3D printing of Fe-based bulk metallic glasses and composites with large dimensions and enhanced toughness by thermal spraying

Large sized Fe-based bulk metallic glasses (BMGs) and BMG/stainless steel (SS) composites with excellent mechanical properties were successfully fabricated using a thermal spray three-dimensional (3D) printing (TS3DP) technique. The 3D-printed BMG and BMGC (reinforced with 50% SS powder) parts exhibited high fracture strength (similar to 2 GPa) and fairly good fracture toughness (13-21 MPa m(1/2), which is 200-400% greater than that of the as-cast BMG of the same composition). The enhanced fracture toughness originates from the intrinsically layered structure of the 3D-printed BMG components, which caused crack deflection and thus the increase of energy dissipation during crack propagation. The TS3DP technique developed in this work opens up a new avenue for the production of BMGs and BMG composites of theoretically limitless size, and facilitates their application as structural and functional materials.