GM GLOBAL TECHNOLOGY OPERATIONS LLC

Patent Trials and Appeals Board

Nov 18, 2021

2021000443 (P.T.A.B. Nov. 18, 2021)

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.
15/668,027 08/03/2017 Su Jung Han P041655-US-NP 8823
286 7590 11/18/2021
GENERAL MOTORS LLC
LEGAL STAFF
MAIL CODE 482-C24-A68
P O BOX 300
DETROIT, MI 48265-3000
EXAMINER
BAREFORD, KATHERINE A
ART UNIT PAPER NUMBER
1718
MAIL DATE DELIVERY MODE
11/18/2021 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 PATENT TRIAL AND APPEAL BOARD
Ex parte SU JUNG HAN, MARTIN S. KRAMER, PENG LU, ZHE LI,
and YUCONG WANG
Appeal 2021-000443
Application 15/668,027
Technology Center 1700
Before TERRY J. OWENS, N. WHITNEY WILSON, and
SHELDON M. McGEE, Administrative Patent Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–13, 21, 22, and 24–26. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. The
Appellant identifies the real party in interest as GM Global Technology
Operations, LLC (Appeal Br. 2).
Appeal 2021-000443
Application 15/668,027

2
CLAIMED SUBJECT MATTER
The claims are directed to a method for coating an inner surface of an
engine cylinder bore. Claims 1 and 24, reproduced below, are illustrative of
the claimed subject matter:
1. A method of coating an inner surface of an engine
cylinder bore, the method comprising:
cleaning the inner surface to remove carbon formed
thereon, resulting in the inner surface having a maximum of 30
atomic percent of carbon on the inner surface, the inner surface
being formed of one of aluminum and an aluminum alloy;
texturing the inner surface until the inner surface exhibits
a developed interfacial area ratio of at least 100%;
heating the inner surface to a temperature between about
100 and about 200 degrees Celsius to provide a heated surface;
and
thermal spraying a steel coating onto the heated surface
to adhere the coating to the heated surface, wherein the
combination of performing the steps of cleaning, texturing, and
heating results in a metallurgical bond being formed between
the inner surface and the coating, the metallurgical bond having
interlayer region that includes a combination of iron of the
spray coating and aluminum of the inner surface.

24. A method of coating an inner surface of an engine
cylinder bore, the method comprising:
cleaning the inner surface to remove carbon formed
thereon, resulting in the inner surface having a maximum of 30
atomic percent of carbon on the inner surface;
texturing the inner surface until the inner surface exhibits
a developed interfacial area ratio of at least 100%;
heating the inner surface to a temperature between about
100 and about 200 degrees Celsius to provide a heated surface;
thermal spraying a coating onto the heated surface to
adhere the coating to the heated surface; and
forming a metallurgical bond between the inner surface
and the coating.
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Application 15/668,027

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REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Vierow US 4,164,066 Aug. 14, 1979
Heck US 4,302,482 Nov. 24, 1981
Leatham US 5,143,139 Sept. 1, 1992
Kramer US 5,271,967 Dec. 21, 1993
Palazzolo US 5,691,004 Nov. 25, 1997
Zaluzec US 5,958,521 Sept. 28, 1999
Goto US 2014/0182619 A1 July 3, 2014
Kabelitz ’853 US 2017/0312853 A1 Nov. 2, 2017
Mochizuki JP 2001-38791 A Feb. 13, 2001
Kabelitz ’533 WO 2016/071533 A1 May 12, 2016
Weeks https://www.researchgate.net/
publication/258543820
Jan. 2011
REJECTIONS
The claims stand rejected under 35 U.S.C. § 103 as follows:
1) claims 1–3, 6, 13, 21, 22, and 24–26 over Heck in view of Kramer or
Zaluzec, further in view of Weeks, alone or further in view of Mochizuki;
2) claims 4, 7, and 9 over Heck in view of Kramer or Zaluzec, further in
view of Weeks, alone or further in view of Mochizuki, and further in view of
Leatham; 3) claim 5 over Heck in view of Kramer or Zaluzec, further in
view of Weeks, alone or further in view of Mochizuki, and further in view of
Kabelitz ’533; 4) claim 8 over Heck in view of Kramer or Zaluzec, further in
view of Weeks, alone or further in view of Mochizuki, and further in view of
Vierow; 5) claims 10–12 over Heck in view of Kramer or Zaluzec, further in
view of Weeks, alone or further in view of Mochizuki, and further in view of
Leatham and Goto; and 6) claims 24 and 25 over Palazzolo in view of
Weeks, Leatham, either alone or further in view of Mochizuki.
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OPINION
Rejections over Heck and additional references
The Appellant does not separately argue the claims that depend from
claim 1 (Appeal Br. 8–15). We therefore limit our discussion to claim 1.
Claims 2–13, 21, 22, and 24–26 stand or fall with that claim. See 37 C.F.R.
§ 41.37(c)(1)(iv) (2013).
Heck, before plasma spraying a steel coating onto an internal
combustion engine’s hollow aluminum alloy cylinder’s inner surface, heats
the cylinder to 200 ºC and then cools it progressively to approximately
120 ºC to induce pressure shrinkage tensions that improve the coating’s
adhesion (col. 1, ll. 41–43, 52–56; col. 1, l. 67 – col. 2, l. 2; col. 2, ll. 29–47).
Kramer, before thermal spraying a metal coating onto an internal
combustion engine’s hollow aluminum alloy cylinder’s inner surface,
pretreats that surface with a high velocity, high pressure water jet to
thoroughly clean the surface of machining debris, lubricants and other
foreign matter that would impede adherence of the coating, and to texture
the surface with a large number of small pits having a mean peak-to-peak
distance on the order of 50 microns or less to provide a roughened surface
having increased surface area and surface irregularities that are filled with
the coating to improve its bonding and anchoring to the cylinder surface
(col. 1, ll. 8–10, 61–63; col. 2, ll. 43–54; col. 5, l. 60 – col. 6, l. 3).
Zaluzec, before thermal spraying a steel coating onto an internal
combustion engine’s hollow aluminum alloy cylinder’s inner surface, uses
vapor degreasing or washing with an aqueous solution to remove from the
surface all grease and oils that result from casting and machining operations,
applies a flux or chemical stripping agent to remove any surface oxide when
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heat activated, roughens the surface by grit blasting, high-pressure water
jetting, machining, or honing to change the surface finish to more readily
lock with the coating and to remove some surface oxides, and removes any
surface contaminants remaining from that roughening (col. 1, ll. 15–16, 20,
49–50; col. 2, ll. 50–64). The coating can metallurgically bond to the metal
substrate (col. 5, ll. 22–24).
Weeks discloses that a surface to be plasma sprayed which has a low
average roughness of about 5–7 microns average roughness (Sa) gives lower
lifetime results than surfaces with a higher average roughness of about 13–
18 microns Sa (p. 45; Fig. 3.3).
Mochizuki, before thermal spraying a Ni-based or Co-based self-
fluxing alloy onto a cast iron hollow member, decarburizes the hollow
member’s surface, shot blasts it, and to prevent cracks in the member during
thermal spraying, preheats the member to 100–200 ºC (¶¶ 4, 8, 15, 16).
The Appellant argues, in reliance upon a Declaration of Martin S.
Kramer under 37 C.F.R. § 1.132, that for a metallurgical bond to form
between a metal surface and a metal coating thermally sprayed onto the
surface, the surface must first be cleaned, textured, and heated as recited in
the Appellant’s claim 1 (Appeal Br. 9–10). Kramer states (Decl. ¶ 8):
My colleagues and I have discovered the exact parameters
necessary to create a metallurgical bond, as opposed to merely a
mechanical bond, between a substrate and thermal spray
coating. The combination of our cleanliness, temperature, and
texture parameters creates such a metallurgical bond between
the substrate and the thermal spray coating. Performing any of
the process steps by itself would not result in a metallurgical
bond being fully formed. As evidenced by none of the cited
references showing the performance of all three of the process
steps together at these parameters, other persons having
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ordinary skill in the art in the field were not using all three
process steps together at the unique parameters claimed to
arrive at a metallurgical bond between the coating and the
substrate.

As pointed out above and by the Examiner (Final Act. 4–11), Heck
heats the surface to 200 ºC, Kramer and Zaluzec clean thoroughly and
texture the surface, Mochizuki decarburizes the surface, and Weeks indicates
that texturing to provide Appellant’s recited interfacial area ratio provides
higher lifetime results. The applied prior art would have suggested, to one of
ordinary skill in the art, use of those surface preparation techniques in
combination to obtain their combined benefit. Because the combination of
techniques would be the same as that used by the Appellant, the combined
benefit would be the same as that obtained by the Appellant, including
metallurgical bonding.
Kramer states (Decl. ¶ 12):
[W]e have found that washing engine blocks with production
style equipment resulted in surfaces that looked and felt very
clean. However, upon closer examination, we discovered that
the surfaces had residual contaminates that ranged from 100-
300 nanometers in depth that could not be seen or detected by
normal means. This is the norm for industries and most thermal
spray applications, so an understanding of the level of
cleanliness needed is not obvious or understood.

The cleaning techniques disclosed by Kramer, Zaluzec, and
Mochizuki appear to be thorough. The Kramer Declaration does not address
those techniques and establish that they do not provide the degree of
cleaning needed for metallurgical bonding.
The Appellant argues (Appeal Br. 9–10):
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[T]he references are missing the synergy that results in using all
three of the process steps in combination to create such a
metallurgical bond. Performing any of the process steps by
itself would not result in a metallurgical bond being formed. As
evidenced by none of the cited references showing the
performance of all three of the process steps together, other
persons having ordinary skill in the art in the field were not
using all three process steps together at the unique parameters
claimed to arrive at a metallurgical bond between the coating
and the substrate. The cited references generally refer to
mechanical or chemical bonding, but not metallurgical bonding
having an interlayer region that includes a combination of
material from the coating and from the inner surface, as Martin
Kramer has stated in his Declaration.

Synergism is a factor to consider when determining obviousness. See
In re Huellmantel, 324 F.2d 998, 1003 (CCPA 1963). Synergism, to be
probative of nonobviousness, must be unexpected synergism, and evidence
must be provided which shows that unexpected synergism exists. See In re
Diamond, 360 F.2d 214, 214 (CCPA 1966); Huellmantel, 324 F.2d at 1003.
The Appellant does not provide evidence that one of ordinary skill in the art
would not have expected cleaning thoroughly, texturing, and heating an
aluminum or aluminum alloy surface prior to thermal spraying it with a steel
coating would result in a metallurgical bond having an interlayer region that
includes a combination of iron of the spray coating and aluminum of the
surface.
Rejection over Palazzolo and additional references
Palazzolo, before thermal spraying a metallic coating onto an internal
combustion engine cylinder’s internal surface, improves the adhesion
between the coating and the surface by honing the surface to create tears,
folds, and undercuts rendering a hook and ladder effect, washing the honed
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surface with a hot alkaline solution comprising a non-soaping aluminate
agent and surfactants, and rinsing the surface (col. 1, ll. 7–8, 21–24. 49–51;
col. 1, l. 57 – col. 2, l. 17). The washing solution is sprayed at a temperature
of 120–160 ºF and a pressure of about 5–30 psi to clean out surface pores
and facilitate surface film removal without erosion (col. 4, ll. 2–6). The
honed surface has a surface roughness of about 0.5–17 microns, with 15 Ra
being exemplified (col. 3, ll. 48–51).
Leatham, before spray-depositing liquid metal onto a collector to form
a shaped deposit, grit blasts the collector to remove oxide film and provide a
mechanical key to bind initially-deposited metal droplets to the collector,
and preheats the substrate to a temperature between room temperature and
the solidus temperature of the collector, preferably towards the solidus
temperature, to form or partially form a metallurgical bond between the
metal and the collector (col. 1, ll. 8–10; col. 3, ll. 34–37, 47–52). Using
plasma for the preheating is advantageous for rapidly preheating the
collector surface and remove residual oxide film (col. l. 62 – col. 4, l. 3).
During the preheating, “[t]he collector is suitably heated to a temperature
greater than 20% of the melting temperature of the metal being sprayed”
(col. 6, l. 68 – col. 7, l. 2).
The Appellant argues that neither Palazzolo nor Weeks discloses
metallurgical bonding, and neither Leatham nor Mochizuki discloses or
suggests a metallurgical bond having an interlayer region that includes a
combination of iron of the spray coating and steel of the inner surface
(Appeal Br. 15–16).
“Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
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combination of references.” In re Merck & Co., 800 F.2d 1091, 1097 (Fed.
Cir. 1986). The test for obviousness is what the combined teachings of the
references would have fairly suggested to those of ordinary skill in the art.
See In re Keller, 642 F.2d 413, 425 (CCPA 1981).
Mochizuki decarburizes, shot blasts, and preheats to 100–200 ºC a
surface to be coated by thermal spraying, Kramer and Zaluzec clean
thoroughly and texture the surface, and Weeks indicates that texturing
provides higher lifetime results. The applied prior art would have suggested,
to one of ordinary skill in the art, use of those surface preparation techniques
in combination to obtain their combined benefit. Because the combination of
techniques would be the same as that used by the Appellant, the combined
benefit would be the same as that obtained by the Appellant, including
metallurgical bonding.
CONCLUSION
For the above reasons, we are not persuaded of reversible error in the
Examiner’s rejections. Accordingly, we affirm the rejections.

Appeal 2021-000443
Application 15/668,027

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DECISION SUMMARY
In summary:
Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1–3, 6, 13,
21, 22, 24–
26
103 Heck, Kramer,
Zaluzec, Weeks,
Mochizuki
1–3, 6, 13,
21, 22, 24–
26

4, 7, 9 103 Heck, Kramer,
Zaluzec, Weeks,
Mochizuki,
Leatham
4, 7, 9
5 103 Heck, Kramer,
Zaluzec, Weeks,
Mochizuki,
Kabelitz ’533
5
8 103 Heck, Kramer,
Zaluzec, Weeks,
Mochizuki, Vierow
8
10–12 103 Heck, Kramer,
Zaluzec, Weeks,
Mochizuki,
Leatham, Goto
10–12
24, 25 103 Palazzolo, Weeks,
Leatham,
Mochizuki
24, 25
Overall
Outcome
1–13, 21,
22, 24–26

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). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED