Strengthening Mechanisms of Ti–Mg Composite for Biomaterials: A Review

Titanium (Ti) has been widely used in biomedical implants due to its excellent mechanical properties and biocompatibility. However, the “stress shielding” effect greatly limits the application of titanium alloys in medical devices. Studies have shown that the incorporation of bioactive elements into the titanium alloy matrix is an effective way to impart specific biological functions to the material through the sustained release of biofunctional elements. Magnesium (Mg) and its alloys have good bioactivity and are potential candidates for biodegradable metal implants. Ti–Mg composites are of increasing interest for biomedical applications. However, the incompatibility between Ti and Mg, such as immiscibility and large melting point difference, has been a great obstacle in preparing Ti–Mg composites. In addition, the biocompatibility of Ti–Mg metal matrix composites in vivo still needs to be further investigated. Herein, the recent research progress of Ti–Mg composites for biomedical implants is reviewed, focusing on their preparation methods and properties. The preparation methods such as powder metallurgy technology and 3D printing are introduced in detail. In addition, the mechanical and corrosion resistance as well as biocompatibility of Ti–Mg composites are discussed. Based on this, the problems and development prospects of Ti–Mg metal matrix composites are presented.