High strength, chromium-and lithium-free aluminum casting alloy and related vehicular structural components

Abstract

There is claimed a high strength, aluminum alloy composition especially suited for cast vehicular structural components. This chromium- and lithium-free, alloy consists essentially of: about 3-3.6 wt. % zinc, about 1.3-1.6 wt. % magnesium, about 0.2-0.8 wt. % manganese, about 0.08-0.16 wt. % zirconium, up to about 0.3 wt. % copper, up to about 0.15 wt. % silicon, and up to about 0.25 wt. % iron, the balance aluminum, incidental elements and impurities. It exhibit a typical tensile yield strength greater than about 29 ksi without having to undergo T6-type thermal processing.

What is claimed is:  
     
         1 . A high strength, chromium- and lithium-free aluminum alloy product cast from a composition consisting essentially of: about 3-3.6 wt. % zinc, about 1.3-1.6 wt. % magnesium, about 0.2-0.8 wt. % manganese, about 0.08-0.16 wt. % zirconium, up to about 0.3 wt. % copper, up to about 0.15 wt. % silicon, and up to about 0.25 wt. % iron, the balance aluminum, incidental elements and impurities.  
     
     
         2 . The cast alloy product of    claim 1    which contains less than about 3.4 wt. %zinc.  
     
     
         3 . The cast alloy product of    claim 1    which contains greater than about 1.4 wt. % magnesium.  
     
     
         4 . The cast alloy product of    claim 1    which contains greater than about 0.4 wt. % manganese.  
     
     
         5 . The cast alloy product of    claim 1    which contains greater than about 0.1 wt. % zirconium.  
     
     
         6 . The cast alloy product of    claim 1    which contains less than about 0.1 wt. % silicon and less than about 0.15 wt. % iron.  
     
     
         7 . The cast alloy product of    claim 1    which is capable of achieving a typical tensile yield strength greater than about 29 ksi without having to undergo T6-type thermal processing.  
     
     
         8 . A chromium-free, lithium-free aluminum cast product which has an ultimate tensile strength of about 40 ksi or higher without having been solution heat treated, said casting consisting essentially of: about 3-3.6 wt. % zinc, about 1.3-1.6 wt. % magnesium, about 0.2-0.8 wt. % manganese, about 0.08-0.16 wt. % zirconium, up to about 0.3 wt. % copper, up to about 0.15 wt. % silicon, and up to about 0.25 wt. % iron, the balance aluminum, incidental elements and impurities.  
     
     
         9 . The cast product of    claim 8    which contains less than about 3.4 wt. % zinc.  
     
     
         10 . The cast product of    claim 8    which contains greater than about 1.4 wt. % magnesium.  
     
     
         11 . The cast product of    claim 8    which contains greater than about 0.4 wt. % manganese.  
     
     
         12 . The cast product of    claim 8    which contains greater than about 0.1 wt. % zirconium.  
     
     
         13 . The cast product of    claim 8    which contains less than about 0.1 wt. % silicon and less than about 0.15 wt. % iron.  
     
     
         14 . A vehicular structural component made from a chromium-free, lithium-free, aluminum casting alloy consisting essentially of: about 3-3.6 wt. % zinc, about 1.3-1.6 wt. % magnesium, about 0.2-0.8 wt. % manganese, about 0.08-0.16 wt. % zirconium, up to about 0.3 wt. % copper, up to about 0.15 wt. % silicon, and up to about 0.25 wt. % iron, the balance aluminum, incidental elements and impurities, said structural component exhibiting a typical tensile yield strength greater than about 29 ksi without having to undergo T6-type thermal processing.  
     
     
         15 . The cast structural component of    claim 14    which contains less than about 3.4 wt. % zinc.  
     
     
         16 . The cast structural component of    claim 14    which contains greater than about 1.4 wt. % magnesium.  
     
     
         17 . The cast structural component of    claim 14    which contains greater than about 0.4 wt. % manganese.  
     
     
         18 . The cast structural component of    claim 14    which contains greater than about 0.1 wt. % zirconium.  
     
     
         19 . The cast structural component of    claim 14    which contains less than about 0.1 wt. % silicon and less than about 0.15 wt. % iron.  
     
     
         20 . The cast structural component of    claim 14    which is a suspension part.