腐蚀降解行为
(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 中南大学 粉末冶金国家重点实验室，长沙 410083；
2. 中南大学 湘雅三医院，长沙 410013)
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1.936 g/cm3，压缩强度为339 MPa，弹性模量为24 GPa；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。
关键字: Mg-6%Zn-10%(β-Ca3(PO)4)；复合材料；腐蚀；力学性能；生物降解
Mg-6%Zn-10%(β-Ca3(PO4)2) composite
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. The Third Xiangya Hospital, Central South University, Changsha 410013, China）
Abstract: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.
Key words: Mg-6%Zn-10%(β-Ca3(PO4)2); biocomposite; corrosion; mechanical property; biodegradation
