Microstructure, mechanical and biodegradable properties of a Mg-2Zn-1Gd-0.5Zr alloy with different solution treatments

Solution treatment is a useful way to improve the degradation resistance of Mg alloys. In this work, effects of solution treatment temperature on mechanical and biodegradable properties of an extruded Mg-2Zn-1Gd-0.5Zr alloy were studied. Microstructure analysis, tensile test, three-point bending test, immersion test and electrochemical test were performed. The results showed that increasing solution temperature decreases the mechanical properties of the alloy. However, three-point bending test revealed that the solution-treated alloy at 510 degrees C could maintain 95% of its maximum bending force (F-max) during the 28-day immersion period. After treatment at 510 degrees C for 5h, all the second phases were dissolved into the alloy, the galvanic corrosion was inhibited, and the alloy exhibited good corrosion resistance with a corrosion rate of 0.35mmyear(-1) in Hank's solution.