Aluminum alloy clad sheet for heat exchangers and method of producing the same

Abstract

An aluminum alloy clad sheet for heat exchangers includes a core material, a cladding material 1 , and a cladding material 2 , one side and the other side of the core material being respectively clad with the cladding material 1 and the cladding material 2 , the core material containing 0.5 to 1.2% of Si, 0.2 to 1.0% of Cu, and 1.0 to 1.8% of Mn, with the balance being Al and unavoidable impurities, the cladding material 1 containing 3 to 6% of Si, 2 to 8% of Zn, and at least one of 0.3 to 1.8% of Mn and 0.05 to 0.3% of Ti, with the balance being Al and unavoidable impurities, and the cladding material 2 containing 6 to 13% of Si, with the balance being Al and unavoidable impurities, the cladding material 1 being positioned on the outer side of the aluminum alloy clad sheet during use.

1 . An aluminum alloy clad sheet that is used to form a refrigerant passage of a heat exchanger, the aluminum alloy clad sheet comprising a core material, a cladding material  1 , and a cladding material  2 , one side and the other side of the core material being respectively clad with the cladding material  1  and the cladding material  2 , the core material comprising 0.5 to 1.2% (mass %, hereinafter the same) of Si, 0.2 to 1.0% of Cu, and 1.0 to 1.8% of Mn, with the balance being Al and unavoidable impurities, the cladding material  1  comprising 3 to 6% of Si, 2 to 8% of Zn, and at least one of 0.3 to 1.8% of Mn and 0.05 to 0.3% of Ti, with the balance being Al and unavoidable impurities, and the cladding material  2  comprising 6 to 13% of Si, with the balance being Al and unavoidable impurities, the cladding material  1  being positioned opposite to the refrigerant passage during use. 
     
     
         2 . The aluminum alloy clad sheet according to  claim 1 , wherein the core material further comprises at least one of 0.3% or less of Cr and 0.3% or less of Zr. 
     
     
         3 . The aluminum alloy clad sheet according to  claim 1 , wherein the core material further comprises 0.5% or less of Mg. 
     
     
         4 . The aluminum alloy clad sheet according to  claim 1 , wherein the cladding material  1  further comprises 0.005 to 0.05% of Sr. 
     
     
         5 . The aluminum alloy clad sheet according to  claim 2 , wherein the cladding material  1  further comprises 0.005 to 0.05% of Sr. 
     
     
         6 . The aluminum alloy clad sheet according to  claim 1 , wherein the cladding material  1  further comprises at least one of 0.3% or less of Cr and 0.3% or less of Zr. 
     
     
         7 . The aluminum alloy clad sheet according to  claim 1 , wherein the cladding material  1  further comprises at least one of 0.001 to 0.1% of In and 0.001 to 0.1% of Sn. 
     
     
         8 . The aluminum alloy clad sheet according to  claim 1 , wherein the cladding material  1  has an Ni content of less than 0.05%. 
     
     
         9 . The aluminum alloy clad sheet according to  claim 1 , wherein the cladding material  2  further comprises 0.005 to 0.05% of Sr. 
     
     
         10 . The aluminum alloy clad sheet according to  claim 2 , wherein the cladding material  2  further comprises 0.005 to 0.05% of Sr. 
     
     
         11 . The aluminum alloy clad sheet according to  claim 4 , wherein the cladding material  2  further comprises 0.005 to 0.05% of Sr. 
     
     
         12 . The aluminum alloy clad sheet according to  claim 5 , wherein the cladding material  2  further comprises 0.005 to 0.05% of Sr. 
     
     
         13 . The aluminum alloy clad sheet according to  claim 1 , wherein the cladding material  2  further comprises 0.1 to 0.5% of Cu. 
     
     
         14 . A method of producing the aluminum alloy clad sheet according to  claim 1 , the method comprising: homogenizing an ingot of an aluminum alloy that forms the core material at 550 to 620° C. for 2 to 20 hours; cladding the ingot with an aluminum alloy that forms the cladding material  1  and an aluminum alloy that forms the cladding material  2 ; hot-rolling the resulting product; cold-rolling the hot-rolled product, the hot-rolled product being heated at 300 to 400° C. for 2 to 5 hours during the cold-rolling so that the core material has a recrystallized structure; cold-rolling the resulting product to a final thickness at a rolling reduction rate of 10 to 40%; and subjecting the resulting product to a recovery treatment by heating the product at 200 to 450° C. for 2 to 5 hours. 
     
     
         15 . An aluminum alloy clad sheet that is used to form a refrigerant passage of a heat exchanger, the aluminum alloy clad sheet comprising a core material and a cladding material  1 , one side of the core material being clad with the cladding material  1 , the core material comprising 0.5 to 1.2% of Si, 0.2 to 1.0% of Cu, and 1.0 to 1.8% of Mn, with the balance being Al and unavoidable impurities, and the cladding material  1  comprising 3 to 6% of Si, 2 to 8% of Zn, and at least one of 0.3 to 1.8% of Mn and 0.05 to 0.3% of Ti, with the balance being Al and unavoidable impurities, the cladding material  1  being positioned opposite to the refrigerant passage during use. 
     
     
         16 . The aluminum alloy clad sheet according to  claim 15 , wherein the core material further comprises at least one of 0.3% or less of Cr and 0.3% or less of Zr. 
     
     
         17 . The aluminum alloy clad sheet according to  claim 15 , wherein the core material further comprises 0.5% or less of Mg. 
     
     
         18 . The aluminum alloy clad sheet according to  claim 15 , wherein the cladding material  1  further comprises 0.005 to 0.05% of Sr. 
     
     
         19 . The aluminum alloy clad sheet according to  claim 16 , wherein the cladding material  1  further comprises 0.005 to 0.05% of Sr. 
     
     
         20 . The aluminum alloy clad sheet according to  claim 15 , wherein the cladding material  1  further comprises at least one of 0.3% or less of Cr and 0.3% or less of Zr. 
     
     
         21 . The aluminum alloy clad sheet according to  claim 15 , wherein the cladding material  1  further comprises at least one of 0.001 to 0.1% of In and 0.001 to 0.1% of Sn. 
     
     
         22 . The aluminum alloy clad sheet according to  claim 15 , wherein the cladding material  1  has an Ni content of less than 0.05%. 
     
     
         23 . A method of producing the aluminum alloy clad sheet according to  claim 15 , the method comprising: homogenizing an ingot of an aluminum alloy that forms the core material at 550 to 620° C. for 2 to 20 hours; cladding the ingot with an aluminum alloy that forms the cladding material  1 ; hot-rolling the resulting product; cold-rolling the hot-rolled product, the hot-rolled product being heated at 300 to 400° C. for 2 to 5 hours during the cold-rolling so that the core material has a recrystallized structure; cold-rolling the resulting product to a final thickness at a rolling reduction rate of 10 to 40%; and subjecting the resulting product to a recovery treatment by heating the product at 200 to 450° C. for 2 to 5 hours.