Aluminum Casting Alloy for Near Net Shaped Casting of Structural or Non-structural Components

Abstract

An aluminum casting alloy for near net shaped casting of structural or non-structural components containing, in % by mass, Zn: 4.5-7.5%, Mg: 0.7-2.0%, Fe: 0.8-2.0%, Si: <0.3%, Cu: <0.1%, V: ≤0.2%, Ti: ≤0.2%, B: ≤0.04%, balance Al and unavoidable impurities, the sum of the contents of the impurities being≤0.1%. Also, a method for the manufacture of a cast part which has a yield strength of 180 to 200 MPa, an ultimate tensile strength of 300 to 320 MPa and an elongation of 11 to 14% and a method for the manufacture of a cast part which has a yield strength of 210 to 400 MPa, an ultimate tensile strength of 340 to 450 MPa and an elongation of 2 to 11% utilizing the described alloy.

1 . An aluminum casting alloy for near net shaped casting of structural or non-structural components, the aluminum casting alloy consisting of, in % by mass, 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Zn:  
                   4.5-7.5%;  
                 
                     
                   Mg:  
                   0.7-2.0%;  
                 
                     
                   Fe:  
                   0.8-2.0%;  
                 
                     
                   Si:  
                   <0.3%;  
                 
                     
                   Cu:  
                   <0.1%;  
                 
                     
                   V:  
                   ≤0.2%;  
                 
                     
                   Ti:  
                   ≤0.2%;  
                 
                     
                   B:  
                   ≤0.04%; 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
               
            
           
         
         balance Al and unavoidable impurities, a sum of the contents of the impurities being≤0.1%. 
       
     
     
         2 . The aluminum casting alloy according to  claim 1 , wherein the Zn content is not more than 5.5% by mass. 
     
     
         3 . The aluminum casting alloy according to  claim 1 , wherein the Zn content is at least 4.6% by mass. 
     
     
         4 . The aluminum casting alloy according to  claim 1 , wherein the Mg content is not more than 1.0% by mass. 
     
     
         5 . The aluminum casting alloy according to  claim 1 , wherein the Mg content is at least 0.8% by mass. 
     
     
         6 . The aluminum casting alloy according to  claim 1 , wherein the Fe content is not more than 1.5% by mass. 
     
     
         7 . The aluminum casting alloy according to  claim 1 , wherein the Fe content is at least 1.0% by mass. 
     
     
         8 . The aluminum casting alloy according to  claim 1 , wherein the Si content is less than 0.2% by mass. 
     
     
         9 . The aluminum casting alloy according to  claim 1 , wherein the alloy contains at least 0.05% by mass of Ti. 
     
     
         10 . The aluminum casting alloy according to  claim 1 , wherein the alloy contains at least 0.1% by mass of V. 
     
     
         11 . The aluminum casting alloy according to  claim 1 , wherein the alloy contains 4.6 to 5.0% by mass Zn and 0.8 to 1.0% by mass Mg and the alloy has in the as-cast state (“F-temper”) a yield strength of 140 to 160 MPa, an ultimate tensile strength in the range of 280 to 300 MPa and elongation ranging from 11 to 14%. 
     
     
         12 . The aluminum casting alloy according to  claim 1 , wherein the alloy contains 5.0 to 5.5% by mass Zn and 1.6 to 2.0% by mass Mg and the alloy has in the as-cast state (“F-temper”) a yield strength of 180 to 210 MPa, an ultimate tensile strength in the range of 300 to 340 MPa and an elongation ranging from 4 to 7%. 
     
     
         13 . A method for the manufacture of a cast part which has a yield strength of 180 to 200 MPa, an ultimate tensile strength of 300 to 320 MPa and an elongation of 11 to 14% comprising the following working steps:
 a) providing an aluminum melt alloyed in accordance with  claim 11 ;   b) casting a cast part from the aluminum melt;   c) subjecting the cast part to a T4 temper treatment which involves a solution heat treatment at temperatures of 460 to 480° C. for 1 to 8 h optionally followed by a forced air quench and natural aging for 14 to 75 days.   
     
     
         14 . A method for the manufacture of a cast part which has a yield strength of 210 to 400 MPa, an ultimate tensile strength of 340 to 450 MPa and an elongation of 2 to 11% comprising the following working steps:
 a) providing an aluminum melt alloyed in accordance with claim  12 ;   b) casting a cast part from the aluminum melt;   c) subjecting the cast part to heat treatment, wherein   c.1) the heat treatment is a T4 temper treatment which involves a solution heat treatment at temperatures of 450 to 480° C. for 2 to 24 h optionally followed by a forced air or water quench and natural aging for 7 to 75 days   or   c.2) the heat treatment is a T7 temper treatment which involves a solution heat treatment at temperatures of 450 to 480° C. for 2 to 24 h followed by forced air or water quench and 1-2 days of natural aging and an artificial aging at temperatures between 120 to 200° C. for 1 to 24 h in single or dual-stage aging.