Nature Asia Pacific Materials - Glassy metallic wires can be controllably manufactured by drawing from a supercooled rod
The metals we are most familiar with adopt a periodic, crystalline atomic arrangement. Metallic glasses, on the other hand, have an amorphous structure that is well suited for certain fabrication processes such as casting. Glassy metallic wires with widths of micrometers or nanometers are also less brittle than their bulk metallic counterparts, but such wires have proved difficult to fabricate. Wei Hua Wang and colleagues from the Chinese Academy of Sciences in Beijing have now developed a simple method for producing well-controlled and defect-free metallic glass wires.
The researchers found that the resulting wires had high structural uniformity. Their surfaces were as smooth as those of industrial silica glass fibers, and the wires could tolerate a much greater bending angle, in excess of 90° (see image). The diameters of the wires were easily controlled by adjusting the drawing force, allowing the researchers to draw wires as thin as 70 nm—ten times thinner than any wires produced previously.
This work increases the feasibility of using metallic glass fibers as building blocks for microscale and nanoscale devices, with possible applications in composites, sensors, intelligent fabrics, circuit interconnects and optical waveguides. It also holds considerable intrinsic scientific interest, says Wang. “Our fibers can be used as a model system to study many fundamental issues in metallic glasses.”