【摘要】 采用电化学测试技术和化学浸泡试验对生物医用TiNi基形状记忆合金在生理盐水中的腐蚀行为进行了研究。结果表明,TiNi合金比TiNiCu合金阳极钝化区拓宽,孔蚀电位正移,腐蚀率减小。通过EDX分析和SEM观察发现,TiNi合金蚀孔内存在富Ti贫Ni的Ti2Ni析出相,而TiNiCu合金存在Cu原子富集的CuNi相,从而验证了这些析出相是萌生孔蚀的敏感位置。在生理盐水中TiNiCu合金的耐蚀性比TiNi合金劣,其原因是TiNiCu合金有较多的残余奥氏体及单斜和斜方的马氏体结构,存在不同晶体结构区域,造成电化学性质不均匀性,从而形成了腐蚀微电池,加速了活性溶解。更多还原

【Abstract】 The corrosion behaviors of on TiNi based shape memory alloys(SMA) in saline solution was investigated by electrochemical measurement techniques. The results show that the TiNi SMA’s passivation potential zone is wider, its pitting corrosion potential shift positively and its corrosion rate is lower than that of TiNiCu SMA. The analysis of EDX and SEM, indicat that there is a Ti2Ni precipitate phase with rich Ti and poor Ni in the corrosion hole of TiNi SMA, while there is a CuNi phase with rich Cu in the TiNi alloy,hence which prove that the precipitates are the sensitive positions that result in the pit corrosion. The corrosion resistantce of TiNiCu SMA is inferior to that of TINi SMA in saline solution. It is a mainly cause that TiNiCu SMA has retained austenite, orthorhombic and monoclinic martensitic structures, which cause irregular electrochemical behaviors and might form the corrosion original cell to accelerate the anodic dissolution.更多还原