We investigated the deformation behavior of Mg-Gd-Y(-Sm)-Zr alloys during high-temperature uniaxial compression (T=350 °C, 400 °C, 450 °C and 500 °C; $\dot{\epsilon }$=0.003 s^-1, 0.01 s^-1, 0^.1 s^-1 and ¹ s^-1). The dynamic recrystallization (DRX) critical strain of Mg-Gd-Y(-Sm)-Zr was calculated, and its accuracy was verified by the transmission electron microscope (TEM). The hot deformation activation energy and constitutive equation after hot compression were calculated. The effect mechanism of Sm on microstructure evolution was also analyzed by the electron backscatter diffraction (EBSD) and TEM. It can be concluded that the hot deformation activation energies of Mg-Gd-Y-Zr and Mg-Gd-Y-Sm-Zr were 206.17 kJ/mol and 263.07 kJ/mol, respectively. The addition of Sm can increase flow stress and make DRX occur earlier. With the increase of strain, Sm delayed the DRX by inhibiting the activity of pyramidal <c+a> slip. Under the deformation condition of 400 °C/0.003 s^-1/0.7, the continuous dynamic recrystallization (CDRX) mechanism was dominant in Mg-Gd-Y-Zr and Mg-Gd-Y-Sm-Zr. In addition, the dynamic precipitation phase after adding Sm was the β-Mg₅(Gd, Y, Sm) equilibrium phase with a face-centered cubic structure. There was a staggered chain distribution between DRX grains and precipitates at the original deformation grain boundary, which effectively hinders dislocation rearrangement and grain boundary migration. Finally, we constructed the DRX mechanism diagram and the interaction diagram between the precipitated phase and DRX grains.’

我们研究了 Mg-Gd-Y(-Sm)-Zr 合金在高温单轴压缩（T = 350 ℃、400 ℃、450 ℃和500 ℃）过程中的变形行为；$\dot{\epsilon }$=0.003  s ^-1 , 0.01  s ^-1 , 0 ^.1 s ^-1和¹ s ^-1 )。计算了Mg-Gd-Y(-Sm)-Zr的动态再结晶(DRX)临界应变，并通过透射电子显微镜(TEM)验证了其准确性。计算了热压缩后的热变形活化能和本构方程。还通过电子背散射衍射（EBSD）和TEM分析了Sm对微观结构演化的影响机制。可以得出，Mg-Gd-Y-Zr和Mg-Gd-Y-Sm-Zr的热变形活化能分别为206.17  kJ/mol和263.07 kJ/mol，分别。Sm的加入可以增加流动应力，使DRX发生得更早。随着应变的增加，Sm通过抑制锥体<c+a>滑动的活性而延迟DRX。在400 ℃/0.003  s ^-1 /0.7的变形条件下，Mg-Gd-Y-Zr和Mg-Gd-Y-Sm-Zr以连续动态再结晶(CDRX)机制为主。此外，加入Sm后的动态析出相为β - Mg ₅ (Gd, Y, Sm )具有面心立方结构的平衡相。DRX晶粒与原始变形晶界处的析出物之间呈交错的链状分布，有效地阻碍了位错重排和晶界迁移。最后，我们构建了DRX机理图和析出相与DRX晶粒的相互作用图。