SLM钴铬合金在含氟人工唾液中的电化学耐腐蚀性能研究

目的通过电化学阻抗谱方法研究选择性激光熔覆（Selective laser melting,SLM）技术制作的钴铬合金在含氟人工唾液中的耐腐蚀性能。方法运用SLM技术和传统铸造（CAST）技术,使用相同成分的钴铬合金,分别制作40个直径10mm×3mm厚度的圆柱形试件。在p H值为2.5和5.0,含氟浓度为0.00%、0.05%、0.1%和0.2%的人工唾液中,利用电化学阻抗谱检测2种加工方法制作的钴铬合金的耐腐蚀性能。结果当p H=5.0时,Na F 0.1%环境下SLM组和CAST组Rp值分别为3.49±0.44和1.59±0.88;Na F 0.2%环境下SLM组和CAST组Rp值分别为5.30±3.29和1.71±1.10。当p H=2.5时,Na F0.00%环境下SLM组和CAST组Rp值分别为6.40±0.26和2.05±0.35;Na F0.05%环境下SLM组和CAST组Rp值分别为5.67±0.25和1.15±0.83;Na F0.1%环境下SLM组和CAST组Rp值分别为4.74±0.50和0.24±0.10;Na F0.2%环境下SLM组和CAST组Rp值分别为4.76±0.97和0.30±0.09。在以上各实验条件下,SLM组和CAST组之间的表面氧化层电阻Rp值差异均具有统计学意义（P〈0.05）。结论 SLM技术制作的钴铬合金耐腐蚀性能优于铸造组。

Study of electrochemical-corrosion behavior of SLM cobalt-chromium alloy in the artificial saliva solution containing fluoride

Objective To study the corrosion behavior of a SLM cobalt-chromium alloy in the artificial saliva solution containing fluoride by electrochemical impedance spectroscopy method. Methods 40 cyindrical specimens of 10 mm diameter and 3mm thickness were fabricated with the same Co-Cr alloy by SLM and the traditional casting technology（CAST）. The corrosion behavior of these specimens were tested in a fluoride（0.00%、0.05%、0.1% and 0.2%） containing artificial saliva solutions at PH 2.5 and 5.0. Results In the p H 5.0 of artificial saliva containing 0.1% Na F, the Rp values of SLM and CAST groups were respectively 3.49±0.44 and 1.59±0.88, and in the case of 0.2% Na F, the Rp values of SLM and CAST groups were respectively 5.30±3.29 and 1.71±1.10. In the p H 2.5 of artificial saliva containing 0.00% Na F, the Rp values of SLM and CAST groups were respectively 6.40±0.26 and 2.05±0.35, and in the case of 0.05% Na F, the Rp values of SLM and CAST groups were respectively 5.67±0.25 and 1.15±0.83, in the case of 0.1% Na F, the Rp values of SLM and CAST groups were respectively 4.74±0.50 and 0.24±0.10;in the case of 0.2% Na F, the Rp values of SLM and CAST groups were respectively 4.76±0.97 and 0.30±0.09. At the above exprimental conditions, there was significantly statistical difference on the Rp value between the two groups（P〈0.05）. Conclusion The SLM Co-Cr alloy has better corrosion behavior than the cast Co-Cr alloy under a fluoride containing oral environment.