TiN/Ti纳米涂层修饰镍钛合金的体外腐蚀行为

In vitro corrosion behavior of nano-multilayered TiN/Ti coated NiTi alloy

背景:拥有超弹性、形状记忆效应及良好抗疲劳性能的镍钛合金成为封堵器支架核心部分的最佳选择,但镍钛合金含50%的镍元素,其生物相容性仍有争议。目的:通过体外浸泡实验和电化学实验测试用于治疗先天性心脏病的封堵器镍钛合金多弧离子镀改性前后的抗腐蚀性能。方法:利用多弧离子镀在镍钛合金表面形成具有纳米梯度的TiN/Ti多层薄膜,通过镍钛合金在PBS中静态浸泡1个月,检测镍离子浓度;采用开路电位-时间曲线和极化曲线观察镀膜前后镍钛合金抗腐蚀性能。结果与结论:在PBS静态浸泡中镍钛合金在1个月时释放量达到顶峰,而经过多弧离子镀改性后的镍钛合金没有镍离子的释放。开路电位-时间曲线和极化曲线表明改性后的镍钛合金的抗腐蚀性得到了很大提高。

BACKGROUND： A nickel-titanium alloy with super-elastic, shape memory effect and good fatigue resistance has become the optimal choice for the core component of occluder stent, but the nickel-titanium alloy containing 50% nickel has a controversial biocompatibility. OBJECTIVE： To study anti-corrosion property of occluder nickel-titanium alloy before and after multi-arc ion plating by static immersion in vitro and electrochemical methods. METHODS： Nano-gradient TiN/Ti multilayered films had been fabricated on nickel-titanium alloy by multi-arc ion plating. Nickel ion concentration was investigated by static immersion in PBS for one month. The anti-corrosion property of nickel-titanium alloy before and after surface modification was measured by open circuit potential-time curve and polarization curve. RESULTS AND CONCLUSION： Nickel-titanium alloy had been released and reached the maximum values during one-month immersion period, while no nickel ion was found released from the TiN/Ti multilayered coated NiTi alloy. Open circuit potential-time curves and polarization curves show that the corrosion resistance of nickel-titanium alloy has been greatly improved after modification.