Numerical simulation of physical field during different ultrasonic power assisted casting of 7085 aluminum alloy

High‐energy ultrasound has the effect of purifying the aluminum (Al) melt and improving the uniformity of temperature and flow field distribution. In this article, a finite‐element numerical model of ultrasonic‐assisted casting of 7085 Al alloy melt is established, and the changes of acoustic pressure field, temperature field, and flow field in the solidification process of alloy melt with different ultrasonic power are investigated. In the numerical simulation results, it is shown that the thickness of the 7085 Al melt mushy zone decreases by 89, 97, 108, 114, and 99 mm, respectively, compared without ultrasonic (WNU) when the ultrasonic power is 150, 350, 550, 750, and 950 W. The area of the alloy mushy zone increases by 38.1%, 43.5%, 61.0%, 206.5%, and 45.6%, respectively. According to numerical simulation results, when the ultrasonic power is 750 W, it has the best effect on improving the macroscopic physical field, increasing the mass and heat‐transfer rate in the center of the Al melt. Meanwhile, the experimental results of industrial melting and casting of 7085 large‐scale Al alloy ingots are basically consistent with the numerical simulation, which provide technical support for ultrasonic‐assisted fabrication of large‐scale 7085 Al alloy ingots.