【摘要】 采用应变诱发熔化激活法(SIMA)制备WE43镁合金半固态坯料，研究保温温度和保温时间对其半固态组织的影响，分析了不同工艺参数下合金的平均晶粒尺寸、液相率及固相形状因子的变化规律，探讨半固态组织演变机制。结果表明：随着保温温度升高和保温时间延长，WE43镁合金的平均晶粒尺寸和液相率显著增加，而固相形状因子则呈现先上升后下降的趋势；半固态组织由α-Mg晶粒、晶界液相及晶内“小液池”组成，其晶粒演变过程分为初始长大、球化分离及合并粗化3个阶段，演变机制为Ostwald熟化机制和晶粒合并长大机制；采用SIMA工艺制备WE43镁合金半固态坯料的最佳工艺为在610℃保温45 min。更多还原

【Abstract】 The semi-solid billet of WE43 magnesium alloy was prepared using strain-induced melt activation(SIMA) method, and the effects of holding temperature and holding time on its semi-solid microstructure were studied. The changes in the average grain size, liquid fraction, and solid phase shape factor of the alloy under different process parameters were analyzed, and the evolution mechanism of the semi-solid microstructure was discussed. The results show that with the increase of holding temperature and holding time, the average grain size and liquid fraction of the WE43 magnesium alloy significantly increase, while the solid phase shape factor shows a trend of first increasing and then decreasing. The semi-solid microstructure consists of α-Mg grains, grain boundary liquid phase, and intragranular “small liquid pools”. The grain evolution process is divided into three stages: initial growth, spheroidization separation, and coalescence coarsening, and the evolution mechanism is Ostwald ripening mechanism and grain coalescence mechanism. The optimal process for preparing WE43 magnesium alloy semi-solid billets using SIMA technology is to hold at 610 ℃ for 45 min.更多还原