波浪形振动倾斜板半连续铸造半固态AZ91D镁合金

将自制的波浪形倾斜板振动装置与半连续铸造机结合,制备了AZ91D镁合金铸锭.分析了不同工艺条件对合金组织的影响.结果表明,在一定范围内,随着倾斜板长度增加,合金受到冷却剪切作用的时间增长,组织得到细化;振动作用可以提高形核率,细化合金组织;较低的铸造速度使合金在结晶器内的二次结晶率提高,使组织细化.当浇注温度为680℃,倾斜板长度为400 mm,铸造速度为100 mm/min时,制备了组织优良的AZ91D镁合金半固态铸锭,经二次加热后获得了优良的半固态组织.

Semi-continuous Casting of Semisolid Billet of AZ91D Magnesium Alloy by Vibrating Wavelike Sloping Plate Process

A self-made vibrating wavelike sloping plate device and a semi-continuous casting machine were combined.The semisolid billet of AZ91D magnesium alloy was prepared by the proposed process,and the effects of the different process conditions on the microstructures were investigated.The results showed that in a certain scope,the shearing and cooling time is enlarged with the increasing of the plate length,which leads to the grain refinement.Vibration can improve the nucleation rate and obviously refine the microstructure.At the lower casting speed,the nucleation rate in the crystallizer is higher,which causes the finer microstructure in the billet.Under the conditions that the casting temperature is 680 ℃,the sloping plate length is 400 mm and the casting speed is 100 mm/min,the semisolid billet of AZ91D magnesium alloy with fine microstructure is prepared by the semi-continuous casting process.After re-melting,the fine semisolid microstructure is obtained.