EFFECT OF Gd ON THE MICROSTRUCTURES AND CORROSION BEHAVIORS OF MAGNESIUM ALLOY Mg-8.0Al-1.0Zn

Magnesium alloy is a promising candidate for use as biodegradable implant material. However, its corrosion rate is too fast in human body fluid. Thereby, improving corrosion resistance is an urgent problem for application of the magnesium alloy in the medical field. Presently, Mg-8.0Al-1.0Zn-xGd alloys were prepared. Effect of rare earth Gd on the microstructures and corrosion resistance of magnesium alloy were investigated. Results showed that the most of Al₃Gd particles, a high melting point rare earth compound, are distributed in β phases (Mg₁₇Al₁₂). With the increase of the content of Gd, the amount of precipitation of β phases increased and interconnected each other. Fine network-like β phases acted as corrosion barrier and effectively impeded the corrosion extending. The corrosion resistance improved with the increase of rare earth Gd.