The Mg-6Zn alloy with different contents of Ce was prepared by the gravity casting method, and then the Mg-6Zn-xCe (x=0, 0.5, 1.0, 1.5, wt.%) alloys were extruded at 300 °C and 350 °C after solution treatment. The phase constitution and microstructure evolution of Mg-Zn-xCe alloys were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electron backscattering diffraction (EBSD). Meanwhile, the mechanical properties of the alloy were tested at room temperature. For as-cast alloys, the results show that the main compound in Mg-6Zn alloy is Mg₄Zn₇ phase, and the main compound is T-(MgZn)₁₂Ce phase after the addition of different amounts of Ce. The microstructure and distribution of second phases are greatly improved after extrusion at 300 °C and 350 °C. Compared with initial mechanical properties, the strength and elongation increase obviously by means of extrusion at different temperatures. In addition, the microstructure after extrusion at 350 °C is further analyzed according to EBSD data. The results show that rare earth element Ce probably promotes the activation of non-basal slip during the deformation process with the increase of Ce, which reduces the strength of basal texture and thus improves the plasticity of the alloy. Meanwhile, the increase of grain boundary migration ability leads to the gradual increase of recrystallization grain size and decreases the strength.

The effect of the extrusion process on the microstructure, corrosion, and mechanical properties of Mg–Zn–Ca–Zr alloy has been investigated. Zn and Ca were both in a solid solution and only the Zr-rich phase was observed in the homogenized and extruded alloys. The Zr-rich phase was obviously refined after extrusion. The corrosion rate of the homogenized alloy decreased by about 25% after extrusion. This is because the refined Zr-rich phase was easier to cover with the deposited corrosion products, which reduced the cathodic reaction activity of the Zr-rich phase. The corrosion rate is similar for the alloys extruded at 320 °C and 350 °C since the size and distribution of the Zr-rich phase were not different in the two conditions. The alloy extruded at 320 °C has a smaller grain size and better comprehensive mechanical properties.