ALUMINUM ALLOYS FOR FLUXLESS BRAZING APPLICATIONS, METHODS OF MAKING THE SAME, AND USES THEREOF
Provided are new aluminum alloys for use as one or more cladding layer(s) in clad aluminum alloy products for brazing applications. The cladding layer(s) include constituents that break and remove the oxide film on metal parts to be joined to produce high-strength brazing joints without the use of corrosive flux. Also provided herein are corrosion-resistant aluminum sheet packages including one or more of the aluminum alloy cladding layer(s) and an aluminum alloy core.
1 . A aluminum alloy comprising 7.0-14.0 wt. % Si, 0.05-1.0 wt. % Fe, 0.01-0.60 wt. % Cu, 0.01-0.30 wt. % Mn, 0.01-0.50 wt. % Mg, 0.0-0.60 wt. % Zn, 0.001-0.50 wt. % Bi, up to 0.30 wt. % Sb, up to 0.20 wt. % Sr, up to 0.20 wt. % Na, up to 0.25 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
2 . The aluminum alloy of claim 1 , comprising 8.0-12.0 wt. % Si, 0.10-0.90 wt. % Fe, 0.01-0.50 wt. % Cu, 0.05-0.20 wt. % Mn, 0.01-0.40 wt. % Mg, 0.05-0.40 wt. % Zn, 0.01-0.40 wt. % Bi, up to 0.25 wt. % Sb, up to 0.15 wt. % Sr, up to 0.10 wt. % Na, up to 0.20 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
3 . The aluminum alloy of claim 1 , comprising 8.5-11.0 wt. % Si, 0.15-0.50 wt. % Fe, 0.01-0.40 wt. % Cu, 0.05-0.15 wt. % Mn, 0.05-0.30 wt. % Mg, 0.10-0.30 wt. % Zn, 0.05-0.30 wt. % Bi, up to 0.20 wt. % Sb, up to 0.10 wt. % Sr, up to 0.06 wt. % Na, up to 0.15 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
4 . The aluminum alloy of claim 1 , comprising 9.0-10.5 wt. % Si, 0.15-0.25 wt. % Fe, 0.30-0.40 wt. % Cu, 0.05-0.15 wt. % Mn, 0.15-0.30 wt. % Mg, 0.15-0.30 wt. % Zn, 0.10-0.35 wt. % Bi, up to 0.15 wt. % Sb, up to 0.05 wt. % Sr, up to 0.05 wt. % Na, up to 0.10 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
5 . The aluminum alloy of claim 1 , comprising 9.5-10.5 wt. % Si, 0.30-0.50 wt. % Fe, 0.01-0.05 wt. % Cu, 0.05-0.15 wt. % Mn, 0.01-0.05 wt. % Mg, 0.20-0.25 wt. % Zn, 0.10-0.20 wt. % Bi, 0.01-0.05 wt. % Sb, 0.001-0.02 wt. % Sr, up to 0.01 wt. % Na, up to 0.10 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
6 . The aluminum alloy of claim 1 any of claims 1 , wherein the aluminum alloy is produced by direct chill casting, followed by hot rolling and cold rolling.
7 . The aluminum alloy of claim 1 , wherein the aluminum alloy comprises a corrosion potential of 660-720 mV or less, measured after brazing.
8 . The aluminum alloy of claim 1 , wherein the aluminum alloy withstands at least 28 days without perforation during airside corrosion testing after brazing.
9 . A clad aluminum alloy product, comprising:
a core layer; and
at least one cladding layer comprising the aluminum alloy of claim.
10 . The clad aluminum alloy product of claim 9 , wherein the core layer comprises an aluminum alloy comprising up to 0.25 wt. % Si, up to 0.35 wt. % Fe, 0.50 wt. % to 0.60 wt. % Cu, 1.4 wt. % to 1.6 wt. % Mn, 0.06 wt. % to 0.62 wt. % Mg, up to 0.05 wt. % Cr, up to 0.04 wt. % Zn, 0.10 wt. % to 0.20 wt. % Ti, up to 0.05 wt. % Sr, up to 0.15 wt. % of impurities, and Al.
11 . A clad aluminum alloy product, comprising:
a core layer, wherein the core layer has a first side and a second side;
at least one cladding layer on the first side or the second side;
wherein the at least one cladding layer comprises 7.0-14.0 wt. % Si, 0.05-1.0 wt. % Fe, 0.01-0.60 wt. % Cu, 0.01-0.30 wt. % Mn, 0.01-0.50 wt. % Mg, 0.0-0.60 wt. % Zn, 0.001-0.50 wt. % Bi, up to 0.30 wt. % Sb, up to 0.20 wt. % Sr, up to 0.20 wt. % Na, up to 0.25 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
12 . The clad aluminum alloy product of claim 11 , wherein the core layer comprises an aluminum alloy comprising up to 0.25 wt. % Si, up to 0.35 wt. % Fe, 0.50 wt. % to 0.60 wt. % Cu, 1.4 wt. % to 1.6 wt. % Mn, 0.06 wt. % to 0.62 wt. % Mg, up to 0.05 wt. % Cr, up to 0.04 wt. % Zn, 0.10 wt. % to 0.20 wt. % Ti, up to 0.05 wt. % Sr, up to 0.15 wt. % of impurities, and Al.
13 . A corrosion resistant brazing sheet comprising the clad aluminum alloy product of claim 11 .
14 . A heat exchanger comprising the clad aluminum alloy product of claim 11 .
15 . A method of forming a brazing joint, comprising the steps of:
providing one or more metal parts;
providing a clad aluminum alloy product on or between the one or more metal parts to form an assembly, wherein the clad aluminum alloy product comprises at least one cladding layer;
brazing the assembly without applying flux to join the clad aluminum alloy product and the one or more metal parts to produce a brazed assembly; and
cooling the brazed assembly, wherein the at least one cladding layer comprises 7.0-14.0 wt. % Si, 0.05-1.0 wt. % Fe, 0.01-0.60 wt. % Cu, 0.01-0.30 wt. % Mn, 0.01-0.50 wt. % Mg, 0.0-0.60 wt. % Zn, 0.001-0.50 wt. % Bi, up to 0.30 wt. % Sb, up to 0.20 wt. % Sr, up to 0.20 wt. % Na, up to 0.25 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
16 . The method of claim 15 , wherein brazing occurs in a controlled atmosphere brazing furnace comprising an inert gas, wherein the controlled atmosphere brazing furnace comprises less than 100 ppm oxygen.
17 . The method of claim 16 , wherein the controlled atmosphere brazing furnace has a dew point of less than —40° C.
18 . The method of claim 16 , wherein the assembly is brazed at a brazing temperature from 590° C. to 610° C., wherein the controlled atmosphere brazing furnace is heated to the brazing temperature in less than five minutes.
19 . The method of claim 16 , wherein the assembly is brazed for 3 minutes at 600° C. in the controlled atmosphere brazing furnace having an oxygen concentration less than 50 ppm and a dew point less than —40° C. in a nitrogen atmosphere.
20 . The method of claim 15 , wherein the at least one cladding layer comprises 8.0-12.0 wt. % Si, 0.10-0.90 wt. % Fe, 0.01-0.50 wt. % Cu, 0.05-0.20 wt. % Mn, 0.01-0.40 wt. % Mg, 0.10- 0.40 wt. % Zn, 0.01-0.40 wt. % Bi, up to 0.25 wt. % Sb, up to 0.15 wt. % Sr, up to 0.06 wt. % Na, up to 0.15 wt. % Ti, and up to 0.15 wt. % of impurities, and Al.