生物可降解Mg-Zn-Zr/β-TCP复合材料组织结构及性能(英文)

Microstructure and properties of biodegradable β-TCP reinforced Mg-Zn-Zr composites

镁合金具有优异的生物相容性,但在生理环境中过快的腐蚀降解速率制约其成为可降解植入材料。此外,镁合金的力学性能也较低。通过添加纳米β-TCP颗粒来改善Mg-Zn-Zr合金的显微组织及性能,制备挤压态的Mg-3Zn-0.8Zr合金和Mg-3Zn-0.8Zr/xβ-TCP(x=0.5,1.0,1.5)复合材料。添加纳米β-TCP增强体的复合材料其晶粒明显细化。拉伸实验结果表明,添加β-TCP后,复合材料的极限拉伸强度和伸长率均有所提高。电化学测试结果表明,复合材料在模拟体液中的抗蚀性较合金基体显著提高,其中Mg-3Zn0.8-Zr/1.0β-TCP复合材料的腐蚀电极电位为1.547V,其腐蚀电流密度为1.20×106A/cm2.

Magnesium alloys have good biocompatibility, but their mechanical properties and corrosion resistance may not be satisfied for using as degradable materials within bone due to its high corrosion rate in the physiological environment. Nano β-TCP particles were added into Mg-Zn-Zr alloy to improve its microstructure and the properties. As-extruded Mg-3Zn-0.8Zr alloy and Mg-3Zn-0.8Zr/xβ-TCP （x=0.5%, 1.0% and 1.5%） composites were respectively fabricated. The grains of Mg-Zn-Zr/β-TCP composites were significantly refined. The results of the tensile tests indicate that the ultimate tensile strength and the elongation of composites were improved with the addition of β-TCP. The electrochemical test result in simulation body fluid shows that the corrosion resistance of the composites was strongly enhanced comparing with that of the alloy. The corrosion potential of Mg-3Zn0.8-Zr/1.0β-TCP composite is 1.547 V and its corrosion current density is 1.20×10 6 A/cm 2 .