|About this Abstract
|2022 TMS Annual Meeting & Exhibition
|NOW ON-DEMAND ONLY – E-19: Effect of ECAP on Corrosion Properties of ZK40 Magnesium Alloy for Biodegradable Load-bearing Applications
|Hamza Ghauri, Marwa AbdelGawad, Matthew Vaughan, Bilal Mansoor, Ibrahim Karaman, Hans Jürgen Maier
|On-Site Speaker (Planned)
Equal channel angular extrusion was employed on Mg-4%Zn-0.5%Zr (ZK40) to explore its potential for biodegradable orthopedic applications. The as-extruded and heat-treated starting material displayed inhomogeneous microstructure while after ECAP by 4Bc, significant grain refinement and precipitate modifications resulted in a relatively more homogenous microstructure. Preliminary investigations of time-dependent EIS plots and corroded surface morphologies revealed evidence of galvanic couples between populations of grains with different grain sizes as well as the grain matrix and the precipitates. The ultra fine-grained structure was also found to reduce the overall corrosion resistance of ZK40 indicating an underlying contributing factor which was linked to the composition and integrity of the developing surface film. Cross-section SEM images and X-ray photoelectron spectroscopy (XPS) results revealed a more compact and thicker surface film on pre-ECAP ZK40 despite having an inhomogeneous microstructure, in addition to evidence of the disassociation of Zr from the matrix into the surface film.
|Magnesium, Biomaterials, Other