脉冲磁场对Al-20Si合金中初生Si的影响

Effects of Pulsed Magnetic Field on Primary Silicon in Al-20Si Alloy

研究了不同脉冲电压和脉冲频率对Al-20Si合金中初生Si分布和形态的影响。结果表明,在脉冲磁场的作用下,初生Si主要表现为偏聚和粗化,为梯度材料的制备提供了可能;当脉冲电压为80V时,初生Si有所粗化且偏聚,其大量集中在边部,心部几乎不含初生Si;当脉冲电压为160V时,初生Si进一步粗化且有所团聚,但整体上分布趋于均匀化;当脉冲电压增加至240V时,初生Si团聚和粗化现象有所减弱,且其分布也较均匀。当脉冲频率变化较小时(1~5Hz),初生Si的分布和形态不会随脉冲频率的增加而改变;当脉冲频率增加到10Hz时,初生Si出现了偏聚和粗化的现象。

Effects of different pulsed voltage and pulsed frequency on distribution and morphology of primary silicon in Al-20Si alloy were investigated.The results show that primary silicon mainly presents segregation and coarsening under pulsed magnetic field,which provides possibility for the preparation of gradient materials.When the pulse voltage is 80 V,the primary silicon is coarsened with segregation,which is concentrated in the edge not in the core position.With the pulsed voltage of 160 V,primary silicon tends to be coarsened and agglomeration,however the whole distribution tends to be uniform.When the pulse voltage is 240 V,the agglomeration and coarseness of primary silicon is weakened with more uniform distribution.When the pulsed frequency is 1~5 Hz,the distribution and morphology of primary silicon will be independent on the increase of the pulse frequency.However,when the pulse frequency is increased to 10 Hz,the primary silicon presents segregation and coarsening effects.