Micro-Nano Structure On The Surface Of A Zr-Based Bulk Metallic Glass Is Prepared And Its Biocompatibility

Zr-based bulk metallic glass(BMG)alloys have shown broad development in biomedical materials due to their excellent properties.However,the surface of untreated Zr-based BMG is biologically inert,and it is difficult to form a bone bond with target tissues after implantation in the body.In this study,the easily prepared and representative Zr₅₀Cu₂₁Ni₁₃Al₈Ti₈ BMG was used as the modified object.Zr-based BMG alloy was modified by electrochemical dealloying in NaF-HCl and choline chloride-thiourea.The micro-nano 3D porous structure is constructed in-situ on the surface of the Zr-based BMG to reduce the biological inertness.In the NaF-HCl,a 3D porous structure was successfully prepared on the surface of the Zr-based BMG,and the pore size of the porous structure prepared under the optimal conditions was 200-700 nm.By studying the passivation and element dissolution of Zr-based BMG,it is found that the addition of F^-strengthens the selective dissolution of Zr-based BMG.The focus is on the phase change of Zr-based BMG and the formation mechanism of porous structure.The results show that the main elements dissolved in the dealloying process are Zr,Al,Ti,and the main phases on the surface are still amorphous,forming Cu₁₀Zr₇,Al Ti₃,Zr₂Ni₇.The electrochemical dealloying process of this system can be divided into two stages:the initial stage is dominated by Cl^-,and the second stage is dominated by F^-.In the choline chloride-thiourea,a 3D porous structure was successfully prepared on the surface of the Zr-based BMG,and the pore size of the porous structure prepared under the optimal conditions was 20-180 nm.The focus is on the phase change of Zr-based BMG and the formation mechanism of porous structure.The results show that the main elements dissolved in the dealloying process are Cu and Al,and the main phases on the surface are still amorphous,forming Ni Zr₂,Al₃Ti,Cu Zr₂.The electrochemical dealloying process of this system is dominated by the pitting corrosion of Cl^-.The biomineralization activity of electrochemical-dealloyed Zr-based BMG in the two systems was evaluated in simulated body fluids.The results showed that the electrochemical dealloyed Zr-based BMG were compared with untreated Zr-based BMG.In comparison,its biomineralization activity is significantly improved.