Measurement of the Degradation Rate of Anodized AZ91 Magnesium Temporary Implants Using Digital Image Processing Techniques

BUCHELLY IMBACHÍ, FRANCISCO; BALLARRE, JOSEFINA; BUCHELLY IMBACHÍ, FRANCISCO; BALLARRE, JOSEFINA; CERE, SILVIA; PASTORE, JUAN IGNACIO; CERE, SILVIA; PASTORE, JUAN IGNACIO; GOMEZ, MARTINA; BALLARIN, VIRGINIA LAURA; GOMEZ, MARTINA; BALLARIN, VIRGINIA LAURA

IFMBE PROCEEDINGS

Springer

Año: 2019 vol. 75 p. 290 - 297

1680-0737

To be used as intracorporeal temporary orthopedic biomaterial,magnesium alloys have to be biocompatible but also to have an adequate andcontrolled corrosion rate. It means that its degradation accompanies the formationof bone tissue since it is expected that the material maintains itsmechanical properties until it fulfills its function and then degrades in the body.The degradation of AZ91 magnesium alloy generates the release of hydrogengas. It is important to quantify the hydrogen evolution since it is directly relatedto the Mg corrosion rate. Hydrogen evolution can be experimentally quantifiedwith high associated errors. Digital image processing tools allow the evaluationframe by frame of the hydrogen release from the surface. In this work, weperformed a set of digital image processing operations to determine the gasgeneration rate in the surface of metallic pieces of AZ91 magnesium alloy withand without a surface oxidation process, captured from an optical microscopycamera. The proposed approach detected gas bubbles in a region of interest andthen it measured the present volume in each frame of the video sequence.Surface oxidized AZ91 samples showed a slow rate of hydrogen release at shortimmersion times, showing a retarding in corrosion or degradation of the sampleat early times.