CORROSION-RESISTANT ALLOYS IN CHLORIDE SOLUTIONS - MATERIALS FOR SURGICAL IMPLANTS
CORROSION-RESISTANT ALLOYS IN CHLORIDE SOLUTIONS - MATERIALS FOR SURGICAL IMPLANTS
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DOI：
10.1098/rspa.1966.0220
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发表时间：
1966-01-01
影响因子：
--
通讯作者：
MEARS, DC
中科院分区：
文献类型：
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作者：
HOAR, TP;MEARS, DC
许多耐腐蚀合金在氯化物溶液、汉克斯生理溶液（模拟细胞外体液）和外科植入物中的行为已经通过电化学手段进行了研究，即孤立标本的电位-时间曲线、阳极的电位-电流密度曲线和以电子方式保持恒定电位的阳极的电流密度-时间曲线。显微观察了点蚀攻击过程。以铁（如不锈钢）、镍（如铬镍铁合金、镍镍合金等）、钴（钽）、钛和钽为基础的合金暴露在氯化物溶液中，都表现出一定范围的钝化电位，并且在足够高的氯化物浓度和足够的正电位下，击穿产生电光亮的凹坑。这种普遍现象发生在0.17 m氯化钠溶液中，在0.2至0.5 V（正常氢标度）下，不锈钢，ca。钴基合金为0.9 V；某些钛合金和钽的电压为20 ~ 30v。在钝化范围内，所有合金的阳极电流密度都在10-6到10-9A/cm2之间，大多数钝化合金（如钛- 5%铌）的电流密度越小，随着时间的推移，电流密度往往会进一步降低。我们的结论是，不锈钢（即使是高铬镍质量的）和镍合金在无限期地暴露于体液（或其他含氯化物的介质）时，不太可能通过点蚀来抵抗所有的破坏；钴基合金可以很好地承受这种暴露很长时间；而且钛和（尤其是）它的一些合金应该能无限期地承受这样的暴露。钴和钛进入环境的（极其缓慢的）通道是由阳离子通过它们的钝化氧化膜而不被击穿引起的。
The behaviour of a number of corrosion-resistant alloys in chloride solutions, in Hanks’s physiological solution (simulating the extracellular body fluids) and as surgical implants has been investigated by electrochemical means, namely potential-time curves for isolated specimens, potential-current density curves for anodes, and current density-time curves for anodes maintained electronically at constant potential. Microscopical observation of pitting attack has also been made. Alloys based on iron (e. g. stainless steels), nickel (e. g. Inconel, Nimonic 75, etc.), cobalt (Vitallium), titanium and tantalum exposed to chloride solutions all show a range of potential in which they are passive, and, at sufficiently high chloride concentration and sufficiently positive potential, breakdown giving rise to pits that are electrobrightened. This general phenomenon occurs, in 0·17M sodium chloride solution, at 0·2 to 0·5 V (normal hydrogen scale) for stainless steels,ca. 0·9 V for the cobalt·based alloys, andca. 20 to 30 V for certain titanium alloys and tantalum. In the passive range, all the alloys show anode current densities in the range 10-6to below 10-9A/cm2, the smaller current densities given by the most passive alloys (e. g. titanium-5 % niobium) often tending to decrease yet further with passage of time. We conclude that stainless steels (even of the higher chromium-nickel quality) and nickel alloys are unlikely to resist all breakdown by pitting when exposed to the body fluids (or other media containing chloride) indefinitely; that the cobalt-based alloys may well withstand such exposure for very long times; and that titanium and (especially) some of its alloys should withstand such exposure for an indefinite period. The (extremely slow) passage of cobalt and titanium into the environment is caused by passage of cations through their passivating oxide films, without breakdown.