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. © 2012 Institute of Materials, Minerals and Mining.