Thermoplastic formability of CaMgZn bulk metallic glasses for biomedical applications

Bulk metallic glasses (BMGs) based on the Mg-Zn-Ca ternary system have shown promise as a potential bioresorbable material. Amongst these, Ca-rich BMGs have demonstrated superior thermoplastic formability. However, corrosion assessments showed that these BMGs can disintegrate within hours. Ca55Mg17.5Zn27.5 was synthesised to improve its corrosion resistance over other Ca-rich BMGs whilst maintaining its thermoplastic formability. In the present study, the thermoplastic formability of Ca55Mg17.5Zn27.5 is compared with Ca-rich and Mg-rich BMGs. A dilatometer was used to measure the associated contraction (softening) in the material as it is heated above its glass transition temperature. Although the enrichment of Zn in Ca55Mg17.5Zn27.5 reduced the temperature range of its supercooled liquid region, this alloy exhibits significantly lower viscosity within this region compared to the other BMGs, deeming it more favourable for complex thermoplastic forming processing.