The effects of ultrasonic treatment

Sr-Y alloying treatment and ultrasonic-alloying compound treatment on the solidification structure and mechanical properties of Mg-9Al-3Si alloy were investigated.The effects of different ultrasonic parameters on the solidification structure and mechanical properties of the alloy were analyzed.The results reveal that the solidification structure and mechanical properties of the alloy are obviously improved under the condition of ultrasonic-alloying treatment

which is superior to those of the single alloying treatment or ultrasonic treatment.Compared with untreated ones

the size of treated primary Mg

2

Si phase is reduced by 72.9%.Meanwhile

tensile strength and elongation of the alloy are increased by 125% and by 310%

respectively

compared with those of untreated alloy.With the increase of ultrasonic power or ultrasonic time

the size of primary Mg

2

Si phase is decreased gradually

and the change of mechanical properties corresponds to the size and morphology of primary Mg

2

Si phase.