Appeal No. 2003-0208 Page 11
Application No. 08/578,996
columns being aligned toward the coating surface from the substrate surface. The
coating is formed on the substrate by contacting the substrate with a gas phase mixture
containing chromium and nitrogen in a PVD process. In a preferred embodiment the
PVD process is an ion plating process. The composition of the coating is preferably
CrN, Cr2N or a mixture thereof in a uniform phase. A foundation layer of chromium may
be present between the substrate and the coating. Preferred characteristics of the
coating are a porosity of from 1.5% to 20% and a microhardness of from 600 HmV to
1000 HmV. The crystals of the coating may be oriented with the (111) face parallel to
the surface. The coating is typically between 1 µm and 80 µm thick. Komuro teaches
that the coating has superior resistance to peeling, abrasion and baking.
The examiner determined (answer, p. 4) that "Takiguchi does not disclose the
mixing ratios, however, as determined by the previous Board Decision (Paper No. 22),
it would have been obvious to one of ordinary skill in the art 'to have optimized the
mixing percentages of these materials [Cr, CrN and Cr2N] to obtain the high wear
resistant coating with high resistance to peeling off taught by Takiguchi' (Decision, page
10)." The examiner also determined (answer, p. 5) that Takiguchi "does not specifically
disclose the claimed broad porosity range." The examiner then determined that it
would have been obvious to produce a coating having the claimed porosity for the
benefits disclosed by Komuro. Lastly, the examiner ascertained (answer, p. 5) that the
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