TiNiCu形状记忆合金在人工模拟体液中的电化学性能

Electrochemical behaviors of TiNiCu shape memory alloy in physiological solution

采用电化学测试方法对TiNiCu形状记忆合金在Hank’s人工模拟体液中的电化学性能进行研究．结果表明，阳极极化时，在100～150mV电位区间出现了活性溶解．随pH的降低和Cl^-浓度升高，孔蚀电位Eb值负移，孔蚀敏感性增大，而温度对TiNiCu形状记忆合金的电化学性能影响不大．比较而言，在Hank’s人工模拟体液中，TiNiCu形状记忆合金的电化学性能比TiNi形状记忆合金劣，其原因可能是TiNiCu形状记忆合金在常温下的马氏体B19能掺杂着中间相B19，造成材料晶体结构不单一，易形成腐蚀原电池．此外，扫描电镜与X-射线分析表明，在晶界析出的Ti2Ni相及表面疏松的富Cu结构也促进了阳极活性溶解．

The corrosion behaviors of TiNiCu shape memory alloy （SMA） in Hank＇s physiological solution were studied by electrochemical measurements. The results showed that TiNiCu SMA exhibited an active anodic dissolution at the potential range of 100-150 mV vs. SCE in Hank＇ s solution. Temperature had little effect on anodic polarization. With the decrease of pH and the increase of Cl^- concentration, the breakdown potentials feb） shifted to negative. The electrochemical capability of TiNiCu SMA in Hank＇s solution was inferior to that of TiNi SMA. It could be explained that martensitic B19 phase with intermediate B19 of TiNiCu SMA at ambient temperature might cause irregular electrochemical behavior and form the original cell. Moreover, Ti2 Ni precipitate and loose structure with rich copper on the surface, which were observed by means of XRD and SEM, might accelerate the anodic dissolution.