Aluminum alloy for a welded construction and welded joint using the same

Abstract

Disclosed is an Al alloy for a welded construction having excellent welding characteristics, which Al alloy comprises 1.5 to 5 wt % of Si (hereinafter, wt % is referred to as %), 0.2 to 1.5% of Mg, 0.2 to 1.5% of Zn, 0.2 to 2% of Cu, 0.1 to 1.5% of Fe, and at least one member selected from the group consisting of 0.01 to 1.0% of Mn, 0.01 to 0.2% of Cr, 0.01 to 0.2% of Ti, 0.01 to 0.2% of Zr, and 0.01 to 0.2% of V, with the balance being Al and inevitable impurities. Also disclosed is a welded joint having this Al alloy base metal welded with an Al—Mg— or Al—Si-series filler metal.

What is claimed is:  
     
         1 . An aluminum alloy comprising: 
 a percent by weight of: 
 approximately 2.6 to 5% silicon;  
 approximately 0.2 to 0.8% magnesium;  
 approximately 0.2 to 1.5% zinc;  
 approximately 0.2 to 2% copper;  
 approximately 0.1 to 1.5% iron;  
   at least one additional ingredient selected from the group consisting of a percent by weight of approximately 0.01 to 1% manganese, 0.01 to 0.2% chromium, 0.01 to 0.2% titanium, 0.01 to 0.2% zirconium, and 0.01 to 0.2% vanadium; and    a balance of aluminum including inevitable impurities.    
     
     
         2 . A method of welding comprising: 
 forming a joint between two pieces of aluminum alloy base metal wherein the aluminum alloy comprises a percent by weight of: 
 approximately 1.5 to 5% silicon;  
 approximately 0.2 to 1.5% magnesium;  
 approximately 0.2 to 1.5% zinc;  
 approximately 0.2 to 2% copper;  
 approximately 0.1 to 1.5% iron;  
   at least one additional ingredient selected from the group consisting of a percent by weight of approximately 0.01 to 1% manganese, 0.01 to 0.2% chromium, 0.01 to 0.2% titanium, 0.01 to 0.2% zirconium, or 0.01 to 0.2% vanadium;    a balance of aluminum including inevitable impurities; and    welding said joint with an aluminum alloy filler material comprising 2 to 6% by weight of magnesium.    
     
     
         3 . The method of  claim 2  wherein said base metal comprises 2.6 to 5% by weight silicon.  
     
     
         4 . The method of  claim 2  further comprising heat treating said joint.  
     
     
         5 . A welded joint made by the method of  claim 2 .  
     
     
         6 . A welded joint comprising: 
 approximately 0.5 to 4% silicon;    approximately 1.0 to 5.5% magnesium;    approximately 0.05 to 1.4% copper; and    a balance of aluminum including inevitable impurities.    
     
     
         7 . The welded joint of  claim 6  wherein said joint is heat treated at at most 220° C.  
     
     
         8 . A method of welding comprising: 
 forming a joint between two pieces of aluminum alloy base metal wherein the aluminum alloy comprises a percent by weight of: 
 approximately 1.5 to 5% silicon;  
 approximately 0.2 to 1.5% magnesium;  
 approximately 0.2 to 1.5% zinc;  
 approximately 0.2 to 2% copper;  
 approximately 0.1 to 1.5% iron;  
   at least one additional ingredient selected from the group consisting of a percent by weight of approximately 0.01 to 1% manganese, 0.01 to 0.2% chromium, 0.01 to 0.2% titanium, 0.01 to 0.2% zirconium, or 0.01 to 0.2% vanadium; a balance of aluminum including inevitable impurities; and    welding said joint with an aluminum alloy filler material comprising 3 to 13% by weight silicon.    
     
     
         9 . The method of  claim 8  wherein said aluminum alloy base metal comprises 2.6 to 5% by weight silicon.  
     
     
         10 . The method of  claim 8  further comprising heat treating said joint.  
     
     
         11 . A welded joint made by the method of  claim 8 .  
     
     
         12 . A welded joint comprising: 
 approximately 2.0 to 11% silicon;    approximately 0.05 to 1.4% magnesium;    approximately 0.05 to 1.8% copper; and    a balance of aluminum including inevitable impurities.    
     
     
         13 . The welded joint of  claim 12  wherein said joint is heat treated at at most 220° C.  
     
     
         14 . The welded joint of  claim 5 , wherein said joint comprises: 
 approximately 0.5 to 4% silicon;    approximately 1.0 to 5.5% magnesium;    approximately 0.05 to 1.4% copper; and    a balance of aluminum including inevitable impurities.    
     
     
         15 . The welded joint of  claim 11 , wherein said joint comprises: 
 approximately 2.0 to 11% silicon;    approximately 0.5 to 1.4% magnesium;    approximately 0.05 to 1.8% copper; and    a balance of aluminum including inevitable impurities.