Xiaoming Yu

Study on microstructure and properties of extruded Mg-2Nd-0.2Zn alloy as potential biodegradable implant material.

Mg-2Nd-0.2Zn (NZ20) alloy was prepared for the application as biodegradable implant material in this study. The effects of the extrusion process on microstructure, mechanical and corrosion properties of the alloy were investigated. The as-cast alloy was composed of α-Mg matrix and Mg12Nd eutectic compound. The solution treatment could lead to the Mg12Nd phase dissolution and the grain coarsening. The alloy (E1) preheated at 380°C for 1h and extruded at 390°C presents fine grains with amounts of tiny Mg12Nd particles uniformly dispersed throughout the boundaries and the interior of the grains. The alloy (E2) preheated at 480°C for 1h and extruded at 500°C exhibits relatively larger grains with few nano-scale Mg12Nd phase particles dispersed. The alloy of E1, compared with E2, showed relatively lower corrosion rate, higher yield strength and slightly lower elongation.

Biodegradable Metals for Orthopedic Applications

A new round of studies on biodegradable metals from the end of last century has made remarkable progress as magnesium based alloys are now represented in orthopedic implants. The development is introduced in this chapter, including the degradation mechanism and its affecting factors, its bio-functions (promoting osteogenesis, antimicrobial and inhibiting tumor cell survival) and its orthopedic applications (bone fixation, bone substitute, osteomyelitis and Mg coating on bio-inert materials).

Mechanical properties of magnesium alloys for medical application: A review

Magnesium alloys as a class of biodegradable metals have great potential to be used as implant materials, which attract much attention. In this review, the mechanical properties of magnesium alloys for medical applications are summarized. The methods to improve the mechanical properties of biodegradable magnesium alloys and the mechanical behaviors of Mg alloys in biomedical application are illustrated. Finally the challenges and future development of biodegradable magnesium alloys are presented.

Biofunctional Mg coating on PEEK for improving bioactivity

High purity Mg was successfully coated on polyetheretherketone (PEEK) by vapor deposition method in order to improve the bioactivity including antibacterial property of PEEK implant. The morphology and elemental composition of the coating were characterized by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), showing that the coating was mainly composed of Mg at deposition temperature of 175u202f°C, 185u202f°C, 200u202f°C and 230u202f°C. The higher the substrate temperature was, the larger the Mg particle size was. The coating degraded and gradually peeled off from the surface of PEEK after up to 21 days immersion. It was found that the degradation of Mg coating could strongly kill Staphylococcus aureus with antibacterial rate reaching to 99%. Mg can be expected to be coated on those bio-inert biomaterials to offer specific bioactivities.