Multipurpose aluminum alloy composition

Abstract

An aluminum alloy and shaped aluminum alloy parts cast therefrom. The aluminum alloy including, by mass, ≥about 6.5% to ≤about 8% silicon, ≥about 0.1% to ≤about 0.35% magnesium, ≥about 0.2% to ≤about 0.25% iron, ≥about 0.05% to ≤about 0.15% manganese, and ≥about 0.1% to ≤about 0.2% chromium. The mass percentage of iron (Fe%), the mass percentage of manganese (Mn %), and the mass percentage of chromium (Cr %) in the aluminum alloy satisfy the relationships: (i) [Mn %+(a×Cr %)]/Fe %>1, and (ii) Fe %+(b×Mn %)+(c×Cr %)>0.6%, where about 1.3≤a≤about 1.7, about 1.2≤b≤about 1.7, and about 2.5≤c≤about 2.9.

1 . An aluminum alloy for casting shaped aluminum alloy parts, the aluminum alloy comprising, by mass:
 greater than or equal to about 6.5% to less than or equal to about 8% silicon;   greater than or equal to about 0.1% to less than or equal to about 0.4% magnesium;   greater than or equal to about 0.2% to less than or equal to about 0.25% iron;   greater than or equal to about 0.05% to less than or equal to about 0.15% manganese; and   greater than or equal to about 0.1% to less than or equal to about 0.2% chromium, wherein a mass percentage of iron (Fe %), a mass percentage of manganese (Mn %), and a mass percentage of chromium (Cr %) in the aluminum alloy satisfy the following mathematical relationships:   (i) [Mn %+(a×Cr %)]/Fe %>1, and   (ii) Fe %+(b×Mn %)+(c×Cr %)>0.6%,   where a is greater than or equal to about 1.3 and less than or equal to about 1.7, b is greater than or equal to about 1.2 and less than or equal to about 1.7, and c is greater than or equal to about 2.5 and less than or equal to about 2.9.   
     
     
         2 . The aluminum alloy of  claim 1 , wherein a is greater than or equal to about 1.4 and less than or equal to about 1.6, b is greater than or equal to about 1.4 and less than or equal to about 1.6, and c is greater than or equal to about 2.6 and less than or equal to about 2.8. 
     
     
         3 . The aluminum alloy of  claim 1 , wherein a is about 1.5, b is about 1.5, and c is about 2.7. 
     
     
         4 . The aluminum alloy of  claim 1 , wherein the aluminum alloy further comprises, by mass:
 greater than 0% to less than or equal to 0.2% copper;   greater than 0% to less than or equal to 0.2% zinc; and   aluminum as balance.   
     
     
         5 . The aluminum alloy of  claim 1 , wherein the aluminum alloy comprises, by mass:
 greater than or equal to about 6.5% to less than or equal to about 7.5% silicon;   greater than or equal to about 0.05% to less than or equal to about 0.1% manganese;   greater than or equal to about 0.12% to less than or equal to about 0.18% chromium;   greater than or equal to 0% to less than or equal to 0.1% copper;   greater than or equal to 0% to less than or equal to 0.1% zinc; and   aluminum as balance.   
     
     
         6 . The aluminum alloy of  claim 1 , wherein the aluminum alloy comprises, by mass:
 greater than or equal to about 6.5% to less than or equal to about 7.5% silicon;   greater than or equal to about 0.08% to less than or equal to about 0.12% manganese;   greater than or equal to about 0.10% to less than or equal to about 0.15% chromium;   greater than or equal to 0% to less than or equal to 0.1% copper;   greater than or equal to 0% to less than or equal to 0.1% zinc; and   aluminum as balance.   
     
     
         7 . The aluminum alloy of  claim 1 , wherein the aluminum alloy comprises, by mass:
 greater than or equal to about 6.5% to less than or equal to about 7.5% silicon;   greater than or equal to about 0.3% to less than or equal to about 0.4% magnesium;   about 0.25% iron;   greater than or equal to about 0.08% to less than or equal to about 0.12% manganese; and   greater than or equal to about 0.11% to less than or equal to about 0.14% chromium.   
     
     
         8 . The aluminum alloy of  claim 1 , wherein, after the aluminum alloy is cast into a shaped aluminum alloy part, the aluminum alloy exhibits a multiphase microstructure including an aluminum matrix phase and an Fe-containing intermetallic phase distributed throughout the aluminum matrix phase, and wherein the Fe-containing intermetallic phase comprises a plurality of a AlFeSi intermetallic particles and a plurality of Al(M, Fe)Si intermetallic particles, where M is Mn and/or Cr. 
     
     
         9 . The aluminum alloy of  claim 8 , wherein the Al(M, Fe)Si intermetallic particles account for, by volume, greater than 50% of the Fe-containing intermetallic phase and the AlFeSi intermetallic particles account for, by volume, less than 50% of the Fe-containing intermetallic phase. 
     
     
         10 . The aluminum alloy of  claim 9 , wherein the Al(M, Fe)Si intermetallic particles account for, by volume, greater than 75% of the Fe-containing intermetallic phase and the AlFeSi intermetallic particles account for, by volume, less than 25% of the Fe-containing intermetallic phase. 
     
     
         11 . The aluminum alloy of  claim 9 , wherein the Al(M, Fe)Si intermetallic particles have a mean aspect ratio of less than 3 when viewed in a two-dimensional cross-section. 
     
     
         12 . The aluminum alloy of  claim 9 , wherein the AlFeSi intermetallic particles have a mean aspect ratio of greater than 3 when viewed in a two-dimensional cross-section. 
     
     
         13 . The aluminum alloy of  claim 1 , wherein the aluminum alloy does not exhibit die soldering when cast in a steel mold cavity at a temperature of about 705° C. 
     
     
         14 . An aluminum alloy part comprising, by mass:
 greater than or equal to about 6.5% to less than or equal to about 8% silicon;   greater than or equal to about 0.1% to less than or equal to about 0.4% magnesium;   greater than or equal to about 0.2% to less than or equal to about 0.25% iron;   greater than or equal to about 0.05% to less than or equal to about 0.15% manganese; and   greater than or equal to about 0.1% to less than or equal to about 0.2% chromium, wherein a mass percentage of iron (Fe %), a mass percentage of manganese (Mn %), and a mass percentage of chromium (Cr %) in(Cr %)in the aluminum alloy satisfy the following mathematical relationships:   (i) [Mn %+(a×Cr %)]/Fe %>1, and   (ii) Fe %+(b×Mn %)+(c×Cr %)>0.6%,   where a is greater than or equal to about 1.3 and less than or equal to about 1.7, b is greater than or equal to about 1.2 and less than or equal to about 1.7, and c is greater than or equal to about 2.5 and less than or equal to about 2.9.   
     
     
         15 . The aluminum alloy part of  claim 14 , wherein the aluminum alloy part is manufactured via a permanent mold casting process or a sand casting process in which a volume of an aluminum alloy is cast in a mold defining the shape of the aluminum alloy part at a pressure of less than or equal to about 50 psi and then cooled to ambient temperature at an average cooling rate of less than or equal to about 10 degrees Celsius per second. 
     
     
         16 . The aluminum alloy part of  claim 15 , wherein the aluminum alloy part has a wall thickness of greater than 5 millimeters to less than or equal to about 10 millimeters. 
     
     
         17 . The aluminum alloy part of  claim 16 , wherein, after the aluminum alloy part is solution heat treated and artificially aged, the aluminum alloy part exhibits a Yield Strength in the range of greater than or equal to about 180 MPa to less than or equal to about 270 MPa, an Ultimate Tensile Strength in the range of greater than or equal to about 260 MPa to less than or equal to about 330 MPa, Fatigue Strength in the range of greater than or equal to about 70 MPa to less than or equal to about 100 MPa, and Elongation at Break in the range of greater than or equal to about 8% to less than or equal to about 13%. 
     
     
         18 . The aluminum alloy part of  claim 14 , wherein the aluminum alloy part is manufactured via a high-pressure casting process in which a volume an aluminum alloy is cast in a mold defining the shape of the aluminum alloy part at a pressure in a range of about 1,500 psi to about 25,400 psi and then cooled to ambient temperature at an average cooling rate in a range of about 100 degrees Celsius per second to about 1,000 degrees Celsius per second. 
     
     
         19 . The aluminum alloy part of  claim 18 , wherein the aluminum alloy part has a wall thickness of greater than or equal to about 0.5 millimeters to less than about 5 millimeters. 
     
     
         20 . The aluminum alloy part of  claim 19 , wherein, after the aluminum alloy part is cooled to ambient temperature, the aluminum alloy part exhibits a Yield Strength in the range of greater than or equal to about 100 MPa to less than or equal to about 130 MPa, an Ultimate Tensile Strength in the range of greater than or equal to about 220 MPa to less than or equal to about 280 MPa, and an Elongation at Break in the range of greater than or equal to about 8% to less than or equal to about 17%.