| In this paper,several common aluminum alloys are selected as the research objects.The solidification structure of Al-Mg,Al-Si,Al-Cu and Al-Sn binary alloys is analyzed by changing the ultrasonic field treatment time.The 2024,3103,G609,G750 b and G716 w aluminum alloy melts are analyzed by DC casting.It is better to use the ultrasonic tool head with diameter of ?=10mm to treat the melt refinement than that with diameter of ?=20mm.In addition,proper ultrasonic treatment can improve the comprehensive mechanical properties of ingots.When the time of ultrasonic treatment of aluminum alloy melt is 90 s and the temperature is 790?,the refining effect of solidification structure is obvious and cavitation effect is obvious after ultrasonic treatment.However,with the increase of solute of Mg,Si and Cu,in order to achieve better refining of solidification structure,the ultrasonic treatment time also needs to be strengthened,and the effect is best when the forced cooling treatment time at the bottom of ultrasonic ingot is 120 s The results show that ultrasonic treatment can refine the solidification structure of ingot,and the refining effect of edge solidification structure is the best,the refining effect of 1/2 radius and center solidification structure is slightly worse.In addition,the refining effect of ultrasonic treatment on DC ingot is closely related to the original grain size of ingot.If the original grain size of ingot is less than 150?m,the effect of ultrasonic field is not obvious.The solidification structure of DC casting ingot can be refined by composite ultrasonic.After(2000W+3000W)composite ultrasonic treatment,410?m of the untreated edge of G716 W aluminum alloy was reduced to 150?m,which decreased by 63.4%;while 320?m of the untreated edge of 1/2 radius was reduced to 76?m,which decreased by 76.3%;the grain size of the central part was reduced from 220?m to 98?m,which decreased by 55.5%;the overall ultrasonic refining effect was good,and the structure was relatively uniform. |
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