Abstract:Al-Mg-Ga-Sn alloys with different Ga contents were prepared by electric furnace melting. Their microstructure morphology and compositions were characterized by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffractometry (XRD); their degradation rates were measured in pure water at 30 °C,40 °C, 70° C, and 90° C; and their electrochemical performance at room temperature was tested using the electrochemical workstation. The results revealed that in case that Mg+Sn is 10 wt.%, Al-Mg-Ga-Sn alloys with 0 wt.%, 4 wt.%, 8 wt.%, 12 wt.%, and 16 wt.% Ga, respectively, all contain Al matrix phase and Mg<sub>2</sub>Sn phase. Moreover, Ga<sub>5</sub>Mg<sub>2</sub> phase appears with the increase in Ga content. The degradability of Al-Mg-Ga-Sn alloys primarily present start-up with pitting corrosion in aluminum matrix phase, and acceleration with intergranular corrosion between Mg<sub>2</sub>Sn and Ga<sub>5</sub>Mg<sub>2</sub> compound phases. The initial degradation temperatures of alloys with different Ga content depend on the content of low melting point elements (Ga+Sn) solved in the aluminum matrix; the alloy with the same Ga content rapidly degrade with elevating temperature, and the degradation reaction kinetics follows Arrhenius. Uz formula. Electrochemical analysis at room temperature indicated that as Ga content raises in Al-Mg-Ga-Sn alloy, the corresponding corrosion potential negatively shifts to different extent, while the corrosion current gradually improves.