Composite of Magnesium and Carbonate Apatite for Biodegradable Bone Implants: A Comparative Study on Sintering and Extrusion Techniques

Abstract

Developing biodegradable bone implants using magnesium-based materials has garnered significant attention in research. Magnesium offers favorable properties, such as low density, biocompatibility, elastic modulus like bone, and high toxicity limits. However, improvements are needed in mechanical properties and degradation rate. This study focuses on enhancing these properties by developing a novel composite of magnesium with carbonate apatite (CA) reinforcement, Mg/5CA. Compared to hydroxyapatite (HA), CA offers better absorption and avoids fibrotic tissue formation. However, CA undergoes carbonate decomposition during sintering, leading to composite degradation. To address this, an extrusion process is employed to prevent carbonate decomposition. The advanced sintering and extrusion compaction processes are compared for the Mg/5CA composite, examining density, microstructure, hardness, compressive strength, and biocorrosion. Results demonstrate that extrusion increases relative density while CA slightly reduces it. Microstructural analysis reveals finer and elongated grains, tighter bonding between CA and Mg particles, and reduced microporosity in the extruded composite. Mechanical properties, including hardness distribution and compressive strength, are improved in the extruded composite, and the degradation rate decreases compared to sintering. Overall, the extrusion process effectively enhances Mg/5CA composite properties, positioning it as a promising manufacturing technique for biodegradable implant materials. This research contributes to the development of advanced biodegradable implants, which can have significant applications in the field of medical science. Further investigations in this area can contribute to the ongoing advancements in biodegradable implant technology.