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研究了脉冲磁场作用下长周期结构增强Mg-Y-Cu-Zr-Sr合金凝固组织的变化,研究了不同的脉冲电压、脉冲频率、浇注温度和模具预热温度对合金凝固组织的影响。结果表明,在脉冲磁场作用下,合金的凝固组织显著细化,其初生α-Mg相转变成细小、圆整的近球状或蔷薇状晶体,第二相分布变得均匀。当脉冲电压在0~240V范围内或脉冲频率在1~10Hz范围内,随着脉冲电压或脉冲频率的增加,合金的凝固组织逐渐细化;当浇注温度在660~750℃范围内或铸型预热温度在200~600℃范围内时,随着浇注温度的升高或模具预热温度的降低,合金的凝固组织逐渐细化。
The changes of solidified microstructure of Mg-Y-Cu-Zr-Sr alloy reinforced with long periodical structure under pulsed magnetic field were studied. The effects of different pulse voltage, pulse frequency, pouring temperature and mold preheating temperature on the solidified microstructure of the alloy were investigated. The results show that under the action of pulsed magnetic field, the solidified microstructure of the alloy is refined remarkably. The primary α-Mg phase is transformed into fine, round and nearly spherical or rosette crystals, and the second phase distribution becomes uniform. When the pulse voltage is in the range of 0 ~ 240V or the pulse frequency is in the range of 1 ~ 10Hz, the solidified microstructure of the alloy is gradually refined with the increase of the pulse voltage or pulse frequency. When the pouring temperature is in the range of 660 ~ 750 ℃, When the preheating temperature is in the range of 200 ~ 600 ℃, the solidification microstructure of the alloy is gradually refined with the increase of pouring temperature or the preheating temperature of the mold.