Hank's人工模拟体液中离子注氮对4种植入金属材料腐蚀行为的影响

Effect of Nitrogen-ion Implantation on the Corrosion Behavior of Surgical Materials in Hanks Simulated Body Fluid

采用电化学测试技术研究了离子注氮对SUS316L不锈钢,Co-Cr合金,工业纯钛和Ti-6Al-4V植入合金在Hanks人工模拟体液中腐蚀行为的影响。腐蚀电位和极化曲线的测量结果表明,注氮使4种植入金属材料的腐蚀电位正移,钝化电位区间扩大,耐蚀性明显提高。注氮的工业纯钛和Ti-6Al-4V合金的耐蚀性最佳,其钝化区拓宽为4V以上。通过AES分析发现,离子注氮后钛及其合金表面形成的氮化钛膜层及弥散的氮化钛析出相的化学效应,使基体电化学性能得到提高。注氮的Co-Cr合金的耐蚀性略优于SUS316L不锈钢。Co-Cr合金表面形成的钴氮化合物相对基体起到保护作用,降低了腐蚀速率。SUS316L不锈钢表面形成铁和铬氮化合物膜,有效地阻止了Cr3+的水解,且氮离子注入促进Fe3O4的产生,提高了耐腐蚀性能。

Effect of nitrogen(N)ion implantation on the corrosion behavior of surgical materials,such as SUS316L stainless steel,Co Cr alloy, commercially pure titanium and Ti 6Al 4V alloy,have been investigated in Hanks simulated body fluid by electrochemical technology.The results show that after N ion implanting the anti corrosion properties of the surgical materials are improved significantly due to the corrosion potential shifting positively and the passivation area extending.Among the four surgical materials studied, commercially pure titanium and Ti 6Al 4V responded most strongly to N ion implantation. Analysis using AES indicated that in response to N ion implantation the resulting TiN film and TiN dispersed phases on the alloy surface isolate the matrix from the environment and improved the electrochemical behavior of the material. After nitriding the corrosion resistance of the Co Cr alloy is better than that of SUS316L due to the appearance of cobalt and chromium nitrides on the surface that protect the matrix and reduce the corrosion rate. As for SUS316L stainless steel,the surface was coated with iron and chromium nitrides which could prevent the Cr+from hydrolyzing and increases the formation of Fe3O4,which plays an important role in protecting the matrix.