Layered sheets of aluminum and nickel can forget their own identity and act like a completely new material if they are hit hard enough.

Ultrahigh strain rates allow nanoscale architectures to enter a 'mechanically hybridized' regime where they ignore the properties of their constituent metals. This state is transient and only occurs when the material is subjected to extreme, high-speed impacts. Materials scientists previously assumed that any alloy or structure would always be limited by the properties of the aluminum or nickel inside it. This research proves that structure can override chemistry under the right pressure conditions. This discovery could lead to body armor or spacecraft shielding that becomes much tougher precisely at the moment it is struck. It reveals a hidden defense mechanism baked into the geometry of matter.