What is Purdue Cobalt-Aluminum Nanolaminate (CoAl Intermetallic)?

The Purdue cobalt-aluminum nanolaminate is a layered metal composite that alternates extremely thin sheets of a hard cobalt-aluminum intermetallic compound with a softer, more ductile metal phase. Stacking the two materials at the nanoscale lets the composite combine the intermetallic layer's hardness with the ductile layer's ability to absorb strain, producing a material that resists cracking better than the brittle intermetallic would on its own.