The quantitative study of rare earth compounds is important for the improvement of existing magnesium alloy systems and the design of new magnesium alloys. In this paper, the effective separation of matrix and compound in Mg–Zn–Ce–Zr alloy was achieved by a low-temperature chemical phase separation technique. The mass fraction of the (Mg, Zn)12Ce compound was determined and the effect of the (Mg, Zn)12Ce phase content on the heat deformation organization and properties was investigated. The results show that the Mg–Zn–Ce compound in both the as-cast and the homogeneous alloys is (Mg, Zn)12Ce. (Mg, Zn)12Ce phase formation depends on the content and the ratio of Zn and Ce elements in the initial residual melt of the eutectic reaction. The Zn/Ce mass ratios below 2.5 give the highest compound contents for different Zn contents, 5.262 wt.% and 7.040 wt.%, respectively. The increase in the amount of the (Mg, Zn)12Ce phase can significantly reduce the critical conditions for dynamic recrystallization formation. Both the critical strain and the stress decrease with increasing rare earth content. The reduction of the critical conditions and the particle-promoted nucleation mechanism work together to increase the amount of dynamic recrystallization. In addition, it was found that alloys with 6 wt.% Zn elements tend to undergo a dynamic recrystallization softening mechanism, while alloys with 3 wt.% Zn elements tend to undergo a dynamic reversion softening mechanism.

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The solid solution amount of rare earth elements and the mass fraction of compounds were measured by low-temperature phase separation technology, the existing forms of rare earth elements in ZK-RE(Ce, Y, Gd) alloy were quantitatively studied, and the difference of solid solution ability of rare earth elements and the factors affecting the number of rare earth compounds were analyzed. The experimental results show that the solid solution amount of rare earth elements mainly depends on their addition amount, Zn and RE inhibit each other's solid solution amount, and the order of solid solution amount (wt.%) of rare earth elements with the same addition amount is GD > Y > Ce. Rare earth elements are mostly distributed in Mg-Zn-RE compounds, and the increase of rare earth content is helpful to form more Mg-Zn-RE compounds. With the same content of elements, the order of mass fraction of Mg-Zn-RE compounds is ZK-Ce system > ZK-Y system > ZK-Gd system. The order of solid solution ability of rare earth elements is Gd >Y > Ce, and the amount of solid solution directly affects the initial element content of compound precipitation in the remaining melt. The influence of Zn/Ce ratio in the residual melt of ZK-Ce alloy is shown in the number of rare earth compounds, while the Zn/Y(Gd) ratio in the residual melt of ZK-RE(Y, Gd) alloy determines the type and number of rare earth compounds.