Mg-6％Zn-10％(β-Ca3(PO4)2)复合材料的制备及腐蚀降解行为

摘要

以Mg-6％Zn合金为基体、β-Ca3(PO4)2为强化相,采用粉末冶金工艺制备Mg-6％Zn-10％(β-Ca3(PO4)2)复合材料.利用光学显微镜观察复合材料的显微组织,采用X射线衍射仪分析相组成,采用压缩试验评估复合材料力学性能,采用动电位极化法和浸泡实验研究复合材料在模拟体液(SBF)中的腐蚀行为.结果表明:β-Ca3(PO4)2在烧结过程中与基体合金没有发生明显反应；复合材料密度为1.936g/cm3,压缩强度为339 MPa,弹性模量为24GPa;添加β-Ca3(PO4)2可降低Mg-6％Zn在SBF中的腐蚀速度；Mg-6％Zn-10％(β-Ca3(PO4)2)复合材料在SBF中的电化学腐蚀速度为2.277 mm/y,浸泡30 d的浸泡腐蚀速度为2.133 mm/y,SBF的pH值随着浸泡时间的延长而上升,最终稳定在10.%Using Mg-6%Zn as the matrix and β-Ca3(PO4)2 as reinforcement, the Mg-6%Zn-10%(β-Ca3(PO4)2) bio-composite was fabricated by the powder metallurgy method. The microstructure of Mg-6%Zn-10%(β- Ca3(PO4)2) biocomposite was observed by optical microscopy and the phases were analyzed by X-ray diffractometry. The mechanical properties were evaluated by compression tests. The corrosion behavior of the bio-composite in simulated body fluid (SBF) was studied by potentiodynamic polarization and immersion tests. The results show that the reaction between β-Ca3(PO4)2 particles and Mg-6%Zn matrix during sintering is not observed. The density of the biocomposite is 1.936 g/cm3, the compression strength is 339 Mpa and the elastic modulus is 24 Gpa. The additive of β-Ca3(PO4)2 reduces the corrosion rate of Mg-6%Zn. The electrochemical corrosion rate of Mg-6%Zn-10%(β-Ca3(PO4)2) is 2.277 mm/y, and the calculated corrosion rate of the biocomposite immersed in SBF for 30 d is 2.133 mm/y. During the immersion test, the pH value of SBF increases gradually, and at last stabilizes at 10.