Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1637176 | Transactions of Nonferrous Metals Society of China | 2012 | 7 Pages |
Abstract
The effects of cooling conditions on the microstructure of semi-solid AZ91 slurry produced via ultrasonic vibration process were investigated. AZ91 melts were subjected to ultrasonic vibration in different temperature ranges under different cooling rates. The results show that fine and spherical α-Mg particles are obtained under ultrasonic vibration at the nucleation stage, which is mainly attributed to the cavitation and acoustic streaming induced by the ultrasonic vibration. The reduction of lower limit of ultrasonic vibration temperature between the liquidus and solidus increases the solid volume fraction and average particle size. Increasing cooling rate increases the solid volume fraction and reduces the average shape factor of particles. The appropriate temperature range for ultrasonic vibration is from 605 °C to 595 °C or 590 °C, and the suitable cooling rate is 2-3 °C/min.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Liang ZHANG, Guo-hua WU, Shao-hua WANG, Wen-jiang DING,