Ex Parte Huang et al

Patent Trial and Appeal Board

Oct 24, 2012

11889917 (P.T.A.B. Oct. 24, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte AIJUN HUANG, MICHAEL LORETTO, XINHUA
WU, and DAWEI HU
____________________

Appeal 2011-005830
Application 11/889,917
Technology Center 1700
____________________

Before CHUNG K. PAK, CATHERINE Q. TIMM, and MARK NAGUMO,
Administrative Patent Judges.

TIMM, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF CASE
Appellants appeal under 35 U.S.C. § 134 from the Examiner’s
decision to reject claims 1-12. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
Appellants’ invention relates to a process of subjecting a titanium
aluminide alloy to a temperature cycle that produces a massively
transformed gamma microstructure (Spec. 1:9-25; Spec. 6:18-25). As
conveyed by the Specification, the particular temperature cycle used to
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obtain the massive transformation is taught by EP1378582A1 (Compare
Spec. 1:9-25 with Spec. 3:6-12). Appellants’ improvement involves adding
up to 0.5 at% of oxygen scouring means (e.g., yttrium) to the TiAl alloy
(Spec. 2:28-32).
Claim 1 is illustrative of the invention on appeal:
1. A method of enhancing massive transformation of a titanium
aluminide alloy having a single alpha phase field, said method
comprising:
incorporating up to 0.5 at% of oxygen scouring means
into the alloy which inhibits diffusion of oxygen within the
alpha phase field to the grain boundary as the alloy is subjected
to a temperature cycle which produces a massively transformed
gamma microstructure.
(Claims App.)
The Examiner rejects claims 1-3, 5, and 8 under 35 U.S.C. § 102(b) as
anticipated by Wu1, and claims 1-12 under 35 U.S.C. § 103(a) as obvious
over Hu2 in view of Wu.
OPINION
A. ANTICIPATION BY WU
All of the claims require forming a massively transformed gamma
microstructure (see Claim 1).
The Examiner finds that Wu teaches subjecting a TiAl alloy to a
temperature cycle to produce a massively transformed gamma
microstructure (Ans. 4, citing Wu, Abstract and Experimental section).
Further, the Examiner finds that “since Wu teaches an identical process as

1 Wu et al., Influence of Y-addition on the oxidation behavior of Al-rich γ-
TiAl alloys, Intermetallics 12(2004) 519-532.
2 Hu, US 2004/0003877 A1, pub. Jan 8, 2004.
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claimed, one skilled in the art would have envisaged that the process of Wu
would have produced a massively transformed product as claimed.” (Ans.
6.)
Wu’s Abstract states that Wu’s paper is directed to the study of the
influence of yttrium on Al-rich γ-TiAl alloys containing 0.1-1.0 at% Y with
equiaxial gamma microstructure, and explains Wu’s results (Abstract).
Wu’s “Experimental procedure” section discloses the method of
forming Y-free TiAl alloy and 0.1-1.0 at% Y containing TiAl alloy ingots to
be tested. Forming the ingots involved annealing the ingots at 1200 °C for
72 h in an argon atmosphere to keep their compositional uniformity and
stabilize the microstructure, and applying heat treatment cycles consisting of
a solution treatment at 1400 °C for 1 h followed by air cooling (Wu,
Experimental Procedure section at p. 520, ¶ 1). Wu states that
“[m]etallographic examinations and X-ray diffractometry (XRD) revealed
that microstructures consisted predominantly of equiaxial TiAl grains as
shown in Figs. 1 and 2.” (Id.)
Appellants contend that Wu’s figures illustrate non-massive
microstructures, and massively transforming TiAl alloys requires rapid
quenching whereas Wu discloses a slower air cooling (Br. 4).
Appellants’ Specification discloses that the cooling rate affects the
massive transformation of the gamma titanium aluminide (Spec 2:7-8). Cool
too fast and the microstructure retains its alpha phase (Spec. 2:8-10). Cool
too slow and the alloy will precipitate gamma grains (Spec. 2:10-11)
The Examiner states that the process is identical without addressing
Appellant’s argument concerning the cooling rate. The evidence as a whole
indicates that cooling rate affects the conversion of the microstructure.
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Therefore, it was necessary for the Examiner to point out why it would have
been reasonable to conclude that a massively transformed gamma
microstructure would have necessarily resulted when performing the
procedure of Wu. This the Examiner did not do. Moreover, the Examiner
has not provided the level of evidence necessary to support the finding that
one skilled in the art would have at once envisaged that the process of Wu
would have produced a massively transformed product as claimed. Such a
finding requires evidence of what those of ordinary skill in the art would
have understood with regard to the microstructures described by Wu.
We do not sustain the anticipation rejection.
B. OBVIOUSNESS OVER HU AND WU
With respect to the rejection of claims 1-12 as obvious over Hu in
view of Wu, Appellants separately argue claims 3 and 9. We select claim 1
as representative for the claims not separately argued.
1. Claim 1
There is no dispute that Hu describes a method of subjecting a TiAl
alloy to temperature cycling to obtain a massively transformed gamma
microstructure (Compare Ans. 4-5 with Br. 5-7 and Reply Br. 2-4; see also
Hu, Fig. 1, ¶¶ [0007-13]). The Examiner acknowledges that Hu does not
teach incorporating oxygen scouring means, but that Wu teaches
incorporating yttrium (an oxygen scouring means) in an amount of 0.1 at%
into a TiAl alloy (Ans. 5). The Examiner concludes that it would have been
obvious to one of ordinary skill in the art to incorporate yttrium, as taught by
Wu, into the alloy of Hu since Wu teaches the addition of yttrium would
improve the oxidation resistance of the alloy (id.).
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Appellants contend that Wu teaches using air cooling to provide a
non-massive microstructure, which is a direction away from the claimed
method and Wu cannot be used in combination with references teaching the
opposite, i.e., to produce a massive microstructure (Hu) (Br. 5). Therefore,
according to Appellants, Hu cannot be combined with Wu (id.). Appellants
also contend that there is no motivation to incorporate yttrium into the
method taught by Wu and that, even if Hu were combined with Wu, the
claimed method would not have been obvious over the combination (Br. 5-
7).
Appellants’ arguments give rise to the following issues:
a. Have Appellants established that Hu “teaches away,” as that
terminology is used in the context of obviousness, such that those
of ordinary skill in the art would have been discouraged from
incorporating yttrium into the TiAl alloy of Hu?
b. Have Appellants identified a reversible error in the Examiner’s
finding of a reason to incorporate concentrations of yttrium within
the claimed range into the TiAl alloy of Hu to form a massively
transformed gamma microstructure?
We answer both questions in the negative based upon a weighing of
the facts under the preponderance of the evidence standard and application
of the applicable law. The following facts are relevant.
Hu teaches a method of heat treating TiAl alloy that produces a
massively transformed gamma microstructure (Hu, ¶¶ [0007-13]).
Wu teaches that adding a small amount of yttrium (0.1 and 0.3 at%) to
TiAl-based alloys improves the oxidation resistance of the alloy (Wu,
Abstract). Wu states that oxidation rates, structures of scale, and scale
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spallation resistance were closely related to the concentration of yttrium in
the TiAl alloys tested (Wu, Abstract; see also § 5 Conclusions).
When forming the TiAl alloys to be tested, Wu subjected ingots of the
TiAl alloys to heat treatment cycles consisting of solution treatment at 1400
°C for 1 h followed by air cooling, but Wu does not state that the heat
treatment forms massively transformed gamma microstructure (Wu,
Experimental procedure, ¶ 1).
Appellants state that Wu clearly teaches using air cooling to provide a
non-massive microstructure, however, Appellants do not point to any
language in Wu indicating that Wu teaches a non-massively transformed
gamma microstructure (Br. 5). Nor do Appellants explain the basis of their
interpretation of the figures in Wu as showing non-massively transformed
microstructures. Wu appears to be merely silent with respect to the presence
of a massively transformed gamma microstructure (Wu, generally).
“What the prior art teaches and whether it teaches toward or away
from the claimed invention . . . is a determination of fact.” Para-Ordnance
Mfg., Inc. v. SGS Importers Int’l., Inc., 73 F.3d 1085, 1088 (Fed. Cir. 1995)
(citing In re Bell, 991 F.2d 781, 784 (Fed. Cir. 1993)). When there is
nothing within the reference teaching that the claimed element should not, or
cannot, be used, and further cited prior art teaches the propriety of
employing the missing element, the teachings of both references must be
weighed together. Para-Ordninace, 73 F.3d at 1090.
Hu discloses the propriety of employing a temperature cycle to
produce a massively transformed gamma microstructure in TiAl alloys.
Appellants have not pointed to any disclosure within Wu teaching that TiAl
alloys should not be so temperature cycled to form a massively transformed
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gamma microstructure or that one of ordinary skill in the art would have
been lead to believe from Wu that adding yttrium in the small amounts
disclosed by Wu would have not been thought to provide TiAl alloys having
such microstructure with the oxygen resistance properties disclosed by Wu.
Wu does not criticize, discredit, or otherwise discourage the path of the
proposed combination. Therefore, Appellants have not established that Hu
teaches away from the claimed method.
With regard to the second issue, we do not agree with Appellants that
the Examiner’s finding of a suggestion to combine the references is
unsupported by the evidence.
As pointed out by Appellants, Wu incorporates oxygen for a
somewhat different reason than Appellants, i.e., to obtain oxygen resistance
rather than to scour oxygen during temperature cycling. That fact, however,
does not translate to a conclusion of non-obviousness.
The problem faced by an applicant is a relevant factor to take into
consideration in an obviousness determination. However, it is error to look
“only to the problem the patentee [or applicant] was trying to solve.” KSR
Int. Co. v. Teleflex Inc., 550 U.S. 398, 420 (2007). There may be other
reasons within the prior art for making the combination. “As long as some
motivation or suggestion to combine the references is provided by the prior
art taken as a whole, the law does not require that the references be
combined for the reasons contemplated by the inventor.” In re Beattie, 974
F.2d 1309, 1312 (Fed. Cir. 1992).
In the present case, Wu indicates that small amounts of yttrium will
increase the oxidation resistance of TiAl alloys. Hu teaches a TiAl alloy.
Under the circumstances, there is a reasonable expectation that small
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amounts of yttrium will provide the properties of oxidation resistance
discussed by Wu when used in the TiAl alloy treated in accordance with the
method of Hu.
Appellants discuss an unexpected advantage arising from the
combination (Br. 6-7). According to Appellants, adding yttrium allows the
quench to be performed at a slower rate (Br. 6). However, the fact that there
is an additional advantage does not negate the fact that there is a reason
within the prior art to add yttrium to the alloy of Hu. Appellants do not
appear to be relying upon any showing of unexpected results. Suffice it to
say that Appellants have not presented any objective data showing an
unexpected result commensurate in scope with claim 1.
Appellants have not identified a reversible error in the Examiner’s
finding of a reason to incorporate concentrations of yttrium within the
claimed range into the TiAl alloy of Hu to form a massively transformed
gamma microstructure.
2. Claim 3
Claim 3 recites that the temperature cycle of claim 1 comprises steps
of heating, maintaining, and cooling (Claim 3 as reproduced in Claims App).
There is no dispute that the temperature cycle steps are taught by Hu
(Compare Br. 5-7 with Ans. 4-5; see also Hu, ¶¶ [0007-13]).
Appellants merely point out what the Examiner acknowledges the
references fail to teach (Br. 7) without addressing the Examiner’s specific
findings and conclusions (Ans. 4-5). We cannot say that Appellants have
identified a reversible error in the Examiner’s rejection of claim 3.
3. Claim 9
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Claim 9 further requires that the cooling step of claim 3 comprise
cooling at a rate of 4 °C.S-1 to 150 °C.S-1.
Appellants state that prior to their invention the quenching step had to
be conducted rapidly to maintain the massive transformation, but that
surprisingly the addition of the claimed oxygen scavenging means allows the
quenching rate to be significantly reduced (Br. 8, citing Spec. 7:3-6 and 8:7-
18). Appellants contend that the claimed cooling range, having a lower limit
of only 4 °C.S-1 is obtainable using the claimed oxygen scavenging means,
and alloys such as those disclosed in Hu cannot be cooled at this slow rate to
product a massive transformation (Br. 8).
The claimed cooling rate encompasses cooling rates as high as 150
°C.S-1.
Hu discloses air cooling or oil cooling at a rate sufficient to induce
massively transformed gamma microstructure (Hu, ¶¶ [0019] and [0040]).
A preponderance of the evidence supports a determination that the
cooling rate one of ordinary skill in the art would have applied to the TiAl
alloy would have been within the very broad range of claim 9, which
encompasses very high cooling rates of 150 °C.S-1.
Appellants have not convinced us of a reversible error in the
Examiner’s rejection.
CONCLUSION
We do not sustain the Examiner’s rejection of claims 1-3, 5, and 8
under 35 U.S.C. § 102(b) as anticipated by Wu. However, we sustain the
Examiner’s rejection of claims 1-12 under 35 U.S.C. § 103(a) as obvious
over Hu in view of Wu.
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DECISION
The Examiner’s decision is affirmed.
TIME PERIOD FOR RESPONSE
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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