两种表面改性方法对钴-铬合金化学腐蚀行为的影响

Effects of two coatings on chemical corrosion of cobalt-chromium alloy

目的研究钴-铬合金表面镀氮化钛薄膜和镀金薄膜后对其化学腐蚀行为的影响。方法利用多弧离子镀和电镀方法分别在钴-铬合金表面沉积氮化钛和金薄膜,将两种镀膜和未镀膜试件分别浸入人工唾液,在37℃恒温下浸泡,在第30、60、90天定量取浸泡的人工唾液10 ml,采用原子吸收光谱法测定唾液中的钴离子含量,浸泡结束后,检测试件的重量变化。结果在3个时间点,镀氮化钛试件释出的钴离子量都显著小于镀金和未镀膜组,镀氮化钛组和未镀膜组试件浸泡前后的失重量显著小于镀金组。结论在钴-铬合金表面镀氮化钛膜可显著减少金属离子释出,提高其耐腐蚀性能,效果可靠,优于镀金。

Objective To investigate the effects of TiN and Au coating on chemical corrosion of Co-Cr alloy in a marination environment. Methods TiN and Au coating was prepared by multi-are ion plating and galvanization respectively. The groups of samples coated with TiN and gold film respectively were immersed into the same artificial saliva at 37 ~C for three months. During the whole immersion period, the concentration of cobalt ion in the 10 ml artificial saliva was analyzed with atomic absorption speetrophotometer after 30,60 and 90 days. Finally, the weight change of the post-immersion samples was measured. The samples without coating were used as the controls. Results In all the groups, Co ion concentration in the artificial saliva increased while the immersion continued. Co ion concentration from TiN film coated samples into the immersed artificial saliva was lower than that of other two kinds of samples after the same immersion time. The weight loss of TiN coated and uncoated samples was statistically smaller than that of the gold coated samples. Conclusion The anti-corrosion property of the Co-Cr alloy can be strengthened by TiN coating.