Engineers create cobalt-aluminum alloy up to ten times stronger than steel yet bendable

Purdue researchers have engineered a cobalt-aluminum intermetallic that combines ultra-high strength with notable ductility, achieving yield stresses six to ten times that of high-strength steel while deforming 15% at room temperature.

Engineers at Purdue University have transformed the traditionally brittle cobalt-aluminum (CoAl) intermetallic into a material that is both exceptionally strong and surprisingly flexible. By depositing the alloy via magnetron sputtering, they introduced a large number of dislocations and designed a network of amorphous interface layers that crystallize under stress, fostering further dislocation activity. Mechanical testing showed a yield strength of about 6 GPa—roughly six to ten times that of high-strength structural steel—while the material sustained 15% plastic strain at room temperature.

In-situ electron microscopy and molecular dynamics simulations confirmed the deformation mechanisms. The researchers aim to produce bulk nanocomposite versions for industrial use and to apply the same strategy to other intermetallics, potentially improving turbine blades, aerospace engines, energy systems, and defense applications. Funding came primarily from the National Science Foundation’s Metals and Metallic Nanostructures program.