Bulk metallic glasses (BMGs) are a relatively new class of metal alloy exhibiting an amorphous (glassy) structure. These unique materials behave very differently to conventional crystalline alloys and often exhibit an attractive combination of mechanical, thermal, and chemical properties.  Furthermore, the discovery that BMGs can be produced by various casting routes, such as die casting and direct strip casting, has generated considerable world-wide interest in the production of these materials into useful components.  This discovery has also generated substantial interest in the development of forming processes since these materials can be formed at slightly elevated temperature in the same manner as thermoplastic polymers.

Due to the remarkable superplastic formability of BMGs, there is considerable scope for forming by micro- and nano-replication, extrusion, forging and blow moulding (similar to the production of plastic bottles).  Figure 1 shows the exceptional formability of BMGs into components of a range of shapes and sizes demonstrating that these processing methods provide considerable scope for the mass production of components for a range of applications including nanodevices, medical implants and various other components.

Figure 1. Demonstration of the remarkable formability of bulk metallic glasses: (a) blow moulding; (b) micro-, and (c) nano-forming, showing the generation of ultra-fine-scale surface features.

Funded by the ARC Centre of Excellence for Design in Light Metals, researchers within the School’s BMG research group are synthesizing a range of new lightweight amorphous alloys and casting and fabricating them into various components and devices.

Some recent research notable outcomes are outlined below:

  • The development of manufacturing facilities for casting BMG components in a range of shapes and sizes.
  • The development of new silver-, calcium-, zinc-, copper- and magnesium-based glass-forming alloys with a range of novel properties including some alloys with good ductility.
  • Synthesis and fabrication of lightweight BMGs exhibiting properties suitable for their use as biocompatible implant and bioabsorbable orthopaedic fixation materials.
  • The development of a range of lightweight BMG composites with properties rivalling the strongest steels and titanium alloys. These materials have potential future automotive, defence and aerospace applications.

Michael Ferry, Kevin Laws, Martin Xu, Philip Boughton, Karl Shamlaye, Fitri Wahid, Olga Biletska

Yang Cao, Yi Cao, Afrin Ninnia, Zakaria Quadir, Lalu Robin, John Scicluna, Khalid Hamidy

ARC Centre of Excellence for Design in Light Metals