Mg-Gd-Dy-Zr医用镁合金的组织与性能

Microstructure and Properties of Mg-Gd-Dy-Zr Biomedical Magnesium Alloys

通过纯净化冶炼技术制备了Mg-2.58Gd-1.32Dy-0.12Zr和Mg-10.94Gd-4.98Dy-0.13Zr镁合金。采用X射线衍射仪、金相显微镜、扫描电镜、显微硬度计和万能试验机研究了合金的组织和力学性能,采用pH值评价合金在模拟体液中的耐腐蚀性能,采用合金与血液直接接触法测试材料的溶血率,使用MTT法测试材料的细胞毒性。结果表明,铸态Mg-2.58Gd-1.32Dy-0.12Zr的微观组织仅含有α-Mg相,而Mg-10.94Gd-4.98Dy-0.13Zr的微观组织由α-Mg基体和少量Mg5RE第二相组成;Mg-10.94Gd-4.98Dy-0.13Zr合金的力学性能均高于Mg-2.58Gd-1.32Dy-0.12Zr合金,但是耐腐蚀性低于后者。另外,Mg-2.58Gd-1.32Dy-0.12Zr和Mg-10.94Gd-4.98Dy-0.13Zr合金的溶血率均低于5%,不会引起溶血现象;细胞毒性为1级,无细胞毒性。

Mg-2.58 Gd-1.32 Dy-0.12 Zr and Mg-10.94 Gd-4.98 Dy-0.13 Zr(mass fraction)alloys were prepared by pure purification and smelting technology.The phase constituent and microstructure,microhardness,room temperature tensile and compressive performance of as-cast alloys prepared were analyzed by X-ray diffraction,metallographic microscope and scanning electron microscope,micro hardness tester as well as universal testing machine.In addition,the pH value was measured to evaluate the corrosion resistance of alloys in simulated body fluids,and the blood compatibility of alloys were investigated by hemolysis test,meanwhile,cytotoxicity of alloys was determined by MTT method.The results reveal that the microstructure of as-cast Mg-2.58 Gd-1.32 Dy-0.12 Zr is composed of onlyα-Mg phase,while the microstructure of Mg-10.94 Gd-4.98 Dy-0.13 Zr alloy is composed ofα-Mg matrix and a small amount of Mg5 RE second phase.The microhardness,tensile strength and compressive strength of the as-cast Mg-10.94 Gd-4.98 Dy-0.13 Zr alloy are superior to those of the Mg-2.58 Gd-1.32 Dy-0.12 Zr alloy.The corrosion resistance of as-cast Mg-2.58 Gd-1.32 Dy-0.12 Zr alloy is better than that of Mg-10.94 Gd-4.98 Dy-0.13 Zr alloy.The hemolysis rates of Mg-2.58 Gd-1.32 Dy-0.12 Zr and Mg-10.94 Gd-4.98 Dy-0.13 Zr are lower than5%,which dosen’t cause hemolysis.The cytotoxicity of Mg-2.58 Gd-1.32 Dy-0.12 Zr and Mg-10.94 Gd-4.98 Dy-0.13 Zr reach level 1,presenting cytotoxicity-free.