The role of Ga in the microstructure, corrosion behavior and mechanical properties of as-extruded Mg-5Sn-xGa alloys

The effect of Ga element on microstructure, corrosion behavior and tensile mechanical properties of as-extruded Mg-5Sn-xGa (x = 0, 1, 2, 3, all in wt%) alloys was investigated using immersion test, electrochemical test and tensile test. The results show that the Mg2Sn and Mg5Ga2 particles are dynamically precipitated during extrusion process, and the volume fraction of Mg5Ga2 precipitates increases with increasing Ga content. The corrosion resistance of Mg-5Sn alloy in the immersion test is increased approximately by four times after adding 2 wt% Ga, due to the fact that the Ga element weakens the cathodic reaction, and more stable corrosion products are formed in the Ga-containing alloys in the inner corrosion layer. The tensile strength of investigated alloys is improved monotonously with increasing Ga content. The maximum elongation to fracture reaches up to 21.7% for Mg-5Sn-1Ga alloy due to the modified basal grain texture. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The addition of Ga element was found to enhance the corrosion resistance and tensile strength of Mg-5Sn alloy, with the maximum elongation to fracture achieved in Mg-5Sn-1Ga alloy. The precipitation of Mg5Ga2 particles and the formation of more stable corrosion products were observed with increasing Ga content in the alloy.