表面改性SUS316L不锈钢的电化学行为研究

分别以表面镀Rh,表面离子束增强沉积Ta2O5膜及溶胶凝胶法沉积TiO2膜对冠状动脉支架用材料SUS316L不锈钢进行表面改性.采用电化学方法研究了该表面改性试样在Tyrode's模拟人工体液中的电化学行为.结果表明,上述3种表面改性方法均可提高SUS316L不锈钢在模拟人工体液中的阳极极化性能.其中对于采用离子束增强法沉积的Ta2O5膜和溶胶凝胶法沉积的TiO2膜,因Ta和Ti上的d轨道空位已被氧的电子占据,不利于氢吸附,从而抑制了阴极的析氢过程.X射线衍射分析发现,3种改性方法在SUS316L不锈钢表面依次形成均匀而致密的Rh金属层,Ta2O5的无序膜层和TiO2晶态膜层,阻止了合金元素的溶解,改善不锈钢的电化学性能.

Study on Electrochemical Behavior of SUS316L Stainless Steel After Surface Modification

The surface modification for SUS316L stainless steel was carried out by electroplating Rh, ion beam assisted deposition Ta2O5 and sol_gel_derived TiO2. In Tyrode's stimulated body fluid, the surface modified samples had been investigated with electrochemical techniques. The results indicated that the electrochemical stability and dissolution were improved significantly after surface modification.Moreover, as to ion beam assisted deposition Ta2O5 and Sol_gel_derived TiO2 film, the metal's d orbit electron holes filled up by the oxygen electrons made against the adsorption of hydrogen. Thus the cathode process, which is controlled by the hydrogen reduction,was held back. X_ray diffraction analysis of SUS316L stainless steel after surface modification revealed that each method formed the uniform and compact film on SUS316L stainless steel. These films also prevented dissolving of elements and improved the electrochemical behavior of the SUS316L stainless steel.