Appeal No. 1997-0538
Application No. 08/262,168
According to Larsen (column 4, line 2), the presence of a
minor amount of alpha-2 (Ti Al) phase is also present in the
3
duplex microstructure. These gamma titanium aluminide
products are also made from a process which is substantially
identical to that claimed. Kim discloses (column 2, lines 46-
57) that:
Further, in accordance with the invention, there
is provided a method for producing article of gamma
titanium aluminide alloy having improved properties
which comprises the steps of: (a) shaping the
article at a temperature in the approximate range of
about
130° C. below the titanium-aluminum eutectoid
temperature of the alloy to about 20° C. below the
alpha-transus temperature of the alloy; (b) heat
treating the thus-shaped article at about the alpha-
transus temperature of the alloy for about 15 to 120
minutes; and (c) aging the thus-heat treated article
at a temperature between about 750° and 1050° C. for
about 4 to 300 hours.
The term “about the alpha-trances temperature of the alloy” as
used in Kim includes the claimed “about 5 F” below the alphao
transus temperature. Similarly, Larsen discloses (column 3,
line 61 to column 4, lines 7) that:
Typically, the case alloy is hot isostatically
pressed to close internal casting defects (e.g.
internal voids). In general, the as-cast alloy is
hot isostatically pressed at 2100°-2400° F. at 10-25
ksi for 1-4 hours. A preferred hot isostatic press
8
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007