Stent Galvanic Corrosion Testing: Measured parameters
- Rest potential before and after the experiments
- Galvanic current (in A) and galvanic corrosion evolution in function of time
- Corrosion rate using equation (mm/year)
Stent Galvanic Corrosion Testing: Scope
- Stent Corrosion Testing
- Device with different type of metals (for example a base stent material with added marker bands)
Stent Galvanic Corrosion Testing: Applicable standards
- ASTM G71-81: STANDARD GUIDE FOR CONDUCTING AND EVALUATING GALVANIC CORROSION TESTS IN ELECTROLYTES
- ASTM F2129: STANDARD TEST METHOD FOR CONDUCTING CYCLIC POTENTIODYNAMIC POLARIZATION MEASUREMENTS TO DETERMINE THE CORROSION SUSCEPTIBILITY OF SMALL IMPLANT DEVICES
Stent Galvanic Corrosion Testing: Associated tests
Stent Galvanic Corrosion: Test Method Description
Test specimens should be electrically joined before exposure. External electrical connection should be employed such as to allow current measurement. The coupled assembly is next immersed in the test electrolyte for the period of exposure. Data recorded during exposures may include galvanic current measurements and couple and control specimen potentials measured relative to a suitable reference.
Data are converted into corrosion rate in penetration per unit time (for example, millimetres per year). Rates for both control (uncoupled) and coupled samples should be reported, with the change in rate due to the coupling reported as either the difference between control and coupled samples or as the coupled rate divided by the control rate (acceleration factor).
If required, an optical microscopic metallographic inspection of the sample at the end of the corrosion test and a final SEM inspection could be performed to detect any localized corrosion phenomenon.