Effect of ultrasonic vibration-assisted two-stage age forming on properties of 7075 aluminum alloy

Aluminum alloy can obtain good forming effect and strength after age forming. The addition of an ultrasonic field in the two-stage age forming process could have a positive effect on the forming performance and microstructure. In this study, we aimed to combine the ultrasonic vibration and two-stage age forming. The application of ultrasonic waves could reduce the rebound rate of aluminum alloy component. When the ultrasound application time was 6 h, the minimum rebound rate was 40.2%. The higher the two-stage aging temperature with the aid of ultrasound, the lower the rebound rate. Ultrasonic energy shortened the time for the Guinier Preston zones (GP zones) to reach the stable η phases during the age forming process and refined the η phases in the grains. With the extension of the ultrasonic application time, the strength showed a trend from declined to rose, and the elongation increased. The higher the two-stage aging temperature, the larger and coarser the size of the grains, and the strength of the aluminum alloy component will decrease.