ZL201合金低频电磁铸造与二次加热的合金组织

采用低频电磁铸造技术制备ZL201合金半固态坯料,研究了电磁场频率以及二次加热温度和保温时间对合金微观组织的影响.结果表明,随着电磁场频率从10 Hz增大到30 Hz,组织的枝晶化趋势逐渐减弱,当电磁场频率为30 Hz时,可以获得均匀、细小的蔷薇状和等轴晶组织.对电磁场频率为30 Hz时铸造的半固态坯料进行二次加热表明,当二次加热温度为630℃,保温20 min后,铸造组织逐渐转变为均匀的近球形组织,具有良好的触变成形性.

Low-Frequency Electromagnetic Casting of ZL201 Alloy and Its Microstructure After Reheating

Preparing the semi-solid billets of ZL201 alloy by low-frequency electromagnetic casting (LFEC), the effects of electromagnetic frequency, reheating temperature and holding time on their microstructures were studied. The results showed that the trend of dentritic microstructure is gradually down with increasing electromagnetic frequency from 10 Hz to 30 Hz, and a homogeneous and fine rosette/equiaxial grain microstructure can be obtained at 30 Hz. When reheating the semi-solid billets cast at 30 Hz and 630°C for 20 min, the as-cast microstructure turns gradually into homogeneous and near-spherical grains which are suitable for thixoforming.