Helm, Dietmar et al.

Patent Trials and Appeals Board

Nov 12, 2020

14237929 - (D) (P.T.A.B. Nov. 12, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
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.
14/237,929 03/03/2014 Dietmar Helm 6570-P50118 5753
13897 7590 11/12/2020
Abel Schillinger, LLP
5929 Balcones Drive
Suite 300
Austin, TX 78731
EXAMINER
HEVEY, JOHN A
ART UNIT PAPER NUMBER
1735
NOTIFICATION DATE DELIVERY MODE
11/12/2020 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
hmuensterer@abel-ip.com
mail@Abel-IP.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte DIETMAR HELM, FALKO HEUTLING, ULRIKE HABEL, and
WILFRIED SMARSLY

Appeal 2019-005516
Application 14/237,929
Technology Center 1700
____________

Before MICHAEL P. COLAIANNI, N. WHITNEY WILSON, and
DONNA M. PRAISS, Administrative Patent Judges.

COLAIANNI, Administrative Patent Judge.

DECISION ON APPEAL

Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 8, 11–14, 17–19, 21–25, and 28–35.
We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies MTU Aero Engines AG as the real party
in interest. (Appeal Br. 3).
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Appellant’s invention is directed to a method of producing forged
components of TiAl alloy, in particular components for gas turbines. (Spec.
1:8-9; Appeal Br. 21, Claims App.).
Claim 8 is representative of the subject matter on appeal:

8. A method for producing a forged component of a TiAl
alloy, wherein the method comprises forging the component
and thereafter subjecting it to a two-stage heat treatment, and
wherein (i) a first stage of the heat treatment comprises
recrystallization annealing for 50 to 100 minutes at a
temperature below a γ/α transition temperature, (ii) a second
stage of the heat treatment comprises stabilization annealing in
a temperature range of from 800°C to 950°C for 5 to 7 h, and
(iii) a cooling rate during the first stage of the heat treatment is
greater than or equal to 3°C/s in a temperature range of from
1300°C to 900°C to afford a finely lamellar micro structure of
α2-Ti3Al and γ-TiAl in a corresponding α2 and γ phase.

Appellant appeals the following rejections:
1. Claims 8, 11, 13, 14, 17–19, 22, and 28–33 are rejected under
35 U.S.C. § 103(a) as unpatentable over Droessler (Droessler et
al., Microstructure and Tensile Ductility of a Ti-43A1-4Nb-
1Mo-0.1B Alloy, Mater. Research Society Symp. Proc., Vol.
1128, 121–126 (2009), hereinafter “Droessler”) in view of
Clemens (Clemens, et al., Design of Novel ß-Solidifying TiAl
Alloys with Adjustable ß/B2-Phase Fraction and Excellent Hot-
Workability, Advanced Engineering Materials, Vol. 10, No. 8
(2008), hereinafter “Clemens”) and Park (Park et al.,
Microstructural Refinement and Mechanical Properties
Improvement of Elemental Powder Metallurgy Processed Ti-
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46.6Al-1.4Mn-2Mo Alloy by Carbon Addition, Metallurgical
and Materials Transactions A, Vol. 32A, 251–259 (2001),
hereinafter “Park”).
2. Claim 21 is rejected under 35 U.S.C. § 103(a) as unpatentable
over Droessler in view of Clemens, Park, Smarsly (Smarsly et
al., US 2011/0189026 A1; pub. Aug. 4, 2011, hereinafter
“Smarsly”), and Eberhardt (Eberhardt et al., US 6,161,285; iss.
Dec. 19, 2000, hereinafter “Eberhardt”).
3. Claims 23–25, 34, and 35 are rejected under 35 U.S.C. § 103(a)
as unpatentable over Droessler in view of Clemens, Park, and
Kim (Kim et al., US 5,558,729; iss. Sept. 24, 1996, hereinafter
“Kim”).
4. Claims 8, 11, 13, 14, 22, 23, 34, and 35 are rejected under
35 U.S.C. § 103(a) as unpatentable over Kim in view of
Clemens.
5. Claim 21 is rejected under 35 U.S.C. § 103(a) as unpatentable
over Kim in view of Clemens, Smarsly, and Eberhardt.

FINDINGS OF FACT AND ANALYSIS
Rejections (1) to (3)
Appellant’s arguments focus on the subject matter of claim 8 and the
group of claims 29–31 under rejection (1) and claim 23 under rejection (3).
(Appeal Br. 6–15). With regard to claim 21, Appellant argues Smarsly and
Eberhardt do not cure the argued deficiencies of Droessler, Clemens, and
Park. (Appeal Br. 13). Accordingly, claim 21 will stand or fall with our
analysis of the rejection of claim 8. Appellant does not separately argue any
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of claims 29–31. Therefore, we select claim 29 as representative of the
arguments made with this claim grouping. 37 CFR § 41.37(c)(iv).
The Examiner’s findings regarding the obviousness rejections (1) and
(3) are located on pages 3–5 and 7–8 of the Final Action, respectively. The
Examiner finds Droessler generally teaches the method recited in claim 8 for
forming a TiAl alloy, except for “a cooling rate during the first stage of the
heat treatment is greater than or equal to 3°C/s in a temperature range of
from 1300°C to 900°C.” (Final Act. 3). The Examiner finds Droessler
teaches the same two-step heat treatment method with temperatures and
times that overlap those recited in claim 8. (Final Act. 3). The Examiner
finds Clemens teaches forming a TiAl alloy using a two stage heat treatment
with similar temperatures and times as recited in claim 8 and in Droessler.
(Final Act. 3). The Examiner finds Clemens teaches air cooling after the
first heat treatment using a high cooling rate in order to obtain a very fine
lamellar spacing. (Final Act. 3). The Examiner finds Park teaches the effect
of cooling rates on the grain size of lamellar α2 and γ phase of a TiAl alloy
material. (Final Act. 4). The Examiner finds Park teaches using a cooling
rate of 200°C/min (i.e., 3.33°C/s). (Final Act. 4). The Examiner finds Park
teaches air cooling occurs at a higher cooling rate and results in smaller
lamellar phase grain size. (Final Act. 4).
Based upon the similarity of the processes in Droessler, Clemens, and
Park, the Examiner concludes that it would have been obvious to modify the
method of Droessler to perform a step of rapid air cooling at a rate above
3.3°C/s after a first heat treatment in order to obtain a desired microstructure
such as lamellar α2 and γ phases of TiAl. (Final Act. 4). The Examiner
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finds that the selection of the temperature and time within the overlapping
ranges would have been obvious. (Final Act. 4).
Appellant argues that neither Droessler nor Clemens discloses any
specifics regarding the cooling step that follows the first heat treatment such
that there would have been no reason other than hindsight to use Park’s
cooling rate in Droessler’s method. (Appeal Br. 7–8, 11). Appellant argues
Droessler’s silence on the time or cooling rate used during the air cooling
step evinces that the cooling conditions are of no importance for the
microstructure or properties of Droessler’s final product. (Appeal Br. 10).
Appellant argues air cooling is not associated with a single cooling rate but,
rather, is dependent on velocity of the cooling air. (Appeal Br. 11).
Appellant contends that Park’s alloy compositionally differs from
Droessler’s alloy in that Park’s alloy contains more Al, no Nb, no B, more
Mo, and Mn, which is not present in Droessler’s alloy. (Appeal Br. 9).
Appellant argues that because there is a difference in alloy compositions, a
person of ordinary skill in the art would not have expected that a cooling rate
of 3.3°C/s in Park’s alloy would have the same effect in the alloy
investigated by Droessler. (Id.). Appellant argues the Examiner has not
shown that the effect of the cooling rate on microstructure of the alloy is
independent of the alloy composition. (Id.).
We have fully considered the Examiner’s findings and conclusions
and Appellant’s arguments. We find that the preponderance of the evidence
favors the Examiner’s obviousness conclusion. In the present case, the
Examiner acknowledges that there may be “some compositional differences”
between the alloys of Droessler, Clemens, and Park, but the Examiner finds
that all three references teach methods of making TiAl-based alloys
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comprising lamellar α2 and γ phases. (Ans. 6). The Examiner finds that
Droessler and Clemens teach two heat treatment steps followed by air
cooling after the first step. (Ans. 6). The Examiner finds that Park teaches a
first heat treatment step followed by cooling and the effect of cooling rates
on microstructural features of the alloy. (Ans. 6). The Examiner finds that
because TiAl alloys are processed in all three references, a person of
ordinary skill in the art would have recognized the applicability of
parameters for an air cooling step, such as cooling rate, for one TiAl-based
alloy to another TiAl-based alloy. (Ans. 6). We agree.
Appellant does not dispute that Droessler, Clemens, and Park teach an
air cooling step after a first heat treatment of a TiAl-based alloy. (See
generally Appeal Br.). The Examiner relies on Parks to teach the particular
air cooling rate recited in claim 8 (i.e., greater than or equal to 3 °C/s).
(Final Act. 4). The Examiner finds that Park teaches air cooling takes place
at a higher cooling rate and results in smaller lamellar phase grain size.
(Final Act. 4). Appellant does not particularly address this finding other
than to argue that air cooling does not have a particular cooling rate.
(Appeal Br. 11). Park experiments with three cooling rates: air cooling, 200
°C/min (i.e., 3.3 °C/s) and furnace cooling. (Park 253). Park determines
from the experiment that grain size of the TiAl-based alloy increased with
slow cooling regardless of the presence of carbon in the alloy composition
from 70, 100 and 150 μm, which correspond to air cooling, 200°C/min and
furnace cooling grain sizes, respectively. (Park 253). Based on Park’s
teachings, the cooling method that produces the smallest grain size would
appear to be the one with the greatest cooling rate. In this case, Park’s air
cooling would have a higher cooling rate than 200 °C/min because air
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cooling yielded the smallest grain size (i.e., 70 μm) of the three cooling
methods tested.
Droessler teaches the grain size of the TiAl-based alloy after air
cooling following the first heat treatment step is about 20 μm. (Droessler
123). Droessler’s grain size (20 μm) is smaller than Park’s grain size (70
μm) for the air cooled sample. This smaller grain size would have suggested
that Droessler’s air cooling rate is greater than Park’s air cooling rate, which
is faster than 3.3 °C/s. In light of Park’s teachings regarding grain size and
cooling rate, the Examiner properly determines that the combined teachings
of Droessler, Clemens and Park would have suggested using a cooling rate
within the range recited in claim 8 in Droessler’s method.
Appellant’s arguments about the differences in composition are not
persuasive because the Examiner has shown that each reference has a similar
composition based on titanium and aluminum. (Final Act. 3–4; Ans. 6).
The Examiner finds that each of the references forms lamellar α2 and γ phase
TiAl alloy. (Ans. 6). In other words, despite the difference in the presence
of C, Mo, Nb, W, or other elements, the Examiner finds that the
microstructure achieved is similar. All three references use a cooling step as
part of the process to form the microstructure. (Droessler 122 (Table 1);
Clemens 712; Park 253). Contrary to Appellant’s argument, a person of
ordinary skill in the art would have had a reasonable expectation that using
an air cooling method, which the art teaches has a high cooling rate, would
have yielded a TiAl-based alloy having a finely lamellar microstructure as
recited in claim 8.
Appellant’s argument that Park’s and Clemens’ hot extrusion methods
of forming the alloy are different than Droesseler’s forging process is not
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persuasive. (Appeal Br. 10). Clemens teaches forging a TiAl alloy and then
subjecting the forged alloy to a two-step heat treatment. (Clemens 712).
Park teaches a hot extruded alloy that is subject to a heat treating and
cooling step. (Park 251). The Examiner finds and Appellant does not
dispute that “the method of forming the material prior to the first heat
treatment does not impact the effect of the cooling step nor the final
microstructure of the alloy.” (Ans. 6; generally Reply Br.). Appellant’s
argument does not establish reversible error with the Examiner’s findings
and conclusions based thereon.
With respect to dependent claim 292, Appellant argues that Droessler
in view of Clemens and Park do not teach a method comprising substantially
the same method of making the alloy as discussed with respect to claim 8
(Appeal Br. 12). The Examiner finds the particular proportions of β, α, and γ
phases in the TiAl would have been expected to be similar because the prior
art teaches similar TiAl alloys with minor amounts of other elements that
differ and the TiAl alloys are heat treated and cooled using similar methods
to those recited in claim 8 as found by the Examiner. (Final Act. 5). The
Examiner further determines that it would have been obvious in light of
Droesseler’s, Clemen’s and Park’s teachings to select optimum working
conditions to obtain desired properties and microstructure with a reasonable
expectation of success. (Final Act. 5). Appellant does not respond to the
Examiner’s rationale based on optimizing the methods to obtain the desired

2 In the event of further prosecution, the dependency of claims 17, 18, and
28-33 must be corrected. All of these claims include cancelled claim 16 in
their respective chain of dependency. Claim 16 was cancelled in an
amendment filed May 4, 2018 (Advisory Act. 2).
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properties and microstructure (Appeal Br. 12–13) and, therefore does not
demonstrate reversible error in it. .
Regarding § 103 rejection (3) of independent claim 23 over Droessler
in view of Clemens, Park, and Kim, Appellant argues that Kim does not cure
the deficiencies argued in Droessler, Clemens, and Park. (Appeal Br. 14).
We disagree for the reasons discussed above in the context of rejection (1)
and because we find no deficiencies in the Examiner’s combination of
Droessler, Clemens, and Park.
The Examiner finds Droessler, Clemens, and Park would have
suggested an accurate heating method in order to obtain precise results and
avoid unwanted temperature variations, in order to obtain desired
microstructure and properties. (Final Act. 7). The Examiner finds Droessler
teaches a first heat treatment temperature below the α transition temperature,
but does not specify that the transition temperature is 10°C below the α
transition temperature. (Final Act. 7–8). The Examiner finds Kim teaches
selecting a heating temperature between 1 to 20°C below the α transition
temperature in order to obtain a fully lamellar microstructure. (Final Act. 8).
The Examiner concludes it would have been obvious to modify the method
of Droessler in view of Clemens and Park to select a first heat treatment
temperature of from 1 to 20°C below the α transition temperature as taught
by Kim in order to form a fully lamellar microstructure. (Final Act. 8).
Appellant argues that Kim’s alloys differ significantly from the alloy
of Droessler and Clemens because Kim’s alloys contains more aluminum,
tungsten, but no molybdenum, and boron. (Appeal Br. 14). Appellant
contends that Kim’s alloys include chromium and niobium which are not
present in Droessler’s alloys. (Appeal Br. 15). Appellant contends that
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because of these significant alloy compositional differences, a person of
ordinary skill in the art would not have combined the teachings of Kim and
Droessler. (Appeal Br. 16).
As with rejection (1) of claim 8, Appellant’s arguments about the
differences in composition are not persuasive because the Examiner has
shown that each reference has a similar alloy composition based on a
titanium and aluminum. (Final Act. 3–4, 7–8; Ans. 6, 8). The Examiner
finds that each of the references forms lamellar α2 and γ phase TiAl alloy.
(Ans. 6, 8). In other words, despite the difference in the presence of C, Mo,
Nb, W, or other elements, the Examiner finds that microstructure achieved is
similar. All three references use a cooling step as part of the process to form
the microstructure. (Droessler 122 (Table 1); Clemens 712; Park 253; Kim,
col. 4, ll. 25–42). Contrary to Appellant’s argument, one of ordinary skill in
the art would have had a reasonable expectation that using an air cooling
method, which the art teaches has a high cooling rate, would have yielded a
TiAl-based alloy having a finely lamellar microstructure as recited in claim
23.
Based on this record, we affirm the Examiner’s § 103 rejections of
claims 8, 11, 13, 14, 17–19, 21–25, and 28–35 over the combined teachings
of Droessler, Clemens, Park, and Kim.
Rejections (4) and (5)
Appellant’s arguments focus on the subject matter common to claims
8 and 23. (Appeal Br. 16–19). We select claim 8 as representative of the
argued group. 37 CFR § 41.37(c)(iv). Regarding rejection (5) of claim 21,
Appellant relies on arguments made regarding rejection (4). (Appeal Br.
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19). The rejection of claim 21 will stand or fall with our analysis of the
rejection of claim 8.
The Examiner’s findings and conclusions regarding Kim and Clemens
are located on pages 8 to 10 of the Final Office Action. The Examiner finds
that Kim teaches that the a method of making a TiAl alloy that involves
forging the alloy and using a two-step heat treatment process with a cooling
step between the two heating steps. (Final Act. 8). The Examiner finds that
the time and temperatures used for the two heat treatments in Kim overlap
with the temperatures and times recited in claim 8. (Final Act. 8). The
Examiner finds that Kim teaches an air cooling rate of approximately
16.7°C/sec (i.e., 1000°C/min). (Final Act. 8). The Examiner finds that
Clemens teaches a two-step heat treatment process for forged TiAl alloy
using high cooling rate between heat treatment steps to obtain very fine
lamellar spacing. (Final Act. 9). The Examiner concludes that it would
have been obvious to modify Kim’s method to use rapid air cooling rates up
to 16.7°C/s in order to obtain a microstructure with very fine lamellar
spacing as taught by Clemens. (Final Act. 9).
Appellant argues that the presently recited cooling rate in claim 8,
3°C/s, is more than 30 times greater than the minimum cooling rate recited
in Kim (i.e., 5°C/min or 0.083 °C/s). (Appeal Br. 16). Appellant contends
that Clemens does not specify what constitutes a “high cooling rate.”
(Appeal Br. 16). Appellant argues that Kim teaches that air cooling rates
can vary over an extremely broad range (i.e., 5 to 1000°C/min). (Appeal Br.
16). Appellant contends that Kim’s disclosures of times and temperatures
for the heating steps are too broad and lead to a virtually infinite number
potential embodiments in Kim. (Appeal Br. 17). Appellant contends that
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the Examiner has not explained why a person of ordinary skill in the art
would have select the claimed times and temperatures for the first and
second heating steps and the cooling rates. (Appeal Br. 17). Appellant
argues that Kim has not identified the time and temperatures to be result-
effective variables. (Appeal Br. 17). Appellant argues that the Examiner
engaged in impermissible hindsight. (Appeal Br. 17). Appellant argues that
Kim’s and Clemen’s alloys differ significantly in that Kim’s alloy contains
the following relative to Clemen’s alloy: more aluminum, tungsten, no Mo
or B. (Appeal Br. 18).
Contrary to Appellant’s argument, the Examiner’s rejection is based
upon overlap in the time and temperature treatment of the two heat treatment
steps and the cooling rate of Kim with those recited in claim 8. A prima
facie case of obviousness typically exists when the ranges of a claim overlap
with ranges disclosed in the prior art. In re Peterson, 315 F.3d 1325, 1329
(Fed. Cir. 2003). Appellant does not dispute that the claimed ranges
overlap. (Appeal Br. 16–18). In this case the overlapping ranges create a
prima facie case of obviousness at which time Appellant may submit
evidence of criticality or unexpected results in using the particularly claimed
time and temperature ranges. Peterson, 315 F.3d at 1330. The Examiner
finds Appellant has not provided any evidence establishing criticality in the
claimed cooling rate range. (Ans. 9). We find that Appellant also does not
provide any evidence of criticality in the time or temperatures used by
Appellant. The prior art’s teaching of overlapping ranges would have
rendered obvious the claimed subject matter.
Appellant’s argument about the ranges being too broad is not
persuasive. Kim’s disclosure of a multitude of effective times, temperatures
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and cooling rates does not render any one combination of them less obvious.
Merck v. Biocraft, 874 F.2d 804, 807 (Fed. Cir. 1989). Kim discloses that
annealing at a temperature about 20°C below the transition temperature
yields a fully lamellar TiAl alloy for a period of time from 0.25 to 15 hours
depending on the desired microstructure, alloy selected, annealing
temperatures selected, material section size and grain size desired. (Kim,
col. 4, ll. 28–36). The cooling schemes and rates in Kim depend mainly on
microstructure type and stability. (Kim, col. 4, ll. 36–38). The second
heating step involves temperatures from 700 to 1050°C for 4 to 150 hours
(Kim, col. 4, ll. 39–41). Kim’s teaching would teach a person of ordinary
skill in the art to tailor the time, temperature and cooling rate within the
claimed ranges to achieve the desired lamellar microstructure.
Contrary to Appellant’s arguments, the Examiner is not generally
relying on a result-effective variable analysis to conclude obviousness but,
rather, the fact that Kim’s time, temperature and cooling rate ranges overlap
with those recited in claim 8. (Ans. 9–10). The Examiner does find that
Kim’s cooling rate is a result-effective variable that is critical for achieving
the desired microstructures and mechanical properties. (Ans. 10). Kim’s
teaching at column 5, lines 10–12 supports the Examiner’s finding.
Moreover, Appellant does not specifically dispute that Kim’s cooling rate is
a result effective variable. (Reply Br. generally).
Appellant’s arguments regarding the difference in alloy composition
are not persuasive for the same reasons discussed above with respect to Kim
and Clemens in rejections (1) and (3). We add the difference in the amounts
of interstitial (e.g., O and C) and substitutional (e.g., Cr, Mn, Ta, and W)
alloying elements are known to decrease the transus temperature. (Kim,
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col. 2, ll. 34–41). Kim further teaches that transus temperature can be
determined relatively routinely by standard isothermal treatments and
metallography. (Kim, col. 2, ll. 38–40). Clemens teaches that Nb, Ta, Mo,
and other elements stabilize the β-phase of the TiAl alloy and improve hot-
workability of the alloy. (Clemens 707, 711). In other words, the prior art
teaches the effect the alloying elements have on the alloy microstructure and
it would have been within the skill level of the ordinarily skilled artisan to
determine elemental amounts and alloy heat treatments/cooling rates to
arrive at the process of claim 8.
On this record, we affirm the Examiner’s 35 U.S.C. § 103 rejections
(4) and (5) over the combined teachings of Kim, Clemens, Smarsly, and
Eberhardt.
CONCLUSION
In summary:

Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
8, 11, 13, 14,
17–19, 22,
28–33
103(a) Droessler, Clemens, Park
8, 11, 13,
14, 17–19,
22, 28–33

21 103(a) Droessler, Clemens, Park, Smarsly, Eberhardt 21

23–25, 34, 35 103(a) Droessler, Clemens, Park, Kim
23–25, 34,
35

8, 11, 13, 14,
22, 23, 34, 35 103(a) Kim, Clemens
8, 11, 13,
14, 22, 23,
34, 35

21 103(a) Kim, Clemens, Smarsly, Eberhardt 21

Overall
Outcome
8, 11–14, 17–19, 21–

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Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
25, and 28–
35

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

AFFIRMED