Numerical and experimental study on the effect of forming speed in gradient warm deep drawing process

The use of aluminum and magnesium alloys is limited due to their low formability at ambient temperature, in comparison to steels. The invention of new methods for increasing the formability of these alloys has always been investigated in the sheet metal forming industry. Studies have shown a dramatic increase in the formability of aluminum and magnesium alloys by increasing temperature. As a result, the necessity of application of warm forming processes requires the study and investigation of effective parameters on process. In this paper, numerical and experimental study of forming speed have been investigated in gradient warm deep drawing process of cylindrical parts for aluminum alloy 5083 sheet with 2mm thickness. To this end, some tests have been performed at three speeds of 60, 200 and 378mm/min at different temperatures with constant blank holder force. The effects of forming speed on punch force, thickness distribution and earing behavior, as well as limit drawing ratio and temperature gradient have been discussed and analyzed. Results show, by increasing temperature and reducing the punch speed, punch force has been decreased, drawing ratio has been increased and more uniform thickness distribution has been obtained. It has been also observed that by increasing temperature, the number and position of the ears have remained constant despite the reduction of the ears amplitude.