脉冲磁场对Mg-Y-Cu-Zr-Sr合金凝固组织的影响

Effects of Pulsed Magnetic Field on Solidified Structure of Mg-Y-Cu-Zr-Sr Alloy

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。

Effects of processing parameters,such as different pulse voltage,pulse frequency,pouring temperature and mold temperature,on solidified structure of Mg-Y-Cu-Zr-Sr alloy with long period ordered structure were investigated under pulsed magnetic field.The results show that solidified structure of the alloy can be refined obviously by pulsed magnetic field.Primary phase of the alloy is transformed into rosette crystal with uniform distribution of second phase.When the pulse voltage is at 0-240Vor pulse frequency is at 1-10Hz,with the increase of pulse voltage or pulse frequency,solidified structure of the alloy is refined gradually.When the pouring temperature is at 660-750 ℃ or the mold temperature is at 200-600 ℃,with the increase of pouring temperature or the decrease of mold temperature,microstructure of the alloy is refined gradually.