Effect of high-intensity ultrasonic on microstructure and properties of Mg-Zn-Er alloy
Mg-Zn-Er alloy was prepared by high-intensity ultrasonic melt treatment. The effects of the ultrasonic treatment time and ultrasonic output power on microstructure and properties of Mg-Zn-Er alloy were investigated. The results show that with increase in the ultrasonic treatment time or ultrasonic output power, the microstructure of the as-cast Mg-Zn-Er alloy transforms from bulky dentrite into small uniformity rotundity grain. Further prolonging time or output power rising will cause the microstructure to become coarse when the ultrasonic treatment time or ultrasonic output power reaches a fixed value. It was found that the separated discontinuous phases existed along grain boundaries and a mass of particulates uniformly dispersed in the matrix of the alloy. When the melt temperature, ultrasonic treatment time and ultrasonic output power are 718°C, 100 s and 600 W, respectively, the Mg-5Zn-2Er alloy has small uniform and roundness grain, and its tensile strength and elongation under room temperature are 199.6 MPa and 11.6%, respectively.
