Effects of carbon coupling on thein vitro corrosion of cast surgical cobalt-base alloy
✍ Scribed by Buchanan, R. A. ;Lemons, J. E. ;Griffin, C. D. ;Thompson, N. G. ;Lucas, L. C.
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- English
- Weight
- 201 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0021-9304
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✦ Synopsis
Investigations describing the galvanic corrosion effects when either the low-temperature isotropic &TI) or vapor-deposited forms of carbon are coupled to surgical-grade type 316L stainless steel or Ti-6Al-4V alloy have been presented.' Questions regarding the possibly deleterious effects of carbon coupled to surgical grade Co-base alloys continue. This paper addresses the questions by presenting the results of an in vitro electrochemical study of the carbon / Co-base-alloy system.
Advantages of carbon as a synthetic biomaterial have been proposed by several investigators.2,3 Although carbon is an inert material per se, it is an electrical conductor and a very noble material electrochemically. The latter characteristics suggest that if carbon were in contact with a metal in the physiological environment, the carbon could accelerate the metallic corrosion through a galvanic coupling mechanism. Such concerns become relevant when considering a number of possible design applications, e.g., metallic hip prostheses with components coated with carbon, carbon coated metallic heart valves, or carbon dental implants with metallic cores.
In this study, cathodic polarization curves were determined for Low-Temperature Isotropic (LTI) pyrolytic carbont and vapor-deposited carbon?, while both anodic and cathodic polarization curves were determined for ASTM F75 cast surgical Co-base alloy.* The electrochemical cell, the isotonic saline electrolyte at 37"C, the potentiostatic circuit, and the experimental methods employed were identical to those previously described.' The surface preparations of the materials prior to testing were also as previously described. The carbon samples were cleaned in detergent and rinsed with distilled water, whereas the * The following paper supplements the work of Thompson, Buchanan, and Lemons as reported in