Thompson N G, Buchanan R A, Lemons J E
J Biomed Mater Res. 1979 Jan;13(1):35-44. doi: 10.1002/jbm.820130106.
In vitro corrosion experiments were conducted employing potentiostatic polarization techniques, a saline environment and candidate biomaterial alloy/carbon combinations. Corrosion currents and potentials of carbon/metal couples were predicted by mixed-potential theory utilizing the polarization curves generated. The alloys examined were annealed ELI grade Ti-6A1-4V and cold-worked 316L stainless steel while the types of carbon examined were LTI pyrolytic carbon and vapor-deposited carbon. It was determined that galvanic couples of carbon to cold-worked 316L stainless steel with carbon/metal area ratios of 10:1 to 100:1 produced coupled corrosion potentials in the range of the observed breakdown potential of the stainless steel. It was therefore predicted that localized corrosion in the form of pitting could occur on the cold-worked stainless steel when coupled to carbon with area ratios of 10:1 or greater. The titanium alloy did not exhibit a breakdown potential up to a potential of 1.2 V. Therefore, accelerated corrosion was not predicted for the titanium alloy to carbon galvanic couples under these experimental conditions. Direct carbon/alloy coupling experiments were conducted to verify the corrosion currents and potentials predicted from mixed-potential theory and polarization curve analysis. The experimental and theoretical values showed good agreement.
采用恒电位极化技术、盐水环境和候选生物材料合金/碳组合进行了体外腐蚀实验。利用所生成的极化曲线，通过混合电位理论预测碳/金属偶对的腐蚀电流和电位。所检测的合金为退火的超低间隙（ELI）级Ti-6Al-4V和冷加工的316L不锈钢，所检测的碳类型为低温各向同性（LTI）热解碳和气相沉积碳。结果表明，碳与冷加工316L不锈钢形成的电偶对，碳/金属面积比为10:1至100:1时，产生的耦合腐蚀电位在不锈钢观察到的击穿电位范围内。因此预测，当与碳面积比为10:1或更大时，冷加工不锈钢上可能会出现点蚀形式的局部腐蚀。钛合金在高达1.2V的电位下未表现出击穿电位。因此，在这些实验条件下，预计钛合金与碳的电偶对不会加速腐蚀。进行了直接碳/合金耦合实验，以验证混合电位理论和极化曲线分析预测的腐蚀电流和电位。实验值与理论值吻合良好。
