RESUMEN
Implementing the ultrasonic vibration-assisted incremental sheet-forming (UISF) process has been proven to significantly reduce the forming force, improve the surface quality, and enhance the accuracy of the sheet-forming process. However, such effectiveness has primarily focused on easily deformable materials (such as AA1050 and AA1060 aluminum alloys) and small step-down sizes (from 0.3 mm to 0.5 mm). To further enhance the process, it is crucial to study larger step-down sizes and harder materials. In this study, a series of UISF experiments were conducted, with step-down sizes ranging from 0.5 mm to 1.5 mm and feed rates ranging from 200 mm/min to 1200 mm/min. The influence of ultrasonic vibration on the effectiveness of force reduction and the optimal operation parameters was experimentally tested. Forming aluminum alloy AA5052, a difficult-to-deform material with two thicknesses of 0.5 mm and 1.0 mm, indicates that the axial force Fz and the tool movement resistance force Fy tend to decrease significantly with ultrasonic vibration assistance. Optimal equations for force reduction Fz and Fy have been developed for plate thickness based on the step-down size and feed rate. The optimal results show that for 1.0 mm thickness, reductions in Fz and Fy can reach 58.73% and 69.17%, respectively, and that of 64.17% and 71.98%, respectively, for 0.5 mm thickness.
