Al-Mg-Si-Mn-Fe CASTING ALLOYS

Abstract

New aluminum casting (foundry) alloys are disclosed. The new aluminum casting alloys generally include from 2.5 to 5.0 wt. % Mg, from 0.70 to 2.5 wt. % Si, wherein the ratio of Mg/Si (in weight percent) is from 1.7 to 3.6, from 0.40 to 1.50 wt. % Mn, from 0.15 to 0.60 wt. % Fe, optionally up to 0.15 wt. % Ti, optionally up to 0.10 wt. % Sr, optionally up to 0.15 wt. % of any of Zr, Sc, Hf, V, and Cr, the balance being aluminum and unavoidable impurities. The new aluminum casting alloys may be high pressure die cast, such as into automotive components. The new aluminum alloys may be supplied in an F or a T5 temper, for instance.

What is claimed is: 
     
         1 . An aluminum casting alloy comprising:
 from 2.5 to 5.0 wt. % Mg;   from 0.70 to 2.5 wt. % Si;
 wherein a weight ratio of magnesium to silicon (wt. % Mg/wt. % Si) is from 1.7:1 to 3.6:1; 
   from 0.40 to 1.5 wt. % Mn;   from 0.10 to 0.60 wt. % Fe;   optionally up to 0.15 wt. % Ti;   optionally up to 0.10 wt. % Sr;   optionally up to 0.15 wt. % of any of Zr, Sc, Hf, V, and Cr;   the balance being aluminum and unavoidable impurities.   
     
     
         2 . The aluminum casting alloy of  claim 1 , wherein the aluminum casting alloy comprises from 3.0 to 4.60 wt. % Mg. 
     
     
         3 . The aluminum casting alloy of  claim 2 , wherein the aluminum casting alloy comprises from 1.10 to 2.1 wt. % Si. 
     
     
         4 . The aluminum casting alloy of  claim 3 , wherein the aluminum casting alloy comprises from 0.60 to 1.2 wt. % Mn. 
     
     
         5 . The aluminum casting alloy of  claim 4 , wherein the aluminum casting alloy comprises from 0.30 to 0.60 wt. % Fe. 
     
     
         6 . The aluminum casting alloy of  claim 1 , wherein (0.4567*Mg−0.5)<=Si<=(0.4567*Mg+0.2). 
     
     
         7 . The aluminum casting alloy  claim 1 , wherein:
 (1) wt. % Si≤(0.4567*(wt. % Mg)+0.2*(wt. % Mg)+0.25*(wt. % Fe); and   (2) wt. % Si>(0.4567*(wt. % Mg)+0.2*(wt. % Mg)+0.25*(wt. % Fe)-0.6).   
     
     
         8 . The aluminum casting alloy of  claim 1 , wherein the aluminum casting alloy realizes at least one of:
 an ultimate tensile strength of of at least 200 MPa;   a tensile yield strength of at least 110 MPa; and   an elongation of at least 10%.   
     
     
         9 . The aluminum casting alloy of  claim 1 , wherein the aluminum casting alloy comprises not greater than 0.012 wt. % of β-Al 5 FeSi compounds. 
     
     
         10 . The aluminum casting alloy of  claim 1 , wherein the aluminum casting alloy realizes a hot cracking tendency index of not greater than 0.30. 
     
     
         11 . A method comprising:
 (a) shape casting an aluminum casting alloy into a shape cast product, wherein the aluminum casting alloy comprises:
 from 2.5 to 5.0 wt. % Mg; 
 from 0.70 to 2.5 wt. % Si;
 wherein a weight ratio of magnesium to silicon (wt. % Mg/wt. % Si) is from 1.7:1 to 3.6:1; 
 
 from 0.40 to 1.5 wt. % Mn; and 
 from 0.10 to 0.60 wt. % Fe; 
   
       wherein, after the shape casting, the shape cast product is crack-free; and
 (b) tempering the shape cast product. 
 
     
     
         12 . The method of  claim 11 , wherein the shape casting is high-pressure die casting. 
     
     
         13 . The method of  claim 11 , wherein the tempering step comprises tempering the shape cast product to one of an F temper and a T5 temper. 
     
     
         14 . The method of  claim 11 , wherein the tempering step is absent of a solution heat treatment step. 
     
     
         15 . The method of  claim 11 , wherein the shape cast product is in the form of an automotive component. 
     
     
         16 . The method of  claim 15 , wherein the automotive component is a structural component. 
     
     
         17 . The method of  claim 15 , wherein the automotive component is a door frame, or a shock tower, or a tunnel structure. 
     
     
         18 . A shape cast aluminum alloy product comprising:
 from 3.0 to 4.60 wt. % Mg;   from 1.20 to 2.0 wt. % Si;
 wherein a weight ratio of magnesium to silicon (wt. % Mg/wt. % Si) is from 1.85:1 to 3.5:1; 
   from 0.60 to 1.20 wt. % Mn;   from 0.20 to 0.60 wt. % Fe;   optionally up to 0.15 wt. % Ti;   optionally up to 0.10 wt. % Sr; and   optionally up to 0.15 wt. % of any of Zr, Sc, Hf, V, and Cr;   the balance being aluminum and unavoidable impurities;   
       wherein the shape cast product is in the form of an automotive component. 
     
     
         19 . The shape cast aluminum alloy product of  claim 18 , wherein the automotive component is a structural component. 
     
     
         20 . The shape cast aluminum alloy product of  claim 18 , wherein the automotive component is a door frame, or a shock tower, or a tunnel structure.