Effect of vibration frequency and amplitude on formability in rotational vibration-assisted incremental sheet forming (RV-ISF)

Incremental sheet forming (ISF) is a flexible manufacturing process, potentially for producing small-batched and customized sheet products. To improve formability of hard-to-form materials, part surface finish and forming accuracy, the rotational vibration-assisted ISF (RV-ISF) has been developed by the University of Sheffield with the use of novel tool designs with either offsets or grooves on the tool surface to introduce both mechanical vibration and localized heating into the conventional ISF process (C-ISF). With the use of double-offset (T2) and four-groove (T4) tools in the experiments, this work studies the effects of tool design and tool rotational speed on sheet vibration amplitude and frequency, as well as their effects on forming temperature and force reduction and formability improvement. Results show that the sheet vibration amplitude is mainly influenced by the tool design, while the vibration frequency is affected by both tool design and rotational speed. RV-ISF with T4 shows greater material formability improvement of AA3003-O due to greater temperature rise and low-frequency-low-amplitude vibration. RV-ISF with T2 results in greater reduction of forming force because of the higher sheet vibration amplitude.