Mg-Zn-Ce非晶合金力学与耐蚀性能的研究

Study on Mechanical Properties and Corrosion Resistance of Mg-Zn-Ce Amorphous Alloys

镁合金作为生物可降解材料具有很多优势,但传统多晶镁合金腐蚀速率过快的问题限制了其更广泛的应用。与多晶镁合金相比,非晶态镁合金因具有独特的无定形结构,使其耐腐蚀能力比多晶镁合金的要好。采用铜辊甩带法制备得到了新型Mg70-xZn30Cex(x=2, 4, 6和8)非晶镁合金,并对其进行了力学性能和耐腐蚀性能的研究。结果表明:x为4和6时,Mg-Zn-Ce非晶合金的非晶形成能力最好;Ce的添加可以有效改善镁基非晶合金的脆性,使其弹性模量低于60 MPa,与人骨相似,从而能有效避免植入后因弹性模量过大导致的应力遮蔽效应的产生;同时,Ce的添加显著地提高了合金的耐腐蚀性,使其开路电位达到-0.2 V,腐蚀电流密度低至10^-6 A/cm^2。

As biodegradable materials,Mg alloys show many advantages,however,the excessively fast corrosion rate of traditional polycrystalline Mg alloys limits their wide application.Compared with polycrystalline Mg alloys,amorphous Mg alloys have better corrosion resistance than that of polycrystalline Mg alloys due to the unique amorphous structure.Novel Mg70-xZn30Cex(x=2,4,6 and 8)amorphous Mg alloys were prepared by copper roll spinning method,and the mechanical properties and corrosion resistance were studied.The results show that when x is 4 and 6,the Mg-Zn-Ce amorphous alloys show the best glass formation ability.The addition of Ce can effectively reduce the brittleness of the Mg-based amorphous alloy and make the elastic modulus less than 60 GPa,which is similar to human bone.Therefore,the stress shielding effect caused by too high elastic modulus after implantation can be effectively avoided.Meanwhile,the addition of Ce significantly improves the corrosion resistance of the alloys,so the open circuit potential reaches-0.2 V and the corrosion current density is low to 10^-6 A/cm^2.