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

摘要

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 Mg_(66)Zn_(30)Ca_(4)/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 Mg_(66)Zn_(30)Ca_(4) metallic glass(MG)as a second phase,which led to an improvement in the corrosion resistance and mechanical strength.The standard potential of Mg_(66)Zn_(30)Ca_(4)/Fe bulk metallic glass(BMG)composites increased as compared to Mg_(66)Zn_(30)Ca_(4),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 Mg_(66)Zn_(30)Ca_(4) and Mg_(66)Zn_(30)Ca_(4)/Fe did not cause cell toxicity on day 3 and 5,while the EM×6 of the Mg_(66)Zn_(30)Ca_(4) showed cytotoxicity on day 1,3 and 5.Thus,Mg_(66)Zn_(30)Ca_(4)/Fe BMG composites exhibit significant potential for fabricating implants with good mechanical strength and corrosion resistance.