Extrudable Al-Mg-Si alloys

Abstract

High strength high extrudability Al—Mg—Si alloys have the composition in weight %: Mg 0.25-0.40; Si 0.60-0.90; Fe up to 0.35; Mn up to 0.35 preferably 0.10-0.25.

1 : An alloy which consists of in weight % 
     
       
         
               
               
               
             
                   
                   
               
                   
                 Mg 
                 0.25-0.40 
               
                   
                 Si 
                 0.60-0.90 
               
                   
                 Mn 
                   0.12 -0.35 
               
                   
                 Fe 
                 up to 0.35 
               
                   
                 Others 
                 up to 0.05 each, 0.15 total 
               
                   
                 Balance Al. 
               
                   
                   
               
           
              
             
             
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       2 : An alloy as claimed in  claim 1 , wherein the Si content is more than 0.30% by weight greater than is required to form Al—Fe—Si and Mg 2 Si with all the Mg and Fe present. 
   
   
       3 : An alloy as claimed in  claim 1  comprising 
     
       
         
               
               
               
             
                   
                   
               
                   
                 Fe 
                 0.15-0.35 
               
                   
                   
               
           
              
             
             
              
              
             
          
         
       
     
   
   
       4 : An alloy as claimed in  claim 1  comprising 
     
       
         
               
               
               
             
                   
                   
               
                   
                 Mn 
                   0.12 -0.15. 
               
                   
                   
               
           
              
             
             
              
              
             
          
         
       
     
   
   
       5 : An extrusion ingot of the alloy of  claim 1 , in which Fe is present substantially in the α-AlFeSi form. 
   
   
       6 : An extrusion of the alloy claimed in  claim 1 . 
   
   
       7 : An extrusion made from an ingot as claimed in  claim 5 . 
   
   
       8 : An extrusion as claimed in  claim 6  which has after ageing an ultimate tensile strength of at least 240 MPa. 
   
   
       9 : An extrusion as claimed in  claim 6  which has been thermally aged, wherein the rate of heating for ageing was 10-100° C./hr. 
   
   
       10 : An extrusion as claimed in  claim 7  which has been thermally aged, wherein the rate of heating for ageing was 10-100° C./hr. 
   
   
       11 : An alloy which consists of in weight % 
     
       
         
               
               
               
             
                   
                   
               
                   
                 Mg 
                 0.33-0.40 
               
                   
                 Si 
                 0.73-0.90 
               
                   
                 Mn 
                 0.12-0.35 
               
                   
                 Fe 
                 up to 0.35 
               
                   
                 Others 
                 up to 0.05 each, 0.15 total 
               
                   
                 Balance Al. 
               
                   
                   
               
           
              
             
             
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       12 : An alloy as claimed in  claim 11  comprising 
     
       
         
               
               
               
             
                   
                   
               
                   
                 Mn 
                 0.12-0.25. 
               
                   
                   
               
           
              
             
             
              
              
             
          
         
       
     
   
   
       13 : An extrusion ingot of the alloy of  claim 11 , in which Fe is present substantially in the α-AlFeSi form. 
   
   
       14 : An extrusion made from an ingot of an alloy which consists of in weight % 
     
       
         
               
               
               
             
                   
                   
               
                   
                 Mg 
                 0.33-0.40 
               
                   
                 Si 
                 0.73-0.90 
               
                   
                 Mn 
                 0.12-0.25 
               
                   
                 Fe 
                 up to 0.35 
               
                   
                 Others 
                 up to 0.05 each, 0.15 total 
               
                   
                 Balance Al, 
               
                   
                   
               
           
              
             
             
              
              
              
              
              
              
              
             
          
         
       
     
     wherein Fe is present in said ingot substantially in the α-AlFeSi form, wherein said extrusion has been thermally aged, and wherein the rate of heating for ageing was 10-100° C./hr.