Appeal 2007-0501
Application 10/747,956
fluorozincate and potassium fluoroaluminate is mixed with isopropanol for
application to an aluminum coupon (id., e.g., col. 8, ll. 26-31).
We find Lauzon would have disclosed to one of ordinary skill in this
art a method for brazing aluminum and aluminum alloys using aqueous flux
preparations selected from the group consisting of, inter alia, potassium
fluorozincate and potassium fluoroaluminate, and mixtures thereof (Lauzon
col. 1, l. 5, to col. 2, l. 41). The aqueous flux preparation is applied by
spraying the components to be brazed at approximately 600°C (id. col. 2,
ll. 45-56).
We find Popoola would have disclosed to one of ordinary skill in this
art a method for brazing aluminum and aluminum alloys including spraying
a flux material onto the metal surface, wherein the flux can be “a eutectic of
potassium aluminum fluoride containing up to 50 molar % of other fluoride
salts . . . applied as a solution utilizing water or alcohol solvents” (Popoola
col. 2, ll. 3-22). “The eutectic has a melting point of about 560°C” and
“[o]ther double fluoride salts . . . can be used as long as they have a melting
temperature that can be heat activated without disturbing the case aluminum
alloy” (id. col. 3, ll. 15-31). “[T]he particle size of the fluoride salts is
preferably controlled to less than 10 micrometers, with at least 70% of such
salts being in the particle size range of 2-4 micrometers resulting in 20-30%,
by volume, of the particles remaining in suspension at all times without
stirring” for spraying (id. col. 2, ll. 23-27, and col. 3, ll. 42-59).
We find Shimajiri would have disclosed to one of ordinary skill in this
art a method for brazing aluminum and aluminum alloys including
suspending a flux in nonoxidizing gaseous medium gas in a furnace so it
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