摘要
Effects of ultrasonic treatment on microstructures were investigated by introducing the ultrasonic oscillation into AZ91 alloy melts. The results show that the ultrasonic treatment does not change the phase composition but has great influence on solidification microstructures. The area percentage of lamellar eutectic phase increases to the maximum when the applied ultrasonic power is increased to 600 W and then decreases gradually with the further increase of power;meanwhile, the average area of Al8Mn5 phase owns a completely opposing variation trend. The area percentage of Mg17Al12 decreases gradually with increasing the applied ultrasonic power. Mechanisms accounted for the refinement and fraction of different intermetallic phases were also discussed.
通过在AZ91合金熔体中引入超声振动研究超声处理对合金微观组织的影响。结果表明,超声处理并不改变合金的相组成,但对凝固组织有显著影响;随着超声功率的增加,层片状共晶组织的面积分数呈现先增加后降低的趋势,当超声功率为600 W时达到最高,而Al8Mn5相的平均面积变化规律则完全相反,Mg17Al12相的面积分数则随着超声功率的增加而逐渐降低。讨论了组织细化及相分数改变的超声处理机制。
基金
Project(51071128)supported by the National Natural Science Foundation of China
Project(2011CB610401)supported by the National Basic Research Program of China
Project(SKLSP201002)supported by Free Research Fund of State Key Laboratory of Solidification Processing,China
