Cerium Oxides for Corrosion Protection of AZ91D Mg Alloy

Abstract

Magnesium (Mg) and its alloys have grabbed the interest of material scientists as potential candidates for temporary medical implant applications. Excellent biocompatibility, non-toxicity, and mechanical properties close to natural human bone are the attractive properties which made Mg as the best choice for developing degradable implants for orthopedic and cardiovascular implants. However, uncontrolled rapid degradation in physiological environment is a limitation with Mg that restricts the straight usage of Mg in medical applications. Several strategies such as adding different alloying elements to Mg, producing Mg-based composites, providing surface coatings and microstructural modifications have been adopted to tailor Mg for medical applications. Different Mg based composites were developed through several liquid state and solid state processing routes. The properties and suitability of these composites as biomaterials have been investigated for the past two decades. The degradation behavior of the composites in the presence of physiological environment and fundamental scientific knowledge necessarily required for qualifying these materials for biomaterial applications has been sufficiently acquired and validated by several studies. The present article provides a comprehensive summary of developing Mg-based composites for temporary degradable orthopedic implant applications particularly hydroxyapatite-reinforced Mg composites. Additionally, different processing routes adopted to develop these composites and their merits are briefly discussed. Furthermore, presents the challenges and future perspectives in the context of material development.