脉冲电场对6181铝合金凝固组织的影响

Effect of pulsed electric field on solidification structure of 6181 aluminum alloy

采用自制中频脉冲电流装置.研究了不同占空比、不同频率的脉冲电流对铸造6181铝合金组织、性能的影响规律及机制。研究结果表明:当脉冲电场频率不变时,随着占空比的不断增大,6181铝合金板材的晶粒尺寸逐渐变小直至不变;当脉冲电场占空比保持不变时,随着脉冲电场频率的增加,晶粒尺寸逐渐减小,当频率大于200 Hz时,脉冲电流对晶粒尺寸的影响变弱,硬度有下降的趋势。

The effect of pulse current with different duty cycles and frequencies on microstructure and properties of casting 6181 aluminum alloy was studied by using self-made medium frequency pulse current device.The research results show that the grain size of 6181 aluminum alloy sheet decreases gradually with the increase of duty cycle and then keeps constant when the frequency of pulsed electric field is constant.When the duty cycle of the pulsed electric field remains unchanged,the grain size decreases with the increase of the pulse electric field frequency.When the frequency is higher than 200 Hz,the effect of pulse current on grain size becomes weaker and the hardness tends to decrease.