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Iowa State University and Ames Laboratory researchers have developed a method to form amorphous metal alloys at room temperature without introducing shear bands or micro-crystalline structure into the alloy.

Amorphous alloys are desirable for use in high precision parts because the mechanical properties of these alloys, combined with the lack of grain boundaries, make them particularly suitable for fine-scale imprinting and patterning.  Thermo-plastic forming has often been utilized to form glassy metals, though this technique is inappropriate at room temperature because of the development of narrow shear bands in the metal.  These shear bands induce brittleness into the metal, often resulting in catastrophic failure of the part.  Various techniques may be used to achieve sufficient deformability of the alloy, including adding crystalline particles to create a second phase, controlling the deformation geometry, and raising the processing temperature of the alloy.  All of these techniques result in shortcomings in the resultant product.
Iowa State University and Ames Laboratory researchers have developed a method to cold-plastic form typically brittle Hf-based amorphous alloys by controlling the homogenous flow of the material.  This technique avoids increasing the brittleness of the alloy during thermoplastic forming.

• Room temperature processing avoids embrittlement formed by sub-Tg annealing

• Process does not induce generation of shear bands in the alloy

• Provides control over deformation behavior of bulk amorphous alloys

Forming and patterning of bulk amorphous metal alloys