Warm deep-drawing and post drawing analysis of two Al–Mg–Si alloys

• Increasing the forming temperature reduces the amplitude of the ears.
• The temperature gradient from bottom to flange accentuates the thickness variations.
• Drawn cup ears and thickness are not affected by changes of solutes and precipitates.

The increasing use of aluminium alloys in light weight structural applications is restricted mainly due to their lower room temperature formability compared to steels. Forming at higher temperature is seen as a promising solution to this problem. In the present investigation two Al–Mg–Si alloys (EN AW-6016 and EN AW-6061) were deep-drawn at room temperature and 250 °C and their behaviour during drawing were compared. The effect of ram speed, drawing ratio, holding time, and temper was also investigated. Among the parameters investigated temperature was found to have the most significant effect on the force–displacement response. Because anisotropy has been an important concern during the deep-drawing process, this parameter was also investigated by looking at the earing profile. With increasing temperature the amplitude of earing decreased while the number of ears remained the same, indicating that there is no change in anisotropy with temperature. The cup thickness increases from the bottom of the cup to the flange with a local minimum around the mid-height of the wall.