Mechanical properties and corrosion resistance of powder metallurgical Mg-Zn-Ca/Fe bulk metal glass composites for biomedical application

Abstract

Magnesium (Mg) alloys can be regarded as the most promising biodegradable implant materials for orthopedic and stent applications due to their good biocompatibility and low Young's modulus which is near to that of natural bone. However, its applicability is hindered because it exhibits a high corrosion rate in the physiological environments. In this work, we fabricated Mg66Zn30Ca4/Fe bulk metallic glass composites via spark plasma sintering (SPS). We studied the influence of different contents of Fe on the properties of the composites. The results indicated that Fe was uniformly distributed on the surface of Mg66Zn30Ca4 metallic glass (MG) as a second phase, which led to an improvement in the corrosion resistance and mechanical strength. The standard potential of Mg66Zn30Ca4/Fe bulk metallic glass (BMG) composites increased as compared to Mg66Zn30Ca4, while their mechanical strength improved from 355 MPa to 616 MPa. Furthermore, cytotoxicity was investigated via the CCK-8 assay and calcein-AM staining, which revealed that the extraction mediums diluted 6 times (EM × 6) of the Mg66Zn30Ca4 and Mg66Zn30Ca4/Fe did not cause cell toxicity on day 3 and 5, while the EM × 6 of the Mg66Zn30Ca4 showed cytotoxicity on day 1, 3 and 5. Thus, Mg66Zn30Ca4/Fe BMG composites exhibit significant potential for fabricating implants with good mechanical strength and corrosion resistance.