Light mix makes strong metal

Researchers from the University of Tokyo and Toyota Central Research and Development Laboratories in Japan have found a group of metal alloys that are unusually strong and flexible.

The alloys, various mixtures of titanium, zirconium, niobium and tantalum, could be used in medical equipment, sporting goods, precision parts for outer space, and eventually automobile parts, according to the researchers.

The flexibility and strength of the alloys increase as the material gets colder.

Key to the useful properties are a balance of three atomic properties: the position and energy level of electrons, and the bonds between atoms. The researchers found they could boost the flexibility and strength of the alloys by cold-working the materials to rearrange oxygen atoms in the mix. The process made the microstructure of the material into a marble-like structure of fine filaments. This nanoscale bending is responsible for the alloys' elastic properties.

The researchers are aiming to commercialize the material for use in frames for glasses and precision screws. The materials are especially appropriate for making super lightweight springs and precision instruments for rugged environments like space, according to the researchers.

The work appeared in the April 18, 2003 issue of Science.