This allows the alloys, which are made up of zirconium, nickel, titanium and copper, to be blow moulded like plastic into complex shapes that can't be achieved using regular metal.
The team has created a number of complex shapes, including seamless metallic bottles, watch cases, miniature resonators and biomedical implants. The shapes can reportedly be moulded in less than a minute and are twice as strong as typical steel. The materials also cost about the same as high-end steel, Schroers said, but can be processed as cheaply as plastic.
The team blow moulded the alloys in a vacuum or in fluid at low temperatures and low pressures, where the bulk metallic glass softens and flows as easily as plastic but without crystallizing like regular metal.
"The trick is to avoid friction typically present in other forming techniques," said Jan Schroers, a materials scientist at Yale University, who led the research team. "Blow moulding completely eliminates friction, allowing us to create any number of complicated shapes, down to the nanoscale."
The new processing technique has also been used to fabricate miniature resonators for microelectromechanical systems (MEMS), gyroscopes and other resonator applications.
By blow moulding the BMGs, the team was able to combine three separate steps in traditional metal processing (shaping, joining and finishing) into one. "This could enable a whole new paradigm for shaping metals," claimed Schroers.
The team’s findings are described online in the current issue of the journal Materials Today.
