Effects of introducing ultrasonic temperature on microstructure and properties of Mg-Zn-Er alloy prepared by high intensity ultrasonic melt treatment were analyzed.The results indicate that as-cast microstructure of the alloy is converted from coarse dendrite into uniformly distributed fine spheroidized grain with increasing in introducing ultrasonic temperature in condition of ultrasonic time for 100 s and ultrasonic power of 600W

in which an optimized temperature is 718℃.The grain with desirable size and uniform distribution and roundness in Mg-5Zn-2Er alloy treated by ultrasonic at 718℃ can be observed

and tensile strength and elongation reach 199.6MPa and 11.6% at room temperature

respectively

exhibiting the maximum value

while tensile strength exhibits the minimum values at high temperature.