Corrosion and in vitro cytocompatibility investigation on the designed Mg-Zn-Ag metallic glasses for biomedical application

In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(XRD)analyses indicate the metallic glasses with three composition of Mg_(73)Zn_(23)Ag_(4),Mg_(70)Zn_(26)Ag_(4),and Mg_(67)Zn_(29)Ag_(4)were obtained successfully.The differential scanning calorimetry(DSC)measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis.The maximum glass transition temperature(Trg)was found to be 0.525 with a composition close to Mg_(67)Zn_(29)Ag_(4),which results in the best glass-forming ability.Moreover,the immersion test in simulated body fluid(SBF)demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses.The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content.The sample Mg_(67)Zn_(29)Ag_(4)has the lowest corrosion rate of 0.19mm/yr,which could meet the clinical application requirement well.The in vitro cell experiments show that the Madin-Darby canine kidney(MDCK)cells cultured in sample Mg_(67)Zn_(29)Ag_(4)and its extraction medium have higher activity.However,the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma(RD)tumor cells.The present investigations on the glass-forming ability,corrosion behavior,cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.

Experimental measurement on the phase equilibria of the Mg-Ag-Cu ternary system at 350℃and 400℃

The phase equilibria of the Mg–Ag–Cu ternary system at 350℃and 400℃were experimentally investigated using twenty-eight key samples.The phase equilibria and compositions in key samples were investigated using scanning electron microscopy(SEM)equipped with energydispersive spectroscopy(EDS).Powder X-ray diffraction(XRD)technique was used to analyze the crystal structure and solid solubility of compounds.Five three-phase equilibria and several two-phase equilibria have been determined at 350℃and 400℃.The solid solubility range of Cu in the compounds Mg_(3)Ag,MgAg and fcc(Ag)were examined at 350℃and 400℃.The maximum solid solubility of Ag in the compound MgCu_(2)was found to be 11.46 at.%and 11.25 at.%with a constant value of about 66 at.%Cu at 350℃and 400℃,respectively.Besides,the solid solubility limits of Ag in the compounds Mg_(2)Cu and fcc(Cu)were found to be less than 5 at.%at 350℃and 400℃.No ternary compound was observed in the present work.