Potentiodynamic polarisation study of bulk metallic glasses based on the Mg–Zn–Ca ternary system

Bulk metallic glasses (BMGs) based on the Mg–Zn–Ca ternary system are considered as potential bioresorbable metals for orthopaedic applications as they are comprised solely of biocompatible elements. In the present study, a series of six Ca rich and ten Mg rich BMGs were synthesised and their corrosion behaviours characterised using potentiodynamic polarisation. A complex interaction between the elements in this compositional window was observed, whereby a significant increase in dissolution rate was accompanied by increasing Ca content or decreasing Mg content. Although the addition of Zn had a positive contribution in reducing the rate of corrosion, its effect was not dominant. In addition, a form of passivation was observed in the Mg rich BMGs, although it appears that such passive corrosion behaviour is not directly related to a high Zn content.