Safety component moulded in a1-si alloy

Abstract

The invention concerns a safety component with high mechanical strength and good ductility, moulded in Al—Si alloy consisting (in wt. %) of: Si: 2-11; Mg: 0.3-0.7; Cu: 0.3 0.9; other elements <1 each and <2 in total, the rest being aluminium, and solution heat treated, tempered and hardened resulting in Brinell hardness of more than 125. The invention also concerns a safety component with high mechanical resistance and good ductility, moulded in Al—Si alloy consisting (in wt. %) of: Si: 2-6; Mg: 0.3-0.7; Fe <0.20; other elements <0.3 each and <1 in total; the rest being aluminium; solution heat treated, hardened and tempered resulting in a quality index Q=Rm+log A>485 MPa.

1 . Safety part with high mechanical strength and good ductility, cast from an Al—Si alloy with the following composition (% by weight): 
 Si 2-11; Mg 0.3-0.7; Cu 0.3-0.9; other elements <1 each and <2 total, remainder aluminium,  
 and solution heat treated, quenched and aged to give a hardness of more than 125 Brinell.  
 
     
     
         2 . Safety part according to  claim 1 , characterised in that the Mg content is between 0.5 and 0.7%.  
     
     
         3 . Safety part according to  claim 1  or  2 , characterised in that the Cu content is between 0.3 and 0.6%.  
     
     
         4 . Safety part according to one of  claims 1  to  3 , characterised in that the Ti content is between 0.05 and 0.3%.  
     
     
         5 . Safety part according to one of  claims 1  to  4 , characterised in that the iron content is less than 0.15%, and preferably less than 0.12%.  
     
     
         6 . Safety part according to one of  claims 1  to  5 , characterised in that it contains at least one element modifying or refining the eutectic such as sodium (with a content of between 0.001 and 0.020%), strontium (between 0.004 and 0.050%) and antimony (between 0.03 and 0.30%).  
     
     
         7 . Safety part according to one of  claims 1  to  6 , characterised in that the Si content is between 2 and 7%.  
     
     
         8 . Safety part according to  claim 7 , characterised in that it is cast using one of the following casting processes: casting in the semi-solid state (thixocasting), squeeze casting, casting followed by forging or stamping, casting with lost foam models under isostatic pressure, vacuum die casting, and casting followed by hot isostatic compaction (HIP).  
     
     
         9 . Safety part according to one of  claims 1  to  6 , characterised in that the Si content is between 7 and 11%.  
     
     
         10 . Safety part according to  claim 9 , characterised in that it is moulded using a casting process with a high solidification rate, such that the spacing between dendrite arms is less than 20 μm.  
     
     
         11 . Safety part according to one of  claims 1  to  10 , characterised in that ageing is done within the 170-190° C. temperature range for a duration of between 4 h and 20 h.  
     
     
         12 . Safety part with high mechanical strength and good ductility, cast from an Al—Si alloy with the following composition (% by weight): 
 Si 2-6; Mg 0.3-0.7; Fe <0.20; other elements <0.3 each and <1 total, remainder aluminium,  
 and solution heat treated, quenched and aged to give a quality index Q=R m +150 log A>485 MPa.  
 
     
     
         13 . Safety part according to  claim 12 , characterised in that the Mg content is between 0.45 and 0.65%.  
     
     
         14 . Safety part according to  claim 12  or  13 , characterised in that the Ti content is between 0.05 and 0.3%.  
     
     
         15 . Safety part according to one of  claims 12  to  14 , characterised in that the iron content is less than 0.15%, and preferably less than 0.12%.  
     
     
         16 . Safety part according to one of  claims 12  to  15 , characterised in that it contains at least one element modifying or refining the eutectic such as sodium (between 0.001 and 0.020%), strontium (between 0.004 and 0.050%) and antimony (between 0.03 and 0.30%).