Experimental study on designing optimal vibration amplitude in ultrasonic assisted incremental forming of AA6061-T6

Superimposing ultrasonic vibration with metal working process has been proven as effective auxiliary method for improving the quality characteristics. Since, the incremental forming is a state-of-the-art sheet metal working process, number of researches which applied ultrasonic vibration to this process are limited and further studies are still required to basically understand its influence on performance measures. In the present study, an experimental attempt was made to understand how the vibration amplitude influences the forming force, thickness distribution and dimensional accuracy of the samples formed by incremental forming process. In order to do so, series of single factor experiments were designed by variation of vibration amplitude (0, 5, 10 and 15 µm) as main parameter and other parameters were kept constant. The obtained results revealed that increasing the vibration amplitude up to a certain value results in reduction of forming force and dimensional deviation, as well it results in thinning in critical region. At the end of the work, an optimization framework was designed to find interaction effect of process factors with achieving regarding minimized process time as well desired sample quality. It is found from optimization results that superimposing high vibration amplitude provides condition for obtaining minimum process time as well desired quality characteristic of workpiece.