Mechanical Properties of Open Celled Bulk Metallic Glass Foams Processed by Equal Channel Angular Extrusion

The unique properties of metallic foams make them superior to their solid counterparts for many applications, including lightweight structures, impact protection, filtration and catalysis. This work extends the use of metallic foams for these applications by developing a novel solid state processing method to address some of the scalability and contamination issues that hinder common liquid state processing methods used to create metallic glass foams.;Equal channel angular extrusion is used to consolidate a blend of amorphous Zr58.5Nb2.8Cu15.6Ni12.8Al1 0.3 (Vit106a) or Hf44.5Cu27Ni13.5Ti 5Al10 (ARLloy ;The alignment of the elongated pores leads to anisotropic mechanical properties. As the angle between the elongated pore and the direction of compressive loading increase from 0 to 68°, there is a significant decrease in loading stiffness and peak stress which is confirmed by finite element analysis. Foams with pores aligned 45-68° to the direction of loading show increased bending in individual walls and accumulation of microfracture damage without failure leading to an increase energy absorption capabilities over the other orientations tested. Acoustic emissions techniques are used to verify the increase in diffuse microfracture damage and accumulation for the orientations with high energy absorbing capabilities.