Research on Dynamic Corrosion Behavior and the Microstructure of Biomedical Mg-Y-Zn-Zr-Sr in Simulated Body Fluid Solution after Processing by Solution Treatment

Herein, as-cast Mg-2Y-Zn-0.4Zr-0.3Sr alloy's solution treatment at 500 degrees C in the range of 10-35 h, and then cooled in 80 degrees warm water, is used to investigate its dynamic corrosion behavior and surface morphology using a dynamic stimulating human environment device. Based on the result of corrosion behavior and microstructure, the alloy is mainly composed of alpha-Mg and W-phase (Mg3Zn3Y2) in Mg-2Y-Zn-0.4Zr-0.3Sr alloy. With the increase in solution time, the corrosion resistance is prompted due to the uniform microstructure and second phase dissolved into the matrix. The corrosion resistance of Mg-2Y-Zn-0.4Zr-0.3Sr alloy is increased by enhancing solution time before 25 h due to the uniformly distributed second phases and microstructure, which can alleviate the galvanic corrosion. However, increasing solution time exceeding 25 h reduces the corrosion resistance of the alloy due to coarse grains. Furthermore, twinning, which appears in grains interior after solution treatment, has a positive influence on corrosion resistance. Therefore, the good corrosion resistance of solution-treated Mg-2Y-Zn-0.4Zr-0.3Sr alloy makes it excellent for biomaterial applications.