High-strenght aluminum alloy brazing sheet and method of manufacture

Abstract

An aluminum alloy brazing sheet having a core material of an aluminum alloy, and a filler material cladded on the core is disclosed. The core material is an aluminum alloy having about 0.05 to about 1.2 mass Si, about 0.05-about 1.0 mass % Fe, about 0.05-about 1.2 mass % Cu, and about 0.6-about 1.8 mass % Mn, balance Al and the inevitable impurities. The filler material includes an aluminum alloy having about 2.5-about 13.0 mass % Si. Also, there is provided a method of manufacturing such an aluminum alloy brazing sheet.

1 . A high strength aluminum alloy brazing sheet comprising:
 a core material composed of an aluminum alloy; and   a filler material cladded on at least one surface of said core material and composed of an Al/Si-based alloy,   wherein said core material is the aluminum alloy which contains Si falling within a range of about 0.05-about 1.2 mass %, Fe falling a range of about 0.05-about 1.0 mass %, Cu falling within a range of about 0.05-about 1.2 mass %, and Mn falling within a range of about 0.6-about 1.8 mass %, and which is composed of the balance Al and the inevitable impurities;   wherein said filler material is the aluminum alloy which contains Si falling within a range of about 2.5-about 13.0 mass %, and Fe falling within a range of about 0.05-about 1.0 mass %, and which is composed of the balance Al and the inevitable impurities;   wherein an area percentage, at which an arbitrary cross-section of said core material before a brazing process is occupied with intermetallic compounds having a size falling within a range of about 0.2-about 0.5 m, is at most 5%; and   wherein a solid solution amount of Mn is at least 0.2 mass % in said core material after the brazing process.   
     
     
         2 . A high strength aluminum alloy brazing sheet as set forth in  claim 1 , wherein said core material further contains at least one element selected from the group consisting of Mg falling within a range of about 0.05-about 0.5 mass %, Ti falling within a range of about 0.05-about 0.3 mass %, Zr falling within a range of about 0.05-about 0.3 mass %, Cr falling within a range of about 0.05-about 0.3 mass %, and V falling within a range of about 0.05-about 0.3 mass %, in addition to the aforesaid elements. 
     
     
         3 . A high strength aluminum alloy brazing sheet as set forth in  claim 1 , wherein said filler material cladded to the aforesaid one surface of said core material further contains Zn falling within a range of about 0.3-about 5.5 mass %, in addition to the aforesaid elements. 
     
     
         4 . A high strength aluminum alloy brazing sheet comprising:
 a core material composed of an aluminum alloy;   a filler material cladded on one surface of said core material and composed of an Al/Si-based alloy; and   a sacrificial anode material cladded on another surface of said core material and composed of an aluminum alloy,   wherein said core material is the aluminum alloy which contains Si falling within a range of about 0.05-about 1.2 mass %, Fe falling a range of about 0.05-about 1.0 mass %, Cu falling within a range of about 0.05-about 1.2 mass %, and Mn falling within a range of about 0.6-about 1.8 mass %, and which is composed of the balance Al and the inevitable impurities;   wherein said filler material is the aluminum alloy which contains Si falling within a range of about 2.5-about 13.0 mass %, and Fe falling within a range of about 0.05-about 1.0 mass %, and which is composed of the balance Al and the inevitable impurities;   wherein said sacrificial anode material is the aluminum alloy which contains Zn falling within a range of about 0.5-about 6.0 mass %, Si falling within a range of about 0.05-about 1.5 mass %, and Fe falling within a range of about 0.05-about 2.0 mass %, and which is composed of the balance Al and the inevitable impurities;   wherein an area percentage, at which an arbitrary cross-section of said core material before a brazing process is occupied with intermetallic compounds having a size falling within a range of 0.2-0.5 m, is at most 5%; and   wherein a solid solution amount of Mn is at least 0.2 mass % in said core material after the brazing process.   
     
     
         5 . A high strength aluminum alloy brazing sheet as set forth in  claim 4 , wherein said core material further contains at least one element selected from the group consisting of Mg falling within a range of about 0.05-about 0.5 mass %, Ti falling within a range of about 0.05-about 0.3 mass %, Zr falling within a range of about 0.05-about 0.3 mass %, Cr falling within a range of about 0.05-about 0.3 mass %, and V falling within a range of about 0.05-about 0.3 mass %, in addition to the aforesaid elements. 
     
     
         6 . A high strength aluminum alloy brazing sheet as set forth in  claim 4  wherein said filler material further contains Zn falling within a range of about 0.3-about 5.5 mass. %, in addition to the aforesaid elements. 
     
     
         7 . A high strength aluminum alloy brazing sheet as set forth in  claim 4 , wherein said sacrificial anode material further contains at least one element selected from the group consisting of Mn falling within a range of about 0.05-about 1.8 mass %, Mg falling within a range of about 0.5-about 3.0 mass %, Ti falling within a range of about 0.05-about 0.3 mass %, Zr falling within a range of about 0.05-about 0.3 mass %, Cr falling within a range of about 0.05-about 0.3 mass %, and V falling within a range of about 0.05-about 0.3 mass %, in addition to the aforesaid elements. 
     
     
         8 . A method of manufacturing a high strength aluminum alloy brazing sheet as set forth in  claim 1  comprising:
 casting processes for casting the aluminum alloys of said core material and said filler material, respectively; 
 a combining process in which the cast core material is combined with the cast filler material so that the cast filler material is applied to at least one surface of the cast core material, to thereby produce a composite material; 
 a heating process in which said composite material is heated and held after said combing process; and 
 a hot clad rolling process in which said composite material is rolled after said heating process, 
 wherein a casting speed V (mm/min) and an amount of cooling water W (kg/min×cm) satisfy the following formula (1) in the casting process for said core material:
   25≦0.4 ×V+W   (1);
 
 
 wherein said composite material is held at a temperature within a range of about 400-about 50° C. over a time period within a range of 0- about 10 hrs during said heating process; 
 wherein a time period, which is counted from a rolling start, and which is taken to reduce a thickness of said composite material by 50 mm, is at most 5 min in said hot clad rolling process; 
 wherein a temperature of said composite material falls within a range of about 400-about 45° C. at the time when the thickness of said composite material is reduced by 50 mm; 
 wherein a time period, which is counted from the time when the thickness of said composite material is reduced by 50 mm, and which is taken to reduce the thickness of said composite material to 20 mm, is at most 10 min; 
 wherein a temperature of said composite material falls within a range of about 300-about 40° C. at the time when the thickness of said composite material is reduced to 10 mm; and 
 wherein a time period, which is counted from the rolling start to a rolling end, is at most 40 min. 
 
     
     
         9 . A method of manufacturing a high strength aluminum alloy brazing sheet as set forth in  claim 4  comprising:
 casting processes for casting the aluminum alloys of said core material, said filler material and said sacrificial anode material, respectively; 
 a combining process in which the cast core material is combined with the cast filler material and the cast sacrificial anode material so that the cast filler material is applied to at least one surface of the cast core material, and so that the cast sacrificial anode material to another surface of the cast core material, to thereby produce a composite material; 
 a heating process in which said composite material is heated and held after said combing process; and 
 a hot clad rolling process in which said composite material is rolled after said heating process, 
 wherein a casting speed V (mm/min) and an amount of cooling water W (kg/min×cm) satisfy the following formula (1) in the casting process for said core material:
   25≦0.4 ×V+W   (1);
 
 
 wherein said composite material is held at a temperature falling within a range of 400-500 C over a time period falling within a range of 0-10 hrs during said heating process; 
 wherein a time period, which is counted from a rolling start, and which is taken to reduce a thickness of said composite material by 50 mm, is at most 5 min in said hot clad rolling process; 
 wherein a temperature of said composite material falls within a range of about 400-450 C at the time when the thickness of said composite material is reduced by 50 mm; 
 wherein a time period, which is counted from the time when the thickness of said composite material is reduced by 50 mm, and which is taken to reduce the thickness of said composite material to 20 mm, is at most 10 min; 
 wherein a temperature of said composite material falls within a range of about 300-about 40° C. at the time when the thickness of said composite material is reduced to 10 mm; and 
 wherein a time period, which is counted from the rolling start to a rolling end, is at most 40 min.