Zinc-Rich Aluminum Alloy Gets Tough Orders

An aluminum alloy designated 7085 developed by Alcoa is getting a foothold in tough aircraft and military applications.

The first application of 7085 was for large die forgings on the Airbus A380 wing spars. Higher zinc along with reduced copper and magnesium content give the aluminum alloy excellent strength and high fracture toughness.  It’s used in the Boeing Dreamliner for wing spars and engine pylons.  It’s also being evaluated for thick structural parts, such as blast shields, on military vehicles.

Engineers shifted from titanium to 7085 for large forgings that form the center section of the bulkhead of the multinational Joint Strike Fighter’s F-35B variant for the US Marines and Royal Navy. Reason: To save weight. Titanium is 60 percent more dense than the aluminum alloy.

Photo shows the Marine Corps variant of the Joint Strike Fighter, which uses forgings made from a new aluminum alloy to reduce weight.