MAGNESIUM SINGLE CRYSTAL AS A BIODEGRADABLE IMPLANT MATERIAL

Pure magnesium (Mg) is a suitable candidate for medical implants due to its bio-compatibility and easy desorption in the body. Compared to polycrystalline magnesium, single crystal magnesium shows different and more controllable corrosion behavior due to absence of grain boundaries. Magnesium single crystals were grown with a purity of 99.95% using modified BridgmanStockbarger method. Disc shaped samples with dimensions 6.5 mm diameter x 2 mm thickness were prepared from as-cast Mg single crystals and were subjected to electrochemical and surface treatments using different chemical solutions. DC anodization, micro-arc oxidation and chemical etching treatments were conducted on the samples to alter their surfaces. Immersion and potentiodynamic DC polarization tests were performed to determine the approximate corrosion rate, corrosion potential (Ecorr) and corrosion current (Icorr). The obtained data was compared with in-vivo weight loss measurements after subcutaneous implantation of the disc shaped samples in mice for 8 weeks followed by extraction.