超声波施振参数对Mg-Ca合金除气的影响

Effect of Ultrasonic Vibration Parameters on Degassing of Mg-Ca Alloy

采用了超声场来处理Mg-Ca合金熔体,考察了超声波施振参数(超声功率和作用时间)对合金熔体除气效果的影响.结果表明:超声波施振功率和作用时间均对Mg-Ca合金除气效果有较大的影响,当施振功率过小,作用时间过短或过长均不会有良好的除气效果.这种除气效果和超声波的空化效应有关,且只有在空化效应的发展-发达阶段才会有良好的除气效果.在本实验条件下,超声功率150 W,作用时间为120 s除气效果最好,铸锭的密度值达到最大.在除气的同时,也有效地细化了Mg-Ca合金铸锭的凝固组织.

The effect of different vibration parameters,including ultrasonic power and duration time,on the degassing of molten Mg-Ca alloy was investigated by using ultrasonic field.The results showed that both the ultrasonic power and the duration time have significant effects on the degassing effect.Low ultrasonic power and short or long duration time have weak effect on the degassing.The degassing effect is related with the ultrasonic cavitation,and the optimum degassing effect only occurs in the developing-developed stage of the cavitation.In this experimental condition,when the ultrasonic power and the duration are 150 W and 120 s respectively,there has the optimum degassing effect and the density of ingot reaches the maximum value.The ultrasound refines effectively the solidification structure of Mg-Ca ingot at the same time.