Investigation of the ultrasonic vibration effect in incremental sheet metal forming process

Abstract

The mechanism of incremental sheet metal forming (ISMF) is based on plastic and localized deformation of sheet metal. The sheet metal is form using a hemispherical-head tool in accordance with the path programmed into the CNC milling machine controller. Experimental and numerical analyses have been performed previously on the application of ultrasonic vibration to various metal forming processes. However, thus far, the effects of ultrasonic vibration on ISMF have not been investigated. This paper presents the process of design, analysis, manufacture and testing a vibrating forming tool for the development of UVaISMF (ultrasonic vibration assisted ISMF). The results obtained from modal analysis and natural frequency measurement of the vibrating tool confirmed the emergence of a longitudinal vibration mode and resonance phenomenon the forming tool. Then, the effect of ultrasonic vibration on ISMF was studied. The obtained experimental results from the straight groove test Al 1050-O sheet metals showed that ultrasonic vibration led to decreases in the following parameters as compared with conventional ISMF: applied force on forming tool axis, spring-back and surface roughness of formed sample.