CLAD SHEET ALLOYS FOR BRAZING APPLICATIONS
This application discloses a multilayer aluminum material having an aluminum alloy core and an aluminum alloy cladding, wherein the aluminum alloy cladding contains ≦1.0 wt % Cu, ≦0.5 wt % Fe, ≦1.0 wt % Mn, ≦15 wt % Si, ≦0.15 wt % Ti, ≦7 wt % Zn and at least one of Sr or Na, remainder Al. The aluminum alloy cladding can also contain one or more of ≦0.2 wt % Mg or ≦0.05 wt % Ni. A process for producing the material is also disclosed. The material can be produced in sheet form and is suitable for brazing application. The metal forms fabricated from the multilayer aluminum material by a process comprising brazing steps are also disclosed.
1 . An aluminum material comprising an aluminum alloy core and an aluminum alloy cladding, wherein the aluminum alloy cladding comprises ≦1.0 wt % Cu, ≦0.5 wt % Fe, ≦1.0 wt % Mn, ≦15 wt % Si, ≦0.15 wt % Ti, ≦7 wt % Zn and at least one of Sr or Na, remainder Al.
2 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises 0.2-0.3 wt % Cu, 0.2-0.3 wt % Fe, ≦0.6 wt % Mn, 7-12 wt % Si, 0.05-0.15 wt % Ti, 0-3.5 wt % Zn and at least one of Sr or Na, remainder Al.
3 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises 0.1-1.0 wt % Cu, 0.1-0.5 wt % Fe, ≦1.0 wt % Mn, 3-15 wt % Si, ≦0.15 wt % Ti and ≦7 wt % Zn and at least one of Sr or Na, remainder Al.
4 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises 0.15-0.6 wt % Cu, 0.1-0.4 wt % Fe, ≦0.7 wt % Mn, 5-12 wt % Si, 0.01-0.15 wt % Ti and at least one of Sr or Na, remainder Al.
5 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises 0.15-0.3 wt % Cu, 0.2-0.4 wt % Fe, ≦0.5 wt % Mn, 7-12 wt % Si, ≦0.13 wt % Ti, and at least one of Sr or Na, remainder Al.
6 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises ≦1.0 wt % Cu, ≦0.5 wt % Fe, ≦1.0 wt % Mn, ≦15 wt % Si, ≦0.15 wt % Ti, ≦7 wt % Zn and 0.005-0.05 wt % Sr, remainder Al.
7 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises ≦1.0 wt % Cu, ≦0.5 wt % Fe, ≦1.0 wt % Mn, ≦15 wt % Si, ≦0.15 wt % Ti, ≦7 wt % Zn, 0.01-0.025 wt % Sr and one or more of ≦0.2 wt % Mg or ≦0.05 wt % Ni, remainder Al.
8 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises ≦1.0 wt % Cu, ≦0.5 wt % Fe, ≦1.0 wt % Mn, ≦15 wt % Si, ≦0.15 wt % Ti, ≦7 wt % Zn, 0.01-0.025 wt % Sr, ≦0.2 wt % Mg and ≦0.05 wt % Ni, remainder Al.
9 . The aluminum material of claim 1 , wherein the aluminum alloy cladding comprises 0.2-0.3 wt % Cu, 0.2-0.3 wt % Fe, ≦0.6 wt % Mn, 7-12 wt % Si, 0.05-0.15 wt % Ti, 0-3.5 wt % Zn, 0.01-0.025 wt % Sr, ≦0.1 wt % Mg and 0.005-0.02 wt % Ni, remainder Al.
10 . The aluminum material of claim 1 , wherein the material is in a form of a sheet comprising the aluminum alloy core and having the aluminum alloy cladding on one side of the sheet or on both sides of the sheet.
11 . The aluminum material of claim 1 , wherein the aluminum alloy core comprises a 3xxx or 6xxx series aluminum alloy.
12 . A process for preparing the aluminum material of claim 1 , comprising:
casting the aluminum alloy cladding;
rolling the aluminum alloy cladding to a required thickness, thus producing rolled aluminum alloy cladding;
assembling the rolled aluminum alloy cladding onto at least one side of the rolled aluminum alloy core; and,
hot roll bonding the rolled aluminum alloy cladding onto the rolled aluminum alloy core.
13 . A process for preparing the aluminum material of claim 1 , comprising fusion casting the aluminum alloy core and the aluminum alloy cladding.
14 . The process of claim 11 , further comprising preparing the aluminum alloy cladding prior to casting from scrap aluminum with addition of Si or from a combination of scrap aluminum and smelter grade aluminum.
15 . A process comprising joining by brazing at least one first aluminum alloy form fabricated from the aluminum material of claim 1 with a second aluminum alloy form.
16 . An object fabricated by a process comprising the process of claim 15 .
17 . The object of claim 16 , wherein the object is a heater, an evaporator plate, an evaporator, a radiator, a heater core, a condenser, a tube, a pipe or a manifold.
18 . A process of joining two or more aluminum forms by brazing, wherein at least one of the two or more aluminum forms is fabricated from the aluminum material of claim 1 , comprising:
assembling and securing the two or more aluminum forms together;
heating the two or more aluminum forms to a brazing temperature until joints are created among the two or more aluminum forms by capillary action; and,
cooling the two or more aluminum forms below solidus of the aluminum alloy cladding.
19 . The process of claim 18 , wherein the brazing temperature is between 590° C. and 610° C.
20 . An object fabricated by a process comprising the process of claim 18 .
21 . The object of claim 20 , wherein the object is a heater, an evaporator plate, an evaporator, a radiator, a heater core, a condenser, a tube, a pipe or a manifold.