Investigation of the Deep Drawing Process by Means of Acoustic Emission Characteristics

Deep drawing is a complicated sheet metal forming process that can be improved by using effective real-time condition monitoring techniques. One of these techniques is acoustic emission testing, which provides valuable information about the conditions of the forming process. In the present research, acoustic emissions generated during the deep drawing of AISI 316 stainless steel sheet metal have been studied in order to identify common damage mechanisms. After extracting the characteristics of recorded acoustic emissions with regard to microscopic observations of sheet surfaces and previous reports, the acoustic emissions have been correlated to different damage mechanisms. According to the presented results, the technique can detect common damages that can occur during the deep drawing process, such as plastic deformation, material transfer, and frictional junctions. The effects of some important parameters such as Lubrication condition and forming speed on acoustic emission characteristics are also discussed.