Degradation of pure magnesium alloys in simulated body fluid

[摘要] Biodegradable bone implants have the ability to be resorbed and removed from the human body after the healing process. Polymers and ceramics are common biodegradable implants used in the human body but their mechanical properties are poor for load bearing applications. Magnesium gradually degrades in the human body and also has no adverse side effects on the human body. Furthermore, its mechanical properties are closer to the mechanical properties of bone, compared to other metallic implants. However, magnesium degrades very quickly in the physiological environment and it may be degraded completely before the healing process is finished. It is important to study the corrosion process of magnesium alloys in order to control the corrosion rate in the body during the approximately 12-18 week period. The corrosion behaviour of 5 types of pure magnesium samples were studied in tests involving 480 hour immersion in Simulated Body Fluid (SBF). The weight loss of extruded samples (E and D) was about 7 to 20 times lower, compared to the cast samples (A, B and C), which indicated a higher corrosion resistance for the extruded samples. In addition, the extruded samples (D and E) showed a higher reproducibility and greater uniformity of corrosion compared to the cast samples (A, B and C) after 480 hour immersion in SBF. The main reason for such a difference in the corrosion behaviour, reproducibility and uniformity of corrosion of the samples was related to the presence of porosity within the specimens associated with the casting of the alloy.

[发布机构] University:University of Birmingham;Department:School of Metallurgy and Materials

[关键词] Q Science;Q Science (General)