Nb添加对Ti基非晶合金腐蚀及力学性能的影响

摘要

为研究微量添加Nb元素对Ti40Zr10Cu34-xPd14Sn2Nbx(x为原子数分数,x=0、1％、3％、5％)非晶合金的耐腐蚀性能及力学性能的影响,本文利用动态极化曲线,分析了在0.144 mol/L的NaCl溶液及0.2 mol/L的PBS溶液中非晶合金Ti40Zr10Cu34-xPd14Sn2Nbx(x=0、1％、3％、5％)的电化学性能,并通过材料拉伸试验研究了非晶合金块状样品的室温压缩性能.结果表明:在0.144 mol/L的NaCl溶液中,非晶合金样品在阳极区出现了自发钝化的特征,钝化电流密度在10-7～10-8 A/cm2,钝化电流密度随着Nb的添加略有降低,且点蚀电位随Nb原子数分数的增加分别为200、340、400和490 mV,说明微量添加Nb元素能有效提高Ti基非晶合金的耐点蚀能力,即在0.144 mol/L的NaCl溶液中Ti基非晶合金的耐腐蚀性随着Nb含量的增加而增强;在0.2 mol/L的PBS溶液中,因磷酸根离子的缓蚀作用,Nb添加导致的成分变化对非晶合金的腐蚀行为影响不大;此外,添加了原子数分数为1％及3％Nb的非晶合金,其压缩强度及塑性变形能力变化不大,但添加5％Nb的非晶合金因较大体积分数纳米晶的存在导致其室温断裂强度及塑性变形能力有明显下降.%In this research, the effect of minor addition of Nb on the corrosion behavior and mechanical properties of Ti40Zr10Cu34-xPd14Sn2Nbx (x=0, 1 at.％, 3 at.％, 5 at.％) metallic glasses was studied. The eletrochemical properties of the metallic glasses in 0.144 mol/L NaCl and 0.2 mol/L PBS solutions were investigated by dynamic polarization curves. Results reveal that Ti-based metallic glasses were spontaneously passivated with passivated current density of about 10-7～10-8 A/cm2 in 0.144 mol/L NaCl solution. The pitting potentials were 200 mV, 340 mV, 400 mV, and 490 mV with 0, 1 at.％, 3 at.％, and 5 at.％ Nb additions, respectively, which means that the corrosion resistance of the metallic glasses was enhanced with more addition of Nb in 0.144 mol/L NaCl solution. In 0.2 mol/L PBS solution, the influence of Nb addition on the corrosion behavior of metallic glasses was not distinct because of the existence of PO43- acting as corrosion inhibitors. The compressive strength changed little by adding 1％ and 3％ Nb, but the fracture strength and the plastic deformation ability decreased significantly with 5％ Nb addition due to the existence of a large amount of nanocrystalline phases.