnesia-stabilized zirconia.
(Spec. 1, ¶ [0004].)
3. A typical TBC of choice is said to be a 7 wt% yttria, 93 wt% zirconia
coating.
4. Such TBCs are said to range from about 3 to about 70 mils thick, for
high temperature gas turbine engine parts. (Spec. 1-2, ¶ [0004].)
5. Turbine shrouds are said to have TBC coatings typically from about
30 to 70 mils thick, while turbine blades are said to have TBC coatings from
about 1 to 30 mils thick. (Spec. 9, ¶ [0033].)
6. A “feathery microtexture” is said to develop upon formation by
electron beam physical deposition, which provides enhanced resistance to
heat flow. (Spec. 2, ¶ [0007].)
7. According to the 685 Specification, at higher engine operating
temperatures, the feathery microtexture is lost due to sintering, and the
thermal conductivity of the TBC rises. (Spec. 2-3, ¶ [0008].)
Appeal 2009-0897
Application 10/830,685

6
8. The 685 Specification teaches that inclusion of hafnia to replace some
of the zirconia lowers the thermal conductivity by providing, inter alia, a
more feathery structure having increased porosity and reduced density,
without degrading other desirable properties. (Spec. 4, ¶ [0014].)
9. The 685 Specification teaches further that hafnia has these effects
because it is chemically indistinguishable from zirconia, but has a much
higher mass that affects phonon scattering. (Spec. 6, ¶ [0026].)
10. According to the 685 Specification, the inclusion of hafnium lowers
the specific heat of the thermal barrier coating more than would have been
predicted from its molecular weight. (Spec. 6, ¶ [0026]; 7, ¶ [0029], and
Figure 3.)
11. According to the 685 Specification, “[a]ll amounts, parts, ratios and
percentages” are by mole % unless otherwise specified. (Spec. 5, ¶ [0021].)
12. In the broadest disclosure, and in the originally presented claims, the
inventive ceramic is characterized as comprising about 63 to about 99
mole % zirconia, from about 1 to about 37 mole % hafnia, and at least
about 4 mole % of a metal oxide stabilizer, including ceria with magnesia,
calcia, or yttria. (Spec. 3, ¶ [0010].)
13. The ranges recited in the claims on appeal are said to be the “more
typical” compositions. (E.g., Spec. 5, ¶ [0023]; 6, ¶ [0025].)
14. The 685 Specification provides five examples of TBC ceramic
compositions, only one of which (Example 3) is clearly within the scope of
the appealed claims. (Spec. 11-12, ¶¶ [0039]-[0043].)
Appeal 2009-0897
Application 10/830,685

7
15. The 685 Specification does not disclose numerical values of any of
the properties of the ceramic examples other than the compositions.
Becher
16. Becher relates to toughened ceramics that are said to be useful for
structural applications such as components for internal combustion engines.
(Becher col. 1, ll. 20-23.)
17. Becher describes a ternary ceramic alloy compositions having the
general formula CexHfyZr1-x-yO2. (Becher, col. 1, l. 65 to col. 2, l. 1.)
18. The compositions are said to result in fine grained tetragonal zirconias
(i.e., a stabilized zirconia) that can also undergo “transformation
toughening” under tensile stress to a monoclinic phase. (Becher, col. 1,
ll. 26-36; col. 2, ll. 18-32.)
19. According to Becher, “[a] number of stabilizing oxides, such as MgO,
CaO, CeO2, and Y2O3 have been used to produce tetragonal zirconia.”
(Becher, col. 1, ll. 40-42.)
20. Becher advises that “[t]hese oxides are often mechanically mixed with
the zirconia powders which can result in compositional inhomogen[e]ity of
the stabilizer and thus adversely affect any toughening.” (Becher, col. 1,
ll. 42-45; emphasis added.)
21. Becher, in examples, teaches formation of oxide powders from
aqueous solutions of the components, thereby avoiding inhomogeneous
powders for ceramic formation. (Becher, col. 3, ll. 4-64.)
22. Becher teaches that ceria and hafnia have opposite effects on certain
properties of zirconia ceramics.
Appeal 2009-0897
Application 10/830,685

8
23. In Becher’s words, “[b]y the addition of both CeO2 and HfO2,
substantially all tetragonal phase is obtained and yet the transformation is
permitted to occur in a stress range which will result in an increase in
fracture toughness of the composition.” (Becher, col. 2, ll. 31-35.)
24. Becher also teaches that most commercial grades of zirconium contain
0.5 to 2 mole % hafnium as an impurity, and that its invention accordingly
“involves the controlled addition of greater amounts of hafnium to achieve
the desired effects.” (Becher, col. 2, ll. 33-36.)
25. Becker, in Example I, describes a ceramic composition containing
80.75 mol % ZrO2, 15.00 mol % CeO2, and 4.25 mol % HfO2. (Becher,
col. 3, ll. 5-7.)
26. In particular, Becher teaches that “the tetragonal phase content in a
submicron grained ZrO2 may be >50% when the CeO2 content is in the
range of 5 to 8 mol %.” (Becher, col. 4, ll. 62-64.)
Murphy
27. Murphy relates to thermal barrier coating systems for substrates, such
as engine turbine blades and vanes, that operate in harsh environments.
(Murphy 1, ¶ [0001].)
28. According to Murphy, stabilized zirconia thermal barrier coatings that
include hafnia in amounts above impurity levels have unexpectedly reduced
thermal conductivity. (Murphy 1, ¶¶ [0009], [0028].)
29. Murphy teaches that hafnia and zirconia exhibit complete solid
solubility across all compositions in their binary system as a result of their
Appeal 2009-0897
Application 10/830,685

9
similar chemical properties and essentially equal ionic radii.
(Murphy 1, ¶ [0008].)
30. Murphy teaches further that yttria can be present in an amount to
stabilize the tetragonal phase of zirconia and preferably is present from
about 2.0 to about 36.6 weight %. (Murphy 1, ¶¶ [0012], [0029].)
C. Discussion
As the Appellant, Gorman bears the procedural burden of showing
harmful error in the Examiner’s rejections. See, e.g., In re Kahn, 441 F.3d
977, 985-86 (Fed. Cir. 2006) (“On appeal to the Board, an applicant can
overcome a rejection [under § 103] by showing insufficient evidence of
prima facie obviousness”) (citation and internal quote omitted). Although
there is always the possibility of a showing of unexpected results, “[f]or
obviousness under §103, all that is required is a reasonable expectation of
success.” In re O'Farrell, 853 F.2d 894, 904 (Fed. Cir. 1988) (citations
omitted.
Our reviewing court has instructed that, “in a section 103 inquiry, ‘the
fact that a specific [embodiment] is taught to be preferred is not controlling,
since all disclosures of the prior art, including unpreferred embodiments,
must be considered.’” Merck & Co. Inc. v. Biocraft Laboratories Inc.,
874 F.2d 804, 807 (Fed. Cir. 1989) (internal quote and citation omitted).
Moreover, “[t]he presence or absence of a motivation to combine references
in an obviousness determination is a pure question of fact.” In re Gartside,
203 F.3d 1305, 1316 (Fed. Cir. 2000) (citation omitted.) What a reference
would have conveyed to a person having ordinary skill in the art is also a
question of fact. Bilstad v. Wakalopulos, 386 F.3d 1116, 1126
Appeal 2009-0897
Application 10/830,685

10
(Fed. Cir. 2005). When questions of fact are at issue, mere argument in a
brief cannot take the place of evidence. In re Pearson, 494 F.2d 1399, 1405
(CCPA 1974).
With respect to the compositions recited in claims 1 and 10, Gorman
contends that “Becher provides no guidance as to the effect that other metal
oxides would make on the composition.” (Br. 6.) Gorman asks, “would
hafnia have the same countering effect if ytterbia were substituted for ceria?
What range of ytterbia would provide the desired outcome?” (Id. at 7.)
Gorman asserts further that Becher teaches that certain oxides mixed with
zirconia can have an adverse effect on toughening. (Id., citing Becher,
col. 1, ll. 40-45.) Gorman concludes that Becher cannot stand for the
functional equivalency of the metal oxides, and that the Examiner’s rejection
must be reversed. (Id.)
Initially, we note that Gorman appears to have misapprehended the
teachings of Becher regarding the allegedly adverse effects of certain metal
oxides on the toughening (phase-stabilization) of zirconia. Becher does not
teach that the adverse effects arise due to any chemical issues: rather, Becher
teaches that such problems arise due to inhomogeneities produced when
powders are mechanically mixed. (Becher col. 1, ll. 42-45.) Consistently,
Becher teaches preparation methods involving aqueous solutions of all
components, that would be expected to avoid production of inhomogeneous
solids.
Moreover, Gorman’s arguments are misplaced in that they do not take
into account the scope of compositions covered by claim 1 or the standard of
prima facie obviousness, which requires only a reasonable expectation of
Appeal 2009-0897
Application 10/830,685

11
successfully obtaining such a composition based on the teachings of the
prior art.
The claimed compositions are required to contain a minimum
of 80 mole % of a main ceramic component (that in turn comprises, at a
minimum, about 90 mole % ZrO2, about 6 mole % HfO2), and
about 5.5 mole % of one or more of 14 named stabilizer metal oxides.8 The
Examiner finds that Becher, in Example I, describes a similar ceramic
composition that, but for the presence of stabilizing metal oxide CeO2, which
was recited in the original claims, meets the limitations of appealed claim 1.
Based on the description by Becher that MgO, CaO, or Y2O3, are, along with
CeO2, known as stabilizing metal oxides for ZrO2, the Examiner concluded
that it would have been obvious to substitute one stabilizing metal oxide for
another. Gorman has not directed our attention to any teaching in the record
that a similar composition, in which CeO2 has been replaced by one of the
other stabilizing metal oxides, would not have been expected to yield a
ceramic. Nor has Gorman directed our attention to evidence of record
indicating that those having ordinary skill in the art would have recognized
(or thought) that the stabilizers act in ways that are incompatible with the
way CeO2 acts in the ZrO2:HfO2 system. Put another way, Gorman does not
support with credible evidence its tacit assumption that persons having
ordinary skill in the art would have concluded on the present record that the
effects of HfO2 are peculiar to the CeO2:ZrO2 system. Unexplained
assumptions based on the silence of a patent disclosure have limited

8 The scope of variation encompassed by the modifier “about” has not been
explored during prosecution, but we need not resolve that issue to decide this
appeal.
Appeal 2009-0897
Application 10/830,685

12
probative value, as “a patent need not teach, and preferably omits, what is
well known in the art.” Hybritech v. Monoclonal Antibodies, Inc., 802 F.2d
1367, 1384 (Fed. Cir. 1986). Such argument does not take the place of
evidence.
Whereas the Examiner has supported the rejection by at least a
modicum of evidence of record, Gorman has supported the traverse solely
by attorney argument in the Brief. We conclude that Gorman has failed to
show that the preponderance of the evidence indicates reversible error in the
rejection.
We turn next to the rejection of claim 10, which covers thermal
barrier coated articles. Because Gorman provides no credible evidence that
those skilled in the art would have had such a limited understanding of the
teachings of Becher, we do not credit Gorman’s criticism that Becher
discloses structural ceramics and does not provide a suggestion that the
materials would be useful as TBCs (Br. 8). Murphy teaches that yttria is
widely used to stabilize zirconia in TBCs: but Murphy does not teach that
yttria is the only such stabilizing additive. Notably, Murphy’s claims 1, 2, 7,
8, 15, and 16, which cover stabilized zirconia TBCs, coated articles, and
methods of thermally protecting substrates, are not limited to yttria-
stabilized zirconias. Similarly, the 685 Specification notes that a number of
phase-stabilized zirconia, including yttria-, scandia-, ceria-, calcia-, and
magnesia-stabilized zirconia, are recognized as TBCs. (Spec. 1, ¶ [0004].)
All of this evidence suggests strongly that persons having ordinary skill in
the art would have recognized various stabilized zirconia:hafnia ceramics as
being useful as thermal barrier coatings. Similarly, Gorman’s focus on
Murphy’s preferred embodiments having at least 15 w% hafnia ignore
Appeal 2009-0897
Application 10/830,685

13
Murphy’s more general teachings—as well as Murphy’s claims—that the
addition of hafnia to stabilized zirconia in amounts in excess of naturally
occurring impurity levels—i.e., above about 1-2 wt %, was found
“unexpectedly to be effective to reduce the thermal conductivity of the
thermal barrier coating.” (Murphy 2, ¶ [0010].) The teachings of a
reference are not limited to its examples or its preferred embodiments. We
conclude that Gorman has not shown that the preponderance of the evidence
indicates reversible error in the Examiner’s combination of the teachings of
Becher and Murphy.
Finally, Gorman’s criticisms of the Examiner’s reliance on Spitsberg
rests solely on its criticisms of Becher and Murphy. Gorman does not
dispute that Spitsberg teaches TBCs having thicknesses of about 3-30 mils.
Moreover, the 685 Specification teaches that TBCs are “usually in the range
of 3 to 70 mils . . . thick for high temperature gas turbine engine parts.”
(Spec. 2, ¶ [0004].) It would have been prima facie obvious for a person
having ordinary skill in the art to use a conventional thickness for a thermal
barrier coating.
As Gorman has not made any arguments for patentability based on
unexpected results, such arguments have been waived.
37 C.F.R. § 41.37(c)(1)(vii). We hold that reversible error has not been
demonstrated in the Examiner’s rejections for obviousness.
Appeal 2009-0897
Application 10/830,685

14
D. Order
We AFFIRM the rejection of Claims 1 and 7-9 under
35 U.S.C. § 103(a) in view of Becher.
We AFFIRM the rejection of claims 10-13, 19, 20, and 22-25 under
35 U.S.C. § 103(a) in view of the combined teachings of Becher and
Murphy.
We AFFIRM the rejection of claim 21 under 35 U.S.C. § 103(a) in
view of the combined teachings of Becher, Murphy, and Spitsberg.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED

PL Initial:
sld

GENERAL ELECTRIC COMPANY
GE AVIATION
ONE NEUMANN WAY MD H17
CINCINNATI, OH 45215